Technical &Scientific Papers

2nd IRF Asia
Regional Congress& Exhibition
Connecting Asia with Better Roads
asrc.IRF.global

ISBN: 978-0-692-84440-3

Kuala Lumpur, Malaysia
October 16–20, 2016
Organized in collaboration with

Ministry of Works,
Malaysia

161007

Public Works Department,
Malaysia

Malaysian Highway
AuthorityTS 1.1 SAFETY TREATMENTS

PAGE

•

Innovative Urban Signalized Junctions

16•

Safety Effectiveness of Surface Treatment: A Comparison of Empirical Bayes and Naïve Before and After Study

97•

Safety Improvements To National Route Two Section 27 in Kwazulu-Natal, South Africa

133•

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable Results – A Case Study ofRoad Upgrade Project in Samar

157•

Weight Impact Tests of Light-Weighted Barriers on Expressways

817•

Experiences of Improving Road Safety in Brazil856

TS 1.2 TRAFFIC SAFETY CULTURE•

Protecting Vulnerable Road Users: Traffic Separation with Colored Pavement Markings

212•

Study on Changes of Risk Awareness, Safety Behavior and Position

344•

Determining the Real Impact of Speed Limit Enforcement Cameras in the UK

422•

Investigating the Characteristics of Drives with Multiple Crashes

531•

The Impacts of Climate Change on Transportation Safety and Consequences628

TS 1.3 SAFETY DATA ANALYSIS•Do Crash Rates Really Increase With Increases in Average Speed?

434•

Probability of Crash Involvements Based on Drivers’ Characteristics and Traffic Rule Violation Records

457•

Characteristics of Severe Crashes During the Holy Month of Ramadan

495•Road Accidents in Urban and Rural Areas of Tanzania

606•

Motorcycles Gap Acceptance At Merging Point Of Egress And Ingress Of Exclusive Motorcycle Lane In Malaysia

676

TS 1.4 SAFETY MANAGEMENT INITIATIVES•

Cars – Motorcycles Collisions Prediction Model Based on Road Design Consistency

413•

Strategies for Road Safety in the Caribbean - Exploiting The Lowest Hanging Fruit

705•

Evaluation of Authorised Left (Alt) Traffic Control: A Case Study in Kuala Lumpur

716•

Investigating the Contributing Factors Affecting Traffic Crash Caused by Young Drivers

885•

Construction on Life Traffic, Dilemma Between Progress, Quality and User1

TS 2.1 PAVING MATERIALS & TECHNOLOGIES 1

PAGE

•

Evaluation of Long Term Performance of WMA Using Advanced 3-D Imaging Technique and Indirect Tensile Test

5•

Design, Production, Construction and Performance Evaluation of Recycled Asphalt Concrete

75•

Development of Noncontact Wireless Power Supply Pavement

169•

Sustainable Pavement Design - Delivering Sustainable Options Considering Existing Materials and Pavement Lifecycle

353•

Structural Pavement Design for Saudi Arabian Roads: Outline of the Proposed Research584

TS 2.2 PAVING MATERIALS & TECHNOLOGIES 2•

Resonant Rubblization as a Method to Rehabilitate Concrete Pavement

202•

Effect of Long-term Aging on Properties of Asphalt

256•

Engineering Properties of PAC Thin Surfacing for Pavement Rehabilitation

335•

Performance Evaluation of Developed Rejuvenators for Warm-in Place Recycling Asphalt Pavement

591•

Energy Usage and Greenhouse Gas Emissions of Pavement Preservation Processes for Asphalt Concrete Pavements

644

TS 2.3 PAVEMENT ADAPTATION TO CLIMATE CHANGE• Geocells for Affordable Low Volume Pavements

288• Road Pavement Design for the Pacific Region – Desk Research on the Use of Locally Available Materials

526• Investigating the Impact of Various Climate Change Scenarios on Pavement Service Life

547

TS 2.4 PAVING MATERIALS & TECHNOLOGIES 3• The Effect of Rejuvenators on the Properties of Repetitive Recycled Asphalt

656• Investigation on Engineering Properties of Bio-Based Binder Derived from Palm Oil Plantation as Replacement of
Bituminous Binder767• Cracking Performance Evaluation of Asphalt Mixtures Using Semicircular Bending Test: Experimental Evaluation
and Box-Behnken Optimization

687

TS 2.5 PAVING MATERIALS & TECHNOLOGIES 4• Statistical Evaluation of Crumb Rubber Modification Procedure in Asphalt Binder Modification

696• Advanced Use of Solar Heat-blocking Pavement Technology

723• Cost Analysis of Fiber-Reinforced Pavements

799• Pilot Study of Permeability of Pervious Concrete in Conjunction with Ultrasonic Pulse Velocity and X-Ray
Computed Tomography

8682

TS 3.1 MOBILITY & PLANNING

PAGE

•

The Influence of Trips Generated from New Project Development to the Efficiency of Road Network

389•

Intelligent Transport Planning System

53•

Urban Transport Solutions / BRT vs Tram

739

TS 3.2 SMART TRAFFIC MANAGEMENT SYSTEMS•

Active Traffic Management with Congestion mitigation Tools in Japan110•

The Italian its Logistics Platform for the Management of Dangerous Goods Transport and Parking Area for Heavy Trucks

404•

Decision Support in Real-Time Traffic Management

192•

New Integrated System to support the London Streets Tunnels Operations Control Centre (LSTOC)

267•

Kuala Lumpur Integrated Control Centre - Monorail, LRT, BRT, High Speed and Mass Rapid Transit Systems

280

TS 4.1 INFRASTRUCTURE MANAGEMENT•A New Approach for Estimating Pavement Rutting Progression

31•

Calibration of HDM-4 Road Deterioration Models for Rural Arterials in Victoria

144•

Asset Management on the Main Cables of Suspension Bridges

218•

Asset Management to Highway: Soil-Cement Stabilization Technique240•

High Speed Data Collection and Automatic Crack Mapping at the Network Level on the Bundaberg Region618

TS 4.2 INFRASTRUCTURE MAINTENANCE POLICIES & PROGRAMS•

Establishing Optimal Long Term Funding Allocation Approach based on Network Needs & Availability of Funds

569•

Maintenance of Infrastructures Using GIS and Point Cloud Data

598•

Long Segment Roads: The Indonesian Way to Adopt a Policy of Performance-Based Maintenance Contracts

666•

Slope Maintenance Program in Designing and Constructing Slopes

832•

Sustainable Airport Pavement Management System: Effects of Delay in Maintenance Approach Based on Life-Cycle
Cost Analysis and Life-Cycle Assessment85

TS 4.3 INFRASTRUCTURE INVENTORY & INSPECTION•

Road Surface Condition Surveys at Traffic-Speed

64•

Development of Thresholds for Travel Quality Assessment In Colombian Urban Roads

121•

Review of Estimation Method of Crack Depth in Asphalt Paving

307•

Mobile Mapping Applications for Data Collection and Evaluation of the Rural Road Assets

519•

Development of the Three-Dimensional Road Surface Measurement Technology by the High-Speed Road Surface
Measurement Vehicle

1783

TS 4.4 INFRASTRUCTURE PRESERVATIONPAGE• Application Of Micro-Surfacing System – PLUS Experience along North South Expressway (NSE)325• Integrated Asset Management System for The Second Penang Bridge

365•

Development of Sustainable and Customized Road Asset Management System In Vietnam

377•

Preliminary Report for Iri Changes after Kumamoto Earthquake Japan, by Using Smartphone Roughness Measurement635

TS 4.5 ASSET MANAGEMENT IN PRACTICE 1•

Influence of Roadside Vegetation on Roughness Progression for Pavements Founded on Expansive Soils

229•

Removal Method for Ceiling Board of the Hanshin Expressway’s Tunnels

248•

Wheel Load Running Tests on the Embedded Expansion Joint Using HighFlexibility Stone Mastic Asphalt

748•

Network Evaluation of Flood Impact for Rural Highways Management

755•

The Natural Frequency Measurement of Pedestrian Bridge Using Smartphone

777

TS 4.6 ASSET MANAGEMENT IN PRACTICE 2
New Low-Activity Nuclear Gauge for Soil Wet Density Measurement with Low Regulatory Burden

445•

Doha Survey Project, Applus+ Energy & Industry Division

511•

Road Tunnel Inspection with High Performance Devices

471•

Requirements of an Asset Information Management System

786•

Automated Detection Of Sealed Cracks Using 2D And 3D Road Surface Data809•

TS 4.7 ASSET MANAGEMENT IN PRACTICE 3•

Lessons from Liberia: Monitoring and Supervision of a 10-Year Performance Based Road Contract

44•

6 Critical Steps to Manage Your Pavement Assets without Breaking the Bank

559•

Performance Based Key Performance Indicators for Expressway Concessions in Malaysia

841

TS 5.1 SUSTAINABLE TRANSPORT PRACTICES•

Innovative Improvement to Restrooms in Rest Areas

183•

Layout Design of Korean-Type Road Debris Remover Instrument

824•

A Basic Study on Comparison of Lane Width Measured with Sensors

311•

The Needs of Life Cycle Cost Application for Malaysia Green Highway Projects

318•

The Effective Use on Expressway to Reduce Traffic Accidents in Tokyo Metropolitan Area732

TS 6.1 TRANSPORT FINANCING & ECONOMICS•

Operators’ and Users’ Perspective on Service Quality Dimensions of Toll Road PPP

397•

Status of Electronic Toll Collection (ETC) and the Development of a New ETCbased Traffic Information Service in
Korea

96

4

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Evaluation of Long Term Performance of Warm Mix Asphalt Using Advanced 3-D
Imaging Technique and Indirect Tensile TestTRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Meor Othman HAMZAH

Professor

Universiti Sains Malaysia,
Engineering Campus

Malaysia

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRYTEH Sek Yee

PhD Student

Universiti Sains Malaysia,
Engineering Campus

Malaysia

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Mohd Rosli MOHD HASAN

Lecturer

Universiti Sains Malaysia,
Engineering Campus

Malaysia

E-MAIL(for correspondence)

cemeor@yahoo.com, cemeor@usm.my

KEYWORDS:
Warm mix asphalt, indirect tensile test, image analysis, adhesion failure, stripping

ABSTRACT:
Warm Mix Asphalt (WMA) is produced at lower temperature than Hot Mix Asphalt (HMA) and is more susceptible toadhesion failure at the binder-aggregate interface. To evaluate the potential mechanisms, the extent of failure iscomputed using the indirect tensile test. Two binder types and different compaction temperatures were used for sample
fabrications. Three levels of conditioning were used namely; unconditioned, Long-Term Aged (LTA)+1 Freeze-Thaw(F-T) cycle and LTA+3 F-T cycles. Effects of conditioning on indirect tensile strength (ITS), fracture energy andpercent adhesion failure of mixtures were investigated. Percent adhesion failure was quantified using the advanced 3-D
imaging technique. Test results showed that polymer modified binders have greater ITS and fracture energy thanunmodified binders regardless of compaction temperatures and conditioning levels. Most modified mixtures passed thetest even after 3 F-T cycles. Percent adhesion failures of modified binders were lower than unmodified binders. The
extent of failure also increased with the number of F-T cycles.

5Evaluation of Long Term Performance of Warm Mix
Asphalt Using Advanced 3-D Imaging Technique andIndirect Tensile Test
Meor Othman Hamzah1*, Teh Sek Yee1 Mohd Rosli Mohd Hasan1
1

Universiti Sains Malaysia, Penang, Malaysia
Email for correspondence: cemeor@yahoo.com, cemeor@usm.my*

1 INTRODUCTION
Over the years, extensive research works have been conducted to evaluate the ability of warm
asphalt technology to reduce asphalt production and laying temperatures. Warm mix asphalt (WMA) being
produced at lower temperatures than HMA is more susceptible to adhesion failure at the aggregate-binderinterface due to moisture damage (Khodaii et al. 2012). Various test procedures have been developed to
examine the moisture susceptibility of asphalt mixtures. Moisture sensitivity tests are divided into two maingroups. The first group is based on qualitative measurement on loose mixtures that involves observing
changes in the percentage aggregate coating after immersion in water or in boiling water. Most of the current
qualitative measurements are based upon visual inspections using the naked eye. The second group of tests isbased on quantitative measurement. They are conducted on compacted mixtures to determine the mechanicalstrength. The main drawback associated with these two groups of test is that standard laboratory procedures
are only capable of computing them separately.
Hamzah et al. (2014) combined these two groups of measurements using the strength properties ofasphalt mixture via direct tension test and also image analysis of the fractured surface of asphalt mixture
specimens subjected to direct tensile test. However, the surface of the fractured specimen is not always
parallel to the plane of the 2-D captured image. This may induce a certain degree of inaccuracies whenquantifying the amount of binder stripping from the aggregate surface. To overcome the issue, this study
presents an innovative approach utilizing 3-D imaging techniques to compute adhesion failure in relation toits mechanical strength using the indirect tensile test. Investigations of the adhesive failures of asphalt
mixture in most previous studies have been focused on specimens subjected to only moisture conditionings.
However, the effect of aging that stiffens the binder with time may also contribute to additional adhesive
failure apart from moisture damage. The contribution of this paper which includes the combined effects oflong-term aging and moisture conditioning may provide some preliminary information on the long-term
adhesive strength of both HMA and WMA mixtures. The resistance of each mixture type in terms ofadhesive strength can then be better evaluated by subjecting them to the worst environmental conditions.
2 RESEARCH OBJECTIVES AND APPROACH
This paper investigated the adhesion strength of various asphalt mixtures in relation to its
mechanical strength using indirect tension. All mixtures were subjected to different levels of conditioning.
This paper adopted the approach used by Hamzah et al. (2014) in which the compacted mixture was firstsubjected to the performance test, followed by examination of the fractured surface using the 2-D image
analysis technique. The 2-D imaging technique used was strictly monoscopic with images of specimens takenfrom merely one viewpoint. This paper attempts to overcome this shortcoming by instead employing a 3-D
imaging technique.This gives more precise quantification of the adhesion failure. This study aims tointroduce and explain the basic concepts related to the use of image analysis rather than generalizing on thelaboratory results. The approach adopted in this study was universal and can be applied in various fields tofurther quantify surface failures. In Malaysia, qualitative measurement is still carried out based on visualinspection using the naked eye. Such quantification is very subjective in nature and varies with different
observers. With the introduction of 3-D imaging technique, it may be incorporated into the Malaysian Public
Works Department specifications to evaluate stripping if it is made mandatory in the future. Adhesion
failures attributed to the combined effects of aging and moisture conditioning were investigated. The fracture

6

energy needed to break the unconditioned and conditioned specimens was also computed from the loaddeformation curve of ITS.
3EXPERIMENTAL WORKS

3.1 Materials
Two types of binders were used in this investigation, namely; an unmodified PG-64 and a styrenebutadiene-styrene (SBS) modified PG-76 binder. The granite aggregates used in the preparation of all
mixtures were supplied by Kuad Sdn. Bhd. in Penang. All mixtures incorporated Pavement Modifier (PMD)
as the filler. PMD is a grayish-black powder mineral filler that has been used for anti stripping purposes. The
mix gradation is shown in Table 1. WMA mixtures were prepared using Evotherm® 3G (M1) as the warmmix additive, added at a dosage rate of 0.5 % by mass of binder. According to Hurley and Prowell (2006),
this was the optimum dosage rate. The properties of Evotherm® 3G and its blending parameters with basebinder are presented in Table 2.
Table 1. Aggregate gradation for mixture type AC-14 (PWD 2008).
Sieve sizes (mm)Lower-upper limits
Passing (%)

20
100
100

14
90-100
95

10
76-86
81

5
50-62
56

3.35
40-54
47

1.18
18-34
26

0.425
12-24
18

0.15
6-14
10

0.075
4-8
5

Table 2. Physical and chemical properties of WMA additive (MeadWestvaco 2012).
Properties

Physical
state

Color

Odor

Flash point

Solubility
in waterpH

Boiling/
condensation point

Evotherm®
3G (M1)LiquidAmber(Dark)

Amine
-like

Closed cup:
204.4 °C

Insoluble

1012> 200 °C

3.2 Specimen preparation
A total of 60 specimens was prepared for this investigation, including three conditioning types, four
different mixing and compaction temperatures and one anti stripping agent as the filler. The dimensions of
the specimens prepared and tested in this study were 100 mm in diameter and 63.5 mm in height. The
Servopac Gyratory Compactor was used to compact the specimens to 7±1%air voids. The Marshall Mix
design procedures ASTM D1559 (ASTM 2006) conforming to the Malaysian Public Works Department(JKR) specification (PWD 2008) for mix type AC-14, was applied to determine the optimum binder content
of all mixtures. The optimum binder contents of the base PG-64 binder were 5.0% and 5.2% for HMA and
WMA mixtures, respectively. The resultant optimum binder contents for the PG-76 mixtures were 5.3% and5.6%, respectively. The mixing and compaction temperatures of all mixtures are listed in Table 3.
Table 3. Mixing and compaction temperatures of asphalt mixtures.
Binder
PG-64

PG-76

MixtureHMA
WMA Control (0 % additive)
WMA (0.5 % additive)
HMA
WMA Control(0 % additive)
WMA (0.5 % additive)

Mixing temperature (°C)
160140120-140180
160
140-160

Compaction temperature (°C)
150130110-130170150
130-150

3.3 Laboratory moisture conditioning
Specimens were first aged using the long-term aging process described in AASHTO R30 (AASHTO
2008) followed by moisture conditioning. Moisture conditioning of the specimens was carried out in7

accordance with ASTM D4867 (ASTM 2006) procedures. The only modification made was the addition of
Sodium Carbonate (Na2CO3) to the distilled water at a concentration of 6.62 g per liter to accelerate stripping
within the asphalt specimens (Hicks et al. 2003). The specimens were then immersed in the solution andvacuumed for 15 min. to attain saturation levels in the range of 55% and 80%. Subsequently, these specimens
were subjected to freezing at -18 ± 3 °C for 16h and thawing at 60 °C for 24 h as one cycle. This
investigation was carried out on three sets of specimens; unconditioned, conditioned 1 freeze thaw (1 F-T)
cycle and 3 freeze thaw (3 F-T) cycles.
4 TEST METHODS
The indirect tensile strength (ITS) test was used to characterize the tensile behavior of asphalt
mixtures. The test temperature for all mixtures was set at 15 °C. Such a low temperature stiffened thespecimens and easily disintegrated when loaded until failure (Xie et al. 2012). Hence, this low temperature
condition will ensure that the asphalt mixtures attain close to elastic properties (Huang et al. 2003). The
loading rate of 50.8 mm/min was selected for use in this investigation. The fractured cross-section was
photographed after the test using a high-resolution 16 megapixels digital camera. The percentages ofadhesion failures and broken aggregates were determined by an image analysis software. The Indirect Tensile
Strength (ITS) was computed using Equation (1).
(1)
Where ITS is in MPa; Pmax refers to the maximum force of each stress-elongation curve; D and t are thediameter and thickness of the specimen, respectively in mm.

Figure 1. Experimental setup.

5 IMAGING TECHNIQUE
Images of the fractured surfaces of all specimens were taken after the test for image analysis. An
imaging technique in 3-D was used to compute the percentages of adhesion failures and broken aggregates ofeach specimen.

8

5.1 Imaging technique in 3-D
In this paper, imaging technique in 3-D was introduced to more precisely quantify the amount ofbinder stripping from the aggregate surfaces. Prior to 3-D image analysis, ordinary 2-D photos had to be firstmerged and converted to a 3-D model using the 123-D Catch software.
5.2 Merging 2-D images into a 3-D model
Autodesk 123-D Catch software was utilized for this purpose. In this paper, a minimum of 20 photos
were taken for each specimen at different angles from the horizontal axis. Figure 2 shows the conversion of
2-D photos, captured at various angles, into a 3-D model. These models were then saved and exported into
Cloud Compare for 3-D image analysis.

Figure 2. Conversion of ordinary 2-D images into a 3-D model.
5.3 3-D Image processing
Subsequently, after conversion, these 3-D models were exported into Cloud Compare for image
processing. Figure 3(a) shows one of the 3-D models imported from 123-D Catch. Prior to processing, thismodel had to be first cropped, leaving only the fractured surface of the specimen as depicted in Figure 3(b).
This model was then converted to scalar fields for statistical computations. The multidimensional domain of
the model was reduced to lower dimensions, consisting of only one or two component axis. Conversion tograyscales yielded models with merely one band or intensity. Lower values were associated with binder
covered areas and higher intensities corresponded to strip and broken aggregate surfaces. Figures 4(a) and (b)show the conversion of the segmented fractured surface of the original 3-D model into grayscales.
Thresholding was used for classification of the 3-D models. The default number of classes used inthis software was 255. Determination of the threshold range values for stripped and broken aggregate
surfaces were executed via the trial and error method by narrowing the number of classes between 0 and 255.
Figure 4(c) shows the classification of the model into stripped and broken aggregate areas, respectively. The
statistical tool included in this software conveniently displayed the amount of pixel point clouds that
corresponded to each of the threshold range values selected. These values were then used to compute thepercentages of adhesion failure and broken aggregate.

9

(a)

(b)

Figure 3. (a) A 3-D model of WMA mixture mixed at 130 °C, imported from 123-D Catch, (b) Segmented
fractured surface of the 3-D model.

(a) Original 3-D model(b) grayscales(c) Classification of 3-D model

Figure 4. Conversion of the segmented fractured surface of the original 3-D model into grayscales.
6 RESULTS AND DISCUSSION
The results of the image analysis are used to supply information on the amount of pixels that
correspond to the total fractured surface, stripped and broken aggregate areas. For computation of the results,
failures attributed to the adhesion and broken aggregates are expressed in percentages, while the indirect
tensile strength is expressed in MPa.
6.1 Influence of combined aging and moisture conditioning on adhesion failure
Figure 5 shows the percentage of adhesion failure for PG-64 and PG-76 binders, computed using the3-D imaging technique. Based on these results, it can be observed that combined aging and moisture
conditioning has a notable influence on the adhesive property of the asphalt mixtures, irrespective of binder
type. The percentage of adhesion failure of both HMA and WMAs for PG-64 mixture is relatively higher
than PG-76 mixture, regardless of conditioning levels. Aging of the specimens stiffens the binder
contributing to higher adhesive failures after testing. All mixtures show an increment in adhesion failure after
long-term aging. The percentage of adhesion failure further escalates with the number of F-T cycles.
The percentage of adhesion failure of dry specimens for all PG-64 mixtures, produced at different
mixing temperatures, is relatively similar. However, WMA mixtures prepared at 140°C with 0% additive and120°C, exhibited the highest failure with respect to adhesion after 1 F-T cycle. This may be attributed to theeffect of lower production temperature, resulting in WMA mixtures more susceptible to adhesion failures due
to moisture infiltration. As for the WMA mixture with 0% additive, this may be caused by the absence ofwarm mix additive to further enhance the adhesive properties of the mixture. WMA mixture (with additive)
produced at 140°C and 130°C show comparable performance to HMA even after exposure to 1 F-T cycle.

10After the combination of aging and 3 F-T cycles, the percent adhesion failure for HMA using PG-64 binder isstill lower than the corresponding WMA mixtures at different mixing temperatures. This is an indication of
the superior performance of HMA as compared to WMA for mixtures prepared with PG-64 binder, after
being subjected to aging and higher F-T cycles. As for WMA mixtures, percentages of adhesion failure for
WMA produced at 140°C and 130°C are relatively low and equivalent to one another after 3 F-T cycles.
According to Figures 5(a) and (b), all mixtures made using PG-76 binder exhibit lower adhesion
failures compared to PG-64 mixtures, regardless of mixing temperatures and levels of conditioning. Xie et al.
(2012) also reported similar findings. In contrast to PG-64 mixtures in dry condition, WMA mixtures
produced at different temperatures using PG-76 binder have comparable adhesion failures as HMA. This may
be due to the addition of warm mix additive into the mixture that enhances the adhesive properties of thesemixtures. The benefit of using this additive is therefore more pronounced when used in conjunction with PG76 binder. Lower percentage of adhesion failures signify that PG-76 mixtures perform better than PG-64
mixtures and therefore, more resistant to stripping. This may be explained by the rheological properties of thebinder which make PG-76 mixtures more resistant to stripping at low temperature of 15 °C as compared to
PG-64 mixtures.
Polymer modified binder exhibits higher strain capacity and hence, more ductile at failure comparedwith unmodified binder. This may be attributed to the lower freezing temperatures of PG-76 binders than PG64 binders (Hamzah et al. 2014). Based on Khattak et al. (2007), the general glass transition temperatures of
PG-76 binder ranged from -60 to -127°C, while the equivalent values for unmodified binder remained around-15 to -10°C. The addition of polymers directly contributes to the significant reduction in the glass transition
temperature of asphalts. As a result, unmodified PG-64 binders are more brittle than PG-76 binders. PG-76
mixtures are expected to be more resistant to binder stripping and exhibit lower adhesion failures (Khattak et
al. 2007). In this paper, the results have shown that most WMA mixtures in dry condition, particularly those
prepared using PG-76 binders, are more resistant to adhesion failures than HMA. In addition, the percentage
differences between HMA and WMA in terms of adhesion failure are lesser in PG-76 mixtures compared to
PG-64 mixtures.

(a) PG-64(b) PG-76.

Figure 5. Percentage of adhesion failure results of image analysis on fractured surfaces (Qualitative
measurement).
6.2 Failures due to broken aggregates
Figure 6 shows the percentage of broken aggregates quantified using the 3-D imaging technique.
The percentages of broken aggregate for PG-76 mixtures are generally higher than PG-64 mixtures. Hamzah
et al. (2014) also reported similar trends and attributed this to aggregate gradation and orientation during
compaction. Failures may be caused by the aggregates that are already fractured during the compaction
process. There is also no specific trend or relationship between the percentages of broken aggregate andmixing temperatures as well as levels of moisture conditioning. Therefore, the trend of these failures is
independent of mixing temperature and F-T cycle.

11Based on the results shown in Figure 5(b), PG-76 binders exhibit lower percentages of adhesion
failure compared to unmodified binders. This may lead to the propagation of failures along the cracks within
the aggregates that have already developed during compaction. PG-64 mixtures which are more brittle at low
temperature exhibit higher adhesion failures. As a result, the tendency of failures to occur in PG-64 mixtures
is higher at the binder-aggregate interface rather than at the cracks developed during compaction. This
explains the lower percentages of broken aggregates in PG-64 mixtures as depicted in Figure 6(a). Moreresearch is still required to investigate the nature of aggregate fracture during compaction, which may include
factors such as aggregate gradation, shape, and orientation as well as its physical and chemical properties.

(a) PG-64(b) PG-76.

Figure 6. Percentage of broken aggregate results of image analysis on fractured surfaces.
6.3 Influence of combined aging and moisture conditioning on indirect tensile strength and fracture energy
Figures 7(a) and (b) show the indirect tensile strength (ITS) results of PG-64 and PG-76 mixtures,
respectively. All mixtures show an increment in ITS after long-term aging. The ITS of all mixtures whencombined with moisture conditioning decreases with F-T cycles. The reduction in ITS is more significant
after 3 F-T cycles compared to after 1 F-T cycle and in dry condition. The ITS of all WMA mixtures is foundto be lower than HMA mixture, regardless of binder type. This indicates that WMA mixtures are more
susceptible to moisture damage, attributed to their lower production temperatures. When comparing all
WMA mixtures, WMA mixtures with 0% additive (WMA Control), prepared using PG-64 and PG-76
binders, generally show the lowest ITS after combined aging and 3 F-T cycles. This finding can again be
substantiated by the absence of warm mix additive to help improve its adhesive strength. The overall results
have shown that the ITS of PG-76 mixtures remain higher than PG-64 mixtures. Long-term aging increases
the ITS of the asphalt mixtures, while combination with moisture conditioning decreases the ITS of thespecimens. Based on the figures, a combination of long-term aging and 1 F-T cycle produces ITS of mixtures
almost similar to those of unconditioned specimens.
Figures 8(a) and (b) demonstrate that both binder types have an indirect tensile strength ratio (ITSR)
values above the 80% acceptable limit after aging and 1 F-T cycle. Aging process increases the ITS while,
moisture conditioning lowers the ITS values. Subjecting the specimens to 1 F-T cycle might not be severe
enough to lower the ITSR values below the permissible limit. However, all of PG-64 mixtures show ITSR
values below the limit after 3 F-T cycles. The effect of adding warm additive is more effective in PG-76
mixtures when all mixtures except WMA control, are still able to exhibit ITSR values above the allowable
80% limit even after the severe 3 F-T cycles.
According to Figures 9(a) and (b), fracture energy of both PG-64 and PG-76 mixtures have shown asimilar trend as the ITS of the mixtures. The energy needed to fracture HMA specimens of both binder types
is always higher as compared to WMA mixtures, irrespective of mixing temperatures and conditioning levels.
The aging process helps to stiffen the binder resulting in higher fracture energy required to break the
specimens. However, with the inclusion of moisture conditioning, the fracture energy of all mixtures
decreases correspondingly. Lowest fracture energy can be observed especially after 3 F-T cycles. This can be12explained by the infiltration of moisture into the binder-aggregate interface leading to adhesive failures
within the bond.
Figure 10 demonstrates the effects of aging and moisture on the overall ITS test results. Aging
increases the ITS of asphalt mixtures, while moisture conditioning has the opposite effect. The results showthat binder type and moisture conditioning have notable effects on the ITS. Overall ITS for PG-76 mixtures isalways higher than the corresponding PG-64 mixtures, regardless of conditioning level. Modified mixtures
also exhibit lower reduction in ITS even after the severe 3 F-T cycles. The difference in ITS between
unconditioned and 1 F-T cycle is very minimal for PG-76 mixtures as compared to PG-64 mixtures.
According to Romeo et al. (2010) and Xie et al. (2012), the tensile strength of SBS modified
mixtures were slightly higher than unmodified mixtures. Kanitpong and Bahia (2005) also found that theperformance of polymer modified binders was superior compared to unmodified binders. The addition ofpolymers enhanced the adhesion, cohesion as well as rutting properties of asphalt binders. Adhesion andcohesion properties of asphalt binders can be reliable indicators of the performance of asphalt mixtures
conditioned in the laboratory.
Based on the laboratory results, it can be observed that the overall ITS and fracture energy of PG-76
mixtures is higher than PG-64 mixtures, while the percentages of adhesion failure of PG-76 mixtures arelower than PG-64 mixtures. Hence, it can be concluded from these findings that ITS and fracture energy isinversely proportional to the percentage of adhesion failure. These parameters can, thus be very useful in
predicting the long-term performance of asphalt mixtures in the laboratory.

(a) PG-64(b) PG-76.

Figure 7. Indirect tensile strength results of fractured specimens (Quantitative measurement).

13

(a) PG-64(b) PG-76.

Figure 8. Indirect tensile strength ratio results of fractured specimens.

(a) PG-64(b) PG-76.

Figure 9. Fracture energy results of fractured specimens.

Figure 10. Effect of aging and moisture conditioning on the overall ITS of asphalt mixture.

14

7 CONCLUSIONSThe use of the 3-D imaging technique was necessary for more precise quantification of adhesion
failure. Overall, the percentage failure due to adhesion indicated that PG-76 mixtures possessed better
resistance to combined aging and moisture damage than PG-64 mixtures. The percentage failure increased
with F-T cycles, irrespective of binder and mixture type. The percentage of adhesion failure for PG-76
mixtures was lower than that of the unmodified mixtures, while the percentage of broken aggregate showed
an opposite trend to adhesion failure. Lower adhesion failures in the PG-76 binder have contributed to
cracking in the aggregates already fractured during compaction. Thus, failures in broken aggregates for PG76 mixtures were relatively higher than PG-64 mixtures. The ITS and fracture energy is reduced with thenumber of F-T cycles. These values were inversely proportional to the percentage of adhesion failure. Lower
ITS and fracture energy corresponded to mixtures with higher percentages of adhesion failure.
ACKNOWLEDGEMENTS
The authors would like to acknowledge the Universiti Sains Malaysia that has funded this research
grant through the Research University Individual Grant Scheme (RUI Grant Number 1001/PAWAM/814231)
which enables this paper to be written.
REFERENCES
ASTM D1559 (2006). Test method for resistance of plastic flow of bituminous mixtures using MarshallApparatus. ASTM, West Conshohocken, PA, USA.
ASTM D4867 (2006). Standard test method for effect of moisture on asphalt concrete paving mixtures.
ASTM, West Conshohocken, PA, USA.
AUTODESK®123D®. Accessed on February, 2015, from http://www.123dapp.com/catchBuss, A. (2011). Investigation of warm-mix asphalt using Iowa aggregates. Ames, IA: Iowa Department ofTransportation.
CloudCompare. Accessed on February, 2015, from http://www.danielgm.net/cc/
ERDAS
Imagine.
Accessedon
February,
2015,
from
Hexagon
Geospatial:http://www.hexagongeospatial.com/products/remote- sensing/erdas-imagine/overview
Hamzah, M. O., Kakar, M. R., Quadri, S. A. & Valentin, J. (2014). Quantification of moisture sensitivity ofwarm mix asphalt using image analysis technique. Journal of Cleaner Production 68: 200-208.
Hicks, R. G., Santucci, L. & Aschenbrener, T. (2003). Introduction and seminar objectives. In: Moisturesensitivity of asphalt pavements - a National Seminar. San Diego, California, pp. 3-20.
Huang, B., Li, G. & Mohammad, L. N. (2003). Analytical modeling and experimental study of tensile
strength of asphalt concrete composite at low temperatures. Composites Part B: Engineering 34(8): 705-714.
Hurley, G. C. & Prowell, B. D. (2006). Evaluation of Evotherm for use in warm mix asphalt. NCAT Report
2:15-35.
Kanitpong, K. & Bahia, H. (2005). Relating adhesion and cohesion of asphalts to the effect of moisture onlaboratory performance of asphalt mixtures. Transportation Research Record: Journal of the Transportation
Research Board 1901(1): 33-43.
Khattak, M. J., Baladi, G. Y. & Drzal, L. T. (2007). Low temperature binder-aggregate adhesion andmechanistic characteristics of polymer modified asphalt mixtures. Journal of materials in civilengineering 19(5): 411-422.
Khodaii, A., Tehrani, H. K. & Haghshenas, H. F. (2012). Hydrated lime effect on moisture susceptibility ofwarm mix asphalt. Construction and Building Materials 36: 165-170.
MeadWestvaco (2012). Evotherm® warm mix asphalt. Accessed on January, 2014, from MeadWestvaco:
http://www.meadwestvaco.com/SpecialtyChemicals/AsphaltAdditives/MWV002106
PWD (2008). Standard specifications for road works, Section 4: Flexible pavements.
Romeo, E., Birgisson, B., Montepara, A. & Tebaldi, G. (2010). The effect of polymer modification on hot
mix asphalt fracture at tensile loading conditions. International Journal of Pavement Engineering 11(5): 403413.
AASHTO R30 (2008). Standard practice for mixture conditioning of hot mix asphalt. American Associationof State Highway and Transportation Officials, 444 N Capitol St. NW - Suite 249 - Washington, DC 20001

15

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

AUTHOR

Tarek Eweida

E-MAIL

Innovative Urban Signalized Junctions

POSITION

Director of Roads andBridges- Middle East

ORGANIZATIONCOUNTRY

Louis Berger

United Arab Emirates

teweida@louisberger.com

KEYWORDS:
Urban Signalized Junctions- Compact Underpass- Safety- ITS- Sustainability

ABSTRACT:
Urban signalized junctions normally suffer delays, accidents, pollution from long stopping times at signals. Typically,
grade separations are not considered at these junctions for cost, ROW and aesthetics concerns resulting from long
structures required to achieve minimum clearance and gentle grades for high/heavy vehicles.
In most cases high/heavy vehicles constitute 5%-20% of the traffic mix at urban signalized junctions which means grade
separations are not allowed for less than 20% of the traffic. Cutting clearance requirements to nearly half and increasing
grades to nearly double would take significant amount of traffic off the signal. A through underpass would take theheavier of through movements off the signal while innovative designs can allow taking both through movements and theheavier of left turn movements to level-1 yet allowing a full movement at grade signal. Underpasses with modified
standards to accommodate small vehicles only should result in significant cost reductions, would require considerably
less ROW than conventional underpasses. Additionally, having the grade separation designed fully underground would
eliminate any negative aesthetic impacts of bridges. A full movement at-grade signal will allow high/heavy vehicles
movement in all directions in addition to small vehicles in directions not provided in the underpasses. Priority could be
provided to emergency vehicles and buses at signals through ITS.

16

Table of Contents
Introduction

1

Disadvantages of Traffic Signals

1

Limitations for Providing Grade Separation on Urban Roads

2

Percentage of Heavy and High Vehicles on Urban Roads

4

Providing Grade Separations for the Dominant Vehicles in the Traffic mix

5

Vertical Clearance and Grade Requirements to Accommodate Small Vehicles

6

Innovative Urban Grade Separations

8

Evaluation Against Recognized Sustainability Standards

9

Possible Disadvantages of Compact Underpasses and Proposed Mitigations

10

Conclusion

11

References

12

List of Figures
Figure 1: Proportion of heavy traffic in the peak hour on the State of Qatar roads

5

Figure 2: Compact underpass in the direction of the heavier of through movements withclearance and grade requirements to accommodate small vehicles
Figure 3: Photo for a standard mini bus offered by many auto manufacturers

6

Figure 4: Compact underpass design with 4.0 meters total level difference and 8% grades

7

Figure 5: Conventional underpass design with 6.5meters total level difference& 5%grades

8

Figure 6: Underpass design with 6.5 meters total level difference and 8% grades

8

Figure 7: Innovative urban grade separation

9

6

List of Tables
Table 1: LOS based on seconds of delay per vehicle

1

Table 2: Maximum grades for urban collectors

3

Table 3: Maximum grades for urban arterials

3

Table 4: Grade and vertical clearance requirements from different GCC standards

4

Table 5: National average truck percentage by functional classification on US urban
roadways
Table 6: Greenroads rating system

4

Table 7: Points that could be achieved towards Greenroads certification from ideas in this
paper

10

10

17

Introduction
Traffic signals at urban Junctions despite being a relatively successful means of regulating conflicting traffic
on intersecting roads, they have major adverse impacts not only on road users being drivers, commuters on
public transport or pedestrians but on the neighborhood residents in addition to other species like birds, trees,etc., While grade separations provide the solution for eliminating conflicts of intersecting traffic on
expressways and freeways, transport agencies are always reluctant to use them on urban collectors andarterials due to their high costs, massive footprint requiring wide ROW for long lengths of the intersecting
roads and maybe aesthetically undesirable if bridges are to be constructed facing and overlooking adjacentbuildings. This paper will investigate the value of introducing underground grade separations designed tostandards that allow only small vehicles to go through them accordingly, the high costs and large footprint ofinterchanges can be significantly reduced. The author argues that small vehicles constitute 80-95 % of thetraffic mix at most urban junctions (for ease of reference will be referred to as 90% of the traffic mix
throughout this paper). The remaining high/heavy vehicles which are mainly trucks and buses (for easereference will be referred to as 10% of the traffic mix throughout this paper) will be allowed an at-gradesignal at (level-Zero). Only grade separations at one level below ground (level -1) will be proposed
throughout this paper to have high/heavy vehicles move safely at level-Zero and to eliminate the negative
aesthetic impact of bridges. Innovative ideas will be proposed to allow the maximum number of movementsa free flow operation. The following sections will discuss the disadvantages of traffic signals, limitations forproviding grade separations on urban roads, percentage of heavy/ high vehicles on urban roads, providing
grade separations for the dominant vehicle types in the traffic mix, ideas for innovative urban grade
separations, evaluation of the proposed designs against sustainability standards, potential disadvantages ofthe proposed grade separations and finally a conclusion.
Disadvantages of traffic Signals
Although traffic signals have proven to provide an efficient solution for managing conflicting traffic
whenever two or more roads intersect, they have several disadvantages. It is prudent for the goals of thispaper to identify the disadvantages of traffic signals.
Delays:Delays are inevitable at traffic signals. The Highway Capacity Manual (HCM 2010) defines delay as “theadditional travel time experienced by a driver, passenger, or pedestrian” and chapter 18 of HCM provides
equations for calculating the delay a motorist experiences due to the presence of a traffic signal. This includes
time spent decelerating, in queue, and accelerating. Additionally the HCM attributes the Level Of Service(LOS) Criteria at signalized junctions to delay time experienced by the motorists. Table 1 provides LOS
criteria of HCM based on seconds of delay per vehicle.
Table 1: LOS based on seconds of delay per vehicle

LOS

Control Delay per vehicle(seconds per vehicle)

A

≤ 10

B

> 10-20C> 20-35D> 35-55E> 55-80

F> 80
Source HCM 2010

As delay increases, LOS gets poorer and congestion starts. In addition to the stress and frustration congestion
causes to drivers, it has drastic effects on individual and national economies. A study by INRIX, a leadinginternational provider of real-time traffic information, transportation analytics and connected driver services,in collaboration with the Centre for Economics and Business Research (CEBR), that was intended to quantify

18

the “cost of traffic congestion” on national economies in the U.S., U.K., France and Germany between 2013
and 2030 have concluded that over this period, the cumulative cost of congestion for these economies
combined is estimated to be a staggering $4.4 trillion. At the individual level, traffic congestion costed
drivers $1,740 on average across the four countries in 2013, and this number is expected to grow more than
60% to $2,902 annually by 2030.
Safety:Reports from the National Center for Statistics and Analysis (NCSA) office of National Highway Traffic
SafetyAdministration-USA show that between 2007 and 2011, 751 people died each year in red light runningcrashes and $ 378 million in cost are lost each month due to red light fatalities. According to another reportby ABC news (2013), red light running crashes result in 800 fatalities and 200,000 injuries each year. In theother side of the globe, Dubai, a city having one of the top five growing economies in the world, and now amain business and tourism hub in the Middle East (Everington, 2015) has one of the most advanced roadway
networks in the Middle East. Jumping the red light resulted in 111 crashes killing 3 people and injuring 159
people in the first 9 months only of 2015 (Agarib, 2015).
Important questions to ask are: are red light runners necessarily intentional violators? And is running a red
light the only cause of accidents at traffic signals? The answer is no to both questions as accidents at traffic
signals may take place as a result of drivers being trapped in the dilemma zone. According to the Federal
Highway Administration (FHWA), the dilemma zone is the area in which it may be difficult for a driver todecide whether to stop or proceed through the intersection at the onset of the yellow signal indication.
Although numerous studies by different agencies tackled the problem of dilemma zone and offered possible
mitigations, according to the Institute of Transportation Engineers (ITE) the dilemma zone is still a main
reason for accidents at traffic signals as some drivers trapped in the dilemma zone will decide to stop whileothers will decide to continue. An abrupt stop may result in a rear end crash and a wrong decision to continue
may result in a right angle crash (Ceccarelli, 2012).
Pollution:
Air and noise pollution are two major adverse impacts from stopping at traffic signals. In America, one thirdof carbon dioxide emissions come from moving people or goods, 80 percent of which come from cars andtrucks. As traffic congestion increases, so too do fuel consumption and CO2 emissions. Therefore, congestion
mitigation programs should reduce CO2 emissions (Barth & Kanok, 2009). From human health perspective,
motorized vehicles emit polluting nanoparticles which contribute to respiratory and heart diseases. Traffic
signals has been identified as hot spots for concentration of such pollutants. With drivers decelerating andstopping at signals, then accelerating to move quickly when lights go green, peak particle concentration was
found to be 29 times higher than that during free-flowing traffic conditions (Kumar, 2015). In the samecontext, noise level increases with traffic volumes in an exponential manner (Marathe, 2011). Unlike highspeeds at which noise pollution is mostly attributed to tire and aerodynamics noise, noise pollution oncongested roads is mainly attributed to acceleration and breaking, engine and vehicle horn noise which haveserious impacts on human health including headaches, stress and heart diseases.
This paper argues that at any urban junction, taking 90% of the traffic using an urban signalized junction off
the traffic signal will considerably mitigate such disadvantages hence, will improve the overall traffic
operations, the environment and the quality of life of people.
Limitations for Providing Grade Separation on Urban Roads
Typically, grade separations are not considered on urban roadways (collectors or arterials) for cost, ROW andaesthetics concerns resulting from long structures required to achieve minimum clearance and gentle grades
required by the design standards. This has been best described by Hernandez (2011) stating that although
grade separations allows traffic to move with fewer interruptions, resulting in higher overall speeds, the main
disadvantage of grade separations is the cost. The large physical structures that form this type of roadways
are significant and expensive. The structures are so large that their heights are obtrusive, which make them
unpopular with nearby landowners. Trying to pass a plan for a new grade separation can be difficult becauseof the obtrusiveness and the cost.
The internationally recognized design manual “A Policy on Geometric Design of Highways and Streets2011”, also referred to as the “Green Book” or “AASHTO” referring to the agency that published it “the19American Association of Highways and Transportation Officials” is used by many transport agencies
throughout the world as a complementary document to the local geometric design standards. AASHTO has
set grade and clearance standards for the different classifications of roadways. For the intent of this paper, thestandards for urban collectors and urban arterials from AASHTO will be referred to.
For urban collectors, AASHTO sets the minimum vertical clearance for underpasses at 4.3 meters with anadditional allowance for future resurfacing. Table 2 identifies the maximum grade requirements for urban
collectors.
Table 2: Maximum grades for urban collectors

Source: AASHTO 2011
While, for urban arterials, AASHTO sets the minimum vertical clearance for designs of new underpasses at
4.9 meters. It allows clearances to be designed at 4.3 meters only if an alternate route can be provided with aminimum clearance of 4.9 meters. Table 3 also identifies the maximum grade requirements for urban
arterials.
Table 3: Maximum grade for urban arterials

Source: AASHTO 2011
Many road agencies set more stringent values of minimum vertical clearance and longitudinal grades on
urban roads. Table 4 identifies grades on urban collector and arterial roads (or equivalent depending on eachagency classification) and vertical clearance requirements collected from different standards in the Gulf
Cooperation Council (GCC) countries where the author was involved in roads design of several projects overa span of more than 10 years.

20

Table 4: Grade and vertical clearance requirements from different GCC standards
Standard Name
Highway Design Manual

Authority/ Country
Ministry ofCommunication- Kingdomof Saudi Arabia

Qatar Highway Design
ManualState of Qatar

Geometric Design
Manual for Dubai Roads
Road Geometric Design
ManualDubai- United ArabEmirates (UAE)
Department of TransportAbu Dhabi- UAE

Maximum GradeUrban Arterials 70 KPH:
4.5% Desirable- 6%max
Urban Arterials 60 KPH:
6% Desirable- 8% max
Secondary routes- 6%

Urban Collectors- 6%
Urban Arterials- 6%
City Boulevard: A tablefor different speeds
ranging from 7% to 8%

Vertical Clearance
5.5 meters

5.5 meters (original
manual-1997), 6.0
meters (Circular-2012)
5.5 meters
6.5 meters

Hands on design experience in these countries concluded that unless dictated by extremely stringent
constraints, grades of newly designed grade separations are never to exceed 5% and vertical clearance isnever to be designed for values that are less than those shown in table 4. This is mainly to cater for heavy andhigh vehicles (mainly trucks and busses) in the traffic mix which have overall heights that are significantly
bigger than private cars and vans. Additionally, loads transported on these vehicles (mainly trucks) or thelimitations of the power of their engines or both make it difficult for them to negotiate steep grades.
Accordingly, the provision of a grade separation at a congested signalized junction is a decision driven bycost and ROW availability that is based on achieving vertical clearance and grade requirements for thesevehicles.
Percentage of Heavy and High Vehicles on Urban Roads
It can be argued that most professionals working in the field of transportation engineering would agree thatthe percent heavy vehicles used in their work whether being Transport Master Plans, Traffic Impact Studies
or Pavement Designs in urban areas are mostly in the range of 5% to 10%, sometimes less than 5% andsometimes between 10 and 20% with a very rare likelihood of exceeding 20% and this would be only if the
project is a truck route, located in an industrial area, close to a port, or similar. Hallenbeck, et al (1997)
provided the information shown in table 5 for National average truck percentage by functional classification
on US Urban roadways.
Table 5: National average truck percentage by functional classification on US urban roadways
Functional
Class ofRoadwayFHWA

Cars

Single-Unit
TrucksIncludingBuses

Combination
TrucksMulti-Trailer
Trucks

11

91.5%

2.6%

5.2%

0.7%

12

88.9%

3.7%

5.9%

1.5%

14

90.5%

3.2%

5.8%

0.6%

16

94.4%

2.4%

2.9%

0.3%

Class 11 = Urban InterstateClass 12 = Urban Other Freeways and Expressways
Class 14 = Urban Principal Arterial
Class 16 = Urban Minor Arterial
Compiled from Hallenbeck, et al (1997)21

From a different part of the world, the State of Qatar is an ambitious country that won the 2022 FIFA worldcup bid and have massive construction projects taking place. Qatar roads network currently lacks afreeway/expressway system, accordingly most of its truck traffic serving the mega construction projects
taking place in the country, particularly in the capital “Doha” run on the urban roadway system mainlycomprising urban arterials and urban collectors, the intersections of which are controlled by traffic signals.
“The Doha expressway program is a 5 year program that consists of 30 Expressway projects to improve
traffic flows, reduce congestion, travel time and environmental impacts in Doha with a total cost of US$20bn” (KBR website).
Although, as stated above, most of the truck traffic take place on a network that lacks a freeway/expressway
system, the chart shown in figure 1 below provided by the Ministry of Municipality and Urban Planning(MMUP) limited heavy vehicle percent at peak hour on Urban roads to around 16% while for the road classes
that are the subject of this paper (Collectors and Arterials) represented in the chart by “Secondary Urban” and“Tertiary Urban” heavy vehicle percentage is limited to around 8% and 5% respectively.

Figure 1: Proportion of heavy traffic in the peak hour on the State of Qatar roads
The author argues that further studies in different countries around the globe would result in similar or close
to the same percentages of heavy vehicles on urban roads as in the USA or Qatar, accordingly and as
mentioned in the introduction for ease of reference, on an urban signalized junctions assuming a traffic splitof 90% small vehicles and 10 % high/heavy vehicles (trucks and busses) maybe considered a reasonableassumption.
Providing Grade Separations for the Dominant Vehicles in the Traffic mix
Restricting the decision to provide grade separations on meeting the design criteria for high/ heavy vehicles,in the author’s vision, is a big obstacle to mobility, safety and sustainability goals as it results in having thedominant types of vehicles in the traffic streams suffer stopping at signals and the entire community suffer
the adverse impacts of such recurrent stopping of traffic for 10% only of the traffic travelling on urban roads.
This paper argues that grade separations applying vertical clearance and grade requirements to accommodate
small vehicles only should be thoroughly explored as a solution if congestion is experienced at any urban
junction. As a minimum, a conventional underpass with modified vertical clearance and grade requirements
to accommodate small vehicles in the direction of travel having the heavier of the intersecting throughmovements should be considered. Such design should remove 90% of the traffic in this direction from thesignal significantly enhancing signal timings and the overall cycle length for the remaining traffic using theat-grade signal. While the following section will provide a study on what could be considered a “small

22

vehicle” that maybe allowed in the underpass, accordingly what is the minimum design vertical clearance andmaximum grade proposed for the grade separation, figure 2 shows how the design for the proposed “compact
underpass” should look like. As normally expected, at major urban signalized junctions additional ROW in
the vicinity of the junction is required anyway to accommodate additional left and right turning movement
lanes for lengths of the intersecting roads. It is argued that widening to accommodate a “compact underpass”
will not require additional ROW for lengths that exceed the same required to provide such turning movement
lanes.

Figure 2: Compact underpass in the direction of the heavier of through movements with clearance and grade
requirements to accommodate small vehicles

Vertical Clearance and Grade Requirements to Accommodate Small Vehicles
This section provides an attempt to identify the reasonable vertical clearance and grade requirements that willaccommodate 90% of the traffic mix thus shortening as much as practical lengths of retaining structures forunderpasses and limiting additional ROW requirements to the same lengths required to accommodate
additional turning movement lanes at a conventional urban signalized junction.
Chrest (2011), researched several design codes for multistory car parking garages and concluded that mostcodes require 7’ (2.14 meters) as the minimum height that will accommodate private cars, vans, etc., however
added that NFPA, 101 requirements for means of egress systems would require 7’ 6” (2.28 meters)
A web search on city bus dimensions used by several transport authorities worldwide identified that theminimum height of a one story bus dimension is 4.3 meters, making it impractical to use it for the aimed
compact underpass design, while another search on minibus heights revealed that height of a 30 seater
minibus of the type shown in figure 3 and offered by many auto manufacturers ranges between 2.60 meters to
2.75 meters. The internal height of such minibus is in the range of 1.9 meters.

23

Figure 3: Photo for a standard mini bus offered by many auto manufacturers
The Federal Specification for the star-of-life ambulance (2002) specified the maximum height for ambulancevehicles to be 2.79 meters.
International fire code (2009) identified the minimum vertical clearance for fire trucks to be 4.115 meterswhich again wouldn’t be practical to use if a tangible reduction in vertical clearance is to be offered for theintended compact underpass.
In light of the above, it can be concluded that the reasonable minimum vertical clearance that canaccommodate private vehicles, vans, minibuses and ambulance vehicles would range between 2.85 to 3.0
meters.
For the purpose of calculation of structural lengths of retaining walls in this paper a vertical clearance of 3.0
meters will be used. Added to this, a structural slab depth inclusive of pavement of 1.0 meter will be assumed
giving a total depth of 4.0 meters.
Looking at grades, it could be argued that the upper range of grades in standards is always avoided in thedesign of grade separations for the risk that the 10% of vehicle classifications (heavy trucks) will not be able
to negotiate it. Looking at AASHTO, for urban collectors the maximum grades for the design speed of 60
KPH are 9%, 10% and 12% for level, rolling and mountainous terrains respectively. For the same roadclassification AASHTO states that these grades could be increased by 2% if the grade length is less than 150
meters. For Urban Arterials, the maximum grades for 60 KPH speed are 7%, 8% and 10% for level, rollingand mountainous terrains respectively. For the proposed grade separation a grade in the range of 8-10% may
be considered reasonable for the intended vehicle classifications having relatively light loads and likely
powerful engines.
At 60 KPH speed, the limiting factor for grades for the intended “compact underpass” would be the K-valuesof the adjoining crest and sag curves to achieve the 4.0 meters deep level-1 grade separation. For a 60 KPH
speed the AASHTO K-values are (11 & 18) for crest and sag respectively. While these values areconservative compared to those dictated by several other standards, they will be used in this paper for
AASHTO being a recognized standard worldwide, accordingly the required lengths of vertical curves for a
60 KPH may not seem practical. The AASHTO K-values are reduced significantly for a design speed of 40
KPH (4 & 9) for crest and sag respectively. Accordingly, a design speed of 40 KPH can be used for the
proposed grade separations which will still result in significant improvement in traffic operations compared
to stopping at a signal. In this case, speed reduction measures like rumble strips or similar should beconsidered at the underpass approaches. Using an 8% grade at a 40 KPH speed provided reasonablestructural lengths for underpass retaining structures. The following figures 4, 5 & 6 provide comparisons oflengths of retaining structures for the proposed compact underpass versus a conventional underpass. 1%
grade is assumed at level-Zero in the opposite direction as a conservative approach for algebraic difference ofgrades, hence, the calculation of vertical curve lengths.

24

Figure 4: Compact underpass design with 4.0 meters total level difference and 8% grades
Figure 4 shows a compact underpass with a total level difference of 4.0 meters, a design speed of 40 KPH
and 8% grades, the structural length required to reach level-Zero is around 85 meters. Such length is quite
reasonable compared to the lengths of widening applied to most signalized junctions to add turning
movement lanes.
Comparing this to a conventional underpass as shown in figure 5, using 6.5 meters total level difference and5% grades to accommodate high/ heavy vehicles, the structural lengths are significantly longer requiringaround 189 meters.

Figure 5: Conventional underpass design with 6.5 meters total level difference and 5% grades
And for the purpose of comparison only, figure 6 shows a grade separation of total level difference 6.5
meters with a grade of 8%, which may not be desirable by most agencies as high/ heavy vehicles will beallowed to use the underpass with potential difficulty for overloaded/ less powerful trucks to negotiate the 8%
grade. Such design resulted in a structural length of around 116 meters.

Figure 6: Underpass design with 6.5 meters total level difference and 8% grades
While this paper cannot offer a firm cost comparison between the proposed compact underpass andconventional underpasses as the parameters at each location this design is proposed may vary widely,following are obvious potential advantages compact underpass design may offer over conventional underpass
design.

25

The height of the retaining structure in the covered section of the underpass whether being retaining walls ora trough section if high water table is encountered is less by a minimum of 2.5 meters than conventional
underpasses and will result in considerable cost reductions.
The lengths of retaining structures outside the covered section and until level-Zero is reached is significantly
less than that of conventional underpasses and will result in significant cost reductions.
The total earthwork volumes for a compact underpass are significantly less resulting is considerable cost
reductions.
Additional ROW requirements for compact underpass designs fall in the same limits within the lengths
required for widening of at-grade signalized junctions to provide additional turning lengths while additional
ROW requirements for conventional underpasses maybe required for significantly longer lengths.
Innovative Urban Grade Separations
Figure 7 shows an idea for an innovative urban grade separation proposed by the author. The idea is based on
having one of the two intersecting through movements go in a compact type through underpass (Direction
A). The through, or left movements or both of the other direction (Direction B) will make a right turn at thejunction and will start ramping down to a compact type underpass. At the point where the ramps of thethrough underpass of direction A are back to level-Zero, the ramped down roads of direction B will make a
U-turn under direction A carriageway. The left turn will connect directly at level-1 to the underpass of
direction A while the through movement will continue crossing under the full width of direction A and willramp up again parallel to direction A until it reaches the junction and make another right turn to complete thethrough movement of direction B. This design can obviously offer big flexibility to traffic engineers based on
through and left turning volumes of both directions on which direction is to be taken in a through underpass
and which is to be taken in a “U- Turn” underpass. It is argued that this design will literally keep the traffic
moving in almost all directions as the only traffic that will be stopped at the signal will be the left turning
traffic of one direction only in addition to high/heavy vehicles. The parameters of this design, particularly,
sight distance and grades can be adjusted for a design speed of 40 KPH which is still much better thanstopping at a signal. The swept path for turning curves could be adjusted to accommodate a city bus(horizontally only).

Direction B

Direction A

Demand for pedestrian crossing

Figure 7: Innovative urban grade separation

26

One disadvantage of this design maybe the difficulty to achieve safe pedestrian crossing at the four locations
identified in figure 7 as they will conflict with the proposed free flow through movement of direction B. In
order to achieve safety to pedestrians at these locations one of the following options should be investigated.
Providing on-demand pedestrian signals at the 4 identified locations in figure 7, which will likely
require less stopping time than if vehicles have to stop for the conflicting through and left turning
vehicular traffic. However in this option it may be argued that the through direction of direction B
will be stopped twice for pedestrian crossing significantly challenging the efficiency of the new
design and questioning the value for money for building the proposed U-turn underpasses.
Providing traffic calming measures upstream of pedestrian crossings with “Give way for
Pedestrians” signs. This option will function properly to a certain threshold of through traffic
volumes and demand of pedestrian crossing yet may create safety issues for pedestrians andinconvenience to through traffic seeking uninterrupted flow by using the underpasses.
Providing underground grade-separated pedestrian crossing only from the edge of the intersection to
the right turn channelization islands to eliminate the conflict between pedestrians and through(turning right) traffic. Beyond the channelization islands normal at-grade pedestrian crossings could
be provided. Although this option involves another additional cost, it has merits for serious
consideration to ensure the efficiency of the grade separated lanes, should this design have merits
for implementing.

Evaluation Against Recognized Sustainability Standards
Like LEED for buildings, Greenroads is a third party rating system for road projects that recognizes andrewards roadway projects that exceed public expectations for environmental, economic and social
performance. It is meant to improve roadway sustainability and provide accountability for sustainability on
roadway projects (Muench, Anderson, Hatfield, Koester, & Soderlund et al., 2011).
The Greenroads rating system is a collection of credits, earning points towards those credits would qualify aproject for certification. To achieve certification, there are 12 project requirements that are mandatory and 6
categories of credits, each of which has a maximum number of points that can be achieved. Table 6 describes
the rating system credits, points and certification categories.
Table 6: Greenroads Rating System

Source: Greenroads Manual Version 2
The author made a hypothetical assessment if a normal at-grade signalized junction is to be converted to acompact grade separation by adopting the ideas provided in this paper, how many points such a project could
obtain only by adopting these ideas assuming that mandatory project requirements which are all about having
certain studies, reports and plans in place like ecological impact analysis, energy and carbon footprint
assessment, social impact analysis, quality control plan, etc., will be met and that the project could complete
certification requirements from additional areas like recycling, drainage solutions etc.,

27

Table 7 provides a list of categories and points that could be achieved against each category. As shown, a
total of up to 17 points can be achieved only by adopting ideas provided in this paper.
Table 7: Points that could be achieved towards Greenroads certification from ideas in this paper
Category
Utility and Control
Access and Livability

Creativity and Effort

Credits
Traffic Emission Reduction
Travel Time Reduction
Safety Enhancements
Health Impact Analysis
Noise and Glare Reduction
Innovative Ideas

Points that maybe achieved
Up to 3 points
Up to 2 points
Up to 2 points
Up to 2 points
Up to 3 points
Up to 5 points

Possible Disadvantages of Compact Underpasses and Proposed Mitigations
In order to have a complete assessment of the viability of compact underpass design, it is prudent to also
investigate its possible disadvantages and check if possible mitigations can be provided or not. Following is
an initial assessment of possible disadvantages and possible mitigations. This is of course in addition to what
may be looked at as a disadvantage of adding structures discussed at earlier sections of this paper.
Safety: In the onset of adopting the new design by any agency, many high vehicles may enter the underpassby mistake resulting in major risk of hitting the underpass roof slab. This could be mitigated by planned
publicity efforts in different media sources for the new compact underpasses, their aims, benefits and allowed
users. Also physical gantries, over height detectors and ITS warning systems should be installed at theunderpass entries at least for the first few ones constructed.
Access to fire trucks: Fire trucks may be required to access the underpasses to deal with an emergency
inside the underpass itself or to bypass the signal to shorten the time to their destination. Increasing the
proposed underpass clearance to accommodate fire trucks will discredit the value of compact underpasses as
it may require dimensions and lengths that are equal or close to conventional grade separation dimensions.
For an emergency in the underpass itself, the length of the covered section of the underpass should not belonger than what could be reached by the fire truck fire hose from both directions. For an underpass thatcrosses under 10 lanes inclusive of physical separators the total length of the underpass will never exceed 50
meters which is indeed reachable by fire hoses from both directions. It should also be assumed that
NFPA,502-2011 Edition requirement of having hose connections placed so that no location on the road ismore than 45 meters from the hose and that hose spacing does not exceed 85 meters is achieved with orwithout having a compact underpass on the road.
For the problem of inaccessibility of the fire truck to the underpass for the purpose of bypassing the signal,
considering the significant amount of traffic removed from the at-grade signal, the signal LOS should
experience a remarkable improvement. Additionally, part of the innovative design should include ITS
systems that grant immediate right of way to emergency vehicles through traffic signal preemption.
Additional drainage requirements: Introducing underground traffic lanes at road junctions to replace someof the at-grade lanes will of course involve cost of additional drainage measures like pumping, additional
piping and/or connection to nearby deep storm water tunnels. As for the cost of structures, the additional cost
is countered by the multiple mobility, safety and sustainability benefits offered by providing theseunderground lanes.
Possible Punishment to shared transport commuters: Some may argue that the new design could beconsidered a “punishment” to shared transport commuters, particularly on single or double decker public
buses which will not be allowed access to the underpasses and this may discourage public transport which isagainst sustainability goals that always push in the direction of leveraging public transport.
The answer can simply be that in a conventional signalized junction, public one story or double decker busses
are going to stop at the signal anyway, however as mentioned earlier, the signal in the new design shouldhave remarkable improvement in LOS. Additionally, public busses may have a designated stop in the vicinityof the junction which regardless of clearance restriction will not allow them to access the underpass.

28

ITS solutions may also be provided for buses. One option may be a Transit Signal Priority (TSP) equipmentthat could be added to the busses and traffic signals to give priority, and provide as much as practical green
wave for busses (Smith et al, 2005).
Another possible mitigation is to encourage carpooling. One or more of the underground lanes may be
dedicated to high occupancy vehicles (HOV). In fact, all underground lanes may be assigned as HOV lanes
however such option should be extensively studied by each road agency on a case by case basis as this will
prevent all single occupancy vehicles (SOV) from using the underpasses and will force them to use the signal
which may significantly reduce the efficiency of the new design.
Conclusion
This paper introduced general thoughts on the possible advantages of providing “compact underpasses” that
accommodate “small vehicles” which are argued to constitute around 90% of the traffic mix in mostsignalized junctions. Although “Compact Underpass Design” has the additional cost of structures anddrainage, it significantly contributes to reducing congestion at signals which in addition to its negative
impacts has its enormous cost as well. The implementation of ideas provided in this paper whether being acompact through underpass in one direction or the innovative design of a compact through underpass in one
direction and U-turn compact underpass in the other direction will indeed be subject to thorough feasibility
studies by transport agencies that see merits in such ideas on a case by case basis depending on actual
conditions at locations such designs maybe proposed. The author would like to close this paper with aquestion to bus manufacturers, should bigger busses are to be granted access to the compact underpasses.
What is the possibility of manufacturing city busses with the same horizontal dimensions while maintaining
the external height of minibuses? And if the problem is providing heights that suit all standees, what isaverage percentage of passengers that are taller than the minibus internal height of 1.9 meters amongcommuters? And is it possible to apply the same idea in this paper of maintaining 1.9 meters for the dominant
bus standees and allowing priority seats like those provided for elderly and disabled for the small percentage
of commuters that maybe taller than 1.9 meters?

29

References
ABC News (2013). Running red lights is dangerous. Article. ABC News [on line]. Available at:
http://abcnews.go.com/Travel/story?id=118914&page=1
Agarib, A. (2015). 1 person dies every two days on Dubai roads. Article. Khaleej Times [on line]. Available
at: http://www.khaleejtimes.com/nation/transport/1-person-dies-every-2-days-on-dubai-roads
Barth, M & Kanok, B. (2009). Traffic congestion and greenhouse gases. University of California (2009).
Access. California.
A Policy on Geometric Design of Highways and Streets (2011). American Association of State Highway andTransportation Officials. Washington, D.C.
Ceccarelli, B. (2012) The Dilemma Zone. Defect Caused By Traffic Engineers.
Chrest, A. (2011). Parking Structures: Planning, Design, Construction, Maintenance and Repair. Springer
science and business media (2016).
Everington, J. (2015). Dubai enters top five ranked fastest growing economies. Article. The National [online]. Available at: http://www.thenational.ae/business/economy/dubai-enters-top-five-ranked-fastestgrowing-economies
Federal Specification for Star-of-Life Ambulance (2002). General Service Administration. Federal Supply
Service, Texas.
Hallenbeck, M. et al (1997). Vehicle volume distribution by classification. Washington State Transportation
Center (1997).
Hernandez, R. (2011). Grade Separation- Advantages/ Disadvantages and Types. Sooper Articles. [on line].
Available at: http://www.sooperarticles.com/law-articles/grade-separation-advantages-disadvantages-types694340.html
Highway Capacity Manual (2010). National Research Board. Transportation Research Council, Washington,
D.C.
International Fire Code (2009). International Code Council, INC., Illinois
INRIX (2013). Economic and Environmental Impacts of Traffic Congestion in Europe & The US. Report.
INRIX [on line]. Available at: http://inrix.com/economic-environment-cost-congestion/
Kumar, P. (2015). Stopping at red lights could be slowly killing you. Article. The Conversation. [on line].
Available at: http://theconversation.com/stopping-at-red-lights-could-be-slowly-killing-you-37195
MMUP Guidelines. Heavy Vehicle Percentage by Road Class. Ministry of Municipality and Urban Planning,
The State of Qatar.
Muench, S.T., Anderson, J.L., Hatfield, J.P., Koester, J.R., & Söderlund, M. et al. (2011). Greenroads
Manual v1.5. (J.L. Anderson, C.D. Weiland, and S.T. Muench, Eds.). Seattle, WA: University ofWashington.
NCSA (2011). Red light running dangers in the US. Report. National Center of Statistics and Analysis [online]. Available at: http://fayettevillenc.gov/home/showdocument?id=566
Marathe, P. (2011). Traffic noise pollution. IJED: Vol. 9, No. 1, (January-June 2012): 63-68
NFPA 502 (2011). Standard for Road Tunnels, Bridges, and Other Limited Access Highways. National Fire
Protection Association. Massachusetts.
Smith H. et al. (2005). Transit Signal Priority (TSP): A Planning and Implementation Handbook. TRID.
Washington, D.C.

30

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

A New Approach for Estimating Pavement Rutting Progression

TRACK
AUTHOR(Capitalize Family Name)
Nahla ALASWADKPOSITION
PhD student

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATION
Swinburne University of Technology
ORGANIZATIONCOUNTRY
Australia
COUNTRY

Rayya HASSAN

Dr.

Swinburne University of Technology

Australia

Bayar MOHAMMED

PhD student
Swinburne University of Technology
nalaswadko@swin.edu.aurahassan@swin.edu.aubmohammed@swin.edu.au

Australia

E-MAIL(for correspondence)

KEYWORDS:
Rutting progression, Deterioration model, Multilevel model, Time series data, Pavement management, Model validation

ABSTRACT:
Every road agency responsible for pavement maintenance activities faces the problem of insufficient funding to perform
all required repairs. Accurate prediction models of pavement performance help them in assessing the implications of
optimum maintenance and rehabilitation strategies so that practical decisions can be made. The current study aims atdelivering the application of a new approach for the development of pavement deterioration models for managing a ruralarterial network of flexible pavements. The estimation of pavement rutting progression has been based on longitudinal
datasets that contain observations on the condition of a large volume of pavement sections. The study demonstrates how
to prepare accurate datasets for light and heavy duty pavements with a wide range of pavement rut depths, traffic
volumes, pavement strength and environmental conditions. The study presents hierarchical linear models that canaccount for the correlation among time series data on the same section and capture the effects of unobserved factors. The
contribution and significance of contributing factors in predicting rutting progression are presented and discussed.

31

A New Approach for Estimating Pavement Rutting Progression
Nahla Alaswadko1, Rayya Hassan1, Bayar Mohammed1
1

Swinburne University of Technology, Melbourne, Victoria, Australia
Emails: nalaswadko@swin.edu.au, rahassan@swin.edu.au, bmohammed@swin.edu.au

1 ABSTRACT
Every road agency responsible for pavement maintenance activities faces the problem of insufficientfunding to perform all required repairs. Accurate prediction models of pavement performance help them inassessing the implications of optimum maintenance and rehabilitation strategies so that practical decisions
can be made. The current study aims at delivering the application of a new approach for the development ofpavement deterioration models for managing a rural arterial network of flexible pavements. The estimation of
pavement rutting progression has been based on longitudinal datasets that contain observations on thecondition of a large volume of pavement sections. The study demonstrates how to prepare accurate datasetsfor light and heavy duty pavements with a wide range of pavement rut depths, traffic volumes, pavement
strength and environmental conditions. The study presents hierarchical linear models that can account for thecorrelation among time series data on the same section and capture the effects of unobserved factors. The
contribution and significance of contributing factors in predicting rutting progression are presented anddiscussed.
2 INTRODUCTION
Rutting is described as depression in the transverse profile of the road pavement surface (Haas et al.
1994). It arises from a permanent deformation in pavement layers and/or wearing courses or in the subgrade,which is caused by either consolidation or lateral movement of pavement materials. Permanent deformation
or rutting of flexible pavements has a major impact on structural and surface performance of pavement under
different conditions. It reduces the useful service life of the pavement as it affects pavement integrity andproduces safety hazard for highway users. It affects vehicle handling characteristics and the accumulation of
rainwater in ruts leads to hydroplaning. According to Freeme (1983), there are three phases for thedevelopment of rutting and includes initial densification or bedding-in phase, gradual deterioration phase andaccelerating deformation phase.
The resistance of pavement structure to permanent deformation is dependent on a number ofparameters which include one or more of the following or the combination of all: traffic loads, pavement
structure, environment and construction process. These factors influence the modelling of performance
prediction at different rates through their effects on the initiation and progression phases of various pavement
distress modes (Toole et al. 2009). Deterioration models allow road managers to assess current condition andto predict future conditions of their pavement networks. Once accurate prediction models are identified, thenthe implications of optimum maintenance activities and rehabilitation strategies can be assessed and practicaldecisions made.
3 OVERVIEW
Many road agencies around the world are facing complex decisions about highways maintenance,
repair and rehabilitation in the most cost efficient and effective ways. Therefore, they need to know how
pavement condition will change over time by using accurate deterioration models to maintain high levels ofservice. This change in pavement condition can be due to observed variables or unobserved variables (Hong2007). The former can be captured by including identified causal factors in the deterioration models;
however, the latter arises from factors beyond the already identified causal factors.
A wide range of factors can contribute to rutting progression. These factors generally include trafficloading, climate condition, pavement strength, road type and geometry, maintenance practice, pavement typeand construction quality. Actually, database for any network is unable to capture all possible factors affecting
pavement deterioration process and thereby some critical factors could not be incorporated in models forpredicting pavement deterioration. To overcome this problem, it is required to develop models that are able toaccount for the effect of unobserved factors (i.e. unobserved heterogeneity in pavement condition).

32

The heterogeneity between one pavement section and another may be due to variances inconstruction quality, climate condition and maintenance activities applied in different ways at different times.
There are also differences between the highways from which the sections are extracted which may be caused
by variations in materials properties. Also, there are variances between pavement classes, due to factors suchas class duty function (light or heavy duty pavement). Therefore the data structure is hierarchical with fourlevels of variation within any network. Time series observations (level-1) are nested within sections (level-2),
which are nested within highways (level-3), which are nested within classes (level-4). The development of a
network pavement deterioration model must allow for variation at all these four levels. An approach tocapture the effect of variance at multilevel is presented in the current study. The dataset that has been used inthis study was selected from four types of road classes of the rural arterial network of the State of Victoria,
Australia.
4 STUDY OBJECTIVESThis study aims at delivering the application of a new approach for the development of rutting
progression model for flexible pavements of rural arterial network. The estimation of pavement rutting
progression has been based on longitudinal datasets that contain observations on the condition a large volumeof pavement sections. The study aims at incorporating the effect of unobserved factors in the developedmodels to increase the models’ robustness. In addition, the study has been focused on assessing the effects
and contributions of the different relevant factors on pavement rutting progression, simulating the developedmodels to understand their performance, and validating the models to ensure their ability to predict future
conditions accurately.
5 DESCRIPTION OF SELECTED NETWORK
Representative samples of highways from Victoria’s rural arterial network are considered. The
selected sample network is from 40 highways with a combined length of more than 2,300 km. The coverageof the network sites in terms of relevant modelling parameters is presented below:
 The flexible pavement of all sections have granular bases and sub-bases with single or double coatspray/chip seals but have different thicknesses reflecting the different traffic volumes to which they are
subjected.
 Different climatic zones covering different ranges of Thornthwaite Moisture Index (TMI).
 Drainage condition in terms of good or poor. As all roads considered herein are rural, their drainage
systems consist of table drains or ditches with sealed (fully or partially) or unsealed shoulders.
 Four types of road classes (M, A, B and C) with different duties, geometric standards, and traffic
volumes. Road class (M) represents freeways and motorways, road class (A) represents major arterials,
road class (B) represents main arterials which are state highways connecting major cities, and class (C)roads represent minor arterials which are rural roads connecting smaller towns (VicRoads 2015).
Typically, class M and A roads are classified as heavy duty pavements and class B and C roads areclassified as light duty pavements. The selected network includes 7 road sites of class M, 11 road sites ofclass A, 10 road sites of class B, and 12 road sites of class C.
6 DATA DESCRIPTION AND PREPARATION
Model formula can be used effectively in pavement management system when it depends onvariables that can be easily measured or collected at network level. Therefore, based on the availability of
information for the sample network, time series data for the variables considered in this study include rutting
as the dependent variable (DV) and traffic loading, climate, pavement strength, and drainage condition as theindependent variables. Time series datasets have been extracted from relevant road authority’s databases toaddress the study objectives. Time series data (2004 to 2011) for each 100m-section were collected from aminimum of four surveys for the following variables:
Rutting: In Victoria, rut depth data is collected using a multi-laser profilometer and considering the
maximum depth under a 1.2 m simulated straight-edge center at both wheel paths method (Moffatt & Hassan
2007). The rutting data used was in terms of average rut depth (RD, mm) in both wheel paths (outer andinner) for every 100m section.

33

Traffic loading: Traffic volume data in terms of number of Heavy Vehicles (HV) for the selected
sections was extracted from relevant database for the relevant years. Estimates of traffic data for missing
years were obtained for each highway by using the average growth factor for all its segments over the period
for which data is available. HV numbers at the time of construction for each section were estimated using
current HV, section age and average growth rate (Equation 1). This data was then used to determine
cumulative traffic loading in terms of million equivalent standard axles (MESA) using Equation 2 (Jameson2012) in conjunction with relevant parameters from VicRoads’ code of practice (VicRoads 2013). MESA
was determined for each year condition data is available, for each section. The cumulative growth factor, ineach year for which condition data was available, was calculated using Equation 3.
HVat const = HVcurrent / [(1+ GF) ^ (Age at current HV year)](1)
Where:
HVat const = number of heavy vehicles at time of construction.
HVcurrent = number of heavy vehicles in any year of actual traffic is available.
GF = average annual growth rate of heavy vehicles.
Age = pavement age.
MESA = [365 * HVat const * DF * LDF * CGF * NHVAG * (ESA/HVAG)]/106(2)
Where:MESA = cumulative ESA (equivalent standard axle loads) from construction time to any year ofcondition data.
DF = direction factor =1, (proportion of the two-way HV travelling in the direction of the designlane).
LDF = lane distribution factor, (proportion of heavy vehicles in design lane) =1(VicRoads 2013).
According to VicRoads’ code of practice document (VicRoads 2013); the LDF value is consideredas 1 when the number of road lanes is less than 3 in one direction. Class M roads have two lanes ineach direction, whereas class A, B, and C roads have one lane in each direction.
Cumulative Growth Factor (CGF) = [((1+0.01*GF) ^Age) -1] / (0.01*GF)(3)NHVAG = average number of axle groups per heavy vehicle = 3.1(VicRoads 2013).
ESA/HVAG = average ESA per heavy vehicle axle group = 0.82 for class M and A and 0.66 forclass B and C (VicRoads 2013).
Pavement strength: Insufficient pavement strength or deformation and displacement in the upper
layers of pavement can contribute to pavement deterioration (Paterson 1987). As pavement deflection data
for the selected sections were not available to calculate pavement structural number, the following steps wereused to estimate the modified structural number (SNCi) at different ages:
 Cumulative traffic loading data at design life (MESADL) was determined using Equation 2 and relevant
parameters. Cumulative Growth Factor (CGFDL) over the design life (DL) was estimated using Equation
3. According to VicRoads (2013), the design life for class A, B and C roads is 20 years and for class M
roads is 30 years.
 Initial value of the structural number (SNC0) at time of pavement construction (Age = 0) was calculatedusing the following expression (Equation 4) derived from NAASRA (1979) and Hodges et al. (1975)(cited in Chen & Martin 2012) This expression is based on the cumulative traffic loading (MESA DL) thatis expected over pavement design life.
SNC0 = 0.55 * Log10 (MESADL / 120 * 106) + 0.6(4)
 The modified structural number (SNCi) at any age (i) was estimated from SNC0, pavement age (Age) anddesign life (DL), using the following relationship (Equation 5) (Martin 2008).
SNCi = SNC0* (2- EXP (0.33 * Age / DL))
(5)
Climate condition: Thornthwaite Moisture Index (TMI) deals with engineering applications that lie
on or beneath the ground surface, such as road pavements (Byrne & Aguiar 2010). It is defined as the
combination of annual effects of precipitation, moisture deficit, evapotranspiration, soil water storage andrunoff (Thornthwaite 1948). Historical climate time series data in terms of TMI was extracted from theclimate extraction tool developed by Byrne and Aguiar (2010). It is provided as an Excel database which uses
latitude and longitude values to access relevant data over time for each 100m road section. TMI values wereextracted along all highway sections from 2004 to 2011. Generally, a positive sign of TMI refers to a wet
area while a negative sign of TMI refers to a dry area.

34

Drainage condition: It has been identified as an important factor for both the functional andstructural performance of road pavement (Pearson 2012). The condition of drainage system for the selected
sections was extracted from relevant database; rated as good or poor.
Maintenance activities: The prediction model should account for the maintenance activities which
affect the condition and the rate of deterioration, which could be in a positive or a negative way. However,this influence should be removed from the model, if information on maintenance activities is not available or
not accurate (AASHTO 2001). In this study, the effects of periodic maintenance works were removed for thisreason. Sections that were subjected to maintenance over the study period (relevant survey years) were
removed using the Linear Rate of Progression (LRP) tool (Martin & Hoque 2006). The output of this tool
includes the sections (100m) with positive progression only together with their progression rates. As a result,a significant number of sections were excluded from the datasets.
As mentioned earlier in this paper, the three phases of rutting development are initial, gradual andrapid deterioration phases (Freeme 1983). In this study, rutting progression is modelled during the gradualphase only. The initial phase considers the first deterioration in road pavement after construction. Based on
typical construction standards, the initial surface condition of a new pavement can be assumed (Toole et al.
2009). For Victoria’s rural road classes, the initial rut depth can be assumed to be 1mm for class M roads and
2mm for A, B and C road classes (Toole et al. 2004). According to smith et al. (1996), the transition from
gradual deterioration phase to the rapid deterioration phase is limited for each road class by their terminal
rutting values. The terminal rutting value is considered to be 20mm for M and A road classes and 25mm for
B and C road classes (Smith et al. 1996).
In the current study, the initial and terminal condition values mentioned above were used to establish
boundary limits for the gradual deterioration phase. Hence, all sections with rutting values within the initial
phase (below mentioned values) were removed to ensure pavement deterioration had passed the initial phaseand entered the gradual phase. Also sections with rutting data that have passed the terminal condition values(above mentioned values) were removed to ensure pavement deterioration did not enter the rapid phase.
Due to the variation in chainages between different years, rutting data was aligned and adjusted bychecking the start and end chainages of each 100m segment over consecutive survey years and ensuring thatthey have the same distance to fixed closeby reference points. After available data for all relevant variables
were extracted from different databases, for each 100m segment, the chainages of rutting data (dependent
variable) were treated as the base and chainages of data related to contributing factors (independent variables)
were matched to them for all relevant years. Good and Hardin (2003) recommended that one-fourth to onethird of the data should be set aside for validation purposes. Therefore, random dataset split was utilized todivide the dataset (for each road class) into two parts; approximately 70% of the data was used for model
development and the remaining 30% of the data was used for model validation. Statistics of variables used
for developing rutting progression model are presented in Table 1.

Table 1. Statistics for variables used for developing rutting progression model within gradual phase

Mean

Rutting(mm)
6Traffic loading(MESA)
2.992

Pavement strength(SNCi)
2.543

Climate
(TMI)
1

Age
(years)10

Minimum

1

0.010

1.224

-38

1

Maximum25

36.220

3.725

100

47

Statistics

7 MODELLING USING MULTILEVEL ANALYSISAs mentioned before, there are four levels of variance within the existing panel dataset for the
sample network and nesting of these data is required. The Hierarchical Linear Modelling (HLM) approachhandles models with datasets that have at most a four level nested structure (Raudenbush et al. 2011).
Theoretically, the effect of variance (heterogeneity) can be captured by allowing randomness over the model
parameter(s) (Raudenbush & Bryk 2002, Greene 2004, Field 2009). A study conducted by Hong (2007)35

showed that unobserved heterogeneity could potentially be accounted for through the intercept and other
regression parameters (i.e. slopes). In this study, the random parameter approach is used by allowing theintercepts to vary at level-2, level-3 and level-4, and the slope of time factor to vary at level-2.
If Y is a measure of pavement rutting (RD) and X is a time factor, the pavement rutting progression
in a multilevel model with random intercepts and random slope for the time factor is proposed as:
Level-1: RD = β0 + β1* Time + e
Level-2: β0 = β00 + r0β1= β10 + r1
Level-3: β00 = β000 + u00
Level-4: β000 = β0000 + v000
The final mixed model is:
RD = β0000 + β10* Time + Time* r1 +e + r0+ u00+ v000
(6)Where:
RD: is thepredicted rutting progression value in terms of RD (mm), (dependent variable).
Time: is the time variable in years, (independent variable).
e: is the error value (random variable).
β0 and β1 : are the fixed and unknown coefficients, where β0 is the intercept and β1 is the slope.
r0 and r1: are the level-2 random effects and u00 : is the level-3 random effect.
β00 and β10 : are the level-2 fixed coefficients and β000 and β0000: are the level-3 and level-4 fixedcoefficients, respectively.
In equation (6), only time is included as a predictor in the model. The model estimates the average
growth occurring throughout the year and it could be referred to as a growth model. By incorporating all
available variables that are considered in this study, the above multilevel models can be extended byincluding variables that vary over time within each section (traffic loading, pavement strength and climate) atlevel-1and variables that vary from one section to another (drainage condition) in level-2. They are expressedas:Level-1: RD = β0 + β1* Time + β2*MESA + β3* SNCi + β4*TMI + e
Level-2: β0 = β00 + β01* DR + r0β1= β10 + r1
Level-3: β00 = β000 + u00
Level-4: β000 = β0000 + v000
The final mixed model is:
Y = β0000 + β10*Time + β2*MESA + β3*SNCi + β4*TMI + β01*DR + Time*r1 +e +r0 +u00 + v000 (7)Where:MESA: is the traffic loading variable in terms of Million Equivalent Standard Axles load /lane.
TMI: is the climate condition variable in terms of Thornthwaite Moisture Index.
SNCi: is the pavement strength variable at time (i), in terms of modified structural number.
DR: is the drainage condition variable (good = 0 and poor = 1).
All other variables are as defined previously.
The final mixed model in equation (7) that incorporates all possible available variables is referred toas a conditional model. β0000, β000, β10, β2, β3, β4 and β01 are fixed effect parameters, whereas, e, r1, r0, u00 and
v000 are random variables.
To develop the rutting progression model for the sample network, three types of models were fitted,
null model, growth model and conditional model; details of these models are presented below:
1) Null model: This model predicts the outcome variable with no specified predictors (only intercept).
The null model should be created first as a primary step in a hierarchical data analysis for thefollowing purposes (Raudenbush & Bryk 2002, Field 2009, Garson 2013):
 To provide an estimate of the grand mean of rutting value within gradual deterioration phase for theselected network.
 To use as a baseline model for model comparisons when adding predictors to the model, based on a
deviance statistic test.
 To estimate the proportion of variance at each level in the dataset used to predict rutting progression
and to test whether multilevel modelling is needed. The proportion of variance could be estimatedusing the following formulas (Raudenbush & Bryk 2002):(8)a) Proportion of variance within level-1, PVO = Ve / (Ve + Vr0 + Vu00 +Vv000)b) Proportion of variance within level-2, PVS = Vr0 / (Ve +Vr0 + Vu00 +Vv000)(9)36c) Proportion of variance within level-3, PVH = Vu00 / (Ve + Vr0 + Vu00 +Vv000)d) Proportion of variance within level-4, PVC = Vv000 / (Ve + Vr0 + Vu00 +Vv000)
Where:
Ve: is the variance of level-1 random variable
Vr0: is the variance of level-2 random variable
Vu00: is the variance of level-3 random variable
Vv000: is the variance of level-4 random variable

(10)
(11)

2) Growth model: This model predicts rutting progression as a function of time variable to study the
progression rate over time. As time is the most important factor in time series data, the growth modelis estimated with only time as a predictor with the intercept and slope regarded as random. The model
estimates the average growth of rutting per year.
3) Conditional model: In this model, available independent variables are added to the growth model as
predictors. A backward variable selection procedure has been followed, in which all predictors areadded to the model simultaneously and evaluated together. Then, any non-significant fixed effects are
removed one at a time to determine which variables to include in the final model.
With any regression model, the first step is to assess the normality of the included variables (Garson,2013). In this study dataset, it was observed that the rutting variable (RD) and traffic loading (MESA)
variable were positively skewed. Therefore, these variables were transformed using suitable transformation
function to minimise skewness. The natural logarithm of RD (LN (RD)) and natural logarithm of MESA (LN(MESA)) were found to be the most appropriate transformation functions. In order to remove bias caused byfitting the model to the log transformed rutting data, predictions of rutting are multiplied by the correction
factor (CF), which is based on level-1 variance (Ve) and expressed as (Stow et al. 2006):
CF = Exp (Ve / 2)(12)

8 DEVELOP RUTTING PROGRESSION MODELS
Multilevel analysis was used to develop empirical deterministic models to predict pavement rutting
progression over time as a function of a number of contributing variables using full maximum likelihood
estimation. The analysis was performed using Hierarchical Linear Modelling (HLM7) software (HLM7
2015) and Statistical Package for Social Sciences software (SPSS 2015). A four level model is utilized to findthe results of the three fitted models which are presented below:
1) Rutting null model: The results of the fixed and random effects parameters for the rutting null model
are shown in Table 2. The final mixed model is: LN (RD) = β0000 + e + r0 + u00 + v000
Estimated rutting null model is: LN (RD) = 1.6334(13)

Where:
LN (RD): is the natural logarithm of rutting (RD).
Based on Ve (0.0833) for the null model, the CF is 1.043 (Exp (0.0833/2). The null model inequation (13) estimated that the rutting (RD) grand mean value for the network sample was 5.34 mm (Exp(1.6334)*1.043). The four variance components (Ve, Vr0, Vu00 and Vv000) were statistically significant(p<0.001). Based on equations 8, 9, 10 and 11, the proportions of variances at each level were calculatedusing variance components (for random effect variables) from the null model results, as shown below:
a. Proportion of variance within time series observations (level-1) is: PVO = 34%
b. Proportion of variance among sections within highways (level-2) is: PVS = 54%
c. Proportion of variance among highways (level-3) is: PVH = 7%
d. Proportion of variance among classes (level-4) is: PVC = 5%
These results indicate that there is a high variance among sections within highways (PVS = 54%)
and a high variance within time series observation (PVC = 34%). Also, 7% of the variance was found among
highways, and around 5% among classes. These results indicate that there is a significant variance between
observations, sections, highways and classes for rutting condition variable. This confirms that there isstatistical justification for using multilevel analysis approach rather than depending on traditional regression
analysis to produce a rutting progression model, by capturing the variance between levels correctly.

372) Rutting growth model: The results of rutting growth model are shown in Table (2). Including only
the time predictor, the final growth mixed model is: LN (RD) = β0000+β10* Time+ Time* r1+e + r0+ u00+
v000.
Estimated rutting growth model is: LN (RD) = 1.3175 + 0.0841 * Time

(14)

With all variables as defined previously.
This growth model is statistically significant with R2= 47% (i.e. 47% of explainable variance isaccounted for by the predictor (time) in the model). The rutting growth model suggested that for each
additional year, the log RD increased by 0.0841 mm. On average, the RD value increases by 8.77% [(EXP(0.0841) -1) * 100%] for every additional year. Based on Ve (0.0444), the correction factor (CF) for thegrowth model is 1.022 (Exp (0.0444/2) which must be applied to the rutting predictions. For example, if
Time=12 years then the predicted RD = [Exp (1.3175 + 0.0841 * 12)]* 1.022 = 10.47 mm.
3) Rutting conditional model: The results of the fixed and random effects parameters for this model are
shown in Table 2. The final developed rutting progression model as a function of the available contributing
variables is presented below:
LN (RD) = β0000 + β10* Time+ β2*LN (MESA) + β01*SNCi + β02*TMI + Time* r1 +e + r0+ u00+ v000
Estimated conditional rutting progression model is:
LN (RD) = 2.3652 + 0.0561*Time + 0.0503*LN (MESA) - 0.3795*SNCi + 0.0014*TMI(15)

With all variables as defined previously.
The model is statistically significant with R2 = 51% (i.e. 51% of explainable variance is accounted
for by the predictors in the conditional model). The p-values in Table 2 for the Likelihood Chi-Square test
show that the variables time, MESA, SNCi and TMI have significantly influenced pavement rutting. Also,
there are significant variance components within the random effects variables. However, drainage condition(DR) is not significant (p>0.05), hence excluded from the model.
The model indicates that MESA and time are positively related to rutting progression (i.e. the log
RD increases with time and MESA), whereas SNCi is negatively related to rutting progression (i.e. rutting
increases with decreases in SNCi). The positive sign of TMI indicates that pavement in wet zones experiencehigher rutting progression than in dry zones.
The correction factor for predicting rutting value from equation (15) is 1.021 (Exp (0.0406/2). The tratios are the regression coefficients divided by their standard errors and their absolute values represent theeffect size of each predictor. The t-ratios suggest that the effect of time is stronger than SNCi and effect of
SNCi is stronger than the effect of traffic loading on rutting progression. However, the effect of climate islimited compared to the other variables. The effect of each factor on rutting progression from the conditionalmodel can be explained as follows:

On average, for every additional year, the rutting value increases by 5.77% = [(EXP (0.0561)1)*100%], when controlling all other variables in the model.
For a one percent increase in MESA, a 0.05% = [((1.01) ^ (0.0503)) -1)*100] increase in rutting
value is expected, when all other variables are held constant.
For a decrease of one SNCi unit, about 31.58% = [(1-EXP (-0.3795))*100%] increase in rutting
value is expected, when controlling all other variables.
On average, rutting value will be 0.14% = [(EXP (0.0014)-1) * 100%] higher for pavements in wet
climate than for pavements in dry climate.

9 MODEL ASSESSMENTS AND VALIDATIONSAssessments:
To compare two nested models, the deviance statistic test which is based on the maximum likelihood
estimation procedure is used (Anderson 2012). In this study, in order to assess the developed models, the nullmodel is compared with the growth and conditional models to determine if the independent variable(s)improve the fit of the model or not. The difference between the deviances for any two models follows anapproximate chi-squared distribution with degrees of freedom computed as the difference of the models’38degrees of freedom. The greater the reduction in the deviance value, the greater the improvement in fit. The
significant p-values for chi-square (χ2) test indicate that there is evidence in the data to suggest an association
between rutting progression (RD) and the included IV(s). This indicates that the model fit is significantly
improved by adding these variables (Garson 2013). Table (3) shows the results of the deviance test forpredicted rutting. In this table, it should be noticed that there is always a reduction in deviance from the nullmodel to the growth model and from growth to conditional model. The likelihood ratio tests show that thesechanges are both significant at p<0.001. These results indicate that the time variable in the growth model andall IVs in the conditional model have improved the models’ descriptions of the data.

Rutting conditional model

Rutting growth model

Rutting null model

Table 2. Estimation of the fixed effect variables and variance components for the rutting dataset within
gradual phase
Fixed effectvariable

CoefficientStandarderror

t-ratio

Degree offreedom (df)p-value*

Intercept

1.63340.022373.23

3<0.001

Random effectvariableeStandard
deviation
0.2887

Variancecomponent (V)0.0833Degree offreedom (df)Chi-Statistic(χ2)

p-value*r00.36370.132310933

76781.62.52<0.001u00

0.13330.017835937.08<0.001v000
Fixed effectvariable

0.10560.0123Standard
error

3

20.60
Degree offreedom (df)<0.001

Coefficientt-ratiop-value*

Intercept

1.31750.021062.73

3<0.001Time
Random effectvariable
e
r0
r1
u00
v000
Fixed effectvariableIntercept

0.0841
Standard
deviation
0.21080.44150.01720.12490.1054152.08Degree offreedom (df)10933
Chi-Statistic(χ2)<0.001

10933
10977
35
3

2.36520.0006
Variancecomponent (V)0.04440.19490.00030.01560.0215
Standard
error
0.0701

33.72

52248.89
12576.87
920.3420.03
Degree offreedom (df)3Time

0.05610.0011

50.13

10933

<0.001

LN(MESA)

0.05030.0051

9.93

19653

<0.001

SNCi
TMI
Random effectvariable
e
r0
r1
u00

-0.3795
0.0014Standard
deviation
0.20640.4146
0.0266
0.15670.01220.0005
Variancecomponent (V)0.04060.17190.00070.0246-31.142.91
Degree offreedom (df)

19653
19653
Chi-Statistic(χ2)<0.001
0.004

10933
10977
35

48222.0813144.53
1453.91<0.001<0.001<0.001v000

0.11110.01233

21.33<0.001

Coefficientt-ratiop-value*<0.001<0.001<0.001<0.001p-value*<0.001p-value*

Dependent variable is LN (RD)* All predictors were statistically significant (p < 0.05) with 95% level of confidence39

Table 3. Deviance test results for predicted rutting progression models
Model comparison test with null model

Predicted rutting model

Deviance
test (χ2)

Number of
estimatedparametersχ2statistic

Degrees of
freedomp-value (at 95%
confidence interval)

Rutting null model

36123.49

5

-

-

-

Rutting growth model

17554.80

818568.69

3<0.001

Rutting conditional model

16583.04

11

19540.45

6<0.001

Validations:
To ensure that the developed models have the ability to predict future conditions precisely, both
apparent and internal validation methods are used to test the developed models. These two methods wereconducted as described below:
1) Internal validation
As mentioned before in this paper, approximately one-third of the data (30%) is set aside to use formodel validation. This dataset is used to develop a validation model with the same variables that are used forthe developed models. Multiple statistical testing using a Bonferroni correction is applied when checking
whether the coefficients of the validation model fall within the 99% confidence intervals for the coefficientsof the developed model, or not. The confidence interval estimate (CI) provides a range of likely values foreach of the model coefficients. Based on the general form of a confidence interval, the lower and upperbounds of the 99% confidence intervals are calculated using the following formula:
99% confidence interval = estimated coefficient ± 2.576 * standard error(16)

The results of internal validation for the growth and conditional progression models are presented inTable 4. These results refer that all coefficients of the rutting models based on the validation datasets fallwithin the upper and lower bound intervals for the coefficients of the developed models. This means that all
the models exhibit internal validity.
Table 4. Results of internal validation for growth and conditional rutting progression models

Model fit

Variables

CDM1

p-value(Developedmodel)

Standard
Error

99% CI3
LB4

99% CI
UB5

CVM2

p-value(Validated
model)

Rutting
growthmodel

Intercept

1.318<0.001

0.021

1.263

1.372

1.326

<0.001

Time

0.084

<0.001

0.001

0.083

0.086

0.083

<0.001

Intercept
Time

2.365
0.056

<0.001<0.001

0.070
0.001

2.185
0.053

2.546
0.059

2.287
0.058

<0.001<0.001

LN(MESA)

0.050<0.001

0.005

0.037

0.063

0.044

<0.001SNCi-0.379<0.001

0.012-0.411-0.348-0.350<0.001

TMI

0.001

0.004

0.00050.0002

0.003

0.001

0.029

Rutting
conditionalmodel

1: Coefficient of developed model.
4: Lower bound

2: Coefficient of validated model.
5: Upper bound

3: Confidence interval2) Apparent validation
In this validation method, the fundamental assumption of the initial developed regression model istested by checking the assumptions on the random errors and using diagnostics plots to evaluate the model
fit. The developed regression model assumes that the residuals (i.e. the differences between the predictedvalues and the actual values for the dependent variable) are independent and normally distributed and have azero mean within each section (Raudenbush & Bryk 2002). The residual plots allow for the graphical40

evaluation of the goodness of fit of the selected model. The random errors can be regarded as a random
sample from a distribution by checking whether the residuals might have come from a normal distribution ornot. Thus, two plots (Figure 1 and Figure 2) have been examined to evaluate rutting conditional model fit(equation 15). Figure 1 shows the frequency histogram of the residuals and indicates that the residuals arenormally distributed with mean very close to zero. This suggests that the normality assumption is not
violated. Figure 2 shows the actual DV versus predicted DV with the line of equality. From Figure 2, it isobserved that the predicted rutting data against observed data are very close to the line of quality with R2 =90%.

Figure 1. Residual histogram for the developed rutting conditional model

R2 = 90%

Figure 2. Predicted rutting values versus observed rutting data
10 MODEL SIMULATIONSIn order to understand the behaviour of the developed rutting models under different conditions, adeterministic simulation was used. This simulation analysis was done for the developed conditional rutting
model over time. In simulating the conditional rutting model, mean, maximum and minimum values for
traffic loading and pavement strength were used with wet and dry climate. These statistics are from thedataset used for developing the models, as presented in Table 1.
Figure 3 shows the conditional model under different conditions. When using this model, forexample, for the pavement condition with average traffic loading (MESA=2.99) and average pavement
strength (SNCi= 2.543), the maintenance activities for rutting value of 15 mm could be scheduled at 22 years
and 23 years of the design life for pavements in wet climate (assumed TMI=20) and dry climate (assumed
TMI= -20) (see simulations 1 and 2), respectively. However, these predictions could be more or less indifferent conditions when considering other values of MESA and SNCi. These deterministic simulation plots
for developed model indicate that the model predict the expected rutting progression over time, under
different selected conditions.

41

Figure 3. Simulation of the rutting conditional model under different conditions
11 CONCLUSIONS
The reported study was undertaken to apply a new approach to develop rutting prediction models forsealed granular pavements at network level. Particularly, the study presents hierarchical multilevel models
that can account for the correlation among time series data of the same section and capture the effect ofunobserved variables. The analysis results show that it is an effective approach to present rutting progression
model over time.
The developed models are statistically significant and the parameter estimates are significant andhave correct signs. More than half of the percentage of explainable variance in the log transformed rutting
values was accounted for by the predictors in the conditional model with R2 value more than 50%. The
conditional model indicates that time, traffic loading and climate condition have positive contributions torutting progression within the gradual phase. However, pavement strength has negative contribution to rutting
progression. Drainage condition has no significant contribution to pavement rutting in the selected network.
The analysis also shows that the effect of time is stronger than the other variables on rutting progression.
Deterministic simulation plots for the developed growth and conditional models indicate that the models
predict the expected rutting progression over time under different selected conditions. In addition, both
validation methods supported all developed models. As the results show that there is a significant varianceamong the four road classes (M, A, B and C), it is recommended that a separate model for each road class tobe developed.

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Byrne, M. & Aguiar, G. (2010). Impact of climate change on road performance: updating climate information
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Chen, H. & Martin, T. (2012). dTIMS asset management tool user documentation, Project No. 001538Version 1.1.
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No. RP/19/83, CSIR, Pretoria, South Africa.
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Good, P. I., Hardin, J. W. (2003). Common errors in statistics (and how to avoid them), John Wiley & Sons,
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43

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Lessons from Liberia: Monitoring and Supervision of a 10-Year Performance
Based Road Contract

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Rowan KYLE

Technical Principal Global
Asset Management

Opus International
Consultants

New Zealand

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

E-MAIL(for correspondence)

Rowan.Kyle@opus.co.nz

KEYWORDS:
Output and Performance Based Road Contract, Risk, Force Majeure, Health and Safety, Environmental, Compliance,
Asset Management.

ABSTRACT:The first three years of this multiple international donor funded 10-year contract have seen the reconstruction of
approximately 178km of new highway extending from the outskirts of the capital Monrovia to within approximately
68km of the border of Guinea.
Opus is the appointed Monitoring and Supervision Consultant for this project, supported by Arup Nigeria and Arup
South Africa. Over this time we have encountered a wide variety of unique challenges including the coordination ofteam resources, management of construction delays, emergency events, force majeure due to the Ebola epidemic,
maintenance of health and safety standards, construction quality, and environmental compliance.
This paper will outline how these challenges have been met and the lessons that have been learnt from supervising aperformance based road construction and maintenance project of this scale, in a remote location, and where theavailability of supporting services is very limited.

44Lessons from Liberia: Monitoring and Supervision of a 10-Year
Performance Based Road Contract
Rowan Kyle1
1

Opus International Consultants, Napier, New Zealand
Email for correspondence, Rowan.Kyle@opus.co.nz

1. INTRODUCTION
The Government of Liberia has received the assistance of the World Bank and other donors to
implement an Output and Performance based Road Contract (OPRC) for the Road Asset Management ofsections of the national road network. This form of contract was selected in order to increase the efficiency andeffectiveness of road operations within the life span of the road.
A fundamental feature of the OPRC form of contract is that the contractor is responsible for thedesign, construction, and maintenance of the scheme in order to comply with the required service levels. Theselevels are defined from a road user’s perspective, and include factors such as average travel speeds, riding
comfort, safety features, etc.
A 10-year contract was signed on the 25th January 2012 by both the Liberian Ministry of Public
Works through their Infrastructure Implementation Unit (IIU), and a large international Contractor for the
Design, Rehabilitation and Maintenance of approximately 178km of the main road between the capital city
Monrovia and to a point approximately 68km from the border with Guinea. A second similar contract wasawarded to a separate contractor for the balance of the road to the border itself.
A separate 10-year contract was award to Opus International Consultants, supported by Arup Nigeria
and Arup South Africa in April of 2013 for the monitoring and supervision of the construction and routine
maintenance works. Under this contract the monitoring consultant is responsible for the day-to-day supervisionof the construction works, health and safety compliance, environmental compliance, and general contract
management. Once the routine maintenance phase commences in early 2017, the Consultant’s role will change
to auditing the service level compliance being achieved by the Contractor on a monthly basis. Where service
levels fall below defined thresholds in the contract, then payment deductions may be applied to the monthly
routine maintenance payment unless the recorded defects are rectified within the required response times.
2.

PROJECT ROAD
The project road is located on rolling terrain and consists of an existing two lane single carriageway,with width’s varying from 7.0 to 7.4 m with 1.0 to 1.5 m shoulders. The pre-construction pavement structure
consists of 50 mm thick asphaltic concrete wearing course, sometimes covered by a thin slurry seal. Thisasphaltic layer overlies 100 mm of granular base and 150 mm thick laterite sub-base course. Prior to thecommencement of the rehabilitation phase in 2013, the road pavement and surfacing was in very poor
condition and several of the major bridge structures had been destroyed during the Liberia civil wars (1989 –
2003).

Figure 1: Location of the Project Road

45

Figure 2 Existing Pavement – Pre-rehabilitation.
3.

Figure 3: Destroyed Bridge Structure

CONTRACT FORMAT

Under this form of performance based contract, the contractor is responsible for the detailed design ofthe construction works including all pavements, surfacings, bridges, culverts and other structures necessary tomeet the requirements set-out in the specifications and conceptual designs provided by the Ministry of Public
Works.

Figure 1: Conceptual Design for Rehabilitation Works

Figure 2: Conceptual Pavement Design
The contract works have been broken into four distinct phases:i)

Six month mobilization and detailed design phase providing sufficient time for the Contractor tosurvey and design at least 15km of rehabilitation works for approval and enabling construction works
to commence.

46ii) Three year rehabilitation phase for the complete reconstruction of all new pavements, surfacing,
culverts and bridgesiii) One year periodic maintenance phase (scheduled for the second to last year of the 10-year contract)
requiring the Contractor to construct a full width 50mm Asphalt Cement (AC) overlay over the entire
178km of the project roadiv) Seven year routine maintenance phase commencing from the end of the rehabilitation phase.
Bidders were required to provide a single lump-sum (LS) price covering all four phases of thecontract. This lump-sum price was then artificially split as follows, and the apportioned percentages used todefine the basis of payment to the Contractor:
Rehabilitation works:
Periodic Maintenance works:
Routine Maintenance works

55.4%
17.6%
27%

For the rehabilitation and periodic maintenance works, the Contractor is paid a nominal rate per km ofcompleted works based upon the following formula:(1)
For the routine maintenance works, the Contractor is paid a monthly sum based upon the following formula:(2)
These apportioned percentages are determined through a financial model which is used to achieve thefollowing outcomes:i) Spread some of the Contractor’s profit from the rehabilitation and periodic maintenance phases to theroutine maintenance payments to incentivize the Contractor to remain focused on maintaining thespecified service levels through to the end of the contract, and;ii) Determine to value of an advance payment which will minimize the level of borrowing and financing
costs required by the Contractor and therefore included in their price.
Price adjustment for inflation is applied after the first 12 months of the contract based upon agreed andreported price indices for input items.
4.

PROJECT CHALLENGES AND OUTCOMES TO DATEThis project has now entered its 4th year, and the Contractor is expected to complete the rehabilitation
phase by the end of 2016. The improvement to the existing road in terms of ride and travel time have beensignificant with the resulting benefits to the road users and the general economy now being accrued.

Figure 6: Rehabilitation Works

Figure 7: Completed Construction

47

The specific challenges that have confronted the IIU, the Consultant and the Contractor during therehabilitation phase of this project have been;i)

The completion of the required Resettlement Action Plans that needed to be undertaken by theGovernment of Liberia, including the compensation to Project Affected People. The time required to
identify, consult, agree compensation terms for resettlement, pay compensation, and carry out thenecessary clearance works before any construction works could commence, has been much longer
than anticipated due to the number of people involved and associated logistics. In an effort to reduce
the potential for further delays, the Contractor has been willing to assist the IIU with the actual
clearance works throughout the rehabilitation phase.

ii) Ebola epidemic and Force Majeure suspension of the rehabilitation works. With the outbreak of theEbola in mid-2014, the Contractor was forced to suspend the construction works for several months
until the epidemic was brought under control. Lost time and additional costs were incurred in
evacuating and then repatriating contract personnel as well as through the actual suspension of therehabilitation works. The Contractor again provided assistance to the Government of Liberia during
this crisis, and maintained a residual team in-country during this time to maintain the road, plant, andcamp facilities. This saved time in remobilizing and re-starting the works once the spread of Ebola
virus was contained and the crisis ended.
Due to the pressures of the contractual program, exacerbated by the annual variances in the durationof the rainy season (typically May through to October) construction quality has been constantly monitored to
manage the risk around sub-optimal asset performance. The risk of reduced asset lifecycle occurring as a resultof poor construction practices or the use of sub-standard materials has been reduced through the following:i)Payment for completed works subject to the provision of all specified construction test results by theContractorii) Oversight and inspection of the construction works by the Consultant, including independent
sampling and testing to verify compliance with construction standards

Figure 8: Post Construction Testing

Figure 9: Verification of Minimum Layer Depthiii) The Contractor remaining responsible for the performance of all of the construction works and its
maintenance for a further seven years beyond the end of the rehabilitation phase, which provides afurther incentive to maintain construction quality standards and workmanship.
Work site health and safety compliance has been an important focus of both the IIU and theConsultant. In an effort to maintain acceptable standards the Contractor is required to nominate a safety
supervisor at every work site who is responsible for ensuring the site is safe and all personnel are provided
with the correct personnel protection equipment.
Where any site is found to be deficient in this regard, then the work site supervisor may be dismissedby the Contractor. Further repeated breaches of work site health and safety standards will then result in theConsultant shutting down of the work site completely until such time as the Contractor can demonstrate he has
implemented acceptable safety standards and procedures to avoid further reoccurrences.

48

Figure 10: Acceptable Level of Worksite PersonalProtection Equipment

Figure 11: Common Worksite Traffic Management.

The extent and impact of the construction works have presented a number of social and environmental
challenges over the duration of the rehabilitation phase especially on the residents adjacent to the road
construction corridor. While the Contractor, Consultant and the IIU have endeavoured to avoid or mitigate
these impacts, these efforts have not always been successful in minimising the impact of the project. Where
adverse environmental or social affects have occurred, then the Contractor has been instructed to carry-out
acceptable remediation measures to address the harm that has occurred. The specific issues encountered to datehave included:i)

Storm water run-off and siltation into adjacent properties during construction worksii) Spillages of bitumen from storage drums on land and into water coursesiii) Disposal of waste materials and spoil in unauthorised dump sitesiv) Failure to provide bunds around chemical storage areasv) Inadequate maintenance of work camp septic tanksvi) Quarry blasting noise and vibrations causing damage to near-by buildings and structures.

Figure 12: Bitumen Drum Stockpile

Figure 13: Runoff and Sediment into Adjacent Land

While these issues have been isolated in extent, they have nonetheless had a significant impact upon
the lives of the adjacent communities, and they have taken considerable time and effort to resolve to thesatisfaction of the parties involved.
5.

LESSONS LEARNT - SO FAR.
While not all of the problems could have been foreseen during the project development phase, anumber have arisen as a result of a lack of adequate enforcement or compliance mechanisms within thecontract. The development and inclusion of these mechanisms would have applied a greater level of financial
incentive to the Contractor, and enabled pressure to be applied on the maintenance of minimum acceptable
health, safety, social and environmental standards throughout this phase of the contract.

49

As a result of the issues that have been identified, the following aspects should be carefully
considered in the development and implementation of similar projects in the future:i)

The overall project program must clearly identify all required activities that need to be completed
before the contract is awarded, thereby minimizing the risk of delays to the contractor’s program. It is
crucial that the commencement of the any Resettlement Action Plan, and compensation program forcommunities impacted by the project, occurs sufficiently in advance of the construction works to
avoid this risk.

ii)

The engagement of a monitoring and supervision consultant (if required) should be aligned with thecontractor’s program to avoid overlaps or misalignment. Early engagement can assist with theidentification of the risks that may otherwise adversely impact on the overall project progress alongwith the timely implementation of any appropriate mitigation measures.

iii)

The development of contract documentation and specifications must be sufficiently detailed androbust, especially around the sharing and management of identified contract risks between the various
parties.

iv)

The definition of affordable service levels, both before and after any reconstruction phase, should be
included to ensure the road is adequately maintained at all times, and with clearly linked payment andcompliance mechanisms. Such an approach should include the an appropriate level of payment to thecontractor to ensure he is able to carry-out necessary maintenance works at all phases of the contract.

v)

The development of clear protocols for the road controlling agency and the contractor to use to
manage emergency and other unforeseen events should be completed. In particular these processes
must ensure important contractual timeframes and related costs are recorded, and these are readily
available in support of requested time extensions, claims for costs etc.

Figure 14: An Earth Batter Failure during Constructionvi)

The setting and agreement of appropriate metrics around health, safety, social, and environmental
standards to enable clear contract performance measures to be reported over the duration of thecontract should be undertaken. These metrics should also include adequate community consultation
around activities that have the potential to upset, disrupt or cause damage to communities and theirinfrastructure, e.g. property access, storm water management, quarry blasting etc.

vii)

The development and implementation of a post-construction safety audit procedure to mitigate therisk of higher vehicle speeds and increased rates of road crashes is strongly recommended. The risk ofincreased vehicle crash rates is likely to arise where significant improvements to the road network
have been carried out under the project. Ideally this strategy should be developed in conjunction withenhanced enforcement by the traffic police, and regularly reviewed until such time as the local road
users become more familiar with the improved level of service being provided.

viii)

The development of a set of visual guidelines, with photographs that clearly illustrate what is
acceptable in terms of asset condition, and the defects that would be recorded as a non-conformanceis recommended. This will greatly assist with the understanding of the service level performancemeasures applied during the auditing process, along with agreement on any payment deductions that
may be subsequently applied.

50

Figure 15: Example of a Shoulder Drop-off Defect and Measurement Method

6.

ix)

Incentivize the contractor to achieve and maintain the above standards throughout the contract byincorporating robust but simple compliance mechanisms linked to his regular payments regime. The
application of these mechanisms as part of the auditing process must be clearly understood by allparties, and then rigorously applied. Joint workshops or training exercises at the outset of the contract
are recommended.

x)

Identify and implement appropriate training programmes and other incentives to build capacity within
the road controlling agency and then to retain these skilled personnel over the duration of the project.

xi)

Align and implement supporting asset management systems (e.g. databases for the storage of
inventory and condition information) to ensure those used by the road controlling agency and thecontractor are compatible as soon as possible after the contract commencement. Adequate time should
be made available for system implementation and training to be undertaken for both contractor, andcontract management personnel.

xii)

Design new signage and road furniture assets to minimise the risk of theft or vandalism, thereby
minimizing the risk of the contractor having to carry the cost of on-going replacement or repair.

xiii)

Avoid time-response criteria in the compliance management system where possible to minimise theamount of time required to check and verify that corrective actions have been undertaken by thecontractor. It is recommended that an allowable defect per km approach is adopted which can thentrigger payment deductions once a specified threshold has been exceeded. This allows for single
visual audit to be undertaken which is simpler and requires less time to manage.

SUMMARY AND CONCLUSIONSThe concept behind these long term performance based road contracts, which can embody improvement,
rehabilitation, periodic and routine maintenance works, is to drive improved asset management practices andvalue for money outcomes through:i)

Transferring the responsibility for design, asset performance and long term maintenance to thecontractor, which in turn drives an increased focus on construction quality and innovation;ii)

Clearer definition of roles and functions within the road controlling agency organization, with a focus
away from instructing the contractor on what to do to, to one of long-term asset management andgovernance;iii)

An enhanced understanding of the road assets that are managed by the road controlling agency
through the adoption of improved data collection, condition prediction and reporting systems;

iv)

Defined asset service levels leading to an improved understanding of asset deterioration, residual lives
and lifecycles;v)

Improved forecasting of future investment needs thereby increasing the probability that sufficientfunding for both renewals and routine maintenance requirements will be available at the optimal time.

The issues and challenges identified in this paper are not out of context considering the scale and complexityof such a large road construction project, and they have been valuable in identifying opportunities for
improvement in the design and implementation of these forms of performance based contract in the future. The
51

development of improved metrics for health and safety, social and environmental outcomes is one area inparticular that advances need to be made to further mitigate the potential for adverse impacts inherent withprojects of this scale.
Looking forward there are still a number of risks facing the Contractor, the Government of Liberia, and donor
agencies with regard to the impacts of the delays and associated costs that have been incurred over the last
three years. Nonetheless there is ample evidence that the improvements to this strategic section of the national
highway network is already delivering significant benefits to the road users and the economy of Liberia.
The challenge over the next seven years is to now ensure the road network continues to meet the service level
expectation of the road users in Liberia, with an optimal level of investment by the Contractor, and that thelessons learnt are applied to other similar projects in the future.
7 ACKNOWLEDGEMENTS
Inputs into the preparation of this paper are gratefully acknowledged from;1.

Mr Emmanuel K. Baker – Infrastructure Implementation Unit – Liberia Ministry of Public Works

2.

Mr Tony Porter – Opus International Consultants

3.

Mr Shaun Pearton – Opus International Consultants

8 REFERENCES
Feature Article (September 10, 2015). Making Progress: Liberia Increases Connections to Remote Areas inSpite of Adversity. World Bank. http://web.worldbank.org/
Gericke, B., Henning, T, Greenwood, I, (March 2014). A Guide to Delivering Good Asset Management in the Road
Sector through Performance Based Contracting. World Bank Transport Paper TP 42b.
New Zealand Transport Agency (August 2013). State Highway Network Outcomes Contract Visual Intervention
Guideline. http://www.nzta.govt.nz/

52

2nd IRF Asia Regional Congress &Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLEIntelligent Transport Planning System
Intelligent Transport

TRACK
AUTHOR(Capitalize Family Name)POSITION

Kevin GU

Regional Manager

E-MAIL(for correspondence)

ORGANIZATION
Trimble

COUNTRY
Australia

kevin_gu@trimble.com

KEYWORDS:Intelligent Planning, Alignment Optimization, Environmental Impact, Life-Cycle Costs

ABSTRACT:
Planning road and railway projects is a complex task with numerous quantitative and qualitative criteria to besatisfied. It is acknowledged that the greatest opportunities to contain overall costs and minimise environmental andsocial impact are at the planning stage. However most planners/designers are still using the traditional manual alignment
planning and selection method which is time consuming, inefficient and sometimes could miss a valuable corridor. The
traditional method relies heavily on planners’ professional experience and judgement. Increasing environmental
concerns and growing pressure on project budgets have made the route selection process more complex than everbefore. The lack of purpose-specific tools has greatly limited the planner’s capacity to consider all data and constraints
and to compare and analyse all viable alternatives within a limited time period.
An innovative intelligent transport planning tool has been specifically developed to address the complex planningproblem. The planning tool begins with a digital terrain model of the study area and other relevant geographicalinformation, and then by defining the input parameters such as design standards and cost parameters such as cut/fill rate
and bridge/tunnel unit costs and other constraints such as avoid zones and crossing requirements, the planning tool willautomatically search all possible alternative alignments within the study area. Unlike the traditional planning approach,it explores millions of alternatives and quickly returns a range of 3D alignment models with automated earthworks;
structures such as bridges, tunnels attached, and associated volumes and costs calculated. The process can be operated
iteratively with new constraints added during the planning process which can provide a swift response to public
feedback and re-evaluate alternatives within hours instead of weeks and months. It also empowers planners anddesigners to minimise the negative environmental and social impacts of road projects, whilst reducing construction andlife-cycle operation costs. When the project approaches the construction phase, it can also be used as a valuableengineering tool to refine the final alignment within the corridor, or perform a vertical optimization to reduce earthworks
and other construction costs. The system also equipped with a 3D visualization engine that instantly generates a road orrail model with cut/fill and bridge and tunnel structures attached, so that the planner can perform a virtual drive throughbefore finalizing the alignment.
This paper illustrates how the intelligent transport planning tool can shorten planning time, increase productivity
and reduce project cost, whilst achieving results that have better environmental and social outcomes. A number of casestudies are presented to demonstrate the innovative planning process and its adaptability to different project needs.

53Intelligent Transport Planning System
Dr Kevin Gu
Trimble Planning Solutions Pty Ltd
Level 11, 330 Collins Street, Melbourne, Australia
kevin_gu@trimble.com

1.

INTRODUCTION

Planning transport infrastructure projects is a complex task with numerous quantitative and qualitative
criterions that must be taken into consideration. Aside from operational requirements of vertical gradientsand horizontal and vertical curvatures, other factors such as legislative, environmental, and community
constraints and project budgets must be considered during the planning process.
Conventional global practice for road and rail alignment planning is predominantly intuitive, relying
in the first instance upon professional experience and judgement to identify the likely route. Increasingly,
Geographical Information System (GIS) packages are being used to assist the initial corridor selection.
Whilst most GIS packages enable constraints and anticipated high cost zones to be weighted, and therefore
avoided on a priority basis, they cannot deliver 3D alignment solutions and therefore cannot accurately
estimate the cost of the alignment, and thus only provide an indication of likely low cost routes.
On the other hand, Computer Aided Design and Drawing (CAD) Software are well advanced in a very
competitive market. However, most CAD software developed serve for the purpose of detailed design after
the initial routes or corridors had been selected, and normally have data limitation, and are not suitable forbroader searches for good alignments.
The lack of purpose-specific tools during the planning process has frequently compromised theaccuracy of route selection, for example, a lack of comprehensive study of all potential corridors, or excess
curvature and gradients of the final alignment selected, all without much concern for the longer term
consequences. The missing link is the planner’s capacity to adequately consider all data and the numerous
complex engineering, social, environmental and budget constraints.
The advances of geospatial imagery technology that provide quality and affordable data are runningahead of transport route planners’ understanding and their ability to use it. It requires appropriate tools to takeadvantage of the availability of geospatial data and to effectively convert them into better engineering andenvironmental solutions.
An intelligent transport planning tool has been specifically developed to address the complex planningproblem through geospatial technology and alignment optimization. This approach has changed the paradigmof alignment planning by taking tasks that were previously difficult, time consuming and therefore
potentially very costly, and making them easy, fast and affordable. It uses state-of-the-art technologies toautomatically generate low cost alignments that satisfy defined environmental, community and cultural
heritage constraints. It can be used for corridor analysis and alignment selection; optimized alignments canbe fed into a CAD system for detailed engineering design. The system is unique in its capacity to optimize 3dimentional routes simultaneously in a larger scale whilst accommodating both broad-based and localised
issues during the planning process.
The successful application of such a planning tool around the world has been independently confirmed
by users, documenting better engineering and environmental outcomes and significant reductions in projectplanning time and construction cost.
2.

GEOSPATIAL IMAGERY TECHNOLOGY

Modern alignment optimization processes require a study area with digital elevation models (DEM) or
digital terrain models (DTM) as base data - now easily available from geospatial technologies sourced from54

satellites and aerial surveys. The convergence of new technologies – geospatial and alignment optimization
techniques – as a flow on from increased computing power have already made great impacts on theconventional transport planning process.
The resolution and quality of satellite images is offering increased opportunities for transport planners
to take a strategic perspective of alignment locations. The new generation of imaging satellites provides
spatial resolutions that have never before been available to the public and planners.
The advantages of satellite imaging are that it covers a large area compared with aerial photography sothat it is possible to see the study area in context. Different resolutions are suitable for different stages in theplanning process. The lower resolution can be used for initial route corridor selection, while the higher
resolution can be used for final route alignment.
The 90-meter resolution SRTM global digital elevation data (Web-1), originally produced by NASAand first released in 2003, is a major breakthrough in the digital mapping of the world, and provides a majoradvancement in the accessibility of high quality elevation data for large portions of the tropics and otherareas of the developing world. SRTM elevation data has now been released for the entire earth surface(Web-2).
In October 2011, the release of the Advanced Spaceborne Thermal Emission and Reflection
Radiometer (ASTER) Global Digital Elevation Model Version 2 (GDEM V2) was announced following thefirst version of the GDEM released in June 2009. The improved GDEM V2 adds much more stereo-pairs,
improving coverage and reducing the occurrence of artefacts. The refined production algorithm provides
improved spatial resolution, increased horizontal and vertical accuracy, and superior water body coverageand detection (Web-3). The GDEM data provided an unprecedented level of access to the public and also
provided an opportunity for transport planners to conduct scoping and pre-feasibility studies using GDEM asbase data or platform.
In April 2015, Airbus Defence and Space has officially launched its WorldDEM Digital Terrain
Model (DTM), a highly accurate standardized representation of bare Earth elevation that can be madeavailable for any point on the globe (Web-4). A key feature of this DEM is its unrivalled vertical accuracy at
2m (relative) / 4m (absolute) in a 12m x 12m raster resolution covering the entire land surface of the Earth.
Other satellite sources such as Quickbird and IKONOS provide more detailed data at sub-meter
resolutions which can be used for feasibility studies. The latest WorldView-3 satellite was successfullylaunched on August 13, 2014 and is the first multi-payload, super-spectral, high-resolution commercial
satellite. It is capable of discerning objects on the Earth's surface as small as 31cm in the panchromatic mode.
This will have the highest resolution of any commercial imaging system (Web-5). Table 1 shows a list ofsatellite sourced DEMs available for most scales from early stage project scoping study to the detailed projectscale (Web-4, 5, 6).
At the very detailed level, the LIDAR (Light Detection and Ranging) technology which is capable ofcapturing sub-meter resolution DEMs, can be used for detailed design and construction. LIDAR technology
has become a valuable tool for measuring and recording elevation data for use in topographic mapping and
3D terrain/surface modelling with much improved accuracy and bare earth surface. Its accuracy is further
improved with enhancement in GPS technology (Web-7).
By utilizing the latest geospatial data, planners and environmental groups can perform more advanced
analysis in the early stage of a project, which provides the greatest opportunity to reduce the project cost andavoid potential environmental problems.

55

Table 1. Summary of Satellite Sourced DEMS and Accuracy (Source: Web-4, 5, 6)
SourceAccuracy

resolution (m)(m)

Availability

Planning Stage

Entire earth surface

Scoping studies

SRTM

30-90

6-8

ASTER(GDEM)

30

variable

Most land area

SPOT HR

20-30

8From archive

12

2

5

3-5

From archive<1

0.3-1.0

New capture

Airbus Defence andSpace
ALOS PRISMWorldView-1,2,3,4
GeoEye-1,23.

SpatialScoping studies,pre-feasibility studies
Scoping studies,pre-feasibility studies

New capture

Pre-feasibility studies,

Entire earth surface

feasibility studies
Pre-feasibility studies,feasibility studies
Feasibility studies

TRADITIONAL ALIGNMENT PLANNING PROCESSThe alignment planning process is a complex balancing task. It has normally relied heavily onplanners’ professional experience and judgement; traditionally it is a manual process. Every project is unique;designers are challenged by different engineering requirements, complex topography, geological conditions,community values, safety and environmental concerns. Additionally, road alignments are 3-dimensional
spline structures; a road project may have infinite alternative alignments between the start and end points,
and thus there is no simple solution to the complex problem. In the past, this issue has been simplified byconverting 3-dimensional problems to 2-dimensional problems.
When using a manual method, designers must generate a few horizontal alignments based on
topographic maps or digital terrain models and other knowing factors, and then attempt to fit the verticalalignment along the profile, before checking the cross sections along the route to ensure horizontal andvertical alignments are properly coordinated, all whilst considering all the factors relating to the project
including earthworks and cost. The process is tedious and time consuming and has a vast amount ofconstraints to take into consideration, especially for complex terrain. If problems are encountered inhorizontal or vertical alignments such as violations of radius of curvature or design grade or inadequate crosssections, this process may require to be repeated all over again which may result in a prolonged process orcompromise the final solution.
Even with the extensive use of GIS and CAD packages and some kind of digital terrain model, theinitial corridors and alignments are predominantly selected manually by experienced experts. Furthermore,increasing environmental and construction cost concerns have made the alignment selection process more
complex than ever before. The lack of purpose-specific tools has greatly limited the planner’s capacity toconsider all the data and constraints, and compromises the ease of the comparison and analysis of all viable
alternatives within a limited time period. An intelligent automated alignment optimization model is muchneeded and it could greatly improve the planning process in terms of productivity, cost savings and better
environmental outcomes.
4.

INTELLIGENT TRANSPORT ALIGNMENT OPTIMIZATION TECHNOLOGY

Using DEM as base data, together with geometric standards and other constraints such as crossing
requirements with existing linear features or no-go zones, the generation of sets of low cost alternatives canbe readily achieved by employing one of a number of stochastic optimization techniques. Originallydeveloped to optimize discrete systems by swapping the contents of randomly chosen pairs of locations, themethods can be adapted to working in a continuous space. The technique is similar to the methods employed56

by designers working interactively with standard packages, who move an intersection point defining thealignment subject to defined constraints, however the automated technique has an advantage because it isconsidering the optimal horizontal and vertical alignment simultaneously rather than the traditional two stage
process whereby defining horizontal alignment is followed by vertical alignment design.
The cost of the modified alignment is calculated and compared with the cost of the old alignment, anda decision is made to accept or reject the change. Once a decision has been made, another intersection pointis selected and the process repeated. The rules governing the acceptance or rejection of a point provide themechanism by which the alignment can escape from local sub-optima. The algorithm does not guarantee thatthe alignment will escape; it merely makes it possible. However, careful selection of the parameters
controlling the process can greatly increase the probability of reaching the global optimum. By locatingintersection points in a continuous three dimensional space, the final alignment can be specified to arbitrary
accuracy. However, in practical situations, continuing the optimization beyond a given accuracy does notcontribute significantly to the value of the solution. Accordingly, optimization can stop when the spatial
range of the acceptable moves made by the intersection points declines to a value from which planners anddesigners can work without having to worry about the macro location of the route.
The Quantm system (Gipps et al. 2001) is specifically designed as a planning tool to address thecomplex planning problem. It empowers road planners who need to be able to determine routes that consider
numerous relevant variables including terrain, design standards, existing infrastructure, geological costvariances, and community and environmental constraints. The system considers literally millions ofalternatives to enable planners to consistently identify significantly improved alignments that deliverconsiderable cost savings while protecting environmental and community values.
The system owns a patented optimization engine which is cost driven, but the ‘cost’ of an alignment ismulti-dimensional with many costs being unquantifiable social and environmental impacts. Consequently,
the system focuses on objective costs and generates sets of low-cost alternatives that meet the planner definedconstraints, rather than a single least cost solution. This enables planners to balance environmental and social
impacts against monetary costs for routes using different parts of the study area (Gu 2010).
Objective costs can arise during the construction from the volumes of earthworks, the length andheight of structures, and from life-of-project factors such as fuel consumption and maintenance. Planners
currently use CAD packages to attempt to balance earthworks, minimize structures and haulage and generally
produce an alignment that should be inexpensive to construct, while meeting the specified geometricstandards. However, the results produced by the CAD operators are based on volumes and lengths, notdollars, and are often far from the best that can be achieved for construction. The impact of particularalignment decisions on the life cycle cost is often not part of the brief held by planners despite the fact thatthese may be many times larger than the capital cost of construction. On the construction side, unit rates areused to convert the quantities and lengths involved in construction into dollars. Similarly, forecast traffic andalignment geometry can be used to evaluate impact on operating costs.
Road and rail projects face numerous constraints on their alignment that must be satisfied before they
are allowed to proceed. There are many factors which can have a major impact on the optimum alignment ofa route that need to be considered during planning. Unless a model can cope with a minimum range offactors, it cannot provide the tools necessary to produce realistic solutions. The Quantm system incorporates
all information required to produce 3D alignments that meet all design requirements and other constraints.
Figure 1 shows the application of the Quantm system in the 250km Kyrgyzstan railway Connect Uzbekistan Kyrgyzstan to Kashgar, Xinjiang, China. It shows automatically generated multiple alignments, including theplan, profile and cross section as well as earthwork volumes and associated costs of the alignment identified.
Alignments generated in the system can also be visualised in real-time by a 3D visualization engine (Figure2). This can be used for technical analysis of the alignment quality and presentation to stakeholders and the
public consultation.

57

Figure 1. Quantm 3D Alignment Optimization for a 250km Kyrgyzstan Railway Project

Figure 2. Quantm 3D Alignment Visualization
5.

BENEFITS OF THE NEW TECHNOLOGYWhen all of the constraints feature and cost data exists, the system is fast, effective and consistent.
The speed depends on the number of constraints and the level of detail in the model, but comprehensive
analysis and identification of preferred alignments have been completed within weeks rather than months
compared to traditional alignment selection processes. Planning time and community and environmental
consultation benefits are relevant regardless of terrain type. Users of such a system have also frequently
stated that the system has enabled them to deliver unexpected solutions that had not been identified using theconventional planning approach, where investigation is severely limited and guided by the intuitive skill of
the planner.

58

The new alignment optimization technology such as the Quantm System, allows planners andengineers to collaborate with various road project stakeholders and deliver improved outcomes. The process
maintains positive community relations, considers environmental impact, and reduces project construction
costs - all while maintaining the momentum of the road project.
Improved productivity - Once a project is initialised the system can generate better, less expensivealignments in minutes, whereas using conventional means could take weeks to produce the same result.
Amending constraints and parameters is fast and reruns are completed immediately. Consequently, it is very
easy to consider the impact of variations suggested during consultations on community and environmental
issues. In many large projects, the time and cost involved produces natural resistance to considering
variations when they are not considered to be viable. The impact of considering these variations and gettingback rapidly with cost effective alternatives will significantly reduce community stress and planning blightthat often hampers adoption of proposed alignments.
Improved community relations - Communities globally are increasing the influence they have overwhere new roads are created. The combination of community input and the need to avoid certain urban areas,
cultural heritage zones and areas of environmental sensitivity have made the planning process extremelycomplex. The new technology allows community input to be integrated into the planning study. Community"no-go" constraints can be added in just minutes. Cost implications and alignment alternatives can bereviewed within hours depending on project scale.
Better environmental outcomes - The Quantm System was identified as one of eight emerging
technologies by the Transportation Research Board (TRB) (Web-9) that support the integration ofenvironmental considerations into transportation planning. The Quantm system can rapidly consider new
environmental or social constraints as the project progresses and demonstrate to stakeholders that their input
has been integrated into the study. Planners can be more responsive to public feedback and re-evaluate
alternatives within days instead of weeks or months.
Reduced project planning time and delays - The current industry approach to road and rail planning
addresses each constraint issue in series, which often leads to conflict between the stakeholders and requires
numerous subsequent impact studies. This can lead to a planning spiral that delays, or even terminates, aproject. The new technology encourages cooperation between the road project planners and stakeholders
from the onset. Planners can quickly investigate alignment and cost implications of numerous “what if”
scenarios simultaneously. As a result, planners can demonstrate that they have considered all feasiblealignments and substantially improve the quality of the alignment without project delay or cost increase.
Construction cost savings - The new technology delivers substantial alignment construction costsavings while meeting the defined environmental, community, heritage and design constraints. Consultants
that have adopted the technology have found that the more thorough alignment searches available through thecomputerized technique have allowed them to reduce the project costs, offering a better solution to theirclients.
6.

APPLICATIONS AND CASE STUDIES

In infrastructure planning projects in China, Australia, New Zealand, the United States and Europe,
the Quantm system has demonstrated that it provides an unprecedented capacity for planners to dramatically
improve financial outcomes whilst aligning project outcomes with formal Government policies in Ecological
Sustainable Development. It also enabled the agency to put a dollar value on protecting local environmental,
community and heritage values.
Projects of all types and sizes can take advantage of the benefits of the new technology. Examples
range from regional, state and national transportation infrastructure planning to small bypasses and roadrealignments. In addition, the system can be used for mining, forestry and utility industry infrastructure.
6.1

Scoping Study: Beijing-Shenyang High Speed Rail Project

The 660km Beijing-Shenyang High Speed Rail Project (Figure 3) is part of the China national highspeed rail network with a design speed of 350km/h. The scoping study was conducted in 2008 with the Third
Railway Survey and Design Institute Group Corporation (TSDI). The objectives of the study were to identify

59

viable corridors and alignments that meet the requirement of economic development and environment
constraints en route and to control the project cost.
Based on existing DTM and GIS data, design standards and user defined constraints, the Quantmsystem was effectively applied to conduct a larger scale area search for all viable corridors and to evaluate
different alignment options. The project team was able to consider all the constraints, evaluated ten different
sectional options comprehensively and identify the best corridor and preferred alignments in just three weeks.
The application of the Quantm system enables the project team to gain greater depth of information on which
to make their recommendations and to be able to present alternatives and the rationale for decisions tostakeholders and the community.

Figure 3. Quantm application on the Beijing-Shenyang high speed rail project
6.2

Feasibility Study: Xichang-Shangrila Mountainous Highway Project

The Xichang-Shangrila mountainous freeway project (Figure 4) was conducted by the Sichuan
Transport Design Institute (STDI) in China. The project was located in Sichuan and Yunnan provinces withmountainous terrain. Due to complexity and construction constraints, the design team spent three months
with several site visits and developed a recommended alignment option based on manual selection process,but the design team was not fully satisfied with the alignment option they had identified. The challenges ofthe project are to reduce bridge and tunnel ratio in order to control the project cost to stakeholders, and in themeantime, to maintain the design standard and meet the requirement of construction constraints, i.e.,
maximum bridge height is no more than 350m and maximum tunnel length no more than 16km. The original
design alignment was developed based on traditional alignment selection process with a total length of
363km, bridge/tunnel ratio is 68%, maximum tunnel length was 14km and maximum bridge height is 350m.
Within three days of data preparation and optimization using Quantm technology based on existing
DTM and GIS data with required constraints, a better corridor was identified and a new alignment finalised
which satisfied all constraints including design standard and construction requirements. Compared to theoriginal design alignment derived from a manual selection process, the optimized alignment was significantly
improved in terms of length and alignment quality. The total length of the alignment reduced to 320km,
bridge/tunnel ratio reduced to 66%. While the maximum tunnel length is increased from 14km to 15.5km, it
was worthwhile to reduce the total length of the alignment by 43km. The shorter alignment significantly
reduces both the construction and life-cycle operation costs.

60

Figure 4. Quantm application on the Xichang-Shangrila Highway Project
6.3

Value Engineering Study: Boulder City Bypass in Nevada

Carter & Burgess and the Nevada Department of Transportation (NDOT) commissioned the Quantm
System as a value engineering tool on Phase 2 of the Boulder City Bypass, Nevada USA. The Boulder City
Bypass, Nevada project (Figure 5) will eventually result in a four-lane divided highway route for U.S. 93
traffic bound for Hoover Dam and points beyond. The new route will eliminate the need for through traffic topass through densely developed areas of Boulder City (Phase 1). It will also connect the end of I-515 inHenderson to the start point of the Hoover Dam Bypass between Boulder City & Lake Mead (Phase 2) (Web11).

Figure 5. Phase 1 and Phase 2 of the Boulder City Bypass
Phase 1 of the 2.5 mile bypass was completed by NDOT – Carson City. The project's purpose was toimprove operations and safety near Railroad Pass. A corridor was chosen and the project was estimated tocost US$170 million. The project imposed several challenges, including difficult, hilly and undulating
terrain, and numerous stakeholders (including NDOT, USA Department of Transportation, Regional
Transportation Commission and many environmental bodies). With a corridor already chosen in Phase 1, theprimary purpose of utilizing the Quantm system at this stage (Phase 2) in the project was to reduce
construction cost. With the Quantm system, the project team was successfully able to achieve cost savings of
10-15% within a short period of time.
6.4

Design Study: G207 Highway Jingmen Section Project

The G207 Highway Jingmen Project is a 77km section in Hubei Province China. It is part of the
Hubei highway network with 4-lanes in each direction and a design speed of 80km/h, maximum design gradeof 4%. Jiangsu Transportation Research Institute (JSTI) was commissioned for the design work of the project.

61

Using Quantm technology, JSTI conducted full analyses on a 14km section of the project to compare theresults between Quantm and traditional methods. The purpose of the study was to verify the existing corridor
and the alignment from the feasibility study which derived manually using traditional method; and identifies
potential better alignments within the corridor on 1:20K data; and finally, with the site visits and survey data,
to determine the recommended alignment for presentation to the project owner.
The input parameters and constraints for the projects include geology conditions; crossing
requirements with existing railways, highways and waterways; cost date (unit cost for earthwork andstructures); environmental (built-up areas, avoid zones) and social requirements (local urban planning,land/property acquisition, mining areas, built-up factories and reservoirs).
The speed of the Quantm system allows the JSTI project team to conduct a sensitivity test to analyse
the best design standards for the project (best combination of different minimum horizontal radii andmaximum sustain grades): 4 different sustained grades (1.5%, 2.0%, 2.5% and 3.0%) and 6 different
horizontal radii (250m, 400m, 550m, 650m, 750m and 1000m) were tested. The results were compared forthe 24 combinations. By taking consideration of these sensitivity results together with safety and tunnel
requirements, within just one day the project team was able to quickly determine the 2% as a sustained grade(maximum grade at 4%) and 650m as the minimum horizontal radius as the design parameter for the section.
This would be a very time consuming task using traditional methods.

Figure 6. Manual Alignment from Feasibility

Figure 7. Quantm Generated Alignments

The optimization results based on 1:50K ASTER data and 1:10K local DEM data show that thecorridor identified was the same as the one from the feasibility study; which provided the supporting
evidence of the feasibility study to the project owner (Figure 6 and Figure 7).
By implementing further optimization based on 1:2K local DEM data, the system is able to deliver
better alignments (Quantm 1, Quantm 2 and Quantm Final) compared to the manual alignment as shown in
Table 2. The optimised alignments not only reduced earthworks, but also reduced the number of bridges anddivided long tunnels into smaller tunnels which resulted in an overall reduction in structure length by over
1km and saved a total alignment cost of 20%.
In the JSTI project report on Quantm application, the benefits of the new technology are summarized
as follows: Proving sensitivity tests to determine the best geometric fit to the terrain
 Identifying valuable corridors easily
 Estimating earthworks and structure relatively accurately to reduce project risk at early stage
 Quick response to new constraints, improving communications between stake holders, therefore
reducing overall planning time Reducing construction costs

62

Table 2. Alignment Comparison: Quantm vs Manual

7.

Item

Unit

Quantm 1

Quantm 2

QuantmFinal

Manualalignment

Cut

103m3

733

714

780

1,490

Fill

3

3

10 m

667

858

792

565

Dump

3

3

10 m

725

560

687

1,740

Bridgem/number

1,798/7

1,636/5

1,934/5

2,779/7

Tunnelm/number

2,897/2

3,005/2

2,899/5

3,232/2

Lengthm

13,536

13,60813,484

13,803

Cost

6

588

593

597

745

¥ 10

CONCLUSIONSTechnological advancements have now made it possible for road planners to quickly identify betteralignments that minimize the amount of cut, fill, tunnels and bridges while simultaneously meeting all of theplanner-defined constraints. Successful applications of intelligent transport planning technologies havedemonstrated that planners can now explore the whole study area thoroughly, investigate all feasible routes
without missing any valuable corridors and without influence of preconceptions of where the route should
run and quickly review all alternative strategies. This can be achieved within considerably faster times andenable planners to deliver more cost-effective viable solutions to their clients in every stage of a project,
starting from early scoping studies, feasibility studies to value engineering studies. The speed of optimization
enabled changes to be made to the underlying constraints and evaluated rapidly. The system also enables
users to quickly conduct comprehensive sensitivity analyses with a combination of design variables such as
limiting grades and horizontal curvatures to analyse the impact on alignment construction costs and life-cycle
operation costs.
REFERENCES
Gipps, P.G., Gu, K, Held, A. and Barnett, G. (2001). New Technology for Transport Route Selection.
Transportation Research, Part C 9, 2001. pp. 135-154.
Gu, K (2010). Using Advanced Tools to Plan Faster and Minimize Environmental Impact, Alignment
Planning for High Speed Rail. Proceedings of the 7th UIC High Speed World Congress, Beijing, China,
December 2010.
Web sites:
Web-1:https://lpdaac.usgs.gov/content/view/full/11033, consulted 25 January 2016.
Web-2:http://www.cgiar-csi.org/data/srtm-90m-digital-elevation-database-v4-1, consulted 25 January 2016
Web-3:htps://igskmncnwb001.cr.usgs.gov/aster/GDEM/Summary_GDEM2_validation_report_final.pdf,
consulted 30 January 2016
Web-4:http://www.geo-airbusds.com/, consulted 30 April 2016
Web-5:http://www.satimagingcorp.com/satellite-sensors/, consulted 1 May 2016
Web-6: http://www.geoimage.com.au/satellites/satellite-overview, consulted 31 January 2016
Web-7:
https://docs.google.com/viewer?url=http://lidar.cr.usgs.gov/downloadfile2.php?file=Nayegandhi_Lidar_Tech
nology_Overview.pdf, consulted 31 January 2016
Web-8:www.trimble.com/alignment/, consulted 1 May 2016
Web-9:http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_rrd_304.pdf, consulted 31 January 2016
Web-10:
http://itd.idaho.gov/design/cau/2005%20PROJ%20DEV%20CONF/WebPresentations/Final%20Quantm%20
Paper.pdf, consulted 31 January 2016
Web-11:http://www.c-agroup.com/services.html, consulted 31 January 2016

63

PAPER TITLE

TRACK
AUTHOR
Kars Paul DRENTH

CO-AUTHOR(S)
Feng Hua JU
Jun Yew TAN

Road Surface Condition Surveys at Traffic-Speed

Asset Management
Specialist Consultant

Research Engineer
Senior TechnicalManager

Samwoh Innovation
Centre Pte Ltd

Samwoh Innovation
Centre Pte Ltd

Singapore

Singapore

E-MAILkars.drenth@samwoh.com.sg

KEYWORDS:LCMS, MTD, MPD, SPTM, ELAtextur

ABSTRACT:Road networks may not only be large in nature, but there is also a large investment in the existing andexpanding pavement infrastructure, and this large investment has to be managed as one would do with anyother investment. Road Authorities must decide on how to spend their available budgets effectively in
combination with safety standards and allowable noise levels.
The assessment of the structural and functional pavement condition is nowadays fully machine based andnon-destructive equipment does cover all the data input required for a modern PMS approach. A Multi-Laser
Vehicle is capable of real time continuous traffic-speed measurements of condition data regarding cracking,raveling, rutting, roughness, macro texture and road geometrics in a single run using line-scan camera &ROW based images for an automated analysis. The system of the Multi-Laser Vehicle equipped with a Laser
Crack Measurement System (LCMS) is the latest development in 3D camera technology. The rating of theseverity and area of the distresses can be adjusted according to any existing visual distress procedure.
This paper discusses the results of the equipment used and does show the continuous measured macro texture
based on the MTD as index using the LCMS device in addition to the automated crack detection. A majoradvantage is that no conversion is required as the volumetric MTD is a direct output. The LCMS based
automated MTD analysis is a machine based result not influenced by a human factor such as the Sand Patch.
The results allow as well the automated analysis of loss of aggregate which is a major advantage in rating theseverity and extent of raveling in comparison to the non-consistent wind-screen surveys and manual rating ofcollected images. The MTD does relate as well to the frictional characteristics of a road surface and the noiselevel caused by the tires of a vehicle, which allows to distinguish between the noise reduction achieved using
different types of open graded surface courses.

64

Road Surface Condition Surveys at Traffic-Speed
Kars Paul Drenth1, Feng Hua Ju1 and Jun Yew Tan1
1

Samwoh Innovation Centre Pte Ltd, Singapore
Email for correspondence, e.g. kars.drenth@samwoh.com.sg

1 INTRODUCTION
Road networks may not only be large in nature, but there is also a large investment in the existing andexpanding pavement infrastructure, and this large investment has to be managed as one would do with any otherinvestment. To be able to manage these investments it is essential to have information about the structural andfunctional condition.
The assessment of the structural and functional pavement condition is nowadays fully machine based and nondestructive equipment does cover all the data input required for a modern PMS. The falling weight deflectometer(FWD) defines the structural capacity of a pavement structure, friction testing equipment provides continuous selfwetted coefficients of slip friction and a Multi-Laser Vehicle is capable of real time continuous traffic-speed
measurements of surface distresses like cracking, raveling, longitudinal roughness (IRI), rutting, macro texture, roadgeometrics using high-speed line-scan camera & ROW based images for an automated visual assessments.
This Multi-Laser Vehicle is equipped with a Laser Crack Measurement System (LCMS) the latest and mostenhanced technology for collecting pavement surface condition information. As the name does say it the first
application was focussed on all types of cracks visible at the pavement surface based on sampling transverse texture
profiles at a 2.5-5mm interval. The LCMS does measure extremely accurate rutting with a transverse profile samplinginterval of 1mm and equipped with inertial motion units (IMUs) the LCMS does not require an additional multi laser
profiler anymore for the analysis of IRI as well as other indices. Figure 1 does show the vehicle with LCMS sensors.

Figure 1. Vehicle with LCMS Sensors
The surface images produced by the LCMS analysis software are (see Figure 2):
1. Intensity (2D): the reflective properties of the pavement surface.
2. Range: the distance from the sensors to the road surface corrected to the same reference level.
3. 3D: merging the Intensity and Range images.

65

Figure 2: From left to right – Intensity/Range/3D pictures
The greater the distance from the sensors to parts of the pavement surface the more black the grey-scale range
picture will be. The range image is the perfect tool to observe cracks as shown in Figure 2 in the middle. Figure 3 does
show an Expressway location with cracks and the resulting analysis.

Figure 3: Range (left) and Overlay 3D (right)
An important characteristic of a pavement surface is texture. Texture does relate to friction, noise and ravellingand does change over time due to aging, contamination and loss of aggregate. As such it is an important characteristic
triggering maintenance measures when it does not meet the requirements anymore. The standard procedure is tomeasure texture based on the Mean Profile Depth (MPD), which is a single point measurement along a longitudinal
track sampled at a high frequency. The actual requirement is a volumetric 3D based result to be directly representative
for the characteristics required without the need of a conversion from a 2D based test.
The results presented are sampled to validate and compare MTD’s sampled at traffic-speed using a LCMS withthe results of the static Sand Patch Test Method (SPTM). The LCMS does measure the volumetric properties of theroad surface continuously over its full width and length based on 250 x 250mm squares. The evaluation did include
static SPTM’s and a static ELAtextur device measuring MPD. The test were conducted over different time periods andmultiple runs at a validation site used for calibrating testing equipment operating at roads in Singapore.

66

2 TEXTURE
The texture of a surface layer is an important mechanical characteristic related to noise, friction and reductionof spray. The specific texture based wearing courses such as Stone Mastic Asphalt (SMA), Porous Asphalt (PA), Open
Graded Friction Courses (OGFC) or Noise Reducing Road Surfaces (NRRS) do all have one major disadvantage: theirservice life is reduced due to ravelling. This is the main distress type that dictates the timing of maintenance. However,the development of ravelling is not linear model but closer to an exponential development of loss of aggregate which
does make the prediction of the timing of maintenance very difficult. In addition to this the quantification of theseverity of ravelling using a manual visual distress approach or using pictures is far from accurate and does lackconsistency. This makes it as well difficult to notice the onset of ravelling. Each wearing course has its own surface
characteristics (finger print) which make it almost impossible to notice a change when using a manual based approach.
The picture shown in Figure 4 does make the rating of severe raveling not that difficult but properly rating all
the severity levels of ravelling of different surface courses does make it clear that the actual practice is much moredifficult using a ‘manual’ based approach.

Figure 4. Observed raveling Expressway Singapore
Raveling is the loss of aggregate due to trafficking and /or environmental conditions. But the onset of ravelingcan as well be caused by segregation which does already take place during construction (McGhee et al., 2003).
Uniformity of production is as such not part of the compliance testing based on an objective procedure. Figure 5 takenfrom (McGhee et al., 2003) shows a clear picture of what is meant by segregation.

Figure 5. Segregation example (right)
Segregation is difficult to spot but LCMS data collected at roads in the Netherlands do show that it does exist
but goes quite often unnoticed and when detected will be classified as raveling. The multiple 3D transverse profiles

67collected by the LCMS sensors do allow for measuring texture as a volumetric characteristic instead of the by default
used single profile longitudinal texture lasers.
The greater the distance from the sensors to parts of the pavement surface the more black the grey-scale range picture
will be. The range image is the perfect tool to observe cracks, loss of aggregate (ravelling) and segregation. Figure 6
does give an example of segregation of a PA and shows the same lane but in between the pictures is about 25 meter.
The segregation, visualised by the black speckles, had a length of about 10 meter but did grow in size each consecutive
year as prove that segregation does trigger ravelling at an early age.

Figure 6. Segregation on the right
The time between detecting ravelling and speed at which it will develop into a serious defect is quite often very
short. This does make the accuracy of comparing differences between successive surveys extremely important requiring
a (3D) procedure to measure the level of detail of the surface to identify loss of stone (McRobbie et al., 2015).
The only way achieving this is using a volumetric mechanical based survey procedure to measure the condition of thesurface objectively.

3 SAND PATCH VS LCMS COMPARISONThe SPTM (ASTM E965-96, 2006) is a static procedure for measuring the MTD by spreading a known volume
of material over a pavement surface. The MTD is calculated based on the sample volume divided by the average
diameter of the area covered by the material. Figure 7 shows a picture of the execution of the SPTM at the validation
site.

Figure 7. SPTM in execution
According to (ASTM E1845-09, 2009) an Estimated Texture Depth [ETD], a value close to MTD, can becalculated based on the equation: ETD (MTD) = 0.2 + 0.8MPD to transform a 2D result into a volumetric SPTM result.
Several publications can be found relating MPD’s to ETD’s, however number of publications does match the number ofdifferent relationships found which does show that this approach is not very accurate or relates only to the surface typeused in the research.

68The SPTM is a time consuming relatively inaccurate procedure requiring lanes to be closed for traffic and assuch not very useful for measuring a change in the texture of a road surface over time. Twelve SPTM’s have been
executed in the validation site having a length of 300 meter, split over the wheel tracks and in-between the wheel tracks.
Figure 8 shows the location of SPTM No 8 and the pavement surface automatically divided in 250 x 250mm squares
over its total width and length.

Figure 8. Location of SPTM No 8
The LCMS automatically detects the marking to locate the squares always at the same transverse location
independently of the lateral wander. The index number in the squares does in this case relate to the presence ofravelling. The SPTM as well as the ELAtextur results have been compared which those of the LCMS in calculating the
MTD’s of 250 x 250mm squares as shown in Figure 9. The computed R2 of respectively 0.889 and 0.881 showing avery good linear correlation when taking into account the relative inaccurate procedure of the SPTM plus conversion of
the ELAtextur MPD into MTD and the slightly larger area of the LCMS squares.

Figure 9. Correlation LCMS MTD with SPTM and ELAtextur

4 LCMS BASED MTD DATA
The width of a lane can be divided into multiple longitudinal bands based on usage. For instance AASHTO isrecognising the central band, both wheel tracks and the bands outside the wheel tracks resulting into 5 bands. By default
the central band width is 1000mm and both wheel tracks 750mm, however in the software analysing the LCMS data
this can be adjusted transversely based on the requirements. The output of the analysis (MTD, MPD, and Raveling) can
be averaged longitudinally for every 250mm. To match the position of a texture point laser in the Road Surface Profiler(RSP) attached to the front of the vehicle the central band width has been adjusted to 1500mm and the wheel track
bands to a width of 250mm as shown in Figure 10.

69Figure 10. Bands as shown by the purple lines
To get a better insight in the repeatability of multiple LCMS runs over the same road section the
results of the MTD’s of 5 runs sampled at the validation site are shown in Figure 11. These MTD results arecalculated for the left wheel track band (nearest to the verge) shown in Figure 10 being the average of a
250x250mm square.

Figure 11. MTD results of 5 runs validation site
The quality of the repeatability is checked by comparing each run against the average of all runs. This does
show that all runs are comparable having a very good repeatability with R2-values of respectively 0.854, 0.831, 0.900,
0.917 and 0.936. Figure 12 does show the repeatability of run 5 as example.

70

Figure 12. Repeatability MTD run 5
The validation site does show that the wearing course is having two different textures types. The 3D images of
the LCMS do make this clear by a construction joint at approximately 218m which was difficult to see based on ROW
images only. Of the 12 SPTM’s 3 are located in the section after 218m (the 3 lowest MTD values shown in Figure 9).
The validation site has a dense mix surface course showing only locally loss of aggregate. There was however
one distinct small location at approximately 160.5m in the left wheel track (band 2 250mm wide) showing a higher
severity level of raveling. Figure 13 does show this location with in the top part a camera picture of this location and therange image overlaid by the 250mm raveling indices (94) as the bottom part. Figure 11 shows the same location as apeak in the MTD-values (see red arrow) at a distance of approximately 160.5m from the start of this section.

Figure 13. Detected raveling71

A second set of data was collected at the Expressway shown in Figure 4 having an OGFC as surface layer. There was avery pronounced sub-section showing high severity raveling. In Figure 14 the measured texture is presented based on
the MTD as sampled by the LCMS.

Figure 14: LCMS MTD
To have a check on the repeatability of this OGFC surface course over the same road section the results of the
MTD’s of 5 runs over a length of 300m (375-675m according to Figure 14) are shown in Figure 15. The LCMS based
MTD results are calculated for the same left wheel track band (nearest to the verge) showing a very good repeatability(average R2 around 0.95). The sub-section with the high severity raveling is of course showing more variation in the
results.

Figure 15. MTD results of 5 runs sampled at the Expressway
The LCMS data of the OGFC surface course has been analyzed for rating the level of raveling. In Figure 16 a
range image is shown located in the first 225 meter of Figure 15. The top part does show the range image without
overlay whereas the bottom part is showing the raveling index per 250 square. The range in index values isrepresentative for the variation in texture. A shift factor has to be used to correct the index into an absolute level ofraveling which will require the ‘finger print’ of the type of surface course as well as its initial texture value/porosity.

72

Figure 16. ‘Non-raveled’ range image
Figure 17 does show the same OGFC but at the transition of the ‘non-raveled’ to the raveled sub-section (seeFigure 4). The majority of the types of surface course do have a MTD ranging between 0.5 and 2.0mm being shifted by
the level of raveling. In a process of surveying a road network data of different types of surface courses with adifference in age are periodically sampled. This database of surface courses will allow for a detailed analysis of thevariation of the texture and level of raveling.

Figure 17. Transition from ‘non-ravelled’ to ravelled73

5 CONCLUSIONS
When (macro) texture is discussed the volumetric component (3D) is actual fact being meant instead of thesingle point laser (2D) value. As a reliable LCMS-based volumetric measurement of texture at traffic-speed is now
available a move from MPD to MTD should be aimed at to overcome the inconsistency of multiple correlations. Basedon LCMS data analyzed over the last 5 years the following conclusions and recommendations can be made: LCMS texture data collected over the total width and length of road sections does show that there is much
more variation than thought, starting already when a pavement surface is new.
 Windscreen surveys or HD pictures are capable of giving only a relative subjective rating of the level ofraveling and are unable to detect changes in texture.
 Segregation of a surface layer does take place more often than anticipated and an objective traffic-speed based
approach measuring MTD should be made part of a compliance testing procedure.
 The variability of texture will have a negative influence on the noise reducing characteristics of a surface
course.
 The variability of texture will influence the sensitivity for ravelling, influenced by the mix quality,
construction procedures and the weather conditions during construction.
 The variability of texture will influence the frictional characteristics of a surface course.
 The LCMS measured MTD data is compatible with the SPTM and highly repeatable.
 All defects are detected and progression of the severity can predicted based on the results between consecutive
surveys.
In the next phase the rutting and IRI as measured with the LCMS will be validated.

REFERENCES
ASTM E965-96 (2006). Standard Test Method for Measuring Pavement Macrotexture Depth using a VolumetricTechnique. ASTM International, US, reapproved 2006.
ASTM E1845-09 (2009). Standard Practice for Calculating Pavement Macrotexture Mean Profile Depth. ASTM
International, US, 2009.
Kevin K. McGhee, Gerardo W. Flintsch, Edgar de Leon Izeppi (2003). Using High-Speed Texture Measurements to
Improve the Uniformity of Hot-Mix Asphalt. Virginia Transportation Research Council, Charlottesville, Virginia,
VTRC 03-R12.
Stuart McRobbie, Caroline Wallbank, Kamal Nesnas, Alex Wright (2015). Use of high-resolution 3-D surface data tomonitor change over time on pavement surfaces. Research into pavement surface disintegration: Phase 3. Published
Project Report PPR740, Transport Research Laboratory, UK.

74

2nd IRF Asia Regional Congress & Exhibition
October 16‐20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Design, Production, Construction and Performance Evaluation of Recycled
Asphalt Concrete

TRACK
AUTHOR(Capitalize Family Name)
Jian-Shiuh CHEN

CO-AUTHOR(S)(Capitalize Family Name
Cheng-Te LEE

E-MAIL(for correspondence)

POSITION
Professor

POSITION
Ph.D. student

ORGANIZATION
National
Cheng
Kung
University, Department ofCivil Engineering
ORGANIZATION
National Cheng Kung
University, Department ofCivil Engineering

COUNTRY
TaiwanCOUNTRY
Taiwanjishchen@mail.ncku.edu.tw

KEYWORDS:
hot mix asphalt, reclaimed asphalt pavement, pavement performance, recycling agents, recycled asphalt concrete

ABSTRACT:With increased demand and limited aggregate and binder supply, hot mix asphalt (HMA) producers realized thatreclaimed asphalt pavement (RAP) is a valuable component in HMA. As a result, there has been renewed interest inincreasing the amount of RAP used in HMA. While a number of factors drive the use of RAP in asphalt pavements, thetwo primary factors are economic savings and environmental benefits. RAP is a useful alternative to virgin materials
because it reduces the use of virgin aggregate and the amount of virgin asphalt binder required in the production of
HMA. Recycling of high RAP content mixtures could further preserve more natural resources such as virgin aggregate
and asphalt binder. The majority of highway agencies are concerned with how the high RAP content influences
pavement performance. Three test sections were constructed in this study to determine if the higher percentage of RAP
materials can be used on highways. This paper presents the design, production, and construction and preliminary
performance data, discusses the lessons learned from this experience and develops quality guidelines for inclusion ofhigh RAP content. To meet mix design requirements for mixtures with high RAP contents, it was necessary to
fractionate the RAP materials. Mixtures containing up to 40% RAP were successfully designed, produced, andconstructed after proper procedures were followed and attention to detail was paid during design, production andconstruction. An in-depth investigation of pavement performance involving three typical distresses, ride quality, friction
and rutting, was conducted. The overall evaluation revealed that a well-design mix up to 40% RAP could perform as
satisfactorily as that produced with virgin materials to meet the in-service performance requirement.

75

Design, production, construction and performance
evaluation of recycled asphalt concrete
Jian-Shiuh Chen1, and Cheng-Te Lee2
1,2

Professor and Ph.D. student, respectively, National Cheng Kung University, Department of Civil
Engineering, Taiwan, Email for correspondence: jishchen@mail.ncku.edu.tw

1 INTRODUCTION
Asphalt recycling has become popular since the mid to late 1970’s. Prior to this time relatively few
asphalt mixtures were recycled since there was litter incentive to recycle. As a result of the latest economicchanges and the development of recycling technologies, there is a trend towards increasing the use of
Reclaimed Asphalt Pavement (RAP) contents in asphalt mixtures. The use of increased RAP contents not
only reduces construction costs, but also preserves natural resources such as aggregate, binder and energy.
According to the European Asphalt Pavement Association (2010), over 100 million tons of RAP are
generated each year worldwide.
Recycled asphalt concrete should be designed to produce a hot-mix asphalt mixture (HMA) having
the same properties as that in a new mixture. The first step in designing a recycled mixture is to obtainsamples of materials to be used in the recycled mixture. In a current practice recommended by the Asphalt
Institute (2014) in the U.S. is that, when up to 15% RAP blended with a virgin binder, there is no change inbinder grade. When 15% to 20% RAP was used, the new asphalt cement should be dropped on grade lower.
When 25% or more RAP is blended with a virgin binder, a blending chart should be used to analyse the
combined asphalt cement. Highway agencies in Switzerland allow using a maximum of 70% RAP in subbase courses, 60% in base, and none in the hot mix surface courses (Bressi et al. 2015). In Taiwan, the Public
Construction Commission relaxes its specifications to allow the use of up to 40% RAP in dense-gradedasphalt mixtures.
There are five commonly used asphalt recycling methods, including hot in-place recycling, cold mix
recycling, cold in-place recycling, full depth reclamation, and hot mix recycling (Santucci 2007; Bressi et al.
2015), the latter being the most common. In this method, RAP content, virgin aggregate, asphalt binder,
and/or recycling agents are blended in a central mix plant to produce a recycled mix. Recycling agents arenormally used to help soften aged RAP binder and restore the physical and chemical properties of the oldbinder. This research project focuses on the hot mix recycling approach.
Historically, highway agencies limit RAP in HMA based on RAP percentage by weight of total mix.
The percentage of RAP binder blended with virgin binders, named asphalt binder replacement (ABR), isdifferent from the percentage of RAP mixture in mixtures, as it was calculated as the percentage of RAP
binder divided by the mixture’s total binder content. To be truly sustainable and to reduce life-cycle cost,mixes with high ABR levels must perform equivalent to virgin or low recycle HMA. Because of the cost
reductions for construction, the percentage of allowable ABR increases gradually. Up to 60% ABR would beallowed by some highway agencies (Maupin et al. 2009; Tran & Hassan 2011).
While many highway agencies increased the amount of RAP used in hot-mix asphalt mixtures(HMA), the use of high RAP mixtures is still not common. The major concerns involved in the use of high
RAP contents in wearing courses are related to the quality of the combined binder and its performance duringservice life. The use of RAP as a raw material for asphalt mixtures involves the combination of an aged and avirgin binder. Combining RAP with virgin materials introduces unique challenges as the RAP materials
contain aged bitumen, and are therefore often considered as inactive “black rock.” However, “black rock” isnote really inactive. Aged bitumen could be mobilized, and the blending of old bitumen and recycling agent

76

can be optimized so that RAP mixes with virgin materials thereby reducing the amount of new bitumen
needed (Chen et al. 2015).
Although RAP use varies considerably, the average RAP content was estimated to be around 12% in
the U.S. in 2007. The most recent survey in 2011 indicated little change in RAP use specified by highway
agencies, while contractors did report a significant increase in mixtures using 20-30% RAP with no change inmixtures containing other percentages of RAP (Copeland 2011). For the purpose of this study, high RAP isdefined as using 25% or more RAP in an asphalt mixture by weight of total mix. The majority of highway
agencies in Taiwan require mixtures that incorporate RAP to meet all conventional mix design requirements.
However, most highway agencies place restrictions on the amount of RAP used overall as well as in certain
mix types and pavement layers. Conditions may be placed on the asphalt binder grade, aggregate type, andnominal maximum aggregate size for use with RAP.
As highway agencies are interested in being greener and using environmentally sustainably products,
they are looking way to incorporate higher percentages of RAP into asphalt mixtures without sacrificing thepavement quality. The majority of the highway agencies are concerned with the greater potential for cracking
due to the stiffer RAP binders. Highway agencies have expressed concern over the lack of guidance on theuse of high percentages of RAP (high RAP) in mixtures as well as information on their performance. There isa need for guidance on best practices when using RAP and documented information about long-term
performance of high RAP pavements. This study is the result of RAP design, production, construction andperformance to provide information for including higher percentages of RAP in asphalt mixtures.
2 MIX DESIGN
The basic principle of the mix design is that mixtures with and without RAP meet the samerequirements. The experimental factors included one new aggregate source, one RAP source, two RAP
contents, one rejuvenator, one softening agent, and one virgin binder. Limestone aggregate was used for
dense-graded asphalt mixtures with the LA abrasion value less than 30% to possess sufficient toughness. The
aggregate provided by the RAP was included in determination of the mix gradation and basic properties. In
addition, flat and elongated proportions were limited to be a minimum value, and fracture faces were required
to provide an aggregate structure with high internal friction. Limestone met the current criteria of no morethan 15 percent 3 to 1 and no more than 5 percent 5 to 1 flat and elongated particles.
Fractionation is the act of processing and separating RAP into two sizes, i.e., a coarse fraction(+12.5 mm) and a fine fraction (-12.5 mm). A fine RAP gradation was used in this study because, when RAP
particles are coarse or oversized, they are likely not breakdown completely during the mixing and placement.
For the RAP stockpile, the asphalt binder content and aggregate gradation were examined. The asphalt binder
content of RAP was determined to be 4.5% according to AASHTO T 164. Aged asphalt was recovered using
trichloroethylene to separate bitumen from mineral aggregate according to AASHTO T170. The recovered
binder was then characterized by the viscosity, the penetration value and the softening point, as presented inTable 1. As specified by the Public Construction Commission, the aged binder content inside RAP and thepenetration value of old bitumen is required to be higher than 3% by weight of RAP and 15 dmm,
respectively. The RPA material used in this study met the above specifications.
Table 1. Properties of aged binder

Aged binder

Specific gravity
1.02

Viscosity (60C, poise)
120,800

Pen. (25C, dmm)
16

Soft. pt. (C)
72

Table 2. Properties of virgin asphalt and recycling agents
Source
AC-20
AC-10
RA

Viscosity (60C, poise)
1986
972
65
na = not applicable

Pen. (25C, dmm)
67
89
na

Soft. pt. (C)
51
46
na

Saturate (%)
na
na
12

77

Two types of recycling agents were used to restore the aged binder. The two agents used were one
type of soft asphalt cement and one type of oil-based rejuvenators. The softening agent was AC-10 viscosity
grades. An AC-20 binder was selected as the control binder because this is typical asphalt used for flexible
pavements in Taiwan. Table 2 gives the physical properties of the softening agent and AC20 asphalt cement
used in this study. The rejuvenating agent used in this study was RA which is a petroleum hydrocarbon.
Table 2 summarizes the basic properties of the rejuvenating agent.
For asphalt mixtures containing RAP, a blending chart was used to select the appropriate grade forthe virgin binder. The blending chart developed by the Asphalt Institute (2014) is logarithmic linear graph,and was used to estimate the viscosity of the blended binder. The selection of 2,000 poises at 60C as thetarget viscosity is due to the fact that most highway agencies in Taiwan choose this value for recycled asphalt
concrete. Two recycling agents, i.e., AC-10 and RA, were used to restore the old binder to the AC-20
classification range.

Percent passing (%)

Asphalt mixtures were prepared by mixing RAP, fresh aggregate, virgin binder (AC-20), andrecycling agent. The gradation of the RAP aggregate was determined after the aged binder was extracted
from the RAP mix. Two RAP contents were evaluated in this study, i.e., 10% and 40%. Figure 1 illustrates
the blended gradations of RAP mixtures. The master gradation bands for 19-mm nominal maximum
aggregate size (NMAS) were based on the field test road selected. For clearer presentation, mixtures mixed
with 0%, 10% and 40% RAP were designated as RAP0%, RAP10% and RAP40% mixtures, respectively.
Satisfactory inclusion of up to 40% RAP was achieved for well-designed mixtures with good gradation
characteristics, and with the use of recycling agents. RAP0% represents virgin aggregate mixed with AC-20,
and is used as the reference mix.

Figure 1. Gradation curves of virgin and RAP mixtures.
Table 3. Various binder contents in asphalt mixtures
SourceVirgin binder (AC-20)
Softening agent (AC-10)
Rejuvenating agent (RA)Aged binder
Total binder
Binder replacement

ID
RAP0%
4.9
0.0
0.0
0.0
4.9
0.0

RAP10%
0.4
4.0
0.0
0.5
4.9
10.0

RAP40%
1.5
0.0
1.6
1.8
4.9
36.7

78

All mixtures had similar blended aggregate gradations, and the percentage of mineral fillers used forall mixtures was set at 50.2 percent. The job mix formula was decided using the Marshall mix design
method. Specimens of 100mm diameter and 63.5mm height were prepared by applying 75 blows on eachfaces. The asphalt content of all mixtures was determined as that resulting in 4% air voids. The total binder
content for all asphalt mixtures was determined to be 4.9% by weight of total mix. The asphalt binder
replacement (ABR) level in the experiment varied from a low level of 10% to a high level of 36.7% as listed
in Table 3. In this study, voids in mineral aggregate (VMA) of asphalt mixtures were controlled at 14.80.2
percent. The mixing and compaction temperatures for all asphalt mixtures were selected corresponding to
0.17 Pa.s and 0.28 Pa.s viscosities, respectively. Laboratory-produced mixtures may not reflect the effect of
all of factors affecting high RAP content materials, evaluation of plant-produced mixtures would be moreelastic.
3 PRODUCTION OF RECYCLEDASPHALT MIXTURES
After the asphalt mixtures were designed and checked, all mixes were produced according to the job
mix formula (JMF). Since the moisture in a RAP stockpile would take more fuel for drying, the RAP
stockpile was covered to reduce the amount of moisture in the RAP as shown in Figure 2. The moisture
content of the reclaimed material was kept low by preventing rain from falling on the RAP by keeping it
under a roof. Due to the inherent variability of RAP materials and uncertainty of RAP aggregate true
gradation, actual blend gradation against the design blend was regularly checked.

Figure 2. Covered RAP stockpiles.
Production of recycled asphalt mixtures is similar to that for virgin asphalt mixtures. RAP isbasically treated as an aggregate with some modification to the way it is fed through the asphalt plant. A
batch plant is used in this study and has to be modified, as shown in the schematic in Figure 3, to add the
RAP directly to the pugmill. The modifications require the addition of RAP cold-feed bin, RAP conveyor,
RAP dryer, RAP weigh hopper, and the appropriate instrumentation to control the RAP mix. The feed of the
RAP was separated from the feed of the new aggregate. The material from the bind was deposited onto agathering conveyor for transport to a RAP dryer. The RAP was indirectly heated using the high-temperature
exhaust collected from the burn set up for the virgin aggregate. The RAP entered the pugmill through theweight hopper.

79

Virgin Materials
RAP
RAP ColdFeed Bin

Emission Control

Screens
Hot BinBaghouse

RAP Dryer
Virgin Aggregate
Cold-Feed Bin

Weigh
HopperPugmill

RAP
Conveyor
RAP WeighHopperConveyor
Dryer

Figure 3. Major components of a batch plant for production of RAP mixtures.

Three components of a RAP mixture need to be heated, i.e., fresh aggregate, binder and RAP.
Establishing the sequence of putting materials into the pugmill is chiefly aimed at producing the final
homogeneity of a RAP mix. Mixing constituents consist of dry mixing and wet mixing. The wet-mix time
began as soon as the rejuvenator was added to the pugmill. Wet-mix time was necessary to uniformly
distribute the rejuvenator RA and coat the RAP. RAP wet-mix time is important to allow the rejuvenator topenetrate and diffuse into the inner circle of aged bitumen, and to provide a good degree of blending. The
total mixing time of a cycle for RAP0%, RAP10% and RAP40% mixtures was 60, 70, 95 seconds,
respectively, and included actions shown in Figure 4 for the production of RAP40% mixtures.

Figure 4. Batching sequence of RAP40% mixtures.
As shown in Figure 4, RAP40% dry mixing started the moment RAP was deposited into the pugmill,and it ended the moment the rejuvenator injection began. RAP wet mixing started when RA entered thepugmill. Typically 10-second injection time was needed for all the rejuvenator to be discharged from theweigh bucket. Wet-mix time at this stage should be long enough both to coat the RAP completely with the
rejuvenator, and to allow adequate blending between aged asphalt and recycling agent. In this case, a 30second wet-mix time could uniformly distribute the rejuvenator and coat the RAP. Enough RAP wet-mix
time enabled the RAP binder to act as part of the cohesive binder. A significant amount of blending, if not
total blending, could occur during production. After the addition of the RAP, the following sequence of80

mixing fresh aggregate and virgin bitumen (i.e., AC-20) was similar to that of new asphalt mixtures (i.e.,
RAP0% mixtures).
The total cycle time to produce the RAP40% mix was 95 seconds (assuming a 10-second gateopening, mix-discharge, and gate-closing time). The increased cycle time (95 seconds compared with 60
seconds for the RAP0% mix) would decrease the amount of mix produced in a pugmill with a capacity of 2
tons from 120 tons to 76 tons per hour. Thus, the dry- and wet-mix times could significantly affect theamount of a RAP mix produced by a given plant and the cost of producing that mix.
In a batch plant, the new aggregate temperature upon discharge form the dryer was about 165C inthis study to keep from driving off internal moisture in the aggregate. Since the amount of RAP incorporated
into the mix was 40%, the RAP temperature was heated up to 140C to remove the moisture from the RAP
and to heat the moisture to the desired discharge temperature. The mix discharge temperature was about
155C. The plant production was monitored and adjusted for moisture content.
4 CONSTRUCTION OF TEST SECTIONS
Accordingly, after verifying test results obtained from the asphalt plant, the Taiwan Highway
Bureau began construction of a test road. These test sections as shown in Figure 5 were located along a
county road. Pavement sections in the east bound were selected for the field study. Haul time from the batch
plant to the construction site ranged from 40 to 50 minutes over a distance of approximately 45 km
depending on traffic conditions. The route traverses plan terrain and a two-lane route having approximately
3.5-m lanes. The existing lane was milled prior to a truck and a paver. A vibratory steel roller, a pneumatic
tire roller, and a statics steel roller were used a breakdown, intermediate, and finish roller, respectively. All
the sections were completed with typical equipment and operations similar to those for other flexible
pavement construction. Each section was consisted of a 5-cm dense-graded asphalt concrete surface course
over a 30-cm crushed-stone base course. Cores were taken for quality control and quality assurance. All test
sections were reported passing and within the acceptance rage for compaction (98% to 100% of the reference
density). An in-place air voids target to 8% or lower was achieved against each type of reference density.

Figure 5. Test sections of virgin and RAP mixtures.

Monitoring in-service pavements is one of the best methods for gaining data on how pavements builtwith high RAP contents will perform over time under real environmental and traffic conditions. Three test
sections named as RAP0%, RAP10%, and RAP40% were completed in 2014 with typical construction
equipment and operations. This route has an average traffic volume of 1,200 vehicles per day withapproximately 12% truck traffic. Surveys of pavement performance including skidding resistance, permanent
deformation, and smoothness were conducted at scheduled intervals. The pavement performance of RAP
sections is examined based on a comparison with the reference section, i.e., HMA with virgin materials.

81

5 FRICTION
Pavement skid resistance was measured by the British Pendulum Tester according to ASTM E303,
and expressed by a British Pendulum number (BPN). Figure 6 shows that the measurement of the friction
showed an initial BPN of 63 to 64 right after construction. Each bar represents the average of three replicates,
and the error bars indicate on standard deviation from the average value. Skid resistance was relatively low
just after construction because of the bitumen film coating aggregate particles on the pavement surface. As aconsequence of the disappearance of the binder film covering the surface of the aggregate, skid resistance
was improved after test sections open to traffic. A BPN value higher than 45 is considered sufficient and safe
for roadway pavements. According to test results in Figure 6, all test sections provide reasonably good wet
weather friction. The BPN value of test sections built with RAP appears to provide good skid resistance after
two years in service. Because of the significant amount of macrotexture produced on RAP pavement
surfaces, RAP layers maintained adequate frictional characteristics even after become condensed.
100
Before Construction

1 mo

6 mo

12 mo

18 mo

24 mo

BPN 45

80

60

40

20

0
RAP0%

RAP10%

RAP40%

Figure 6. Friction characteristics of pavement surfaces.
6 RUTTING
A straightedge was placed across the wheelpaths at each trench location to measure rut depth
according to ASTM E1703. As shown in Figure 7, rutting was reduced right after construction. The severity
level is considered to be low when the mean rut depth is less than 12.5 mm, moderate when rutting is
between 12.5 and 25 mm, and high when rutting is higher than 25 mm. Test results indicate that all test
sections possesses good resistance to plastic deformation, although rutting increases with increasing service
time. Linear blending appears to be applicable to the high RAP content mixes. The presence of RAP binder isshown to be beneficial to maintain the mix stiffness even with the addition of a softening agent and a
rejuvenator.

Figure 7. Permanent deformation on pavement surfaces.

82

7 RIDE QUALITY
Roughness is an important index of pavement performance evaluation, which affects the
comfortableness of drivers and passengers. It is an index involving human-vehicle-road interaction, often
evaluated by the International Roughness Index (IRI) and expressed by m/km. For these sections, the IRI
value increases with increasing service time as shown in Figure 8. The initial IRI value is considered to be
acceptable if it is lower than 3.5 m/km right after pavement construction. The IRI value of the RAP0%
section was the lowest, while the roughness of the RAP40% section was larger than that of RAP10%. No
raveling or cracking has been observed on the test sections since open to traffic. Field results suggest that
RAP be a viable pavement surface type for use on roads to provide good performance, including good
friction, reduced rutting, and improved durability.
8
Before Construction

1 mo

6 mo

12 mo

18 mo

24 mo

IRI Value (m/km)

6

IRI < 3.5
4

2

RAP0%

RAP10%

RAP40%

Figure 8. Ride quality of pavement surfaces.

8 CONCLUSIONS AND RECOMMENDATIONSThis study is to evaluate the design, production, construction and performance of hot-mix asphalt(HMA) pavements built with up to 40% reclaimed asphalt pavement (RAP). Three distress indicators, i.e.,
rutting, friction, and smoothness, are adopted to represent pavement performance. Based on the informationand the limited test results, the following conclusions and recommendations could be made.
For all RAP mixtures, the RAP materials were fractioned similar to virgin aggregates. The RAP
material was properly characterized for mix design purposes. The laboratory mixture design wasestablished using RAP as a component. Linear blending appeared to be applicable to the high RAP
content mixes. Satisfactory inclusion of up to 40% RAP was achieved for well-designed mixtures withgood gradation characteristics and with the use of recycling agents. RAP quality was shown to be
associated with proper techniques for obtaining, stockpiling, and processing RAP.



Plant production practices used in the production and placement strategies during the construction of
HMA need to address concerns when using high RAP contents. The plant production was monitored
and adjusted for moisture content. High-quality high RAP mixtures were achieved with processing andproduction practices, which resulted in mixes with good performance in rutting, friction and ride quality.

Mixtures containing up to 40% RAP were successfully designed, produced and paved. Proper
procedures were followed and attention to detail was paid during material selection, mix design, plant
production, and field construction.



The performance evaluation was conducted based on the distresses of the RAP sections and the virginsection, which served as the reference. Mixes with high RAP contents performed equivalent to virgin
HMA. Overall, RAP and virgin sections showed satisfactory performance over two years of the service
period.

83

ACKNOWLEDGEMENTS
The authors are very grateful for the National Science Council (NSC95-2211-E-006-340 – MY2) andthe Taiwan Highway Bureau providing financial supports and field assistance to complete this project.

REFERENCES
Asphalt Institute (2014). Asphalt Mix Design Methods, MS-2, 7th edition, Kentucky.
Bressi, S., A.G. Dumont, and M. Pittet (2015). Cluster phenomenon and partial differential aging in RAP
mixtures. Construction and Building Materials, Vol.99, pp.288-297.
Bressi, S., M.C., Cavalli, M.N. Partl, G. Tebaldi, A.G. Dumont, and L.D. Poulikakos (2015). Particle
clustering phenomena in hot asphalt mixtures with high content of reclaimed asphalt pavements.
Construction and Building Materials, Vol.100, pp.207-217.
Chen, J.S., S.F. Chen, M.C. Liao, and S.W. Huang (2015). Laboratory evaluation of asphalt blends ofrecycling agents mixed with aged binders. Journal of Materials in Civil Engineering, Vol.7(4), pp.1-6.
Copeland, A. (2011). Reclaimed asphalt pavement in asphalt mixtures: state of the practice, FHWA-HRT-11021, Federal Highway Administration, Virginia.
European Asphalt Pavement Association (2010). Recycling of asphalt mixes and use of waste in asphalt
pavements. http://www.eapa.org/. Accessed May 5, 2016.
Illinois Department of Transportation (2012). Standard specifications for road and bridge construction.
Springfield.
Maupin, G.W., S. D. Diefenderfer, and J. S. Gillespie (2009). Virginia’s higher specification for reclaimed
asphalt pavement: performance and economic evaluation. Transportation Research Record: Journal of
the Transportation Research Board, No. 2126, Washington, D.C., pp. 142-150.
Public Construction Commission (2014). Recycled Asphalt Concrete. PCC Designation: 02966, Executive
Yuan, Taipei, Taiwan. (in Chinese)
Santucci, L. (2007). Recycling asphalt pavements - a strategy revisited. Pavement Research Center, Instituteof Transportation Studies, University of California, Berkeley, California.
Tran, B.T., and R.A. Hassan (2011). Performance of hot-mix asphalt containing recycled asphalt pavement.
Transportation Research Record: Journal of the Transportation Research Board, No.2205, Washington,
D.C., pp.121-129.

84

2nd IRF Asia Regional Congress and Exhibition
16-20 October 2016 – Kuala Lumpur, Malaysia

SUSTAINABLE AIRPORT PAVEMENT MANAGEMENT SYSTEM:
PAPER TITLE

Effects of delay in maintenance approach based on life-cycle cost analysis and lifecycle assessment

TRACK
AUTHOR(Family Name Capitalized)

POSITIONORGANIZATIONCOUNTRY

Peyman BABASHAMSI

Ph.D. Candidate

Universiti Kebangsaan
Malaysia

Malaysia

CO-AUTHOR(S)(Family Name Capitalized)

POSITIONORGANIZATIONCOUNTRY

Nur Izzi MD. YUSOFF

Senior Lecturer (Dr.)

Universiti Kebangsaan
Malaysia

Malaysia

Halil CEYLAN

Professor

Iowa State University

USA

Nor Ghani MD Nor

Professor

Universiti Kebangsaan
Malaysia

Malaysia

Correspondence E-MAIL

peymenshams@yahoo.com
peymenshams@siswa.ukm.edu.my

KEYWORDS:
Airport Pavement Management System, Life-Cycle Costs Analysis, Life-Cycle Assessment, Preventive Maintenance,
Pavement Condition Index.

ABSTRACT:
Airport pavements deteriorate with age due to environment influence and air traffic. The most challenging task inpavement management in developed countries is to maintain the performance of airport pavements through preventive
maintenance while in developing countries maintenance is done on a reactive (require to do) basis. There is a dearth ofstudies on the scheduling strategy of airport pavement maintenance. Assessment of different scheduling strategies
depends on the life-cycle cost analysis (LCCA). An analysis of the cost benefit study of delay in maintenancealternatives should be done to determine whether or not a one year delay is beneficial. It should be noted that thesustainability of airport pavement management system takes into consideration economics as well as environmental andsocial factors. This study reviews airport pavement management systems and the significance of delay in maintenanceand preservation scenarios are demonstrated. The scenarios demonstrated are four preventive maintenance strategies,
namely three methods of crack treatments, which are crack sealing, patching and slurry seal, and surface treatment inwhich the overlay method is done in two Pavement Condition Index (PCI 75 and PCI 65), and the resulting service life
enhancement. This article discusses a one year delay in preventive maintenance from the life cycle cost and life cycle
assessment perspectives. The results show that a one year delay in preventive maintenance increase the deterministic life
cycle cost by 52% while the variance is between 50.5% - 53.6% in the probabilistic life cycle cost analysis. From the life
cycle assessment point of view, a delay of only one year cause a 67.5% increase in NOx, SOx and PM.

85

SUSTAINABLE AIRPORT PAVEMENT MANAGEMENTSYSTEM:
Effects of delay in maintenance approach based on lifecycle cost analysis and life-cycle assessment
Peyman Babashamsi 1*, Nur Izzi Md Yusoff 1, Halil Ceylan 2, Nor Ghani Md Nor 3
a. Dept. of Civil and Structural Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi,
Selangor.
b. Dept. of Civil, Construction and Environmental Engineering, Iowa State University, Ames, Iowa
50011.
c. Dept. of Economics and Management, Universiti Kebangsaan Malaysia, 43600 UKM Bangi,
Selangor.
*Corresponding author’s e-mail: peymenshams@yahoo.com
1 INTRODUCTION
The construction and maintenance of airport pavements require a huge amount of public fund. In
both industrialized and developing countries, airport pavements are the lifeline of fundamental economic
activities through which goods and people are transported. The increase in air traffic is the main reason for
the increase in load imposed on pavements with the passage of time, and this affect pavement structures
which have either reached or depleted their service life. For this reason, airport management authorities haveshifted their focus from constructing new pavements to maintenance and rehabilitation (M&R) activities.
Planning future maintenance of fatigue pavement is becoming an increasingly difficult task due to thecomplex behaviour of aging pavement. At the same time the increasingly limited budget, which mostagencies are currently enduring, has caused a decrease in maintenance activities. Most researches tend to
focus on the advancement in airport pavement management systems (APMS) made by several agencies since
the last couple of decades. The main role of APMS is to aid decision-makers in discovering M&R techniques
for the maintenance of airport pavements which are in usable condition over a predefined period of time in
the most cost-effective manner (Haas et al., 1994). Different APMS might adopt a different framework basedon the preferences of agency requirements although there are several similar functions in all APMSs that are
crucial in ensuring performance, such as pavement performance prediction, network inventory, pavement
condition assessment, and planning strategies.
The first airport pavement management system was introduced in the 1970s as a project conductedby the Construction Engineering Research Laboratory (CERL) for the US Air Force and has led to theestablishment of the PAVER and MicroPAVER systems. Harrison and McNerney (1995) conducted anassessment of different APMSs and concluded that the MicroPAVER system, which only look at surface
distress, is a time consuming process which does not take into consideration the costs borne by airlines andairports, such as cost of user delay due to the closing of runways and expanded roughness which cause
fatigue to airplane. A comprehensive economic impact on pavement network, which take into considerationflight delay and operating costs, was addressed in the recently Enhanced APMS (EAMPS) (ARA, 2011).
Broten and Wade (2004) performed a principled evaluation and assessment on airport pavement management
activities by conducting a survey of all aviation agencies in every state in the US. The transportation agencies
from several states, such as Michigan (MDOT, 1999), Minnesota (MNDOT, 2001), Ohio (ODOT, 2001) andCalifornia (CalTrans, 2008), prepared complete pavement maintenance manual in their respective areas ofauthority. The Unified Facilities Criteria (UFC), published by the U.S. Department of Defence, contains
related reports and technical guidelines on the management of pavement maintenance (USDOD, 2004). In
addition to the above-mentioned researches, which are appropriate for both rigid and flexible airport
pavements, other APMSs which are specific to other types of pavement are also available, such as the
AirPACS which was published to answer various questions regarding to maintenance of jointed plain
concrete pavement (JPCP) at airports (Ismail et al., 2009).
Airport pavement management simplifies the life cycle cost analysis (LCCA) for various
alternatives and aids managers in the timing of framework and choosing the most effective alternative. It

86

provides a consistent, systematic method for choosing the maintenance required and identifies the preferred
and the best maintenance schedule by predicting future condition of pavements (FAA, 2007; Santos andFerreira, 2013). APMS can be an important tool which alert managers of the trigger condition of pavements
and determine the proper preventive maintenance (PM) in a life cycle. The LCCA for a particular segment or
project analyses for possible M&R are taken into consideration when determining the available alternatives
for the pavement section and the most cost effective alternative for the life cycle of the pavement. The best
progressive strategy for improving the allocation of available budget for several transportation agencies is themulti-year prioritization which utilizes incremental cost-effectiveness analysis; however this it is very rarely
performed for airport pavement networks (Santos et al., 2015). The reason for the slow implementation
include shorter airport pavement networks, other more significant performance issues at airports, and lack of
airport pavement management programs (ACRP, 2011). A review of current studies on APMSs shows that
only limited determination was made based on available data and information, with the objective of preparing
a review of regular airport pavement maintenance activities and their current application.
As shown in Figure 1, maintenance cost might decrease significantly if maintenance was done
during the early stages of deterioration. Preventive maintenance should be carried out before pavements reach
their threshold performance level (base level of serviceability) and require reconstruction. The trigger valueor threshold performance level is the base adequate execution level below which pavements are deemed
unsuitable for its serviceable plan. This is frequently based on a particular agency’s implementation
requirements or user point of view. Agencies usually use threshold values which are based on performanceplan rather than time planning (Pinto et al., 2015). The effectiveness of short term prevention, which
considers pavement performance jump, is invaluable in ensuring pavement performance and measures theviability of alternative maintenance. The effectiveness of long term prevention, which incorporates service
life extension and average pavement performance and the area jumped by the performance curve, is suitablefor preservation “strategies” or “schedules”, as shown in Figure1.

Figure 1- General life cycle of pavements performance curve (Babashamsi et al. 2016)

The principle components in all APMSs include network inventory, various methods of assessing
and monitoring pavement condition, the framework used to predict the assessment of pavement condition,and management strategies. Conditions reports are presented in the form of quality index, such as pavement
condition index (PCI) related to a single or a combination of various pavement characteristics and represent
the deteriorating state of pavement during its service life (Baladi et al., 1992; Levy et al., 2014). The PCI
process comprises of collecting broad data with regard to various distresses for the calculation of total index.
The disadvantage of using the PCI method is the questionable repeatability of visual survey due to thesubjective nature and distinction between severity of distress, which could be managed through broad andcareful inspection rules or through the use of automated data gathering devices (Lee, 1992). Additionally, thefunctional assessments design and framework process of airport pavements depend on structuralconsiderations such as constraining stresses, strains and deflections (Monismith, 1978).

87

In APMSs, several performance predicting methods play an important role in managing crucial
decision-making process. Pavement performance serves as a tool in the planning of future M&R activities
and can be anticipated through the deterministic and probabilistic methods (Lytton, 1987; Butt, 1991;
Meneses and Ferreira, 2013). PCI prediction models are functional performance models that have generally
been produced for the PAVER framework and are also used in other APMSs, such as Integrated APMS andAirPAVE (Rada et al., 1992). The methods created for performance prediction relate future PCI quality to a
progression of informative or predictive variables such as age of pavement, deflection measurement, timesince last overlay, and traffic. In order to determine the number of cycles of load applied before failure
occurs, structural performance models relate the characteristics of pavement material structure to the load
applied to it. These types of prediction models are widely used by pavement managers and have been
expanded for pavements by different agencies, such as Asphalt Institute, U.S Army Corps of Engineers,
Portland Cement Association (PCA), and Shell International Petroleum Company (Zaniewski, 1991;
Meneses, 2013).
Currently, decisions on airport maintenance in developing countries depends on the historicalexperience of airport pavement experts and the judgment of management authorities without taking into
consideration the LCCA and other management practices. Given the current situation of financial prudence,
pavement infrastructure requires a more deliberate and systematic approach in determining maintenancerequirements and preferences. Decision making agencies responsible for pavement maintenance often
consider urgent requirement or experience instead of adopting long-term management and documenting data.
This method does not allow management organizations to assess the cost effectiveness of various alternative
maintenance strategies and this has led to imprudent spending. The most recent development in airport
pavement management provides a way of managing pavement economically and in a timely manner (Liu etal., 2015). This paper aims to determine the most cost effective maintenance schedule method which would
produce minimum life cycle treatment cost (Economic Benefit). It also takes into consideration
environmental impacts by evaluating various scheduling strategies to determine which strategy has the least
potential of contributing towards global warming (Environmental Benefit). This would empower airport
management companies to determine pavement maintenance requirement through prudent spending ofavailable funds.
2 METHODOLOGY
The surface distress of airport pavements is usually evaluated through PCI. The value of PCI could
range from 0 to 100 and could be set as shown in Table 1. PCI distress data are obtained through a visualsurvey carried out by expert pavement inspectors. PCI depends on the assessment of the type, quantity andseverity of distress (ACRP, 2011; Ferreira and Santos, 2013).
Table 1- Airport Pavement Treatments Based on PCI (ACRP, 2011)
PCI Rating
100-86
85-71
70-56
55-41
40-26
25-11
10-0

Description
Good - minor distress
Satisfactory - medium/low distress
Fair - Severe distress
Poor - low operational problem
Very poor - high operational problem
Serious - operational restriction
Fail

Preservation Treatment
Routine maintenancePreventive maintenance
Corrective maintenance/Rehabilitation
Rehabilitation
Rehabilitation/Reconstruction
Reconstruction
Reconstruction

This paper considers two critical PCI. The first is the higher PCI limit (PCI 75) in which pavement
is in satisfactory condition (medium/low distress). The second point is the lower limit of critical PCI, whichis assumed to be the minimum acceptable PCI (PCI 65), and that pavement is in fair condition (severe
distress) for all alternatives in the airport pavement management system models. Rahman and Tarefder(2012) stated that in high and moderate traffic airports these two critical PCI points could be reached within
less than one year from one another. For a particular treatment alternative in this study, maintenance work
was performed in the base year of 2015 and PCI 75 would be reached in 2017 and PCI 65 would occur in
2018, which means a one year gap within the same preventive maintenance activity. The following
alternatives were considered for implementation during the 25 year pavement life cycle in the two different

88

PCI range for the current study. Crack treatments include crack sealing and spray patching, while surface
treatment include slurry seal and thin overlay.
Crack sealing is a maintenance activity which seal cracks with rubberized bituminous material. It
includes the routing of cracks, cleaning the routed surface, and applying sealant on them. Crack filling issimilar to crack sealing, but without the routing. Crack filling is easily damaged by snow plows and hence is
not cost-effective. Spray patching is a preventive maintenance measure which involves the application of abituminous compound which is then covered with a layer of aggregate. It could be done manually or throughthe use special mechanical equipment to spray emulsion, apply the cover aggregate, and this if followed by
preparation for basic compaction, all in a single pass. If spray patching is applied on the entire width of apavement, it can be categorized as surface treatment. Slurry seal in itself is a surface treatment and uses
unheated mixture of asphalt emulsion, graded fine aggregate, mineral filler, water, and other additives; thesematerials are mixed and spread over pavement surface as slurry. Slurry seal is applied to provide a protective
layer of bitumen-rich mortar. Hot mix overlay of asphalt concrete pavement comprises of setting a layer ofhot mix over existing pavement. Traditional asphalt concrete overlays are typically constructed with a basethickness of 2.5 inches (63.5mm). Overlays less than 2.5 inches are called thin overlay.
The assessment of various scheduling strategies depends on the LCCA. LCCA is an engineering
economic analysis technique used to differentiate the relative monetary benefits of different development or
rehabilitation design alternatives for a project. LCCA aids in the selection of the cheapest method which fulfil
the objectives of a project. LCCA is used to determine the benefits achieved when all choices being
considered are equal. The LCCA procedure starts with the development of alternatives to achieve theperformance targets of a project. Initial and future activities required for executing each project design
alternatives are then planned and the expenses for these exercises were assessed. In this study, only direct
agency expenditures (maintenance activities) are considered while ignoring user costs that result from agency
work zone operations. By utilizing a monetary technique known as discounting, these costs are converted into
present value and are then added to each option. Two calculation approaches, namely deterministic andprobabilistic, can be used in LCCA. The methods differ in the way they handle the variability associated with
the LCCA input. Each LCCA input variable is assumed to have a fixed, discrete value in the deterministic
method whereas in the probabilistic LCCA inputs are specified by probabilistic functions that convey both
the range of likely inputs and the likelihood of them happening (Walls and Smith, 1998). In this study the
integrated LCCA and life-cycle assessment (LCA) program, L2C3A2, is used for probabilistic LCCA. The
Triangular distribution is taken to signify the variability of discount rate as it was suggested by Walls andSmith (1998) in Interim Technical Bulletin. The discount rate can consider in Triangular or normal
distribution the benefit of triangular is reducing the number of irritations and to achieve the results faster(ARA, 2011). For all alternatives, 3%, 4% and 5% are chosen as minimum likely, most likely and maximum
likely value of the discount rate respectively. The maintenance cost is assumed to have a normal distribution.
It would be more likely that the distribution of maintenance costs would be closer to a right skewed normal
distribution and not uniform. This article followed ARA (2011) assumptions.
The mean values of unit cost for crack sealing, patching, slurry seal, and overlay are assumed to be
1.79, 5.05, 3.57, and 8.93 $/m2, respectively. The standard deviation for the four alternatives were determined
to be 0.6, 1.48, 1.20 and 2.23 $/m2 respectively.
The key objective of this study, namely to determine the maintenance schedule which would
produce minimum life cycle cost, was achieved through the probabilistic life cycle cost analysis, and life
cycle gas emissions by using a special tool named L2C3A2. This software/program is comprehensive inconsidering LCCA and LCA as airport pavement management system toward sustainable development in
Universiti Kebangsaan Malaysia (UKM) and will be available online soon. The novel integrated
LCCA+LCA program is introduced by this research, namely, the L2C3A2 to compare alternatives not only inthe economic aspect by considering direct costs, indirect costs and salvage values, but also in theenvironment aspect by various modules such as material, transportation, construction, usage, maintenanceand rehabilitation, and end-of life, which covers every aspect of the pavement’s life-cycle. This tool can beapplied on both flexible and rigid airport pavements to focus on all areas of analysis. The results of this tool
will be of assistance to engineers and airport management as it provides a fair, unbiased, defensible statisticalmethod that evaluates the alternatives throughout the pavement life-cycle. This study attempts to determine
the optimum pavement maintenance strategy. All benefits and costs were converted into monetary value.
Information regarding pavements and their respective maintenance and their unit costs were obtained fromthe Airport Cooperative Research Program Synthesis (ACRP, 2011) and is shown in Table 2. PCI increase89

data was obtained from a previous study (Ningyuan et al., 2001). The unit cost of crack sealing is assumed tohave a typical crack density of 0.25 m/m2 (Hicks et al., 2000). In calculating total cost, all treatments wereapplied over the entire area as surface treatment, except for spray patching. Assumption is made that 50% of
the area should be patched when patching is required.
Table 2 - Unit Cost and Life Extension of the Different Maintenance Strategy (Rahman and Tarefder, 2012)
Maintenance Activity
Crack Treatment
Spray Patching
Slurry Seal
Thin Overlay

Life Extension (Years)
2-3
3-5
4-7
7-12

PCI Rise
5
5
10
15-20

Mean Unit Cost ($/m2)
1.79
5.05
3.57
8.93

Std. Dev. (%)
33.5%
29.3%
33.5%
25.0%

In order to quantify the benefit of a pavement management in monetary terms, a guideline wasobtained from a previous study (Smadi, 2004). The undiscounted expenditure timetable for minimum
acceptable PCI 75 and 65 is shown in Figure 2.

Figure 2- Timetable maintenance strategies on PCI 75 and PCI 65
As shown in Figure 2, when PCI=75 the pavement is in a satisfactory condition and therefore themaximum of life extension was considered for each activity, whereas when PCI=65 the pavement is in faircondition and, due to fatigue and severe distress, minimum life extension was selected.
3 RESULTS AND DISCUSSION

Results for the Deterministic Method
The deterministic results are presented in Table 3 and illustrated in Figure 3. A discount rate of 4%
was used in this deterministic study. Discount rate is the interest rate by which future costs (in dollars) isconverted to present value. In other words, the discount rate is generally the distinction of interest andinflation rates, which show the real value of money over time, as shown in Equation 1. Real discount rates
typically range between 3 to 5%.
𝑖𝑑𝑖𝑠 = 𝑖𝑖𝑛𝑡 − 𝑖𝑖𝑛𝑓 (Decimal)(1)

Present value (PW) is calculated using Equations 2 and 3, where “i” is the discount rate and n is theyear of maintenance. NPW discounts all future costs to the present value using a discount factor:
PW=C× [

(1+𝑖𝑖𝑛𝑓 ) 𝑛](2)(1+ 𝑖𝑖𝑛𝑡 )PW=∑ future cost (1(1+𝑖𝑑𝑖𝑠 )𝑛

)

(3)

90

Where
PW = Present-worth cost ($);
C= Future cost in present-day terms ($),
𝑖𝑖𝑛𝑓 = Annual inflation rate, decimal;
𝑖𝑖𝑛𝑡 = Annual interest rate, decimal;
𝑖𝑑𝑖𝑠 = Annual discount rate, decimal;
n = Time until cost C is incurred, years.
Table 3- NPW of Different Maintenance Scheduling Treatments
Minimum
PCI

75

Maintenance

No. ofapplication

Crack Sealing

3

Spray
Patching
Slurry Seal
Thin Overlay

2
1
1
TOTAL COST

Crack Sealing

2

Spray
Patching

2

Slurry Seal

2

Thin Overlay

265Year ofapplication
2017
2029
2034
2020
2037
2025
2032

PCI
before
80
75
75
80
71-75
70
70

PCI
after
>86
80
80
>86
80
>86
>86

2018
2029
2020
2031
2023
2034
2027
2038

75
70
75
70
71-75
70
65
60

>80
75
>80
75
80
80
>75
>75

TOTAL COST

1000
900
800
700
600
500
400
300
200
100
0

NPW
(10000$)
48.40
77.50
94.30
76.80
149.60132.10434.901013.60
50.30
77.50
76.80
118.20122.10188.00357.40550.201540.50

PCI 75
PCI 65

Crack
Sealing

Spray
Patching

Slurry Seal

Thin
Overlay

Figure 3- Deterministic results of different maintenance schedule activities
The sensitivity analysis method is used to determine the variables which influence result at thehighest level. By utilizing sensitivity analysis, the variables of the model were identified and the ranking of
the considered options can be rearranged by determining the breakeven points. If an adjustment in thevariables of a model is the same as the discount rate, it could influence the position of the achievable design
options but there will be no development of dominant alternative design options (Ferreira and Santos, 2013).
In addition, the impact of a single model variable on the results of analysis can be judged through sensitivity
analysis; however it is not practical for managers to accomplish a simultaneous and consolidated impact of91

the several variables model on LCC outcomes and rankings. Finally, no tendency of specific values was
detected as probability distribution was not assigned to the variables. As shown in Table 4, the sensitivity
analysis of discount rate causes an increase in total cost. This increase is 41%, 43.2% and 44.8% for 3, 4 and5 percent discount rate respectively.
Table 4- Discount rate sensitivity analysis results
Minimum PCI

Maintenance

Crack Sealing
75

Spray Patching

Slurry Seal
Thin Overlay
TOTAL COST
Crack Sealing
Spray Patching
65
Slurry Seal
Thin Overlay
TOTAL COST

NPW 3%(10000$)
47.50
67.70
78.50
73.20
121.00119.90369.00876.80
48.90
67.70
73.20
101.30113.10156.50318.30440.601319.60

2500
2000

NPW 4%(10000$)
48.40
77.50
94.30
76.80
149.60132.10434.901013.60
50.30
77.50
76.80
118.20122.10188.00357.40550.201540.50

NPW 5%(10000$)
49.30
88.60
113.1080.60
184.70145.40511.701173.40
51.80
88.60
80.60
137.80131.90225.50400.90685.701802.80

Δ= 53.6%
Δ= 52%
Δ= 50.5%

1500

PCI 75
PCI 651000
500
0NPW 3%

NPW 4%NPW 5%

Figure 4- Differentiation of maintenance delay in various discount rate (10000$)

Results for the Probabilistic Method
Probabilistic LCCA was performed using L2C3A2 with 5,000 iterations. Figure 5 shows the risk
assessment of NPV for two PCI alternatives at a minimum acceptable level, namely PCI 75 and PCI 65,
where the probability is the area below the curve. The whole range of possible results is displayed with theevaluated probability of every result actually happening. There is no assumption that a specific option isbetter. The fundamental advantage of histogram is that it demonstrates variability about the mean. The wider
distribution shows a larger variability. As can be seen in Figure 5, the result for Alternative II (PCI 65) is
more uncertain than that of alternative I. The cumulative risk assessment for maintenance cost activities isgiven in Figure 6. As can be seen, there is a 40 percent probability that the maintenance cost for Alternative I(PCI 75) will be less than $1,000,000 and a 40 percent probability that Alternative II will be less than92

$1,500,000. This means that for the 5,000 iterations processed, 40 percent of the computed values for NPV isless than $1,000,000 when maintenance activities are carried out one year earlier (PCI 75). A steeper
cumulative slope means that variability is lower while flatter slope indicates greater variability. Since theslope for Alternative II is steeper than that for Alternative I, Alternative II has a higher variability than
Alternative I.

Figure 5- NPW histogram for PCI 75 and PCI 65
With regard to the consequence of making a decision based on risk assessment outcomes, decision
makers need to characterize the level of risk the agency could endure. Stakeholders who could afford lower
risk prefer a small spread in conceivable outcomes, with a greater probability associated with favourable
results. Decision makers who are risk-takers would accept a wider spread, or acceptable variation, in the
distribution of the result (Walls and Smith, 1998).

Figure 6- Cumulative risk assessment for PCI 75 and PCI 65


Environmental Assessment
Air pollution associated with the various maintenance alternatives were calculated using L2C3A2.
The input needed to run the environmental assessment at different acceptable PCI, namely NOx, SOx, andparticulate matter (PM), is presented in Table 5. All the data in this part is borrowed from Rahman and
Tarefder (2012). As shown in Table 6 the result of postponing maintenance activities for only one year (PCI
75 to PCI 65) is an increase of 67.5% in emission.

93

Table 5- Environmental analysis inputs for different schedule of maintenance activities
Minimum
PCI

Maintenance
Activity
Crack Sealing
Spray Patching
Slurry Seal
Thin Overlay
Crack Sealing
Spray Patching
Slurry Seal
Thin Overlay

75

65

Area
Applied(m2)
250,000
125,000
250,000
250,000
250,000
125,000
250,000
250,000

AverageThickness
(mm)
3
6
15
25
3
6
15
25

Density(ton/m3)

No. ofApplication

1.09
1.60
1.60
2.38
1.09
1.60
1.60
2.38

3
2
1
1
2
2
2
2

Volumeofwork (m3)
2250
1500
3750
6250
1500
1500
7500
12500

Table 6- Environmental assessment of different maintenance schedule activities(Rahman and Tarefder, 2012)
Minimum PCI

75

65

Maintenance
Activity
Crack Sealing
Spray Patching
Slurry Seal
Thin Overlay
Overall
Crack Sealing
Spray Patching
Slurry Seal
Thin Overlay
Overall

SOx
(ton)
74.70
49.77
124.47210.56459.5049.80
49.77
248.95421.13769.65

NOx
(ton)
19.16
12.78
31.95
54.08
117.97
12.77
12.78
63.91
108.16
197.62

PM
(ton)
3.21
2.13
5.34
9.03
19.71
2.14
2.13
10.68
18.06
33.01

4 CONCLUSION
One of the most important assets of a country is its airport network, which should be managed andmaintained with satisfactory schedule and condition. The advanced pavement management frameworkprovides a precise and systematic process for keeping track of the inventory of pavement infrastructure,monitoring pavement construction, determining the right maintenance for each pavement alternative with asuitable schedule, planning and funding of airport pavement preservation exercises, and assessing the costeffectiveness of previous pavement preservation activities.
Delaying preventive maintenance for only one year leads to an increase of approximately 52% inlife cycle cost and 67.5% in life cycle assessment of airport pavements. However, it should be noted thatpreventive maintenance in developing countries still is being based on required to do (reactive) basis.
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96

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Safety effectiveness of surface treatment: A comparison of
Empirical Bayes and Naïve before and after study

TRACK
AUTHOR

Nasreen HUSSEIN
CO-AUTHOR(S)(Capitalize Family Name
Rayya HASSAN

E-MAIL(for correspondence)

POSITION

PhD student
POSITION
PhD Engineering/SeniorLecturer

ORGANIZATION

Swinburne University ofTechnology
ORGANIZATION

Swinburne University ofTechnology
nhussein@swin.edu.au, rahassan@swin.edu.au,

COUNTRY

Australia
COUNTRY
Australia

KEYWORDS:
Include up to 5 keywords: Safety Effectiveness, Surface Treatment, Signalised Intersections, Safety Performance
Function, Empirical Bayes

ABSTRACT:In a metropolitan region in Australia, 136 signalised intersections were identified to have been subjected to surface
treatment/resurfacing over the period 2005-2010. In this study the safety effectiveness of treatment was evaluated usingNaïve (simple) before-after study and Empirical Bayes (EB) approach. The results of Naïve before-after study indicatedthat there was a statistically significant reduction in crash rate for all crash severity levels (casualty, high severity andother injury) at 95% confidence level. For conducting EB method a reference group was used to apply Negative
Binomial regression and develop safety performance (SPF) function for three different crash severity levels andpredicting the expected number of crashes at treated sites. The results showed that there was a reduction in total casualty
crashes by 21.3%, high severity crashes (fatality and serious injury) by 15.3% and other injury crashes by 21.4%.

97

Safety effectiveness of surface treatment: A comparisonof Empirical Bayes and Naïve before and after study
Nasreen Hussein1, Rayya Hassan1
1Swinburne University of Technology, Melbourne, Victoria, Australia
Email for correspondence, nhussein@swin.edu.au, rahassan@swin.edu.au

1 INTRODUCTION
To evaluate the change in safety performance on a roadway facility after implementation of a safety
treatment several methods can be used. The most commonly used method is before and after study (Hauer,
1997, Elvik, 2002). Harwood et al. (2002) stated that there are three common approaches for evaluating
safety effectiveness: Naïve or simple before-after study, before-after study with comparison group andbefore-after study with Empirical Bayes (EB) method. The primary goal for all these methods is to compare
observed crash data for before period with crash data in the after period for same roadway facility (Hauer andPersaud, 1983). The simplest technique for conducting such comparison is Naïve or simple before-after
study, where crash rate in the before period is compared with crash rate in the after period (Hauer, 1997).
However, this method does not account for regression to the mean (RTM) bias and traffic volume change.
RTM which is the most serious problem is the tendency of sites with an unusually high or low crash counts toregress to the mean frequency of crashes in the year following (Gross et al. 2010). This phenomenon arises
when sites are selected based on their historical crash records (Hauer, 1997, Shen and Gan, 2003, Gross et al.
2010). The EB method for before and after study has been developed to control for RTM problem (Hauer,
1997, Hauer et al. 2002). The idea behind this method is to evaluate the effect of a treatment i.e. the change
in safety performance at a treated site. This can be done by comparing the expected number of crashes for theafter period had the treatment not been implemented with the reported number of crashes during the after
period. This is based on using reference sites with similar traffic and other site characteristics (Hauer, 1997,
Persaud and lyon, 2007, Gross et al. 2010).
A recent study by Sacchi and Sayed (2015) has been conducted to evaluate before and after safety
effectiveness using common Bayesian approaches and to compare the accuracy of these methods. The
authors found that all approaches including Naïve before and after study resulted in small statistically nonsignificant change in crashes in the case of random selection of sites, with the Fully Bayesian (FB) method
providing more precise estimates. However, when sites were selected according to high crash occurrence, thesafety effectiveness index can be biased by 10%, which can have effect on the evaluation (Sacchi and Sayed,2015).
The objective of this study was to evaluate safety effectiveness of the improvements in pavement
surface condition of signalised intersections. The evaluation was conducted using both Naïve and simple
before-after study and EB approaches to estimate the reductions in total casualty crashes, high severity(fatality and serious injury) crashes and other injury crashes. The targeted facility type was 136 treatedintersections and their approaches (the immediate 200 m approach) along which the crashes occurred. These
intersections were subjected to surface treatment, which involved resurfacing with asphalt. The study
objective was accomplished using traffic volume data and crash data of treated sites and reference sites
during the period 2000-2013.

2 LITERATURE REVIEW
Several studies have been conducted to evaluate safety effectiveness of pavement surface treatment
by using different methodologies. However, Hauer et al. (2002) suggested that for addressing problems ofsafety estimation, EB method provides a more precise estimate of the number of crashes and corrects for the
RTM problem. Provided below is a review of a number of before and after studies for evaluating theeffectiveness of pavement surface treatments in improving safety performance.

98Giles and Sabey (1959) evaluated safety improvement of skid resistance before and after resurfacingin the United Kingdom. The authors utilised data for 128 resurfaced sites with skid related crashes and 100
control sites of similar traffic volumes and site characteristics. The crashes were classified into weather
related crashes (dry/wet) and skidding related crashes. The authors reported that resurfacing demonstrated a
reduction in crashes after applying a surface treatment which confirms an improvement in skid resistance.
They found that the average number of total crashes that occurred in wet pavement conditions decreased
from eight to two and the average number of crashes related to skidding decreased from six to two (Giles andSabey 1959). In another before and after study, reported by Kinnear et al. (1984), the authors assessed safety
improvement associated with three high skid resistance treatments at 39 intersections in Sydney, Australia.
Their study included assessing the cost, wet sideways frictional coefficient and crash occurrence at these sites
in comparison with 12 control sites i.e. untreated. Analysis results of crash data three years before and 18
months after treatment indicated that there was an efficient reduction in crashes of 25% at 99% confidence
level for all surfaces after treatment. The authors suggested that providing an adequate level of skid
resistance for surfaces at intersections is associated with a very high benefit cost ratio (Kinnear et al. 1984).
Cleveland (1987) examined safety effect of improving pavement roughness and skid resistance after
resurfacing. The study revealed that resurfacing resulted in a small increase in total crash frequency in rural
areas and a reduction in wet pavement crashes of about 20%. The author related the negative effect ofresurfacing on safety to increased vehicle speed on smooth surfaces after resurfacing. Hauer et al. (1994)
applied EB approach to evaluate the effect of resurfacing on the safety of two-lane rural roads in New YorkState. The results indicated that non intersection crashes increased by 21% for projects involving resurfacing
only. However, safety was improved for projects where resurfacing was accompanied with additional surface
improvements. Lyon and Persaud (2008) conducted a study to evaluate safety effect of improving pavement
skid resistance in New York, USA. The authors used data from intersections (256 treated intersections) androadway segments (118 treated segments) that had high proportions of wet-road crashes and low friction
numbers. With an equivalent number of reference sites, they evaluated safety improvement using EB method.
The results indicated that the improvements in skid resistance produced considerable safety benefits for bothintersections and road segments.
Abdel-Aty et al. (2009) studied the safety effect of 136 resurfacing projects on multilane arterials in
Florida using EB method. With the application of Negative Binomial (NB) regression, 27 Safety
Performance Functions (SPFs) were developed for three different crash groups (total, rear-end and severe)and for three land uses (urban, suburban and rural) using different length groups of 0.5-1.5, 1.5-3 and > 3
miles. For all developed SPFs, speed limit was found to be not significant for severe crashes except for
urban sections less than 3 miles. The results of EB method indicated that total number of crashes increasedby 62% at the treated sites. However, the rear-end crashes reduced by 0.83% and severe crashes reduced by
4.63%. The authors also reported that although there was a slight reduction in wet-pavement related crashes
from 13.88% in the before period to 11.14% in the after period, the reduction could not be directly related toresurfacing and that it could be related to lower rain fall in the after period.
In a before and after study with a comparison group conducted by Pardillo Mayora and Jurado Pina(2009) on 419 resurfaced pavement segments there was a significant reduction (average of 68%) in wetpavement crash rate. Zeng et al. (2014) applied EB approach to evaluate the effect of pavement condition
improvements on the safety of rural two lane undivided highways in Virginia. The results indicated that thetreatment was significant in reducing fatal and injury crashes by 26%. However, it was not effective in
reducing total crash frequency. According to government reports by Candappa et al. (2007), the applicationof different types of intersection treatments such as line marking, geometry, signage, and resurfacing to
reduce the number of crashes and fatalities on Victorian roads (Australia) has been extremely effective over
the years. Many of the applied surface treatments were related to improving surface skid resistance andtexture loss.

3 SITE SELECTION
Two groups of sites were selected for this study namely; treated sites and reference sites. All thesesites consist of granular pavements (crushed rock bases and sub bases) with thin asphalt surfacing or double
coats of sprayed seal.

99

Treated sites: The evaluation was done through a before and after study where only intersections thatwere subjected to surface treatment over the period 2005-2010 were considered. This period wasselected as it was the period over which relevant condition data were available for reasonable time
periods before and after treatment years. This study could be considered fully controlled as the sameintersections were used before and after treatment hence, the only variation was related to surface
condition and all other road related factors that may affect crash occurrence remained unchanged. It is
important to note that the applied treatments do not cover the whole intersection. They may cover theintersection centre, intersection centre and approaches or any of its approaches. The lengths of treatedsections used in the analysis range between 100 m and 500 m. A large number of signalised intersections
that were treated (with a thin layer of asphalt) over the nominated period was identified frommaintenance records. Out of these sites, only those that had crash data for at least 5 years before and aminimum of 3 years after treatment years (NZTA, 2012) were included. The final set of treated sites hada sample size of 136.



Reference Sites: A group of 66 reference sites were selected to match approximately with their pairs oftreated sites in terms of traffic volumes and site characteristics but were not treated during the study
period.

4 DATA PREPARATION
The data collected for studying safety performance of the identified signalised intersections include
the following:Crash data at the treated approach of each site for 5 years before and 3 to 5 years after treatment year
were considered for the analysis. The collected data included all casualty crashes i.e. covering all
severity levels (fatal, serious injuries and other injuries), type of crash (head on, rear etc.), light condition
when they occurred (day or night), road surface moisture condition (wet or dry) and speed limit. Crash
data of treatment year was not included. Crash data was collected from VicRoads (2014) which contains
information on crashes that occurred during the 13-year period of interest (2000-2013) as provided by
the Victorian police. This data was filtered to select only crashes that occurred along the treated section
which could include the centre of intersection only, the intersection centre and its approaches or theapproaches only i.e. immediate 200 m. In other words, those that occurred within a 500 m long section
as shown in Figure 1. This was achieved by using the chainages where crashes occurred. Locatingcrashes to their exact sites helps to achieve more precise results in crash analysis. This would also help in
relating approach variables to crash injury so their effects can be investigated in the analysis (Wang and
Abdel-Aty, 2008). Crash data for all intersections was available for 5 years before treatment years but
for after treatment years, data was available for 3, 4 or 5 years. Crash frequency has been used for safety
evaluation using EB method. However, evaluating safety effectiveness of surface treatment using simple(Naïve) before and after study is based on crash rate analysis.

Traffic volume data for the years before and after treatment covering the same number of years ofavailable crash data. Traffic volume data used in the analysis was in terms of Annual Average Daily
Traffic (AADT) that used the section of the road where the intersection site was located i.e. not peaktraffic at the intersection. Traffic volume data for the relevant years before and after treatment was used
for developing Safety Performance Functions (SPFs) and estimating expected number of crashes at thetreated sites.

The evaluation period of 5 years before and (3-5) years after treatment year was selected as a multiple of
12 months in length to control for seasonal bias in the evaluation (Highway Safety Manual, 2010).

100

Figure 1. Sketch of an intersection and approaches of immediate of 200 m illustrating thetreated length

5 METHODOLOGY
In this study both Naïve or simple before-after study and EB approaches have been used to evaluate
safety performance at 136 intersections (or the immediate 200 m approach) that were subjected to surface
treatment. Both approaches were used to evaluate treatment effectiveness in terms of reducing or changing
crash rate and frequency. Accordingly, three sets of crash data were considered in the analysis and they
include casualty crashes, high severity crashes (fatality and serious injury) and other injury crashes.
To compare the rate of a measurement under different conditions with the same sample and identify
the effect of treatment using simple before and after study, a paired t-test is suggested by Austroads (2009).
However, when the assumptions of normality are not met for paired groups, a nonparametric test is a
powerful alternative test to paired t-test. In Wilcoxon test, intersection crash rate value under the before
treatment condition is paired with the same intersection crash rate value under the after treatment condition.
The differences between crash rate for the before treatment period and after treatment period are computed
and tested using Wilcoxon signed-rank test. The test ranks these differences and assigns a negative sign to theranks when the crash rate before treatment is less than crash rate after treatment and a positive sign when thecrash rate before treatment is higher than the crash rate after treatment. If the positive ranks are much higher
than negative ranks, then crash rates are higher before treatment than after (Gibbons and Chakraborti, 2011).
EB before-after study has been conducted for safety evaluation to account for regression to the mean
bias and time trend. Annual crash data and Annual Average Daily Traffic (AADT) of the reference sites
were used to develop Safety Performance Functions (SPFs) to account for changes in traffic volume. SPFs
were developed for different crash severity levels including total casualty crashes, high severity crashes andother injury crashes separately using Generalised Linear Model (GLM) (Gross et al. 2010). One of thecharacteristics of crash frequency data is that the variance of crash counts is greater than the mean (overdispersion). Milton and Mannering (1998) suggested that the negative binomial regression is an appropriate
predictive model for applying in crash frequency studies to overcome the over-dispersion problem. Several
criteria were used to choose the appropriate probability model for crash data analysis. These criteria are
examining whether the dispersion statistic is greater than one and testing whether the dispersion parameter(α) > 0 using the Lagrange multiplier test. The values of the dispersion statistic (Pearson chi square/degree of
freedom) for the Poisson model with no covariates (intercept only) of 1.77 for casualty crashes, 1.27 for high101

severity crashes and 1.6 for other injury crashes are greater than 1 which suggest that the dependent variable(crash frequency) is over dispersed. In addition, the dispersion parameter (alpha, α) refers to the parameterused in NB2 model to take account of over-dispersion which is assumed to be zero in the Poisson model.
However, the negative binomial model allows it to be greater than zero. The dispersion parameters for NB2
model with no covariates (intercept only) of 0.41 for casualty crashes, 0.434 for high severity crashes and
0.471 for other injury crashes are greater than zero which again indicate that the dependent variable (crashfrequency) is over dispersed. Results of the Lagrange multiplier test for crash data illustrate that the Z-scoretest is 4.75 for casualty crashes, 2.22 for high severity crashes and 4.36 for other injury crashes with a tprobability of P < 0.001 for casualty and other injury crashes and t-probability of P= 0.026 for high severity
crashes. A significant Lagrange test for all crash severity levels indicates that the model dispersion parameteris different from zero. These results prove that the hypothesis of no over dispersion is rejected and the real
over dispersion exists in all data sets. Therefore, casualty, high severity and other injury crash data should bemodeled as negative binomial which is preferred over Poisson model.
Model coefficients were estimated assuming negative binomial error distribution. SPFs aremathematical models that predict crash frequency for each year at sites with similar traffic volumes and othersite characteristics to treatment sites. This SPF is then used to derive the number of crashes predicted attreated sites. Traffic volume is considered the most important factor in crash occurrence (Abdel-Aty and
Radwan, 2000 and Chin and Quddus, 2003) and is used as an explanatory variable in crash modification
factor (Lord and Persaud, 2000 and Lord and Persaud, 2004). Accordingly, the SPF for this study is based on
total traffic volume entering the nominated approach (where crashes occurred) of each intersection per year
in a reference group. By using relevant information (crash frequency and traffic volume) from both treated
and reference sites, the expected number of crashes at treated sites can be estimated. The detailed procedureof EB method described in Highway Safety Manual (2010) has been followed to evaluate safety effectivenessof pavement surface treatment expressed in percentage change in crashes. The steps followed are summarisedin the Appendix.

6 EVALUATION RESULTS AND DISCUSSION
The evaluation results of treatment effect on safety improvement at signalised intersections for bothNaïve and EB before and after study are presented in the following sections.
6.1 Naïve or simple before-after study results
The Wilcoxon signed-rank test is used to evaluate statistical significance of the changes in crash
rates for all the three crashes categories namely total casualty, high severity and other injury crashes.
Descriptive statistics of crash rate for all crash severity levels before and after treatment periods are shown in
Table 1. The test results are summarised below for each crash category.
Casualty crashes: Table 2 of Wilcoxon ranks shows that in 89 out of 136 cases, positive ranks aremuch higher than negative, which indicates that the rates for crashes were higher before treatment than after(Gibbons and Chakraborti, 2011). Also, the table provides the exact two-tailed p-values for the statistic W(Wilcoxon). Clearly the test shows that the difference between casualty crash rate before treatment (Mean=
5.34, SD= 5.19) and crash rate after treatment (Mean= 3.77, SD= 3.68) is statistically significant (p=0.000).
High severity crashes: Table 2 also shows that for high severity crashes, in 68 out of 136 cases
positive ranks are again higher than negative. This indicates that the rates are higher before treatment thanafter. Wilcoxon test results show that the difference between crash rate before treatment (Mean= 1.64, SD=2.18) and crash rate after treatment (Mean= 1.27, SD= 1.59) is statistically significant (p=0.026).
Other injury crashes: the same test was applied to other injury crashes only and showed that in 88
out of 136 cases, positive ranks have greater rank than negative, which again indicates that the rates werehigher before treatment than after. The results of Wilcoxon test show that the difference between crash rate
before treatment (Mean= 3.84, SD= 4.17) and crash rate after treatment (Mean= 2.47, SD= 2.51) is
statistically significant (p=0.000).

102

Table 1. Descriptive statistics for crash rates in before and after treatment period

Crash Severity
Casualty crash rate before
Casualty crash rate afterHigh severity (F&SI) crash rate before
High severity (F&SI) crash rate after
Other injury crash rate before
Other injury crash rate after

N

Mean

Min

Max

SD

136
136
136
136
136
136

5.33793.76991.63911.27383.83712.4724

0.00
0.00
0.00
0.00
0.00
0.00

32.48
22.83
17.41
11.42
28.54
11.42

5.19277
3.67628
2.18239
1.591814.172992.51007

Sum ofRanks

Wilcoxon
test, Sig.
(2-tailed)1357.50.000

Table 2. Positive and negative ranks

Crash Severity
Casualty crash rate before
Casualty crash rate after

N

Mean
Rank

Negative
30a
45.25
ranks
b
Positive ranks
89
64.97
Ties
17c
Total
136
High severity (F&SI) crash
Negative
43a
54.72
rate before
ranks
High severity (F&SI) crash
Positive ranks
68b
56.81
rate after
Ties
25c
Total
136
Other injury crash rate before
Negative29a
42.64
Other injury crash rate afterranks
Positive ranks
88b
64.39
Ties
19c
Total
136
a. Crash rate before treatment < Crash rate after treatment
b. Crash rate before treatment > Crash rate after treatmentc. Crash rate before treatment = Crash rate after treatment

5782.502353.00.026

3863.00

1236.50.000

5666.50

6.2 Empirical Bayes before-after study
Summary statistics for treated sites (136 sites) and reference sites (66 sites) used in this study areprovided in Table 3. The table includes descriptions for crashes in the three categories namely total casualty,
high severity and other injury crashes for both treated and reference sites. It is important to note that the meanvalue of AADT entering each intersection approach of treated sites is approximately similar to that of thereference sites.

6.3 Safety performance function development
Data from reference sites were utilized to develop the SPF for different crash severity levels
including total casualty crashes, high severity crashes (fatality and serious injury) and other injury crashes
separately using Generalised Linear Model (GLM). Model coefficients were estimated assuming negative
binomial error distribution. The SPF for this study is based on total traffic volume entering the nominatedapproach (where crashes occurred) of each intersection per year in a reference group. By using relevant103information (crash frequency and traffic volume) from both treated and reference sites, the expected numberof crashes at treated sites can be estimated.

Reference Sites

Treated sites

Table 3. Summary statistics for treated and reference sites

Crash Frequency

Mean

Min

Max

SD

Casualty before
Casualty afterHigh Severity before
High Severity after
Other Injury before
Other Injury after
AADTentering before
AADTentering after
Casualty before
Casualty afterHigh Severity before
High Severity after
Other Injury before
Other Injury after
AADTentering before
AADTentering after

9.96
7.43
2.90
2.51
7.05
4.90
12864.90
13485.33
9.02
8.21
2.64
2.56
6.38
5.65
13395.3
13864.8

0.00
0.00
0.00
0.00
0.00
0.00
1600
1600
0.00
0.00
0.00
0.00
0.00
0.00
3420
4495

44.00
32.00
12.00
18.00
36.00
22.00
27136
28250
31.00
28.00
11.00
10.00
21.00
22.00
29135
30250

8.63
6.90
2.99
2.86
6.76
4.81
5537.16
5686.13
6.37
6.25
2.26
2.25
4.81
4.69
6038.626175.75

The primary model form for all SPFs used in this study is:(1)
where:
Nspf = Estimated crash frequency per yearα, β = Regression coefficients
AADT = Annual Average Daily Traffic in veh/day
Results of NB regression for developing SPF for all three crash severity levels are provided in Table
4. The results indicate that the parameters are significant at 95% confidence level. Overall the results indicatethat NB model fits the data well and is a suitable predictive model for applying in SPF development. The
dispersion parameter of 0.374, 0.42 and 0.419 for total casualty, high severity and other injury crashes,
respectively are greater than zero which indicate that the dependent variable (crash frequency) is overdispersed in all three models. Furthermore, the value of deviance of 1.149, 0.996 and 1.125 and Pearson chi
square of 0.951, 0.995 and 0.963 for total casualty, high severity and other injury crashes, respectively
obtained from the goodness-of-fit criteria are close to the ideal value of 1 which supports the use of NB
model.
Necessary yearly factors as SPFs multiplier are applied to Equation (1) to account for time trend in
EB approach as shown in Equation (2).
(2)
where:
Npredicted = Predicted crash frequency per year for each site
Yearly Factor = Yearly correction factors to account for time trend104

Table 4. Results of SPF model development for all crash severity levels

Crash Severity

Parameters

Total Casualty
Estimated value(standard error)
0.303 (0.128)*0.000027 (0.000008)*

Intercept
AADTentering
Dispersion
0.374 (0.076)
Parameter
Deviance
1.149
Pearson chi square
0.951* Significant at 95% confidence level

High Severity(F & SI)
Estimated value(standard error)-0.748 (0.196)*
0.000016 (0.000013)*

Other Injury
Estimated value(standard error)-0.123 (0.148)*
0.000033 (0.00001)*

0.420(0.186)

0.419 (0.101)

0.966
0.995

1.125
0.963

These SPFs multiplier are derived for different crash severity levels for each year before and after
treatment. They are estimated as the total number of observed crashes divided by total number of predictedcrashes for a given year (Highway Safety Manual, 2010) as shown in Tables 5.
Table 5. Applied yearly factors for all crash severity levels

Treatment
year
2005*
2006
2007
2008
2009
2010
Treatment
year
2005
2006
2007
2008
2009
2010
Treatment
year
2005
2006
2007
2008
2009
2010

1st
Year
2.83
0.95
1.52
0.68
2.17
0.6

1st
Year
2.46
1.21
1.86
0.89
1.64
1.48

1st
Year
2.64
0.81
1.4
0.61
2.13
0.9

Casualty crashes
Years Before treatment
2nd
3rd
4th
5th
1st
Year
Year
Year
Year
Year
1.84
2.09
1.48
2.09
2.46
1.05
0.63
0.95
1.23
1.69
1.69
1.22
1.09
1.30
1.82
0.91
1.59
1.59
1.25
1.36
1.85
1.39
2.00
1.60
2.21
1.92
1.18
1.03
1.48
1.43
High severity crashes (F & SI)
Years Before treatment
2nd
3rd
4th
5th
1st
Year
Year
Year
Year
Year
2.46
0.70
1.06
1.76
2.58
1.21
0.60
0.60
0.60
1.50
1.12
0.87
0.99
1.12
1.24
0.89
1.30
0.81
1.14
0.65
1.76
1.29
0.82
1.06
1.76
1.48
2.11
2.53
1.27
2.10
Other injury crashes
Years Before treatment
2nd
3rd
4th
5th
1st
Year
Year
Year
Year
Year
1.88
2.64
2.07
2.07
1.88
0.81
0.97
0.97
1.62
1.62
1.99
1.40
1.13
1.40
1.99
1.04
1.65
2.00
1.30
1.57
2.01
1.44
2.64
1.88
2.46
1.02
1.01
0.90
0.91
2.04

2nd
Year
1.84
2.11
0.96
0.91
1.89
1.43

Years After treatment
3rd
4th
Year
Year
1.97
1.23
0.86
1.48
1.00
1.00
0.97
0.80
1.52
0.62
1.43

Years After treatment
2nd
3rd
4th
Year
Year
Year
2.58
2.58
1.06
2.11
0.91
0.91
0.99
1.73
0.74
0.65
0.64
0.65
1.76
0.94
0.94
0.63
0.63

2nd
Year
1.51
2.10
0.84
1.22
1.93
2.03

Years After treatment
3rd
4th
Year
Year
2.07
1.32
0.97
0.97
0.73
1.06
1.13
0.70
1.66
0.80
0.90

5th
Year
1.23
0.98
1.17
1.14

5th
Year
1.06
0.60
0.99
0.65

5th
Year
1.32
0.97
1.40
1.57

*Example: For a treatment that is applied in 2005, the years before treatment are: 2004 (1st year), 2003 (2nd year), 2002
(3rd year), etc. For after treatment years, they are: 2006 (1st year), 2007 (2nd year) and so on.

105To account for the difference in duration between before (5 years) and after (3-5 years) periods, theadjustment factor ri is recommended by Highway Safety Manual (2010) and is calculated as given by
Equation 5 in the Appendix. This factor is the sum of the annual SPF predictions for the after period divided
by the sum of these predictions for the before period. The result, after using this factor, is the expected
number of crashes for the after period had the treatment not been implemented. The overall results obtained
from EB approach to evaluate safety effectiveness of pavement condition improvement following treatment
are given in Table 6.
Table 6. Results of safety effect evaluation by EB before-after study
Parameters

EB Results

Crash Severity

Total Casualty

Number of intersections

136

High
Severity(F & SI)
136

1010

341

667

1282.94402.21

847.82

0.787

0.848

0.787

983.34239.57559.25

0.787

0.847

0.786

Safety Effectiveness = 100 × (1- OR)

21.3%

15.3%

21.4%

Var (OR)

0.00098

0.003160.00140.0313

0.056

0.037

95% Confidence Interval= OR±1.96× SE (OR)0.72~0.85*

0.74~0.96*

0.71~0.86*

SE (Safety Effectiveness)= 100× SE(OR)

3.13

5.56

3.75

Abs[Safety Effectiveness/SE(Safety Effectiveness)]

6.8*˃2.0

2.75* ˃ 2.0

5.71*˃2.0

Total number of crashes observed in the after period

Other Injury
136(Nobserved,A)
Total number of crashes expected in the after period
had the treatment not been implemented.
(Nexpected,A)
Treatment effectiveness in the form of odd ratio for
all sites, OR'
Var (Nexpected, A)
Unbiased estimate of treatment effectiveness, OR(Crash Modification Factor, CMF)

SE (OR) =* Significant at 95% confidence level

For total casualty crashes evaluated in this study, the value of OR (Highway Safety Manual, 2010)
which is also referred to as Crash Modification Factor (CMF) is 0.787 with a standard error of 0.0313. For
high severity crashes, the CMF is 0.847 with a standard error of 0.056 and for other injury crashes, CMF is0.786 with a standard error of 0.037. The CMF is significant (less than 1) at 95% confidence level since the
95% confidence interval of (0.72~0.85) for total casualty and (0.74~0.96) for high severity (fatality andserious injury) crashes and (0.71~0.86) for other injury crashes does not include 1. This means that it is atleast 95% certain there is a reduction in crashes after pavement surface treatment (Gross et al. 2010). The
absolute value of the measure, Abs [Safety Effectiveness/SE (Safety Effectiveness)] for all total casualty,
high severity and other injury crash categories is greater than 2.0 which confirms that the treatment effect issignificant at the (approximate) 95% confidence level (Highway Safety Manual, 2010). These evaluation

106

results indicate that there is a reduction in total casualty crashes by 21.3% with a standard error of 3.13%, and15.3% with a standard error of 5.56% for high severity crashes. The evaluation results also showed that otherinjury crashes were reduced by 21.4% with a standard error of 3.75%.

7

SUMMARY OF FINDINGS AND CONCLUSION

This paper evaluates the safety effectiveness of pavement surface treatment for 136 signalisedintersections. The authors acknowledge that many studies have been performed on the relationship of surface
condition and safety and the beneficial effects of resurfacing. The reported studies used different approaches
in data collection, different condition parameters and adopted different statistical techniques for analysis.
This is in addition to using appropriate distribution function (NB), following a number of relevant tests. In
this study, a different approach is used in that using existing data collected for other purposes i.e. it is anobservational study as it did not include collecting field data for a fully controlled study. It is acknowledgedthat the changes in driver behaviour and vehicle characteristics over time are impossible to control.
However, during the study period for each site used herein, the variations in these factors are expected to belimited. Additionally, a systematic approach has been adopted in selecting the sites to ensure that limited
variations in possible contributing factors have occurred. Most importantly, the geometry of intersections,
speed limits and signal phasing and timing stayed constant. This means that some of the results could be
affected by the uncontrolled factors. Since it is not a fully controlled study, the results can be considered
indicative and not exact. Results indicated that for the types of crashes assessed/considered herein,
resurfacing has a positive effect on reducing them. The results are discussed in detail in section 6. The
findings from the safety evaluation of resurfacing described in this paper can be summarised as follows:
1- Results of Naïve or simple before-after study using nonparametric Wilcoxon Signed Rank test
indicated that the difference between crash rate before and after treatment for all crash severity
levels (casualty, high severity and other injury) were statistically significant at 95% confidence
level. However, it is not obvious what is the percentage of reduction due to the treatment and whatpercentage is due to the contribution of other factors that changed during the time.
2- The Empirical Bayes (EB) is a state of the art evaluation method in before and after study to find thecrash modification factor and account for regression to the mean bias and traffic volume change
through developing SPFs. Results of EB approach revealed that the treatment effect in improving
safety at the selected sites is significant at the (approximate) 95% confidence level in reducing total
casualty crashes by 21.3%, high severity crashes (fatality and serious injury) by 15.3% and otherinjury crashes by 21.4%.

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Harwood, D. W., Elefteriadou, L., Hauer, E., Rabbani, E., Richard, K. R., Torbic, D. J., Potts, I., andBauer, K. (2002). Safety effectiveness of intersection left-and right-turn lanes. Federal Highway
Administration, Turner-Fairbank Highway Research Center, McLean, Va.
Hauer, E. (1997). Observational Before/After Studies in Road Safety. Estimating the Effect of Highway
and Traffic Engineering Measures on Road Safety, Pergamon/Elsevier Toronto.
Hauer, E., Harwood, D., Council, F., and Griffith, M. (2002). Estimating safety by the Empirical Bayes
method: a tutorial. Transportation Research Record. Journal of the Transportation Research Board, 126131.
Hauer, E., and Persaud, B. (1983). Common bias in before-and-after accident comparisons and its
elimination. Transportation Research Record, No. HS-036 204.
Hauer, E., Terry, D., and Griffith, M. S. (1994). Effect of resurfacing on safety of two-lane rural roads in
New York State. Transportation Research Record: 1467.
Highway Safety Manual. (2010). American Association of State Highway and Transportation Officials(AASHTO). Washington, DC.
Kinnear, D., Lainson, L., Penn, H. (1984). An Evaluation of Four Pavement Treatments in Sydney in
Relation to Crash Reduction, Skid Resistance and Cost. 12th Australian Road Research Board
Conference, 27-31 August 1984 Hobart, Tasmania, Australian Road Research, 12(3), 1-17.
Lord, D., and Persaud, B. (2000). Accident prediction models with and without trend: application of thegeneralized estimating equations procedure. Transportation Research Record: Journal of theTransportation Research Board, 1717 (1), 102-108.
Lord, D., and Persaud, B. (2004). Estimating the safety performance of urban road transportation
networks. Accident Analysis & Prevention, 36 (4), 609-620.
Lyon, C., and Persaud, B. (2008). Safety effects of targeted program to improve skid resistance.
Transportation Research Record, Journal of the Transportation Research Board, 135- 140.
Milton, J., and Mannering, F. (1998). The relationship among highway geometrics, traffic-related
elements and motor-vehicle accident frequencies. Transportation, 25, 395-413
NZTA, New Zealand Transportation Agency. (2012). High-risk intersection guide-consultation.
Pardillo Mayora, J. M.,and Jurado Pina, R. (2009). An assessment of the skid resistance effect on traffic
safety under wet-pavement conditions. Accident Analysis & Prevention, 41,81-886.
Persaud, B., and Lyon, C. (2007). Empirical Bayes before–after safety studies: lessons learned from two
decades of experience and future directions. Accident Analysis & Prevention, 39, 546-555.
Sacchi, E., and Sayed, T. (2015). Investigating the accuracy of Bayesian techniques for before – after
safety studies: The case of a no treatment evaluation. Accident Analysis & Prevention, 78, 138-145.
Shen, J., and Gan, A. (2003). Development of crash reduction factors: methods, problems, and researchneeds. Transportation Research Record: Journal of the Transportation Research Board, 50-56.
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Rural, Two-Lane Highways. Transportation Research Record: Journal of the Transportation Research
Board, 45-52.
APPENDIX
Empirical Bayes (EB) before and after safety effectiveness evaluation steps:
1. Select a group of reference sites with approximately similar traffic and site characteristics to treatedsites which have not been treated during the study period.
2. Develop Safety Performance Function (SPF) using Negative Binomial (NB) regression based on datafrom reference sites.
3. Estimate the predicted number of crashes for treated sites based on SPF for each year in the before
period.
(1)
(2)

108

Where: Nspf = Predicted number of crashes estimated by SPF.
AADT= Annual Average Daily Traffic Entering Intersection
Yearly Factor = Yearly correction factors to account for time trend
4. Estimate the expected number of crashes for the entire before period for treated sites.
(3)
where
W = the weighted adjustment for each site for the before period(4)andN expected, B = Expected number of crashes for treated sites for before periodk= Over dispersion parameter from NB regression for the SPF model
5- Estimate the predicted number of crashes for treated sites in the after period based on SPF developed.
6- Calculate the adjusted factor ri to account for the difference in duration between before and after
periods at each site.
(5)
7.

Estimate the expected number of crashes for the after period had the treatment not been
implemented.

8.

Estimate the treatment effectiveness for each site

(6)
(7)
(8)
9.

Estimate the treatment effectiveness in the form of odd ratio for all sites, OR'(9)

10. Calculate the adjustment for an unbiased estimate of treatment effectiveness, OR(10)

11. Estimate overall unbiased safety effectiveness(11)
12. Calculate the variance and standard error of odd ratio, Var(OR) and SE (OR)

(12)

(13)
13. Estimate the standard error of safety effectiveness(14)
14. Evaluate the statistical Significance of the estimated safety effectiveness by determining whether theAbs [Safety Effectiveness / SE (Safety Effectiveness)] is greater than 2.0. If this measure is greaterthan 2.0 it means that the treatment effect is significant at 95% confidence interval.

109

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Active Traffic Management with Congestion mitigation Tools in JapanTRACK
AUTHOR(Capitalize Family Name)
Jun Takeuchi
CO-AUTHOR(S)(Capitalize Family Name
Toshiyuki Oka
E-MAIL(for correspondence)

POSITIONManager

POSITION
Traffic Engineer

ORGANIZATIONNEXCO-Central

COUNTRYJapan

ORGANIZATIONNEXCO-Central

COUNTRYJapan

j.takeuchi.aa@c-nexco.co.jp

KEYWORDS:
Active traffic management, Traffic congestion, Congestion mitigation tool, VMS, Traffic squad

ABSTRACT:NEXCO-Central (Japan) has introduced “Active Traffic Management” (ATM) with the leading-edge technology that iswell structured to actively manage traffic flow and then carry out all the process automatically, reduce congestion, andsecure safety. Through our traffic control centers, on-site information such as traffic accidents, congestions, weather
conditions, road defects, fallen objects, and lane closures are collected real time and 24/7. Then, this information areappropriately processed and effectively delivered using wide range of mediums.
As one of ATM, we have effectively developed congestion mitigation tools for increasing traffic capacity anddistributing traffic demand. Regarding tools for increasing in traffic capacity, we have introduced “variable message
signs” (VMSs) for alerting reduced speed as well as network expansion, ETC installment, and road widening. The result
showed that approximately 5% of traffic congestion was reduced in a certain section after appropriate deployment ofmobile VMS with their display indicating cautions. Regarding distribution of traffic demand, proactive congestion
prediction and real time information provision have been introduced to encourage drivers to change their choices oftravel time and route. The result brought by proactive congestion prediction applied during a holiday season, with whichcongestion prediction is provided on a time-zone basis so that drivers can easily learn the rough travel time to theirdestinations, showed that approximately 5% of traffic congestion was reduced in a certain section, using the roadpricing, the giveaway campaign, and the issue of guidebook notifying a peak period. As a real time information
provision which is a reactive approach, various VMSs have been prepared between Interchanges, at every exit, toll gate
entrance and general road connecting to an expressway. Also graphic travel time signs are available when drivers havechoices of the route. Furthermore, in order to collect accurate road information promptly, we own and operate welltrained traffic squads for expressway patrol by ourselves, who play an essential part in collecting information andsecuring smooth traffic.
In this paper, our “Active Traffic Management” (ATM) is described focusing on our traffic control center, congestion
mitigation tools applied and traffic squads.

110

Active Traffic Management with
Congestion Mitigation Tools in Japan1

Jun Takeuchi

NEXCO-Central, Aichi, Japanj.takeuchi.aa@c-nexco.co.jp

11.

Overview

NEXCO-Central operates approximately 2,000km of expressways with Japan’s heaviest traffic
volume roadway connecting three major Japanese metropolitan regions that together produce more than 50
percent of Japan’s gross domestic product (GDP). In order to operate these expressways safely and reliably
with high-quality service and ensure the vitality of Japan’s economy, leading-edge construction, operations
and maintenance technologies are essential under severe regional conditions of central Japan such as thediverse climate and geography, dense population and high traffic volume. Due to these unique regional
conditions, continuous efforts have been made in traffic management field not only to offer safety to drivers
but also to alleviate traffic congestion.
In this paper, one of our efforts, which is “Active Traffic Management” (ATM) is describedfocusing on our traffic control center, congestion mitigation tools applied and traffic squads.

2.

ATM’s purpose

There have been three primary purposes in introducing ATM. 1st is providing accurate information
to “every single driver”, 2nd is encouraging drivers to use expressways wisely by offering choice ofalternative routes, and 3rd is leading positive social effects such as declining accidents, alleviating congestion,
reducing CO2 emission, and improving customer satisfaction. To reach these objectives, we have made use of
ATM with the leading-edge technology, that is well structured to actively manage traffic flow and then carryout all the process automatically, reduce congestion, and secure safety. Through our traffic control centers,
on-site firsthand information such as traffic accidents, congestions, weather conditions, road defects, fallen
objects, and lane closures are collected real time and 24/7. Then, information is appropriately processed andeffectively delivered through wide range of mediums such as variable message signs (VMSs), mobile VMSs,
advisory radio. Furthermore, as one of ATM, we have effectively developed a variety of congestion
mitigation tools, making use of this information.

3.

Traffic control center

Our traffic control centers, which are located in four regional areas operating approximately 500km
respectively, play a key role in making ATM work effectively. In close conjunction with theMaintenance/Customer Service Centers, the functions of the traffic control center include monitoring all roadconditions and equipment operation, dealing with the incidents immediately, and providing real-time
expressway-related information, and as a result minimizing the negative effects on the smooth traffic andrecovering the expressway to the ordinary condition as soon as possible. It also coordinates with theExpressway Traffic Police Unit, Fire Department, and other safety and support agencies, and functions
around-the-clock to ensure that expressways are constantly safe and reliable by dispatching tow truck,
maintenance teams, ambulances and fire trucks. To minimize the negative effects such as secondary
accidents and further expansion of traffic congestion and then recover expressways as soon as possible, thetraffic control centers’ systems feature automatic and prompt information dissemination. Figure 1 illustrates
the road information flow centered on the traffic control center.

111

Although mobile devices are becoming popular as ways to obtain and disseminate incident
information, from the view point of higher reliability and accuracy of information, utilizing the traffic control
center is more indispensable. Furthermore, considering the importance of traffic control centers for securingsmooth traffic and safety, we have had a recovery system in case of emergency, meaning that if one of thecenters break down due to earthquake and inclement weather, another traffic control center which is
integrated with others complements the disabled center.

Figure 1. Road Information Flow
As for equipment for information collection and transmission, we actively collect the roadinformation with multiple devices such as vehicle detector (traffic counter), meteorological observatories
monitoring the temperature, the wind and the rainfall, and emergency telephones. Recently the latest
equipment such as CCTV cameras and image processing traffic counters have been installed in certain major
expressways. CCTV cameras automatically detect vehicles’ speed, parked vehicles and wrong-way driving
vehicles on expressways and image processing traffic counters automatically detect traffic congestions andcalculate the number of vehicles in traffic. Figure 2 shows the pictures of the applied equipment. The
collected information is transmitted to the center and provided to the drivers with various systems, including
VMS, advisory radio, and Information Kiosk.

Figure 2. Road equipment for information collection

4.

Traffic congestion in Japan

In order to build suitable congestion mitigation tools, we need to identify the causes of congestion inadvance. The causes of congestion in Japanese expressways are described in Figure 3. 60% of causes occur at
uphill and sag, 18% at tunnel entrances and 13% at merging sections. Therefore, the ratio of bottleneck inJapan occupies 90% of causes, meaning that most of congestions are caused by bottleneck. To solve thisproblem, we have used primarily two types of congestion mitigation tools, the increase in traffic capacity andthe distribution of traffic demands.

112

Figure 3. The cause of traffic congestion in Japanese expressways

5.

Congestion mitigation tools

5.1 Increase in traffic capacity
First mitigation tools aim to increase in traffic volume, and they consist of two types, hardware andsoftware. As for a hardware type of changing road length and structures, four mitigation tools including the
network expansion, the ETC installation, the road widening, and the shoulder use, have been implemented.
As for a software type of deploying equipment on expressways, VMSs for alerting reduced speed have beenused at uphill, sag or non-recurring congestion point. Especially in urban areas with limited right-of-way, thehardware type with which road length and structures have to be changed according to the design could be
difficult to introduce. Therefore, the needs in the software type such as VMSs for road operators operatingurban or narrow areas are expected to be increased. Figure 4 shows congestion mitigation tools for increasein traffic capacity applied by NEXCO-Central.

Figure 4. Congestion mitigation tools for increase in traffic capacity
5.1.1 Shoulder use
In order to increase the traffic capacity, we have considered a tool to effectively use a road shoulder
as a traffic lane. We have temporarily operated the shoulder use in a certain section with heavy traffic volume113

of over 100,000 vehicles per day on the Tomei Expressway. Originally this traffic volume was the largest
among our 4-lane expressway and the congestion was constantly observed during rush hours. After theshoulder use was conducted, we obtained the incredible outcome that the congestion was reduced by 94%
and the number of accidents was reduced by 30% (Figure 5). Moreover, since the shoulder has become
narrowed from 3m to 0.75m after operation, the traffic safety measures were simultaneously applied to thissection such as limiting the driving speed and installing the emergency parking space.

Figure 5. Example of temporary shoulder use and its effect5.1.2 Variable Message Sign (VMS)
Take a look at an example of the bottleneck notification using VMSs at a tunnel. These purposes areto alert speed reduction caused by distracted driving and to encourage quick restoration of driving speed.
Figure 6 shows how to place the VMSs and to prevent reduced speed of vehicles around the bottleneck of thetunnel. The displays of VMSs show messages of “Congestion End 1 or 2km Ahead” at 1 and 2km before theend of congestion, followed by blinking messages of “Congestion Ends at Tunnel Exit” and “Restore Speed”
at the tunnel entrance. Finally, blinking messages of “Congestion Ends” and “Restore Speed” are displayed at
the end of congestion again to remind the drivers. These displays help drivers realize the accurate location of
the congestion end. By applying this method, the annual traffic congestion volume (km/h) has been reduced
by up to 5% (Figure 7).
Although both fixed and mobile VMSs have been used, one of our features is mobile VMS. When
we are not able to place the fixed sign or non-recurring congestions are found, this mobile VMS will betemporarily applied at any point on -site. VMSs become a helpful equipment for any road operator to take anaction for congestion mitigation tools. Figure 8 shows the example of fixed VMS displaying “Restore
Speed”, and Figure 9 shows the example of mobile VMS which is a vehicle with LED information to display“Restore Speed”.

114Figure 6. Use of VMS at a tunnel

Figure 8. Fixed VMS

Figure 7. Effect of VMSs

Figure 9. Mobile VMS

5.2 Distribution of traffic demand
Second tools aim to distribute traffic demand, and they consist of a software type. This software
type is classified into three mitigation tools including the proactive congestion prediction, the real time
information provision, and the reduction in traffic regulation. By using these three tools selected according toeach cause of congestion, it is expected to encourage drivers to change their choices of travel time and route.
Figure 10 shows congestion mitigation tools for distribution of traffic demand applied by NEXCO-Central.

Figure 10. Congestion mitigation tools for distribution of traffic demand115

5.2.1 Proactive congestion prediction
As a proactive congestion prediction, where congestion prediction is provided on a time-zone basis
so that drivers can easily learn the rough travel time to their destinations, we employ the road pricing thatchanges the toll by peak time and off-peak time (Figure 11), the giveaway campaign, meaning that we offer
giveaway to drivers passing during expected off-peak time, and the issue of a special guidebook at a peak
period during a holiday season with predicted congestion information calculated based on the past data
(Figure 12). The drivers are able to use this information to avoid the rush hours. With these approaches, wehave successfully reduced the congestion by 5% in a certain section (Figure 13).

Figure 11. Concept of road pricing

Figure 12. Giveaway Campaign

Figure 13. Effect of proactive congestion prediction
5.2.2 Real time information provision
5.2.2.1 Variable message sign (VMS)
As for real time information provision, we employ a variety of VMSs to change the traffic flow by
notifying real time information to every driver and then making every driver avoid coming closer to a traffic
congestion area. One of the features is travel time signs, with which recently the travel time, which adds
general travel time into the travel time passing current events based on the traffic counter data or the past data
can be displayed. Also, map-based graphic travel time signs have been adopted to achieve better userfriendliness especially for elderly people and enables drivers to select the most appropriate route, lead to thedestinations in a short time and eventually balance the traffic volume. At present, these information provided
by road operators are still more accurate, reliable, and efficient to control the traffic behavior than mobile
apps, which can be one of the popular notification tools. Figure 14 shows examples of VMSs applied by
NEXCO-Central.

116

Figure 14. Examples of VMSs
Table 1 shows the locations and objectives by VMS types in Shin-Tomei Expressway which was
newly opened to traffic in 2012. The key thing is that all drivers are able to receive the information whichenables them to select the most appropriate route and pay careful attention to incidents on the way wheneverthey need. Therefore, locations of VMSs and contents of displays have to be determined so that the
maximum effects can be produced.

Table 1. Location of VMSs
5.2.2.2 Other Information provision
A variety of information dissemination media provide every single driver with the traffic
information. For example, “Vehicle Information and Communication Systems (VICS)” provides thegraphical traffic information with the drivers through the car monitors. “Highway advisory radio” isbroadcasted along expressways, which provides the information before Interchanges. Traffic information isprovided through “Our Mobile Website” and “Information Kiosk” at rest areas. Furthermore, “Japan Road
Traffic Information Center” collects the traffic information nationwide and provides them through radio,
telephone and the internet, updating them every 5 minutes. Figure 15 shows a variety of information
dissemination media used by NEXCO-Central.

117

Figure 15. Information dissemination media

5.3 Reduction in traffic regulation
5.3.1 Intensive maintenance operation
Since regulating traffic flows on heavy traffic expressways can cause congestions, we have adopted
the intensive maintenance operation to avoid traffic regulations, which control the movement of vehicles forsafe traffic flow by restricting usable lanes, and to reduce congestions. That is to say, we have conductedshort-term concentration of improvement and maintenance works instead of long-term separated
improvement and maintenance works. As a result of this operation on the Tomei Expressway during two
weeks in 2013, the number of traffic regulations was reduced by 40% from approximately 3,400 to 2,100,and then the number of traffic congestion was reduced by 70% from approximately 1,400 (assumed) to 450(Figure 16, 17).

3,370

1,360
2,140

Figure 16. Effect on the number of traffic regulation

6.

450
Figure 17. Effect on the number of traffic congestion

Traffic squad

In order to collect accurate road information promptly, we own and operate well-trained trafficsquads by ourselves, which play an essential part in information collection along with other equipment.
However, our traffic squads’ role is not only to collect road information, but also to control traffic flow andprovide roadside assistance. The key role of traffic squads is to patrol on the expressway 24/7 to deal with theincidents such as traffic accidents, disabled cars, falling obstacles as well as to check pavement and road118

equipment. When traffic congestion occurs due to incidents, traffic squads notify the caution to drivers
behind with an LED display mounted on a patrol car. Figure 18 shows traffic squads with patrol cars andequipped items they have on-site. Their role of keeping the expressway in a safe, secure and smoothcondition is different from police officers, who enforce over-speed and illegal vehicles based on the law.

Figure 18. Traffic Squads with patrol cars and equipped items
When receiving a call from a driver in an accident, we notify the nearest traffic squads withdedicated digital radio and make an urgent request on rushing to the scene. They make an instant decision onrequired emergency vehicles and materials, and then request them to the traffic control center.
Spontaneously, they regulate the lanes to alleviate the negative effects on the traffic. Furthermore, they guidethe injured drivers and passengers into the safety area to avoid the secondary accident. Figure 19 shows
traffic squads’ activity against an accident on-site.

Figure 19. Traffic Squads’ activity against an accident on-site
Another important role of traffic squads is to pick up fallen obstacles on expressways. For example,
the big tool box and tires dropped from vehicles are extremely dangerous. Traffic squads run and pick up the
obstacles before severe accidents occur. More than 24,000 fallen obstacles were annually removed under the
direction of one traffic control center. Figure 20 shows traffic squads’ activity of picking up fallen objects.

119Figure 20. Traffic Squads’ activity of picking up fallen objects

7.

Conclusion

In our active traffic management (ATM), the traffic control center with state-of-the-art technology
has been established and promptly and accurately collect and provide road information for all drivers. Using
this information, a variety of congestion mitigation tools have been carefully considered and implemented
on-site. As a result of utilization of these tools at the congestion areas, these tools have brought the positive
outcomes of reducing traffic congestion by increasing traffic capacity and distributing traffic demand.
Besides, traffic squads also play an important role in working ATM effectively by collecting on-site
information and securing smooth traffic.
We strongly believe that our ATM which are well organized with a variety of technologies andresources helps road operators keep safe, reliable and comfortable expressways by collecting and offering
accurate information of the incidents and congestion ahead to every driver and as a result leading the
reduction on traffic congestions and smooth traffic.
8. REFERENCE
 Xing, J. (2010). Effective Congestion Mitigation Tools on Expressways. Meeting for Reading
Research Papers, Express Highway Research Foundation, Tokyo.

120

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
PAPER TITLE

TRACK
AUTHORABUDINEN, Daniel E.
CO-AUTHOR(S)FUENTES, Luis G.

CARVAJAL MUÑOZ,Juan S.
Reyez, Oscar

E-MAIL(for correspondence)

DEVELOPMENT OF THRESHOLDS FOR TRAVEL QUALITYASSESSMENT IN COLOMBIAN URBAN ROADS
Asset Management
POSITION

MSc. Civil Engineering

ORGANIZATION

Universidad del Norte

COUNTRY

Colombia

POSITIONORGANIZATIONCOUNTRY

Head of Department of Civil
and Environmental
Engineering
Professor
Department of Civil andEnvironmental Engineering
Professor
Department of Civil andEnvironmental Engineeringlfuentes@uninorte.edu.co

Universidad del Norte

Colombia

Universidad del Norte

Colombia

Universidad Militar
Nueva Granada

Colombia

KEYWORDS:
Travel quality, International Roughness Index, comfort, urban roads.

ABSTRACT:
Users’ perception of travel quality constitutes a relevant parameter for determining the quality of roadinfrastructure. Therefore, establishing numerical values to quantify this parameter is imperative for theassessment and management of road networks. The International Roughness Index (IRI) has been widelyused for this purpose. However, some limitations in using the IRI in urban roads have been identified as aresult of the speed at which is modeled (80 km/h), which does not represent typical urban conditions.
Subsequently, the main objective of this research study was to establish thresholds for IRI based upon the
Weighted Vertical Acceleration (awz) parameter as an aid to assess the users’ perception. The proposed
methodology allows one to establish maximum allowable IRI values for a given road based on its operational
speed. The results indicated that IRI thresholds are in agreement with international and local Colombianstandards.

121Development of Thresholds for Travel Quality
Assessment in Colombian Urban Roads
MSc. Daniel Abudinen
PhD. Luis G. Fuentes
MSc. Juan S. Carvajal Muñoz
Universidad del Norte. Km 5 Vía Puerto Colombia, Barranquilla, Colombia.
E-mail for correspondence: lfuentes@uninorte.edu.co

1

INTRODUCTION

The quality of a countries´ road network has a relevant impact on the economic development, asthese provide communication links that allow the displacement of both citizens and essential commercial
products. In this sense, the road network represents one of the most important aspects of infrastructure
investments which represent a large share of the city budget, hence, decisions associated with its maintenanceand rehabilitation must be taken under well-defined technical parameters.
Currently, management decisions taken for the maintenance and rehabilitation of urban roads aremostly based on experience rather than well-defined on the basis of technical information and economic
projections over time. Over the last two decades, a conceptual change has been applied in Colombia withrespect to: the quality of roads, maintenance criteria of road infrastructure and considerations on the role ofsafety and comfort of users of the network. Therefore, roadways must not only provide an adequate initialservice, but also guarantee a suitable service condition during the projected design period, which requires abalance between the technical and economic components. Thus, both administrators and engineers should
exercise caution when road investments are planned, and these must be supported by the functional andstructural conditions of existing roads and projected traffic requirements.
Moreover, a pavement should provide a stable and secure surface for users, which will have aperception about the quality of travel, typically quantified by means of the serviceability index, which isdefined as the ability of a pavement to provide a service to users, ensuring comfort and safety conditions forthe traffic for which it was designed. Research has concluded that serviceability is affected to a great extent
by the surface irregularities of the pavement, namely the roughness (Hass, Hudson, & Zaniewski 1994;
Moore, Clark, & Plumb 1987). Moreover, there are different parameters to quantify the roughness of apavement, among those, the most important and widely used is the International Roughness Index (IRI),
introduced in 1986 by the World Bank, after previous efforts from a project funded by the National
Cooperative Highway Research Program (NCHRP). IRI relates the accumulation of the relative verticaldisplacement in absolute value, from the upper to lower mass of a quarter car vehicle type called "Golden
Car", divided by the total distance traveled at a constant speed of 80 km/h. The Golden Car is typically
named Quarter car model, which is characterized by five constants: C s (suspension damping rate), Ks(suspension spring rate), Kt (tire spring rate), Ms (sprung mass) and, Mu (unsprung mass). The model accounts
only for displacements in the vertical direction (Cantisani & Loprencipe 2010).
In spite of the various advantages and applicability of IRI, some investigations have shown that IRI
has some limitations when used in assessing travel quality in urban roads. One of these is due to the speed ofdynamic simulation (Quarter car model at 80 km/h), which does not represent the operating condition on
urban roads, in which typically lower speeds are used (25 to 50 km/h). In addition, urban roads havesingularities related to: 1) short sections, in general no longer than 100 meters; 2) intersections; 3) signage
and, 4) vehicle traffic. All these variables have an impact over IRI measurements made by laser type highperformance vehicles. Additional references regarding limitations of IRI on urban roads are available
elsewhere (ISO 1997; ASTM 2009; Papagiannakis 1997; Papagiannakis 1998; Papagiannakis & Raveedran
1998; La Torre et al. 2002; Rayya & Kerry 2003; Nemmers et al. 2006).
In addition to restrictions of IRI for urban roads, previous research has identified some drawbacks
associated with the use of laser devices for measuring IRI at vehicle operating speeds in urban roads. In thisregard, high-performance lasers are widely used worldwide and have been used for more than 30 years;

122however, there are still deficiencies in the systems that remain a research topic (Nemmers et al. 2006).
Research has shown that changes in the longitudinal gradients adversely affect the accuracy in measuring the
profile and the accuracy of the high performance devices when operating at low speeds (Choubane,
McNamara, & Page 2002; Gagarin, Mekemson, & Lineman 2003; Karamihas & Sayers 1998; La Torre et al.
2002; Reggin, Shalaby, Emanuels, & Michel 2008). According to Sayers and Karamihas (1998), this inertial
equipment requires specific speeds for proper operation. For example, these do not operate well at speeds
lower than 15km/h. Furthermore, Gagarin, Mekemson and Lineman (2003) recommend that these type ofequipments must operate at constant speeds near 40 mph (64 km/h). In practical terms, ensuring these
optimum conditions in urban road becomes a challenge in terms of keeping constant and high speeds due tothe presence of intersections and traffic interactions. Moreover, Karamihas (2005) stated that certain highperformance devices have difficulties in calculating IRI in textured concrete pavement, which lead torepeatability and reproducibility issues. In response to this issue, improved laser sensors have recently beenused for improving the accuracy, reproducibility and repeatability.
Based on the limitations for IRI for assessment of travel quality in urban roads and the need for
defining alternative parameters for its evaluation, this investigation aimed at developing specific thresholds
that reflect the quality of urban road pavements for different operating speeds and provide indication on thetravel quality experienced by the users of a local road network in Colombia.
2

REFERENCE METHODS FOR CALCULATING IRI THRESHOLDSAs presented in previous sections, the current concept of a standardized IRI does not adequately
represent the operating conditions of urban roads since it is based on a dynamic model (Quarter Car Model)that uses 80 km/h as reference speed which, in turn, is higher than the speeds at which vehicles circulate in acity. As a result, this section focuses on previous research performed to account for this and other limitationsof the use of the IRI in urban roads.
Yu, Chou and Yau (2006) proposed threshold levels of IRI for different operating speeds. These
thresholds were defined from the changes of vertical acceleration of a vehicle named “Jolt”. 102 profiles
were selected in rural roads from the Strategic Highway Research Program (SHRP) Long-Term Pavement
Performance (LTPP) database from 1989 to 2002. The authors also stated that different values of “Jolt” arepresented for the same level of roughness IRI, determining the values of acceptance of IRI from a normal
distribution. Table 1 shows the thresholds proposed by the authors.
Table 1. Suggested IRI thresholds for various operational speeds (Yu, Chou and Yau 2006).
Travel Quality

IRI thresholds for various operational speeds (m/km)
120 km/h

100 km/h

80 km/h

70 km/h

60 km/hVery Good

<0.95

<1.14

<1.43

<1.63

<1.9

Good

0.95 – 1.49

1.14 – 1.79

1.43 – 2.24

1.63 – 2.57

1.90 – 2.99

Fair

1.50 – 1.89

1.80 – 2.27

2.25 – 2.84

2.58 – 3.25

3.00 – 3.79

Mediocre1.90 – 2.70

2.28 – 3.24

2.85 – 4.05

3.26 – 4.63

3.79 – 5.40

Poor

>2.70

>3.24

>4.05

>4.63

>5.50

50 km/h

40 km/h

30 km/h

20 km/h

10 km/hVery Good

<2.28

<2.86

<3.8

<5.72

<11.44Good

2.28 – 3.59

2.86 – 4.49

3.80 – 5.99

5.72 – 8.99

11.44 – 17.99

Fair

3.60 – 4.54

4.50 – 5.69

6.00 – 7.59

9.00 – 11.39

18.00 – 22.79

Mediocre4.55 – 6.25

5.70 – 8.08

7.60 – 10.80

11.40 – 16.16

22.80 – 32.32

Poor

>6.25

>8.08

>10.80>16.16>32.32

Similarly, Ahlin and Granlund (2001) stated that, under some circumstances, IRI does notadequately describe the roughness of a road under vehicle-specific operational conditions. The authors also
indicated that under some conditions (normal operating conditions of urban roads), IRI does not adequately

123

describe the users’ ride quality and comfort. As a result, a methodology established by the ISO 2631 standard
was proposed as an alternative evaluation. In particular, the ISO 2631 standard defines a procedure formeasuring the vibrations perceived by a passengers’ body during the journey on a vehicle: some vibrations
are generated by the irregularities of the road, which are translated into vertical accelerations perceived by
the passenger (Ahlin & Granlund 2002).
In the ISO 2631 standard: Evaluation of human exposure to whole-body vibration (ISO 1997), a
widely used methodology for evaluating the effects that occur on the human body due to vibration exposure
is presented: basic evaluation method using quadratic weighted average acceleration awz. This acceleration is
also known as vertical weighted RMS acceleration (frequency-weighted root mean square acceleration). Thisparameter is mainly used in occupational health and risk exposure assessments to the effect of vibration.
Table 2 shows threshold values for awz for public transportarion according to the ISO 2631 standard.
Table 2. Threshold Values for awz for public transportation in accordance to ISO 2631 standard
awz (m/s2)

Users’ comfort level< 0.315

Not uncomfortable

0.315 – 0.63

A little uncomfortable

0.5 – 1.0

Fairly uncomfortable

0.8 – 1.6

Uncomfortable1.25 – 2.5

Very uncomfortable> 2.0

Extremely uncomfortable

ISO 2631 standard was developed by the International Organization for Standardization (ISO) and isregarded to as a standard model adopted by several countries in the globe. For instance, some adaptations arepresented as follows:• Spain (UNE-EN ISO 5349-1): Mechanical Vibrations: Measurement and evaluation of human
exposure to vibration.
• Portugal (NP ISO 2631-1): Vibrações mecânicas e choque - Avaliação da exposição do corpo
inteiro a vibrações.
• Ecuador (NTE INEN ISO 2631): Mechanical vibration and shock. Assessment of human exposure
to vibration throughout the body.
• United Kingdom (BS 6841): Measurement and evaluation of human exposure to whole-bodymechanical vibration.
• Colombia (NTC 5435-1): Mechanical vibration and shock. Assessment of exposure of humans tovibration throughout the body.
Furthermore, a recent research focused on rural roads developed statistical correlations between IRI
and awz, allowing for assessments of comfort when travelling on a pavement (vertical vibrations due toacceleration) (Ahlin & Granlund 2001; Ahlin & Granlund 2002; Cantisani & Loprencipe 2010; Hou Liang,
Ma, & Wanghua 2009; Zhang & Yang 2010). More specifically, Ahlin and Granlund (2002), proposed amodel defined on Equation (1) to determine the comfortable vehicle speed -CVS- from the limit values of
acceptance of awz.
2

CVS = 80 (IRI 1−n)5(1)Where:CVS: comfortable vehicle speed, km/h.
IRI: International Roughness Index, mm/m.
n: amplitude parameter for the terrain roughness.

124

The n parameter values typically ranges between 1,1 and 2,5. The n value is high for roads where thewave amplitude of the prevailing pavement is long and conversely, the n value is low for a given road when
the dominant wave amplitude pavement is short, as in the case of a deteriorated road.
According to Zhang and Yang (2010), RMS weighted vertical acceleration is directly related totraveling comfort perceived by the drivers and users of a road network. In accordance to ISO 2631, awz is
calculated from vertical accelerations obtained in the Quarter Car simulation. The subsequent steps tocalculate the parameters are:
1.
2.
3.

The RMS acceleration of the mass of the passenger (aRMS
iz ) is calculated in terms of the Power Spectral
Density for each ith octave thirds band.
aRMS
values are multiplied by its weight factor (WK), for each frequency band.
iz
After these values are obtained (aRMS
and WK), the RMS can be determined from the square root of theiz
sum of squares of these values as shown in Equation (2):RMSa wz = √∑23
i=1(Wk,i ∗ a iz )2(2)

Where:
Wk,i : factor for each frequency band weight.
aRMS
iz : RMS Vertical acceleration of the mass corresponding to the passenger.
Similarly, Hou Liang, Ma and Wanghua (2009) evaluated the correlation between the International
Roughness Index and Body Ride Comfort, concluding that the road displacement frequency power spectrum
densities (evaluated in terms of awz) are not necessarily correlated to the IRI. Nevertheless, this research study
attempted at developing additional correlations to validate the authors’ findings as further shown in the paper.
More recently, Cantisani and Loprencipe (2010) provided direct correlations between IRI and awz for
different vehicle operating speeds focusing on rural roads. 124 pairs of profiles of rural roads were used (124footprint left and 124 footprint right), which were collected by the Strategic Highway Research Program(SHRP) Long-Term Pavement Performance (LTPP) of the Transportation Research Institute at the Universityof Michigan (1998). Initially, IRI was evaluated according to the standard procedure described by ASTM andcalculated the average of each pair of profiles as indicated on Equation (3).

𝐼𝑅𝐼 =𝐼𝑅𝐼𝑙𝑒𝑓𝑡 +𝐼𝑅𝐼𝑟𝑖𝑔ℎ𝑡
2(3)Then, the awz parameter was determined from the model simulations with Quarter Car, where theaccelerations in the front passenger seat were taken. This calculation for acceleration was performed using
different simulation speeds from 30 km/h to 90 km/h in increments of 10 km/h.
Additional research has been conducted in the Colombian context by the Urban Development
Institute (IDU) in Bogota, 2007. The study included an inventory of the surface quality of 842 kilometers ofpavements in different sectors of the city using a high-performance laser device, which measured IRI withoutchanges in traffic real conditions. The results showed excessively high IRI values (average of 7.63 m/km)
that are consistent with those for pavements with significant surface irregularities.

3.

FIELD EVALUATIONS OF IRI IN COLOMBIAN URBAN ROADS

Measurements on several road sections constituted by rigid pavements were conducted inBarranquilla (Colombia) as shown in Figure 1. In these sections, the surface condition was evaluated byusing IRI on the right wheel path of the right lane.

125Figure 1 Distribution of the pavement sections evaluated in Barranquilla, Colombia.
For collecting the data two (2) devices were used: SurPRO (Figure 2a) and a high performancevehicle (Figure 2b). The SurPRO device is used for measurement of pavement profiles with high accuracy
with a limiting maximum operating speed of 4 km/h (Nazef, Mraz, Scott, & Whitaker 2008). The highperformance Laser Profilometer was used to measure pavement roughness at different operational velocities.

(a)(b)
Figure 2. (a) SurPRO device and, (b) Laser Profilometer.

126

4.

COMPARISON OF IRI MEASUREMENTS FOR SurPRO AND LASER PERFILOMETER

Figure 3 depicts that IRI values evaluated using the SurPRO are consistently lower than thoseobtained using the laser profilometer for all the evaluated pavement sections. The data shown in Figuresuggests that, as the operating speed of the laser profilometer increases, roughness levels approach thoseobtained with the SurPRO. This results highlights the limitations encountered when attempting to evaluate
roughness condition in urban roads using a laser profilometers, since these cannot always operate at highspeeds due, among other factors, to: traffic signs, singularities, traffic lights and interaction with othervehicles.

Figure 3. Comparison of SurPRO and Profilometer IRI-measurements at different speeds.
5.

PROPOSED THRESHOLDS FOR TRAVEL QUALITY ASSESSMENT BASED ON AWZPARAMETER

As a contribution of this research study, thresholds for the International Roughness Index are
proposed. For this purpose, RMS weighted vertical acceleration (awz) is used to estimate the users’ perceptionof accelerations. In this respect, this study-included measurements of 102 urban profiles constituted by rigid
pavements were conducted in Barranquilla using the SurPRO (Figure 2a). Due to the nature of urban roads,
variations occurred in the lengths of the sections evaluated. As depicted in Figure 4a, there is a mathematical
relationship between awz evaluated at 80 km/h and the IRI, which was also calculated using the reference
standard speed of 80 km/h. Nevertheless, as shown in Figure 4a, high dispersion in the dataset was found as
indicated by the low R2 (0.51). Based on the same procedure, trends for each of the awz evaluated using
different simulation speeds are shown in Figure 4b.

127

(a)

(b)
Figure 4. (a) Correlation between IRI and awz parameter at 80 km/h and, (b) correlation between IRI and awz
parameter at evaluated at different speeds.

On the basis of the awz thresholds proposed by Cantisani and Loprencipe (2010), we proposed newthresholds of International Roughness Index using the linear regressions presented above (Figure 4b). Figure
5 depicts the location of the thresholds for 80 km/h. This same procedure was performed for each of theremaining velocities, giving as result thresholds of International Roughness Index - IRI to different operating
speeds (Table 3).

128

1.0
0.8
0.6
0.4
0.2
0.0

Figure 5. awz parameter limits for the assessment thresholds International Roughness Index - IRI.

Table 3. Proposed IRI thresholds for various operating speeds.
Road operating speed (km/h)

Proposed values for IRI (m/km)

Slope(Equation)

R2

Very Good

Good

RegularBad

100 km/h< 0.730.73 - 1.45

1.45 - 2.07

> 2.070.43

0.49

90 km/h< 0.780.78 - 1.55

1.55 - 2.22

> 2.220.41

0.42

80 km/h
70 km/h< 1.04< 1.151.04 - 2.09
1.15 - 2.31

2.09 - 2.98
2.31 - 3.29

> 2.98> 3.29

0.30

0.52

0.27

0.41

60 km/h< 1.54

1.54 - 3.09

3.09 - 4.41

> 4.410.20

0.49

50 km/h< 2.052.05 - 4.1

4.1 - 5.86

> 5.860.15

0.47

40 km/h< 3.233.23 - 6.47

6.47 - 9.24

> 9.240.10

0.52

30 km/hawz Parameter Limit
Values(m/s2)< 5.1

5.1 - 10.19 10.19 - 14.56 > 14.56

0.06

0.48

< 0.3150.315 - 0.63

0.63 - 0.90

> 0.90As presented in Table 3 and Figure 6, higher levels of roughness are permitted in low-speed roads
due to the fact that users will perceive less discomfort as a result of lower vertical accelerations experienced
on the same road while traveling at lower speeds. Conversely, the limits become more demanding as theoperating speed of the road increases. The results shown in Figure 6 may be different from those obtained by
Cantisani and Loprencipe (2010) considering that different road types were used to define the thresholds.
Hence, the discrepancies could be related to the nature of the roads considered for this research (urban roads),
whereas those included in their study, which were highways. In addition, the previous results allow forevaluating roads at different speeds with tighter criteria that provide indication of the comfort level
experienced by the users at different speeds while circulating on the road.
Furthermore, in order to validate the findings of this research, a comparison of the proposed
threshold is made with other regional and local regulation and standards. For this purpose, using theinformation from Table 3 and Figure 6 and selecting 80 km/h as reference speed, an IRI value of 2.98 m/km
is found, which would correspond to a bad road in terms of ridability and users’ comfort. Then, whencomparing this threshold with those proposed in Portugal and Spain by similar research, the values are inclose agreement (2.98 m/km ≈ 3.0 m/km). More specifically, the Colombian standard establishes a maximum

129allowable value of 3.0 m/km for 100% of a given road under a specific traffic level classified as NT2, which
once again, is very close to that found in this research study.

Figure 6. Thresholds for International Roughness Index at different operational speeds.

6.

CONCLUSIONS AND RECOMMENDATIONSThis research is aimed at developing thresholds for assessing travel quality in urban roads. An awz
parameter that accounts for users perception of road quality was used to complement the roughnessassessment which is traditionally based solely on the International Roughness Index (IRI). The main
conclusions of this research are presented below:
Travel speed has a significant impact on the perception of road quality that users have as they travelin a specific pavement section. In particular, it was found that the reference speed used to calculate
the IRI (modelling speed of 80 km/h) is not representative of the actual operating speed in whichusers normally travel on urban roads (30 to 60 km/h). Subsequently, evaluating surface roughness
and users’ comfort should be conducted at specific speeds for specific road types, which in turn,
could provide more realistic data to be used in pavement management systems.

Some deficiencies associated with laser profilers on urban roads were identified as a result of traffic
signs, singularities, traffic lights and interaction with other vehicles that prevent accurate andrealistic measurements of IRI and might induce inappropriate characterization of the surface
roughness. Therefore, the use of high-performance laser equipment on urban roads is recommended
only when very low traffic flow or partial closure of the road is available in order to takemeasurements at the recommended speeds.
Considering that speed is rarely considered as a key parameter in evaluating road quality and users’
perception of ride quality in the local context, an additional contribution of this research is proposed.
Thus, thresholds for International Roughness Index for evaluation of users’ comfort at different
speeds were determined. These thresholds have been developed according to the nature of urban
roads and its wide range of travel speed, which influences different perceptions of pavement surface
quality.

Finally, the proposed thresholds for IRI are congruent when compared with the maximum allowablevalues by international standards and Colombian standards (INVIAS). The thresholds obtained allow not

130only the definition of permissible maximum values for a road section, but also provide insight into theevolution of user comfort throughout the life of the pavement (relationship between IRI and user comfort); so
to determine the ability of a road to increase the operating speed according to IRI values on the road.

7.

ACKNOWLEDGEMENTS

The authors express their gratitude to the Universidad del Norte in Barranquilla, the research project
Diamante Caribe (BPIN: 2014000100012, Contract No 25, May 30 2014), and the research project IMPING-2132 for funding this research.

8.

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Karamihas, S. M. (2005). Critical Profiler Accuracy Requirements: UMTRI-2005-24. The University ofMichigan Transportation Research Institute
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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
PAPER TITLE

SAFETY IMPROVEMENTS TO NATIONAL ROUTE TWO SECTION 27 IN
KWAZULU-NATAL, SOUTH AFRICA

TRACK

Road Safety

AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Ridhwaan Mahomed

Project Manager

South African National
Roads Agency SOC LtdSouth Africa

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Ravi Ronny

Design and Construction
ManagerSouth African National
Roads Agency SOC LtdSouth Africa

E-MAIL(for correspondence)mahomedr@nra.co.za

KEYWORDS:South African National Roads Agency
Decade of Action
Road Safety

ABSTRACT:Road safety is of paramount importance to South Africa. Therefore the South African National Roads Agency has madeit one of its nine strategic objectives. South Africa is regarded to be amongst the highest road fatality countries in theworld. Due to the high number of accidents, the Civil Engineering industry is challenged to improve and retrofit
highways in order to maintain a safe South African road network.
This paper will discuss the strategy adopted to undertake the identification of hazardous curves and improvements madein order to eliminate motor vehicle accidents along the northern part of National Route N2 in the province of KwaZuluNatal, South Africa in the most economical manner. Design proposals will be compared and discussed which will aid in
illustrating why the most favourable option was selected. This paper will also discuss the implementation of a roadsafety audit which ensured an optimum design solution covering all aspects of road safety.

133

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
INTRODUCTION
South Africa is regarded to be among the highest road fatality countries in the world. Due to the increasingly highnumber of road fatalities, in 2015, South Africa was ranked 6 th internationally for fatalities on roads. This is shown
below in Figure 1. (World Atlas, December 2015)

Figure 1. Number of fatalities per country across the globe due to road accidents in 2015
Figure 1 above shows that South Africa is not the only country that experiences a high number of road fatalities and thishas become a global problem. In an attempt to remedy this global problem the General Assembly Resolution 64/255
adopted on 2 March 2010, requested that the World Health Organization and the United Nations regional commissions
in cooperation with the United Nations Road Safety Collaboration and various stake holders, prepare a Plan of Action as
a guideline document to support and assist the drive to reduce road fatalities. This Decade Plan of Action was launchedin May 2011 to assist and attempt to reduce the number of road fatalities globally 2020. In 2011, the global road fatality
toll was approximately 1.3 million according to the Global Plan for the Decade of Action for Road safety 2011-2020.
Road safety is of paramount importance to South Africa. In February 2007 the Minister of Transport and the Health ofAfrican States adopted the Accura Declaration that noted the deteriorating condition of transport infrastructure in Africa
which encouraged member states to use the World Health Organization/World Bank World Report on Road Traffic
Injury Prevention (Geneva, 2004) as a framework or guideline for road safety and implement its recommendations to
reduce the causes and risks associated with road crashes (SARSAM, 2012).
In Figure 2 below the number of road fatalities with South Africa from 2011 to 2015 are shown.

Figure 2. Number of Fatal accidents in South Africa from 2011 to 2015 (Road Traffic management Corporation,
Department of Transport, 2011-2015)134

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
From Figure 2 above it can be seen that in 2011 there were 13945 fatalities and in 2015 there were 10613 fatalities on
South African roads. This is approximately a 24% reduction in the number of road fatalities between 2011 and 2015. It
is evident from the statistics provided above that South Africa has reduced road fatalities from 2011 to 2015 whichcoincides with the objectives of the Decade of Action to reduce the number of crashes by 50% in 2020.
Every accident has an effect to the economy of the country. Table 1 below indicates the average cost of a fatal accident
in South Africa.
Table 1. Average Fatality Cost in South Africa
Average Fatality Cost in South Africa (2015)
City of Cape townreport (2005)

Tshwane- Road Safety
Master Plan Manual(2008)

National Departmentof Transport (2004)

AverageR 1 160 654

R 1 756 342

R 1 213 493

R 1 376 830

The average cost of a fatality is related to the total value of a person that could have benefited the economy of South
Africa over his/her life time. Based on the average cost of R 1 376 830 per fatality in South Africa, the total loss to theeconomy in 2011 was approximately R 19 billion and in 2015 was approximately R 14.5 billion due to road fatalities.
From this it can be seen that there has been a saving of approximately R4.5 billion to the economy due to the reductionin the number of fatal crashes in South Africa. This money can be utilised in various other aspects such as, infrastructuredevelopment, health services, housing, education etc. Hence the reduction in road fatalities is something that willdefinitely strengthen the economy of the country and provide an opportunity for the country to enhance other social
aspects that requires improvement.
South Africa developed a Road Safety Manual (SARSM, 1999) to assist road authorities with the evaluation of traffic
operations and assessment of road safety aspects along the road network nationally. The SARSM was published in 1999
as a draft document and consisted of the following volumes:








Volume 1: Principles and Policies
Volume 2: Road Safety Engineering Assessment on Rural Roads
Volume 3: Road Safety Engineering Assessment on Urban Roads
Volume 4: Road Safety Audits
Volume 5:Remedial Measures and Evaluation
Volume 6: Roadside Hazard management
Volume 7: Design for Safety

Based on the recommendations of the World Health Organisation’s world report on road traffic injury prevention,
countries were encouraged to focus on the following five road safety pillars, namely (Implementing the 2011-2020
Decade of Action in Sub-Saharan Africa, 2010) :






Pillar 1: Road Safety Management
Pillar 2: Safer Roads and Mobility
Pillar 3: Safer Vehicles
Pillar 4: Safer Road Users
Pillar 5: Post-Crash Response

In 1998 the South African National Road Agency SOC Ltd (SANRAL) was established as an independent, statutorycompany with a distinct mandate to finance, improve, manage and maintain the national road network within South
Africa. SANRAL currently manages 21 403 km (2015) of national roads in South Africa. SANRAL’s direct sphere of
influence relates specifically to the Pillars of Safer Roads and Mobility, Safer Road Users, and Post-Crash Response.
For Safer Roads and Mobility reference to road infrastructure interventions relates directly on the road network, for
Safer Road Users reference is made to Road Safety Education and Awareness Programmes, and for Post-Crash
Responses reference is made to the rollout and operations of Road Incident Management Systems on the entire nationalroad network. These are the main focus areas where SANRAL will continue to promote and improve road safety for allroad users.

135

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
In 2005 the Road Traffic Monitoring Corporation (RTMC) was established with the objective of pooling powers andresources to eliminate the fragmentation of responsibilities for all aspects of road traffic management across various
levels of government in South Africa. The RTMC has embarked on a project that focuses on infrastructure safety audits
to promote safer roads which is one of the pillars of the Decade of Action, through the revision of the South African
Road Safety Audit Manual (Volume 4) into a stand-alone South African Road Safety Audit Manual (SARSAM). The
intention for this manual is to be used by all road authorities nationally to conduct road safety audits in order to identify
potentially hazardous locations and implement remedial measures to reduce the number of accidents and fatalities.
For the purpose of this paper, the strategy adopted to undertake the identification of hazardous curves and improvements
made in order to eliminate motor vehicle accidents along the northern part of National Route 2 (N2) in the province of
KwaZulu-Natal will be used as a case study. The location of this case study is shown in figure 3 below.

Figure 3. Locality Map
This section of the N2 has been a notorious area for accidents and fatalities. The section of road has an Average Daily
Traffic (ADT) count of approximately 10,600 vehicles per carriageway of which 12% are heavy vehicles (trucks).
According to accident records, between February 2011 and February 2012, on this section of the N2, there have been 87
vehicles involved in accidents of which 5 were fatalities. This project was therefore identified as a road safety
improvement project to identify hazardous locations and to reduce the accident rate along this section of the N2.
SANRAL appointed a Consulting Engineering Firm to undertake investigations to determine the possible cause of theaccidents and propose possible remedial measures.
METHODOLOGY
The approach and methodology adopted to obtain an optimum solution to the ongoing road accidents will be discussed
under this section of the paper. It should be noted that even though SANRAL was the client and appointed service
providers to undertake the investigations, SANRAL played a fundamental and key role in the management of the service
providers, interpreting the findings and decision making. In this instance SANRAL played the role of the client
including client technical input as well as the overall project manager on this contract.
As part of the investigation SANRAL adopted the following methodology:a) A full Road Safety Audit of the existing road,o Interaction with national and local traffic authorities to obtain accident statistics and information.
o Visual Inspection of the Roado Determine operating speeds/speed profileso Undertake the Road Safety Audit as per SARSAMb) A preliminary design of the proposed safety improvements,o Analyse the existing geometry of the roado Check compliance in terms of design speedo Check compliance in terms of operating speedo Prepare proposals for improvements136

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysiac) A detailed design of the selected proposalo Proceed with selected design proposalo Optimise the solution in terms of costso Finalize design
It should also be noted that as all contracts are governed by a financial budget, it is the responsibility of the Engineer toproduce a financially viable solution. Notwithstanding, this statement should not be interpreted that South Africa and
SANRAL will compromise road safety because of financial constraints. All that is required is that all proposals andsolutions are optimized to eliminate wasteful expenditure.
From the methodological approach as indicated above, it was envisaged that the outcome of such an approach would
enable one to determine the exact locality of the accidents and the potential causes. This approach would also allow
SANRAL to remedy any potential technical factors that may have contributed to accidents.
RESULTS AND ANALYSIS
Road Safety Audit and Visual Assessment of the Road
As part of the road safety audit the initial investigation was to obtain any accident records from national and local traffic
authorities and analyse the existing accident records. Accident records were obtained from three (3) sources, namely: South African Police Services (SAPS) Road Traffic Inspectorate (RTI) – (Road Traffic Police) Intertoll – (Operator of the Toll on this section of the N2)
The SAPS report indicated the number of accidents within the section of road over a length of approximately 15km but
however did not indicate the actual location of the accidents. Table 2 below, shows the statistics from SAPS.
Table 2. Accident Statistics obtained from SAPS
YEAR
2010
2011
2012
2013

NUMBER OF ACCIDENTS
72
120
69
42 (for the 1st half of 2013)

From Table 2 an average of 87 accidents per annum can be expected on this section of the N2. However these records
were not of much help as they were unable to indicate the exact locations of the accidents in order to streamline theinvestigation.
The accident records from the RTI grouped accidents into two (2) locations, namely, uMhlali River Bridge and Mvoti
River Bridge. Accident records for the period 2011 and first half of 2013 are summarised in Table 3 below.
Table 3. Accident Statistics obtained from RTI
LOCATION
uMhlali River
BridgeMvoti River
Bridge

YEAR
2011
2012
2013
2011
2012
2013

TOTAL
7
16
5
5
6
3

FATAL
1
3
0
2
0
1

MINOR
5
7
2
3
1
2

MAJOR
2
9
3
3
5
1

The records obtained from the RTI clearly indicated that these two (2) locations where the problematic areas within thissection of the N2.
The records obtained from Intertoll were for the period between 2009 and 2013. These records were in great detailwhich allowed for a more-in depth analysis. This assisted the analysis of information with more historical data which
resulted in a more accurate position of the locations of the accidents. Fortunately, the records from Intertoll included theexact locations as well. The two (2) locations that were prevalent after analysis was again the Umhlali River Bridge and137

2nd IRF Asia Regional Congress & Exhibition
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the Mvoti River Bridge. Therefore it could be concluded from this initial accident record investigations that these two
locations were the high accident risk zones.
The locations of these two (2) accident zones can be seen in Figure 4 below.

Figure 4. Locations of the Two (2) Accident Zones
Further investigations with regards to the speed profiles along this section of the N2 were undertaken. The results of thiscan be seen in Table 4 below.
Table 4. Indicating Speed Profiles

It should be noted that all the Stations in the Table 4 provide the 85 th percentile speed on the section of the N2 shown in
Table 4 above.
According to the Geometric Design Guidelines of SANRAL, the selected design speed should accommodate the 85 thpercentile desired speed that is likely to materialize. According to the results from the speed profiles these two (2)curves ideally should have a design speed of 120km/h. Detailed surveys were requested to be undertaken in order todetermine the actual horizontal and vertical geometry of the curves. From the survey and further analysis of the curves
in geometric design software one was able to create the exiting geometry of the curves. This clearly showed that the
curves are adequate for a 100km/h design speed but insufficient for 120km/h. It should be noted that this section of theN2 is sign posted at a recommended speed of 100km/h for motorists. So legally the design speed is complaint with thesign posted speed. However, it is evident from the speed profile investigations in Table 4 above that motorists are
exceeding this sign posted speed of 100km/h.
In addition, further investigations were undertaken as indicated in the South African Road Safety Audit Manual(SARSAM). The investigations can be summarised in Table 5 below.

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Table 5. Investigation Summary (SARSM,2012)
ITEM

General Topics

Cross-section and Alignment

SUB-ITEMCOMMENTS

Landscaping and Natural
Vegetation

OK

Headlight Glare

OK

Parking

OK

Temporary Works

N/A

Visibility and Sight DistanceOK for 100km/h but
Not OK for 120km/h

Design Speed and 85th
percentile operating speed

NEEDS ATTENTION

Overtaking

OK

Readability by Drivers

OK

WidthsOK

Batter slopes

OK

Drainage structures

OK

Auxiliary lanes andExclusive Turning Lanes

N/AIntersections-

N/A

Special Road Users-

N/A

Road Signs

OK

Road Marking and delineation

OK

Road Lighting

N/A

-

N/A

Loose gravel

OK

Pavement Defects

OK

Road Signs, Markings,
Delineation and Lighting
Traffic signals
Driver Perception

Pavement

Skid ResistanceOK

Ponding

NEEDS ATTENTION

Table 5 above shows that from the investigations undertaken that two (2) items can potentially be the contributing
factors to the cause of the accidents, namely the Design Speed (85th percentile operating speed) and the Ponding issues
on the pavement that have been identified during site inspections. Ponding was identified within the development of thesuperelevation on both horizontal curves at Umhlali and Mvoti River Bridge
The Road Safety Audit investigation highlighted the following findings:
 Umhlali and Mvoti River Bridge are the 2 locations were accidents occur within this section of the N2
 The exiting curves at these locations were designed with a design speed of 100km/h, and the sign posted speed
is 100km/h
 The speed profile investigation indicated that the operating speeds at both these locations are in excess of
120km/h.
 The curves at Umhlali and Mvoti River Bridge require geometric improvements for 120km/h operating speeds.
 Ponding was evident at these curves.
These findings will be discussed and remedied under the preliminary and detailed design phase.

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2nd IRF Asia Regional Congress & Exhibition
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Preliminary and Detailed Design
For the purpose of the preliminary and detailed design, the SANRAL Geometric Design Guidelines and the G2
Geometric Planning Manual were used. The designs for the safety improvements will concentrate on the curves at
Umhlali River Bridge and the Mvoti River Bridge, as these were identified as the most critical curves were safety
improvements were required. The situational analysis of both curves can be summarised as follows: The speed limit on this section of the road is 100km/hr and is clearly signposted.
 The existing horizontal curve conforms to the design criteria of a 100km/hr design speed.
 The vertical alignments on both carriageways conform to the design criteria for a 100km/hr design speed.
 This section of road has been identified during the initial visual inspections and road safety audit to be anarea of high accident rate and therefore is potentially a safety risk to the road users.
The images of the 2 Curves are shown in Figure 5, 6 and 7 below.

Figure 5. Aerial Photograph of Curves Umhlali and Mvoti

Figure 6. Umhlali River Bridge (South Facing)140

2nd IRF Asia Regional Congress & Exhibition
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Figure 7. Mvoti River Bridge (North facing)
From the investigations undertaken by the geometrics specialist it was discovered that the curve lengths of both curves
were below 190m. According to the SANRAL Geometrics Guideline Manual a desired curve length on freeways shouldbe 3 times the design speed. The existing curves were designed to a design speed of 100km/h. The curve length shouldhave been to a minimum length of 300m. From the information discussed above it if evident that these curves can be
regarded as kinks which is not ideal on a freeway. Hence it was agreed that the curves be redesigned according toacceptable standards as set out in Geometrics Guideline Manual.
The initial proposals for the safety improvements of both these curves were to realign the curves using circular curves at
a design speed of 120km/h. The proposed solution required an excess of 200mm of asphalt to be placed on the bridge
decks in order to accommodate the super elevation development. The super elevation development in the case of acircular is preferable to allow for two thirds of the superelevation development to occur at the tangents (i.e outside thecircular curve) and one third of the development to occur within the curve (TRH 17, 1988). This development will occur
at entry and exit of the curve. This was of concern as this development will have to occur on the bridge decks which
ultimately would require an excess of 200 mm of asphalt in order to accommodate the superelevation development. This
excess 200mm of asphalt will not only affect the structural integrity of the bridge but also the safety standards of thebridge parapets. The parapets have a vertical face of 140mm as shown in Figure 6 below.

Figure 6. Parapet Details

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2nd IRF Asia Regional Congress & Exhibition
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The purpose of the 140mm vertical face is to allow for a surface overlay on the bridge deck of up to 100mm, generally
an asphalt wearing course. The sloped face is very important in that this face is sloped in order to minimize the head on
impact of a vehicle onto the parapet. The angle of the slope allows the impacting tyre of the vehicle to climb up theparapet to a certain point to reduce the impact damage and then reflects the vehicle back onto the lane. In essence it has
important safety advantages and serves an important role in the design of the parapet. Many studies have been
undertaken in this regard and will not be discussed in this paper. Hence allowing the proposal an additional surfacing inexcess of 200mm will definitely compromise the safety of the parapet design as this would reduce the length of thesloped surface which will result in an inadequate parapet design on site.
However in order to accept this proposal , it required a complete structural analysis to determine whether the current
structure is capable of handling the additional dead load of asphalt , which would result in strengthening of the structure
if possible or complete reconstruction. Over and above the dead load issue, all the parapets will have to be demolishedand re-constructed. This proposal initiated a lot of additional costs to the project. SANRAL was of the opinion that
another solution should be explored.
SANRAL advised the service provider to prepare another solution using transition curves as opposed to only using
circular curves as initially proposed. The use of the transition curves will reduce the super elevation development length
as the transition curve allows one to develop the super elevation completely within the curve (Geometric Planning (G2)Manual, 1984). This ultimately allows one to develop the superelevation within the curve and eliminates the problem of
having an excess of 200m asphalt over the bridge decks. With the transition curve option, the overlay on the bridge
decks was reduced to a maximum of 60mm which is acceptable and does not compromise the safety design of theparapets as well as does not impose any additional dead loads that the existing bridge cannot handle. This was possible
as much less of the superelevation development occurs over the bridge.
Ponding was also of great concern on these curves as it was identified during the road safety audit and visualinspections. The actual locations of ponding were observed to be from the centre of the road to the inner side of thecurves i.e. the lowest side of the road through a curve. According to the SANRAL Drainage Manual 6th Edition
published in 2013 the flow depth during a 1:5 year storm should not exceed 6mm. In this case the minimum flow depth
of 6mm was exceeded. In order to eliminate this problem it was agreed to increase the superelevation of the curves to8%, and also to increase the tinning groove depth of the concrete pavement to reduce the depth of flow. Furthermore it
was agreed to also increase the frequency of drainage chutes.
Increasing the superelevation will allow for the surface run-off to flow quicker off the road surface and the increase in
the frequency of drainage chutes will aid in dissipating water of the road prism. In addition the increase insuperelevation will also allow vehicles to take the curve with much more ease as this allows vehicles to track throughthe curve with less centripetal force been exerted.
The ideology behind increasing the tinning depth is to allow for more water to flow within the tinning groove before
reaching the top of the driving surface. This method would reduce the risk of aquaplaning. The disadvantage withincreasing the tinning groove depth is that this will increase the road noise on dry days. This was not of serious concern
as the localities of both these curves are generally remote and away from residential dwellings. However, safety is ofparamount importance and should be highest of priority when compared to the disadvantages of deep tinning grooves in
concrete surfacing. Alternatively, sound barriers could have been considered had it been in an urban area. The final
layout of the curve realignment for each of the areas is shown in Figure 7 and Figure 8 below.

Figure 7. Final Layout of Realignment at Umhlali River Bridge142

2nd IRF Asia Regional Congress & Exhibition
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Figure 8. Final Layout of Realignment at Mvoti River Bridge
CONCLUSION
As highlighted throughout the paper, safety is of paramount importance to South Africa as a country and as well as theSouth African National Roads Agency. With the implementation of the decade of Action and South Africa aligning its
outcomes and objectives to the Decade of Action, it can be seen from the fatality statistics shown in Figure 2 that South
Africa has been successful since 2011 to 2015 in reducing the number of fatalities on their road network by 24%.
Improving the geometric alignment using the transition curve approach to meet the design requirements for a 120km/hr
speed will also provide for a more safe, reliable, effective and efficient road. This obviously was the most suitable andeconomical solution for the safety improvements. In addition this proposal also reduced the construction duration
because of the elimination of structural work to the bridges and the reconstruction of all parapets.
The N2 safety improvement as discussed in the contents of this paper merely showcases one of many safety
improvement projects that are currently being undertaken in South Africa by SANRAL. SANRAL has currently adopted
the policy that all improvement and new construction projects require a road safety audit to be undertaken. Furthermore,close interaction with the Road Traffic Inspectorate as well as the Road Traffic Management Corporation is ongoing as
the Agency in the process of creating a live database that will allow one to identify high accident zones early andimplement remedial measures at a quicker rate.
It should be noted that the improvements adopted at the Umhlali and Mvoti River Bridge were of a technical nature andthat is all that can be done from an engineering point of view. However, many accidents occur due to human error, suchas fatigue, intoxication etc. To target these issues SANRAL and South Africa have implemented awareness throughmedia streams, sign boards along highways to make the motorists aware of the danger.
In conclusion South Africa has placed road safety at the top of its priority and will endeavour to achieve the goal of
reducing the number of accidents by 50% by the year 2020 as set out in the Decade of Action Plan, and various roads
authorities have placed road safety as a strategic objective.
REFERENCES














Implementing the 2011-2020 Decade of Action in Sub-Saharan Africa, 2010
World Health Organisation, World Report on Road Traffic Injury Prevention, Geneva, 2004
National Department of Transport, South African Road safety Manual, 7 Volumes, Pretoria, 1999
South African Road Safety Audit Manual, May 2012
South African National Road Agency, Geometric Design Guidelines
Road Traffic Management Corporation, Department of Transport,2011-2015
City of Cape Town, Traffic Accident Report, 2005
City of Tshwane Metropolitan Municipality, development of Road Safety Master Plans, May 2008
National Department of Transport, the estimation of Unit costs of road Traffic Accidents in South Africa
Contract Report CR-2004/6, March 2004.
www.worldatlas.com/articles/the-countries-with-the-most-car-accidents.html , 23 December 2015
General Assembly Resolution 64/255, 02 March 2010
SANRAL Drainage Manual 6th Edition, 2013
Technical Recommendation for Highways, Geometric Design for Rural Roads, 1988

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PAPER TITLE

Calibration of HDM-4 Road Deterioration Models for Rural Arterials in
Victoria/Australia

TRACK
AUTHOR(Capitalize Family Name)
Bayar MOHAMMED
CO-AUTHOR(S)(Capitalize Family Name
Rayya HASSAN
Nahla ALASWADKO
E-MAIL(for correspondence)

POSITION

PhD student

ORGANIZATION

Swinburne University of Technology

POSITIONDr.
PhD student

ORGANIZATION
Swinburne University of Technology
Swinburne University of Technology

COUNTRY

Australia
COUNTRY
Australia
Australia

bmohammed@swin.edu.aurahassan@swin.edu.aunalaswadko@swin.edu.au

KEYWORDS:
HDM-4, Calibration, Road deterioration, roughness, rutting

ABSTRACT:The highway Development Management (HDM-4) is a powerful pavement management tool capable of performing
technical and economical appraisal and has been adopted by many countries. The purpose of this paper is to report theapproach used in calibrating HDM-4 road deterioration models for both rutting and roughness to suit the conditions ofVictoria’s rural arterial network.
Time series pavement condition data (covering 3 to 5 years) were collected for 29 sections of rural arterials withdifferent lengths covering different road classes (M, A, B and C), traffic volumes, climate zones and subgrade soil
types. The sections were divided into 100 m length segments and only segments that had positive rate of deterioration
were considered in the analysis. These segments were grouped into different combinations of road class, soil type andclimatic conditions, resulting in 31 groups. The results indicate that, the rutting calibration factors are higher androughness calibration factors are lower than the default values of one for class M and variable for classes A, B and C.
The calibrated models have been validated by comparing the observed performance with the predicted performanceobtained from using average group calibration factors and average class calibration factors. It was found that there isgood to very good correlations between the predicted and observed values, when using average group calibration
factors. This indicates that the criterion used for grouping of segments is successful. Also, there is good to very goodcorrelation between the predicted and observed data, when using average class calibration factors.

144

Calibration of HDM-4 Road Deterioration Models for Rural Arterials in
Victoria/Australia
Bayar Mohammed1, Rayya Hassan1, Nahla Alaswadko1
1

Swinburne University of Technology, Melbourne, Victoria, Australia

Emails: bmohammed@swin.edu.au, rahassan@swin.edu.au, nalaswadko@swin.edu.au
1 ABSTRACT
The highway Development Management (HDM-4) is a powerful pavement management tool capableof performing technical and economical appraisal and has been adopted by many countries. The purpose ofthis paper is to report the approach used in calibrating HDM-4 road deterioration models for both rutting androughness to suit the conditions of Victoria’s rural arterial network.
Time series pavement condition data (covering 3 to 5 years) were collected for 29 sections of ruralarterials with different lengths covering different road classes (M, A, B and C), traffic volumes, climate zones
and subgrade soil types. The sections were divided into 100 m length segments and only segments that had
positive rate of deterioration were considered in the analysis. These segments were grouped into different
combinations of road class, soil type and climatic conditions, resulting in 31 groups. The results indicate that,the rutting calibration factors are higher and roughness calibration factors are lower than the default values of
one for class M and variable for classes A, B and C. The calibrated models have been validated by comparing
the observed performance with the predicted performance obtained from using average group calibration
factors and average class calibration factors. It was found that there is good to very good correlations between
the predicted and observed values, when using average group calibration factors. This indicates that thecriterion used for grouping of segments is successful. Also, there is good to very good correlation between thepredicted and observed data, when using average class calibration factors.
2 INTRODUCTION
The highway network provides access and mobility to the industry and communities; therefore, it is
one of the most important infrastructure elements and a major economic asset of any country. A more
efficient network reflects better mobility service and better accessibility. The State of Victoria has the highest
concentration of roads in Australia, and major activity centres are distributed all over the state. These centres
are connected by high quality rural highways categorised into four main classes namely; M, A, B and C whichvary by function, quality and level of service (Vicroads, 2013); a brief description of each is presented below.
Network management requires reliable data and accurate performance models to use for predicting pavement
condition over time. The latter is used with specific intervention criteria to perform gap analysis, develop
short and long term maintenance programs and estimate the budgetary requirements.
 Class M: rural freeways; the main purpose of these roads are connecting Melbourne with othercapital cities and major provincial centres. They have high standard of design and construction, anddivided four lane roads with sealed shoulders.
 Class A: rural arterial highways; they have a similar role to M roads, but carry less traffic.
Generally, they are undivided with two lanes with sealed shoulders.
 Class B: rural arterial highways; their main purpose is connecting the major regions which are notserved by A roads and they are considered to be highly significant tourist roads. They are undivided
two lane single carriageway roads.
 Class C: rural arterial highways; provide important links between Victoria’s rural towns and primarytransport network. They are generally two lanes undivided sealed roads with unsealed shoulders.
The highway Development Management (HDM-4) is a powerful pavement management tool capableof performing technical and economical appraisal. It has been used in more than 100 developed anddeveloping countries that have different technological, climate and economic environments (Bennett andPaterson, 2000). It includes built-in road deterioration models that require calibration to local conditions for
accurate predictions.
The purpose of this study is to calibrate HDM-4 road deterioration models for both rutting androughness to suit the conditions of Victoria’s rural arterial network. The study is focused on calibrating
roughness and rutting road deterioration models, as they are considered the most important parameters for the145reasons highlighted below. Calibration of cracking models is not considered as results from a previous
calibration study, (Toole et al, 2004) are considered sufficient and have be used in this study.
Road surface roughness affects users’ comfort and cost (travel time and delay), vehicle operating
costs and network operation due to its effect on travel speed (Gillespie and Sayers, 1985, Foley,
1999, Loizos and Plati, 2002, Hunt and Bunker, 2004, and Moffatt, 2007, Loizos and Plati,2008). Further, the interaction between surface roughness and heavy vehicles results in dynamic
wheel loads that increase pavement damage (Paterson 1987, Gillepspie et al, 1993, and Mikhail
and Mamlouk, 1997). Roughness is accepted in Australia as the most relevant measure for longterm functional behaviour of pavement network (Haas et al., 1994, Martin, 1996, Foley, 1999 andMoffatt, 2007).
Rutting influences vehicle operation (vehicle tracking), users’ safety (aquaplaning) and is usuallyassociated with other distresses that lead to loss of pavement shape and integrity. These distresses
include transverse shoving, depression, heaving and cracking (Foley, 1999, Morosuik et al, 2004,
and Moffatt and Hassan, 2007).



For Victoria, calibration of these models has been done previously but was not supported by relevantroad agency as the outputs did not match expected performance based on local experience and knowledge of
network performance (Giummarra et al., 2007). Two HDM-4 calibration studies have been done for Victoria
and reported in Tool et al. (2004) and Hoque et al. (2008). In these studies, the HDM-4 models for roughness,rutting and cracking have been calibrated using historical performance data. In Toole et al. (2004) study, 82
separate sections had been chosen from Victorian network covering different road classes, including class M,
A, B and C, and pavement types. Hoque et al (2008) recalibrated the roughness and rutting models using thesame sections, but after excluding the immediate effect of maintenance treatment using a new approachdeveloped by Martin and Hoque (2006). From 82 sections only 55 sections showed positive rate ofdeterioration and had been used in the calibration exercise. Presented in Table 1 are the calibration factors forroughness and rutting models from both studies. They are applicable to classes M, A, B and C roads with
granular pavement and surface treatment (spray seal).
In this study, a new approach for calibrating these models to Victoria’s conditions is used. The
approach includes the following: Development of a representative network of heavy freight routes in rural Victoria with a large sample
size covering different road classes, traffic loading, subgrade soil types and climate conditions.
 Using roughness data from adjusted profile measurements so that same sections of road are actuallycompared over time. Also extracting corresponding rutting and cracking data of these sections fromthe database of relevant authority.
 Using only sections that have positive rate of deterioration for both roughness and rutting to remove
the effect of maintenance.
 Using vehicle fleet composition and loading data that match actual usage of the road classes
considered.
Table 1. Calibration results from previous studies
Road
type

Pavement
type

Traffic
group
Low

A

STGB

Medium
Low

B

STGB

Medium

STGB

Low

STGB

Low
Medium
Heavy

C

1.
2.
3.

Climate group
Dry
Wet
Temperate
Dry
Temperate
Dry
Temperate
Temperate
Wet
Dry
Temperate
Temperate

Rutting Factors (Krst)
Roughness Factors (Kgm)
Toole et al, Hoque et al, Toole et al, 2004 Hoque et al, 2008
2004
2008
2.63
2.13
1.25
0.53
3.00
2.13
0.30
0.26
1.38
0.66
0.30
0.28
0.75
1.40
2.25
1.34
1.53
1.80
0.41
0.44
3.35
3.58
0.95
0.84
3.00
1.58
0.30
0.19
2.37
2.82
0.54
0.33
3.35
1.83
0.55
0.33
0.50
0.48
0.35
0.15
2.67
1.17
0.25
0.36
2.17
1.72
0.42
0.39

Traffic group: low (AADT < 5000), medium (5000 < AADT<15000), heavy (AADT >15000)
Climate group: dry (TMI <0), temperate (0 < TMI <50), wet (TMI > 50)
STGB: surface treatment on granular base146

It is believed that such approach would result in more accurate results. In previous studies a lower
sample size was used and the condition data was extracted from database of relevant road agency. This timeseries data may not represent the actual sections over time as it was extracted from the database of relevantroad agency. It is the result of processing raw longitudinal profiles for different years but without theapplication of proper adjustment to match the actual start and end of each section and ensure that the same
sections are being compared over time.
The study also involved calibrating roughness deterioration model using roughness data extracted
from the database of relevant road agency. They were then compared with those developed using roughness
data from adjusted surface profiles. In addition, the study covers comparison between the study calibration
factors and calibration factors obtained in previous study (Hoque et al., 2008).

3 DATA COLLECTION AND PREPARATIONThis section describes the required data parameters for the calibration study, which include pavement
condition data, traffic data, general network information, and climate data. It also covers data preparation suchas adjustment of longitudinal profile data, matching rutting and cracking data to roughness data chainages,
determining subgrade soil type and extracting climate data. That is in addition to data cleaning and filteringand grouping of pavement segments for calibration.
3.1 Network Selection
The availability of relevant data is a major criterion for the network selection. For this study (29)
freeways and rural arterials with available historical condition data were selected to represent Victoria’s ruralarterial network conditions. These highways are distributed all over the State with variable lengths ranging
from 10 to 128 km. The selected road network consists of 7, 10, 7 and 5 sections from road classes M, A, B
and C, with total lengths of 170.6, 710.8, 571.4, 265.6 km respectively. The total length of the selected
network is approximately 1718 km. These roads are selected to cover approximately all climate zones and soil
types in rural Victoria.
3.2 Data Collection
HDM-4 is a comprehensive and complex system and requires data assembled in an efficient manner.
Data quality and correct interpretation is considered as one of the important key parameters in the applicationof HDM-4, which is necessary for desired reliability of the results. For this study the data required can be
described in the following categories or sets:
 General network information: road type, pavement type, pavement width, shoulder type and width,road side, topography and sub-grade soil type.
 Road condition data: Roughness, rutting, cracking, strength and drainage quality
 Climate data: TMI (Thornthwaite moisture index), rainfall and temperature
 Historical data: pavement age, maintenance history
 Traffic data: AADT and vehicle fleet composition
 Other data relating to HDM-4 input including calibration factors, maintenance standards, and default
coefficient values
All the above data were extracted from relevant road authority databases, except for the following: Roughness data was determined from adjusted raw longitudinal profile data
 Subgrade soil type was identified from Victoria’s expansive soils map
 Climate data (TMI) was extracted from the climate tool as described later Some calibration factors, maintenance standards and default coefficient values were obtained from aprevious study (Toole et al, 2004) and HDM-4 documentation.
3.3 Data Preparation
The required data for the analysis is prepared as described in the following steps.
3.3.1 Roughness
Roughness is a pavement condition parameter and is defined as a measure of irregularities in the
pavement surface (Morosiuk et al, 2004). It affects user’s comfort and perception of ride quality, user’s costand vehicle operating cost and used to predict future network condition (Foley, 1999, Hunt and Bunker, 2004
and Moffat, 2007). Roughness is reported by two units in Victoria, namely, NAASRA Roughness Meter(NRM) in counts/km and the International Roughness Index (IRI) in m/km (Jameson and Shackleton, 2009).

147

The data is used by relevant road agency to trigger investigation into pavement rehabilitation, using certain
intervention levels, together with other performance measures or criteria.
For the sample sections, raw longitudinal profile data were obtained for a number of years, between
1998 and 2010. Each section had available raw longitudinal profile data for 3 or 5 years which were found tovary in their start and end chainages between the different years. This variation may affect the results whencomparing the profile characteristic of the same road over time. Therefore, it was essential to adjust the
profile data for the different years before calculating the roughness data to ensure that the same section of theroad is being compared over time.
The adjustment is done by selecting one year as a reference (usually latest available year) andmaking the required shifting by adjusting the sample interval of the profile data. An in-house Excel-based tool
developed by Evans and Arulrajah (2011) is used for this purpose. The ProVal (Profile Viewing and Analysis)
software (Proval, 2013) was used for viewing the profile data for the different years and deciding on therequired shifts. This software has been used in many studies such as (Chang et al, 2009, Lee and Chou, 2010
and Islam et al. 2014). After ensuring that all profiles are matched, the roughness (IRI) values for both left andright wheel paths are determined using ProVal software for each 100 m segment. This is the recommended
reporting interval in Australia and matches the reporting interval in relevant road authority database forrutting and cracking data.
3.3.2 Rutting and Cracking
Rutting and cracking data of the sample sections are extracted for each 100 m segment from therelevant database, provided by the road agency responsible for managing these roads. This database also
includes corresponding IRI values at different chainages. To match the rutting and cracking data set with theadjusted roughness data, roughness profile from the database for each sample section is matched with its
adjusted roughness profile for each year. Once the two profiles are matched, rutting and cracking values
corresponding to the correct chainages of the adjusted roughness data are selected.
3.3.3 Subgrade Soil TypeThe subgrade provides support to pavement layers and its support depends on the soil type, material
density and moisture content during construction and in-service (Vicroads, 2003, Mann, 2003 and sharp,2009). Over half of the roads in Victoria are built on expansive soils with different degrees of swell potential(Vicroads, 1995). The Majority of Victoria’s rural highway network includes thin granular flexible pavements
built on expansive subgrade soils with different swelling potential levels, and located in different climatic
zones (Hassan et al., 2006). The integrated colour coded map of expansive soils in Victoria produced byMann, (2003) was used to establish the soil type underlying each section. The different colours represent
different soil types with different swelling potential levels. Reactivity of subgrade soils for the selected roads
were determined by plotting the selected road sections on Victoria’s soils map using AutoCAD for precise
location of sections using their start and end chainages. The sample road sections pass through seven different
soil types that have different levels of swell potential from non to high expansive.
3.3.4 Climate Data
Climate is one of the main factors affecting pavement performance. The variation in the moisture
content which is caused by dry and wet periods has a significant effect on the pavement life (Zue et al, 2007).
In expansive soils, seasonal moisture variation changes the volume of expansive soil and makes it become
continually active (Mann, 2003). In this study TMI has been used as an indicator of the climatic condition.
TMI is a number that indicates the relative wetness or dryness of a particular soil climate system(Thornthwaite, 1948). Positive TMI value indicates wet area and negative value indicates dry area.
In this study TMI values for the sample sections are determined using the climate extraction tool
developed by Byrne and Aguiar (2010). The tool is an Excel database that requires inputting a GPS locationin order to access a wide range of historical climate data between 1960 and 2007. In addition, this tool
supplies a range of simulated climate data from 2008 to 2099. This tool has been also used by Sen (2012) for
determining TMI values. The TMI for each 100 m segment over the different years are determined first thenaverage TMI value for each segment is determined as a mean value for the period over which condition data
is available i.e. analysis period. HDM-4 allows inputting one climate zone per section. Furthermore, the dataof mean daily temperature, rainfall and maximum and minimum daily temperature was extracted from Bureauof Meteorology website. This data is required as input in HDM-4.

148

3.3.5 Traffic Data
The average annual daily traffic (AADT) data for the selected sections was extracted from therelevant database for a number of years. The latter includes the years for which the condition data is available,
where possible. The average growth factors for the selected sections were determined form all available dataand have been used for determining traffic volumes of the missing years in the analysis period.
Typical vehicle fleet for each road class was also determined from the traffic data supplied by therelevant road agency. This data was collected using traffic counters at some locations of the sections in thesample. It should be noted that HDM-4 does not allow input of more than one vehicle fleet for all sections in a
network. Hence, a representative fleet composition for each road class was developed from all available datausing the flowing approach.
1. For each site the proportion of each vehicle class shown in Table 2 is determined as the averagevalue over available years.
2. The average of the proportions of that vehicle class over all sites in relevant road class is thendetermined and used as a representative value for the road class.
The vehicle fleets consist of 15 to 20 vehicle types (Toole et al, 2004) as shown in Table 2. The
Equivalent Standard Axles (ESAs) for each vehicle type was determined by assuming 25% of each vehicle
type operate at the tare weight i.e. empty and 75% of them are assumed fully loaded with legal loads under
General Mass Limits scheme (NHVR, 2014).

Courtesy of ARRB GroupLight Vehicles
Light Rigid
Medium Rigid
Heavy Rigid
Heavy Bus
Artic 4 Axle
Artic 5 Axle
Artic 6 Axle
Rigid +5 Ax Dog
B-DoubleTS + 5 Ax Dog
A-Double
B Triple
AB Combination
A-Triple
Double B-Double

1
3
3
4
4
7
8
9
10
10
10
11
11
11
12
12

2
2
2
3
3
4
5
6
8
9
9
11
12
14
16
17

1.60
3.20
12.0
9.00
11.0
13.0
15.0
19.0
22.0
21.0
31.0
34.0
39.0
44.0
47.0

3.75
10.40
19.00
22.50
31.50
39.00
42.50
59.00
62.50
64.00
79.00
82.50
99.00
115.5
119.0

0.01
0.53
2.72
1.81
3.96
4.40
3.89
5.44
4.93
5.90
6.50
5.99
7.54
9.10
8.59

Percentage

ESAs/Vehicle

Fully loaded,
tonne

Tare Load,
tonne

Axle/Vehicle

AustroadClass

Vehicle type

Table 2. Vehicle fleet compositions

M

A

B

C

82.05%
2.13%
2.13%
0.72%
0.72%
1.13%
1.21%
6.15%
1.16%
1.16%
1.16%
0.08%
0.08%
0.08%
0.02%
0.02%

81.6%
2.16%
2.15%
0.79%
0.79%
1.02%
1.05%
6.06%
1.46%
1.46%
1.46%

86.2%
2.40%
2.39%
0.69%
0.69%
0.82%
0.73%
3.80%
0.76%
0.76%
0.76%

88.65%
1.84%
1.84%
0.56%
0.56%
0.67%
0.65%
3.17%
0.68%
0.69%
0.69%

3.4 Data Cleaning and Filtering
Originally 1705, 7108, 5713 and 2655, 100 m segments, for class M, A, B and C, respectively with
their data were available. These numbers were reduced through cleaning and filtering processes described
below.
3.4.1 Data Cleaning
The cleaning process involves removing all 100 m segments that have anomalous roughness values
from all relevant years, as a result of the different events during the automated condition survey. Such events
include bridge joints, lane change, stopping at intersections and rail crossings, which are reported withcondition data in the database together with their locations (Hassan, 2011). Their locations are further
confirmed by viewing the longitudinal profile of each road section and observing the chainages of unusual
spikes. The remaining number of segments after this cleaning process is 1624, 6950, 5679 and 2650 segments
for class M, A, B and C, respectively.

149

3.4.2 Data Filteringg
The calibration approach of HDM-4 road deterioration model applied herein is based on using the segmentswith continuous deterioration i.e. with positive rate of deterioration, where the effects of maintenance andrehabilitation are removed. This has been achieved by determining the rate of deterioration over time forroughness and rutting of each segment using the Linear Rate of Progression (LRP) Excel-based tool
developed by Martin and Hoque (2006). In this tool, the deterioration rate of a segment is determined from atleast three or more valid time series data points. This tool has been used in other studies such as (Hoque et al,
2008, and Sen, 2012). All segments that show negative or zero rate of deterioration are excluded. This meansthat segments subjected to the periodic maintenance and rehabilitation activities are excluded. However, theeffects of routine maintenance activities, such as crack sealing, are already taken into account in the
progression rates of roughness and rutting. The remaining numbers of 100 m segments with positive rate ofdeterioration for both roughness and rutting are 461, 1453, 1211 and 572 (46, 145,121 and 57 km) for class
M, A, B and C, respectively.
3.5 Grouping of Segments
The segments with positive rates of deterioration are grouped according to four soil types by swellpotential level (high, moderate, low and non-expansive) and three climate categories. The climate categories(semi-arid, subhumid and humid) are based on the HDM-4 climate zones classification (Bennett and Paterson,2000) shown below. These grouping criteria resulted in (6, 10, 8 and 7) groups for class M, A, B and C
respectively as shown in Table 3.
 Semi-arid: TMI range = -60 to -21
 Subhumid: TMI range= -20 to 19
 Humid: TMI range= 20 to 100
The calibration process of HDM-4 road deterioration models is repetitive and time consuming
therefore; the 461, 1453, 1211 and 572 segments are merged into 45, 110, 73 and 43 new segments for class
M, A, B, and C respectively, ranging between 0.2 and 3.9 km as shown in Table 3. This is based on a set ofcriteria including starting analysis year, road name, pavement width, pavement strength, drainage condition,
terrain and traffic volume. The conditions and other parameters for these new segments are reported as a meanvalue of the corresponding combined 100 m segments.
4 CALIBRATION OF HDM-4 ROAD DETERIORATION MODELSThe calibration process was focussed on rutting and roughness road deterioration models. According
to the structure of HDM-4 models, there is an interaction between the models. This means that the predictedroughness is influenced by the predicted rutting; therefore, the rutting model was calibrated before theroughness model.
The calibration process contained a number of preparatory, analysis and interpretation steps, which
comprised establishing an organised filing structure. This process generates a large number of files that are all
related to each other and dependent on one another, which are required for the calibration process
implementation.
The following assumptions have been made for conducting the calibration exercise:









The performance data represents pavement condition some year after the construction or
rehabilitation as the performance data for the whole life of pavement is not available
Only segments with positive deterioration rates are included to remove the effect of periodic
maintenance and rehabilitation.
Deterioration of each segment is modelled for the same period over which its condition data isavailable. The segments have different starting condition years namely; 1998, 1999, 2001, 2004,
2005 or 2006 and have condition data for 3 – 5 years (between start year and 2010). Therefore, they
have different analysis periods, which range between 4 and 12 years.
The rutting structural deterioration calibration factor (Krst) and roughness environmental component
calibration factor (Kgm) are calibrated. The roughness structural component Kgs is set equal to Kgm toreduce the gap between predicted and measured roughness (Hoque et al, 2008).
All calibration factors other than the ones being calibrated in this study are assumed to be at thedefault values recommended in HDM documents except for all structural cracking initiation (Kcia),
all structural cracking progression (Kcpa), and ravelling progression (Kvp=0.5), which are taken froma previous study reported in (Toole et al, 2004) and shown in Table 4.
All segments are subjected to routine maintenance to take into account the routine maintenancepractice during the analysis period (Toole et al, 2004). That includes patching (> 1 pothole/km), edge
repairs (> 1 m2/km) and removal and patching of cracked areas (> 2 precent wide cracking).

150

Table 3. Number of segments and relevant range of parameters for all groups
Road
Class

M

Climate/Soil Combination

No. ofCombined
Segments,(length,km)

Initial Rgh
IRI

Initial
Rut
Depth
mm

InitialCracks
%

SNP

AADT

TMI

GF%

Subhumid High
Expansive

7(0.2 – 1.2)

1.23-3.05

3-8

0-10

4.93-5.33

652410361

7-15

5.48

Subhumid Moderately
Expansive

7(0.2 – 1.0)
11
(0.9 – 1.2)
10
(0.8 – 1.1)
3
(0.6 – 1.0)7
(0.7 – 1.1)

1.37-1.97

2-3

0

4.63-4.76(-7)-1

4.28

0.95-2.0

3-7

0-25

4.96-5.90

1.24-1.99

2-4

0-22

4.68-5.61

1.17-1.34

5-6

2-16

5.56-5.57

8889

83

1.33-1.83

4-8

0-4

5.23-5.7086839664

59-83

4.97

1.34 - 2.32

2-6

0 - 184.1 - 4.3

3690 4672(-22) - (21)4.54

1.37 - 2.68

2-3

0 - 104.0 - 4.3

1808 4672
1902 2424
306 4888
306 4432
1178 3588
306 6918
2216 3058
1332 1896
866 2008
146 3160
3160 4164
736 942376 3612
566 1838
594 5018
594 5018
206 6594
562 2180
346 2458
1294 5376
340 760
806 1532
2150 2956(-23) - (21)(-37) - (21)Subhumid Low Expansive
Subhumid Non Expansive
Humid Moderately
Expansive
Humid Non Expansive
Semi-arid High Expansive
Semi-arid Moderately
Expansive
Semi-arid Non ExpansiveA

Subhumid High
Expansive
Subhumid Moderately
Expansive
Subhumid Low Expansive
Subhumid Non Expansive
Humid Moderately
Expansive
Humid Low Expansive
Humid Non Expansive
Semi-arid High Expansive
Semi-arid Moderately
Expansive
Semi-arid Low Expansive

B

Subhumid High
Expansive
Subhumid Moderately
Expansive
Subhumid Low Expansive
Subhumid Non Expansive
Humid Non Expansive
Semi-arid High Expansive
Subhumid High
Expansive
Subhumid Moderately
ExpansiveC

Subhumid Low Expansive
Subhumid None
Expansive
Humid Moderately
Expansive
Humid Non Expansive

5(0.3 – 1.3)
10
(0.4 – 2.5)9
(0.9 – 3.2)
25
(0.4 – 1.9)
19
(0.5 – 1.9)
8
(0.2 – 1.4)
13
(0.3 – 1.9)
6
(1.4 – 1.5)
3
(0.4 – 1.3)
12
(0.7 – 1.7)
13
(0.3 – 2.6)
4
(0.8 – 2.5)
5
(0.7 – 1.7)
23
(0.5 – 3.9)
4
(0.3 – 2.4)
8
(0.5 – 2.9)
4
(0.2 – 1.9)
12
(0.7 – 2.6)
6
(0.2 – 1.1)
12
(0.4 – 3)
6(0.3 – 1.4)
8
(0.5 – 3)
6(0.4 – 1.3)
4
(0.5 – 1.3)
1
1.1

1.58 - 2.73

2-7

0 - 10

3.8 - 4.2

1.11 - 2.69

2-5

0-8

3.0 - 4.2

1.33 - 2.59

1-5

0-9

3.2 - 4.2

1.35 - 2.34

2-7

0-1

3.5 - 4.1

1.49 - 3.31

3 - 110-4

2.9 - 4.0

0.93 - 1.64

3-4

0

3.7 - 3.9

1.71 – 3.22

3-6

0-2

3.6 - 3.7

1.47 – 2.97

3-5

0-2

3.2 - 3.7

1.31 – 3.2

2-5

0-7

2.7 – 3.4

1.52 – 1.96

2-5

0-7

3.6 – 3.8

1.97 - 2.51

2-4

0-3

3.3 – 3.6

1.55 – 3.14

2-6

0 - 11

3.0 – 3.8

1.22 - 3.45

2-4

0-1

3.0 - 3.6

1.47 - 2.88

2-6

0-7

3.1 - 4.0

1.61 – 2.46

3-6

0-5

3.2 - 3.9

1.57 - 3.21

2-7

0-5

2.5 - 4.0

1.67 – 3.13

2-3

0 - 12

3 – 3.6

1.78 – 2.81

2-5

0 - 10

2.9 – 3.4

1.62 – 3.32

2-7

0- 4

2.7 – 3.4

1.79 – 2.85

2-5

0-1

2.8 – 3.2

1.56 – 2.66

2-4

0-2

2.9 - 3.3

2.08 – 3.37

2-4

0-3

2.9 - 3.3

2.47

3

0

3.2

24093413
58989740
24774880

2150

9-15
(-8)-4(-20) - 18(-20) - 19(-20) - 17(-14) - 175.485.71
3.514.28
4.354.97

4.54
2.5 4.54
4.54 6.90
4.54 6.90
4.54 5.68
4.64 6.90

20 - 23

4.88

41 - 45

3.72

22 - 50(-24) - (21)(-23) - (21)(-26) - (24)(-20) - 3(-12) - 3(-11) - 19
2 - 1920 - 96

3.72 –
5.31
2.49 –
5.08
2.49
3.75
3.30 –
5.08
3.30 –
5.08
3.30 –
5.08
3.30 –
4.54
3.87 –
4.54(-24) - (21)

3.66(-20) - 15

3.66 –
4.78

7 - 15

2.67(-20) - (1)3.66 –
4.53
2.67 –
4.78

6 - 1930 - 45

5.34

48

5.34

151

The methodology used for calibrating the road deterioration models to local conditions is todetermine the calibration factor for each individual road segment in a group and then averaging the factors of
all segments in the group to determine the calibration factors for the group, and averaging factors of all groups
to determine the class calibration factor. The calibration process has been done by creating a case study in
HDM-4 including one network covering all segments for classes A and B with one vehicle fleet and two
networks for classes M and C with one fleet for each, one for the adjusted roughness data (Adj) and the otherfor the roughness data from relevant database (Db). The process involved the following steps:
1. Estimate the actual progression rates of rutting and roughness for all segments, from actual(observed) condition data.
2. Identify the analysis period for each segment and its pavement condition at the start of the analysis
period. Due to the variation in starting years and analysis periods, 3 to 6 projects were created.
3. Create HDM-4 project analysis case study and input all parameters that are required to run its models
including trial calibration factors for rutting or roughness.
4. Assign a typical routine maintenance standard to reflect the normal routine maintenance practice as asingle alternative.
5. Run HDM-4 models to predict pavement condition annually up to and beyond the analysis period
and compare with the actual condition trend.
6. Repeat step five after adjusting the calibration factors until the predicted performance trends match
closely the observed performance trends, see examples in Figure 1.
Table 4. Cracking calibration factors from previous study (Toole et al, 2004)
Class
M
A
B
C
1.
2.

Krst = 1.75

Subgrade soil
StableStableUnstable
StableUnstable
StableUnstable

Kcia
1.16
0.87
1.10
0.99
1.00
0.80
0.60

Kcpa
0.30
0.29
0.30
0.36
0.53
0.46
0.30

Stable = non expansive soil
Unstable = expansive soil

Kgm = 0.43

Figure 1. Example of performance trends of rutting and roughness for both predicted and observed data.
First the rutting progression model is calibrated from the relevant historical data and the calibration
factors for the rutting structural deterioration (Krst) are established. Then the roughness deterioration model iscalibrated from the historical data and its calibration Factors (Kgm) are obtained. The ranges of calibration
factors for each group are presented in Table 5, together with the average calibration factors for each groupand class. Furthermore, Table 5 shows the calibration factors from a previous study (Hoque et al, 2008). In theprevious study different criteria were used for grouping the segments, which prevent direct comparison.
Therefore, the comparison had been done just for the closest groups.

152

Table 5. Calibration results for all road classes
Road
Class

Climate/Soil
Combination

Kgm Adj(average)
0.1 - 0.67
(0.49)
0.19 – 0.83
(0.59)
0.01 – 0.52
(0.27)
0.01 – 0.72
(0.19)
0.03 – 0.50
(0.16)
0.01 – 0.03
(0.02)
0.34 – 0.93
(0.64)
0.41 – 1.70
(1.11)
0.27 – 1.07
(0.61)
0.13 – 1.25
(0.55)
0.01 – 0.93
(0.30)
0.02 – 0.75
(0.41)
0.01 – 0.44
(0.23)
0.05 – 0.20
(0.10)
0.26 – 0.51
(0.36)
0.03 – 1.28
(0.48)
0.35 – 1.95
(0.98)
0.02 – 0.97
(0.46)
0.52 – 1.45
(1.02)
0.03 – 1.55
(0.62)
0.01 – 0.99
(0.37)
0.01 – 0.48
(0.26)
0.15 – 0.37
(0.23)
0.30 – 1.11
(0.58)
0.40 – 3.04
(1.41)
0.71 – 1.80
(1.17)
0.13 – 0.37
(0.22)
0.22 – 1.18
(0.64)
0.05 – 0.85
(0.37)
0.26 – 0.38
(0.30)

Kgm Db(average)
0.01 – 0.45
(0.21)
0.05 – 0.60
(0.22)
0.01 – 0.60
(0.22)
0.01 – 0.60
(0.09)
0.01 – 0.40
(0.14)

Subhumid None
Expansive
Humid Moderately
Expansive

Krst(average)
1.2 - 2.85
(2.03)
1.05 – 2.65
(2.07)
1.25 – 2.8(2.05)
1.1 – 3.51
(2.10)
2.34 – 5.45
(3.85)
3.5 – 4.0
(3.7)
1.0 - 1.64
(1.38)
0.85 – 2.10
(1.36)
0.66 – 2.20
(1.03)
0.58 – 3.68
(1.62)
0.45 – 3.06
(1.38)
0.65 – 1.87
(1.22)
0.50 – 3.87
(1.51)
0.91 – 2.08
(1.27)
0.83 – 1.70
(1.23)
0.68 – 2.71
(1.34)
0.44 – 4.48
(1.55)
0.85 – 3.27
(1.67)
0.55 – 2.76
(1.46)
0.55 – 3.03
(1.44)
0.42 – 3.87
(2.15)
0.45 – 4.11
(1.62)
0.57 – 4.45
(2.04)
0.58 - 3.16
(1.74)
0.90 – 1.72
(1.34)
0.70 – 3.20
(1.57)
0.49 – 1.68
(0.98)
0.64 – 2.14
(1.16)
0.69 - 3.13
(1.64)
0.89 – 1.54
(1.08)

Humid Non Expansive

0.58

0.14

0.20

Subhumid High
Expansive
Subhumid Moderately
Expansive
Subhumid Low Expansive
M
Subhumid Non Expansive
Humid Moderately
Expansive
Humid Non Expansive
Semi-arid High Expansive
Semi-arid Moderately
Expansive
Semi-arid Non ExpansiveA

Subhumid High
Expansive
Subhumid Moderately
Expansive
Subhumid Low Expansive
Subhumid Non Expansive
Humid Moderately
Expansive
Humid Low Expansive
Humid Non Expansive
Semi-arid High Expansive
Semi-arid Moderately
Expansive
Semi-arid Low Expansive

B

Subhumid High
Expansive
Subhumid Moderately
Expansive
Subhumid Low Expansive
Subhumid Non Expansive
Humid Non Expansive
Semi-arid High Expansive
Subhumid High
Expansive
Subhumid Moderately
ExpansiveC

Previous study
closest groups

Current study

Subhumid Low Expansive

Krst

Kgm

1.17

0.36

0.48

0.15

1.17

0.36

0.48

0.15

2.13

0.53

2.13

0.53

2.13

0.53

Average for class
Krst

Kgm

2.63

0.29

1.33

0.48

1.71

0.56

1.19

0.61

0.01

0.27 -3.30(1.66)
0.68 – 1.90
(1.17)
0.05 – 0.25
(0.11)
0.08 – 1.10
(0.50)
0.01 – 0.95
(0.20)
0.35 – 0.53
(0.41)

1.40

1.34

1.40

1.34

1.40

1.34

1.8

0.44

2.82

0.33

2.82

0.33

2.82

0.33

153

The closest groups from the previous study are low traffic with dry climate and medium traffic withtemperate climate groups for class M, low traffic with dry climate group for class A, low traffic with dry
climate group and low traffic with temperate climate groups for class B and low traffic with temperate climategroup for class C as shown in Table 1. These groups are close to the study groups shown in Table 5.
Table 5 shows that the rutting calibration factor (Krst) values obtained from this study are greater thanthe default value (1.0) for class M and variable for the class A, B and C. Also the roughness calibration factor(Kgm) values obtained from this study are lower than the default value (1.0) for class M and variable for class
A, B and C. Furthermore, the (Kgm) values obtained from the adjusted roughness data are higher than thoseobtained from the database roughness data for class M and variable for class C. In addition, for the closest
groups, the (Krst and Kgm) values obtained from this study are higher than those obtained from the previous
study for some groups and lower for the others.
5 VALIDATION OF AVERAGE CALIBRATION FACTORSThe following sections cover the validation of average group calibration factors and average classcalibration factors using the correlation between the predicted and observed data.
5.1 Validation for Average Group Calibration Factors
The average calibration factor for the rutting and roughness of each group has been used as thecalibration factor for all road segments within the group. Then HDM-4 was run to predict rutting androughness over the analysis period. To validate the results, the predicted rutting and roughness data is plottedagainst the corresponding actual performance data and the coefficient of determination (R2) of the best fit line
is determined. For all groups it was found that there is good to very good correlation between the two sets ofdata with R2 ranging between (0.64 and 0.98) for rutting and (0.81 and 0.99) for roughness. Figures 2, is an
example that shows the correlation between the observed and predicted data. These results indicate that thecriterion used for grouping the segments is successful.
5.2 Validation for Average Class Calibration Factors
The average class calibration factor for both rutting and roughness of each class was used as
calibration factor for all segments within the class. As described above the HDM-4 was run and the predicteddata was plotted against the corresponding actual performance data for validation. For all classes it was foundthat there is good to very good correlation between the two sets of data with R2 ranging between (0.68 and0.87) for rutting and (0.85 and 0.96) for roughness.

5 FORMULAE

Figure 2. Correlation between observed and predicted rutting and roughness using average calibration factors
for subhumid high expansive group in class M
6 CONCLUSIONSThis paper describes the process of calibrating HDM-4 road deterioration models for rutting androughness using a large sample size to well represent Victoria’s rural arterial conditions and roughness data154

from the adjusted longitudinal profile data to make sure that the same sections are being compared over time.
Only segments with positive rate of deterioration were used. These segments were grouped according to thesubgrade soil type and climate condition into (6, 10, 8 and 7) groups for classes M, A, B and C, respectively.
The HDM-4 road deterioration models were calibrated using the historical data to match the underlying rates
of rutting and roughness progression. The calibration factors for both roughness and rutting progression were
determined for each segment within each group of each class, and then average calibration factors for thegroups in a class and for each class were determined. These factors were then used for each segment within
the group in HDM-4 to predict rutting and roughness values over time over relevant analysis periods. The
predictions have been validated by comparing their trends with the actual ones over the same period. The
main findings are:
 The (Krst) values are more than the default value of one for class M and are variable for class A, B
and C
 The (Kgm) values for both adjusted roughness data and roughness data extracted from relevant
database are less than the default value of one for class M and are variable for class A, B and C
 The (Kgm) values obtained from the adjusted roughness data are higher than those obtained from thedatabase roughness data for class M but are variable for class C.
 The (Krst and Kgm) values obtained in a previous study for the closest groups are higher than thoseobtained from this study for some groups and lower for others
 The criterion used for grouping the segments is successful as there is good to very good correlation
between the predicted and observed data when using the average group calibration factors
 There is good to very good correlation between the predicted and observed data, when using the
average class calibration factors.
When more time series condition data becomes available, the calibration exercise should be repeated to covera longer study period and cover sections within the latter stages of the gradual deterioration phase. In addition
to calibrating the deterioration models of cracking and potholing, when reliable data becomes available.
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156

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines
Yohannes Abebe, Global Practice Leader and Senior Director, Transport and Vertical Structures Group
Jason Jones, Senior Program Officer, Environmental and Social Performance
Millennium Challenge Corporation, Washington DC

1 INTRODUCTIONThe US$ 433.914 million Compact grant (Compact) from the Millennium Challenge Corporation (MCC) of
the US Government was signed with the Philippine Government on September 23, 2010. The Millennium
Challenge Account-Philippines (MCA-P) was thus created, and served thereafter as the Accountable Entity
for the implementation of the grant.
The provinces of Samar and Eastern Samar, part of the Eastern Visayas Region, have long had some of thehighest incidences of poverty in the Philippines. Aiming to improve living conditions and to provide better
access to economic opportunities in the area, MCC granted $214.44 million from the Philippines Compact
for the reconstruction/rehabilitation of the 222-km Wright-Taft-Borongan-Guiuan Road, which links the two
provinces with the rest of the country.
The project, officially known as the Secondary National Road Development Project (SNRDP) of the
Department of Public Works and Highways (DPWH), included the road upgrades and roadway rehabilitation
activities including construction/reconstruction of paved or gravel shoulders, drainage and road safety
improvements, resurfacing (overlay) and full-depth reconstruction, bridge replacement, rehabilitation andseismic retrofitting, road slip/landslide engineering solutions such as retaining walls, drainage improvements
and other feasible and cost effective improvements including a range of Environmental and Social Mitigation(ESM) activities.
In addition, the project incorporated enhanced safety measures including paved shoulders, construction of
sidewalks and curbs in areas of high pedestrian activity, improved gateway treatments to indicate where
lower speeds are required, and increased use of road narrowing, median islands, and traffic humps to slow
traffic speeds. The road segment passes through 14 municipalities and one city, and is the main passage
between provinces. Improving the infamously rundown road has proved to not only help lower transport
costs and travel time, but to also open up the area to new possibilities and new markets (MCA-P 2016) Road
construction was substantially completed, and the road opened for traffic, on May 25, 2016.
SNRDP was implemented in four major contract packages (CP): (see Figure 1).
 CP 1- 16.3km from Buray to Tinani in Paranas, Samar CP 2- 63.78 km from Tinani, Paranas, Samar to San Julian, Eastern Samar CP 3- 64.58 km from San Julian to Balangkayan in Eastern Samar CP 4- 77.51 km from Llorente to Guiuan, Eastern SamarThis paper focuses on the CP1 pre and post construction road safety assessments and findings.

Figure 1 – Project Site

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A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines
Road Safety in the Philippines Context: In 2003, the population of the Philippines was around 94 Million(est.), with a 2.2% annual growth rate. The country has a land area of 300,000 square kilometers, a road
length of 270, 000 km, and a total registered vehicle count of approximately 7,463,393 (2012) with a 4.4%
annual increase rate. The Total Drivers Licenses Issued in the country was 13 Million (Lantin, 2013).
According to WHO data published in May 2014, Road Traffic Accidents Deaths in Philippines reached 9,758
per year, or 1.87% of total deaths. The age adjusted Death Rate of 11.56 per 100,000 of population ranks thePhilippines number 123 out of 172 globally in terms of road accident risk (WHO 2014)
SNRDP Road Safety Program – Pre and Post Construction Assessment: In 2011, as part of theInternational Roads Assessment Programme (iRAP) Philippines project, iRAP1 was invited by DPWH andthe Millennium Challenge Corporation (MCC) to assess road projects in Samar which were being upgradedas part of SNRDP, provide advice on Star Ratings of the new road designs, and to establish a baseline.
iRAP’s Star Rating risk assessment results and a Safer Roads Investment Plan (SRIP) with economic analysis
of safety countermeasure options were used to formulate an approach to road safety that was appropriate to
the project . That assessment was conducted as part of national road assessments financed by the World Bank
Global Road Safety Facility. The assessment found that the majority of the existing roads were rated in thehighest risk 1- and 2-star categories. See Table 1
Table 1. Percentage of road rated 3-stars or better
Road user

Before upgrade

Vehicle occupants

23%

Motorcyclists

10%

Pedestrians

8%

Bicyclists

20%

The 16.3km Buray-Tinani Road section of SNRDP (CP1) was completed in 2014. In May 2015, a study wascommissioned by the Millennium Challenge Corporation (MCC) to compare the baseline iRAP road safetyassessment results produced in 2011 with post-construction assessment results for the recently completed
upgrades, and to provide road safety recommendations that could be implemented along sections of the road
identified as posing a risk to the travelling public.
2 POST-CONSTRUCTION SURVEY METHODOLOGY
Using a video camera, GPS and specially created software, iRAP inspections involve detailed road surveys
and data collection focusing on more than 50 different road attributes known to influence crash likelihoodand severity. These attributes include intersection design, numbers of lanes and markings, roadside hazards,
footpaths and bicycle facilities. The road inspection data underpins subsequent designation of iRAP Star
Ratings and preparation of Safer Roads Investment Plans (SRIP).
iRAP Star Ratings are based on road inspection data and provide a simple and objective measure of the levelof safety which is ‘built-in’ to the road for vehicle occupants, motorcyclists, bicyclists and pedestrians. Fivestar roads are the safest while one-star roads are the least safe. Importantly, Star Ratings can be completed
without reference to detailed crash data, which is often unavailable in low-income and middle-income
countries.
The post-construction survey of CP1 was undertaken as part of a three-day training course for DPWH,
MCAP and MCC staff. The survey was undertaken as follows:

Date: Wednesday 3 June 2015.
Start time: 2:14pm

1

The International Road Assessment Programme (iRAP) is a registered charity dedicated to preventing the more than
3,500 road deaths that occur every day worldwide. At the heart of iRAP is a spirit of cooperation. iRAP provide tools andtraining to help automobile associations, governments, funding agencies, research institutes and other non-governmentorganisations in more than 70 countries make roads safe.

158

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines









End time: 2:32pm
Direction: East-bound.
Start point: KM827.144 (intersection with Daang Mahalika).
End point: KM843.5.
Vehicle and driver: Toyota Hiace and driver organized by MCC.
Camera: One (1) Contour+2 was mounted inside the windscreen of the vehicle.
Images: Continuous video, 1280 x 960 pixels, 170 degrees field of view, .MP4 format.
GPS: Collected using the Contour+2 video camera, downloaded in .CSV format.

Prior to the iRAP survey, a series of site visits to specific locations along the road were conducted by thejoint iRAP, DPWH, and MCA-P team to inform the survey.
The post construction assessments were based on the ‘V3.02’ iRAP model, whereas the original baseline
assessment was conducted using the ‘V2.2’ model. The V3 models series reflects experience in applying theV2.2 to more than 50,000km of roads in low and middle-income countries and new research on therelationships between road attributes and risk. As part of this project, the results from the baseline assessment
were recalculated using the V3 model and migrated into iRAP’s ViDA software. This required some basic
assumptions to be made for road attributes not previously coded. However, taking this step helps ensure a
relatively high degree of compatibility between the analyses.
Traffic speeds: The risk level for death or serious injury on a given road is highly dependent on the speed atwhich traffic travels. iRAP policy is that risk assessments are made using the ‘operating speed’ on a road.
Operating speed is defined as being the greater of the legislated speed limit or the measured 85th percentile
speed.
There were a number of issues to consider in determining the operating speeds for CP1:
 Although the driver of the post-construction survey vehicle was asked to obey the road rules,
the survey vehicle consistently exceeded the posted speed limits. On average, the vehicle
travelled at 8km/h faster than the speed limit. The 85th percentile speed of the survey vehicle
was 68km/h and the maximum speed was 79km/h. To the extent that the survey vehicle driveris representative of all drivers, then it is reasonable to assume that operating speeds exceed
posted speed limits.
 The post-construction survey indicated that there was little relationship between changes inposted speed limits and changes in operating speeds (this is discussed in more detail later in thereport).
 The post-construction survey indicated that there was little relationship between changes in area
type (urban and rural) and changes in operating speeds (this is discussed in more detail later inthe report).
 In the original baseline report, the following speeds were used for the analyses: 51-60km/h inurban/semi urban areas and 61-70km/h in rural areas. However, for this assessment, these
speeds were reduced following a review of the survey vehicle speeds. In that case, the survey
vehicle travelled at an average of 34km/h, an 85th percentile speed of 45km/h and a maximum
speed of 51km/h. As in the post-construction survey, there was little relationship between area
type (urban and rural) and operating speeds (and there were no speed limit signs in place).
Taking into account these factors, the speeds shown in the Table 2 below were used in the modelling. The
speeds selected reflect an attempt to balance the issues discussed above. However, sensitivity tests withdifferent speeds were also undertaken. Further discussion with the DPWH may be necessary to confirm theappropriate operating speeds to use on these roads.

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A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines
Table 2. Assumed operating speeds
Average speed (km/h)

Before upgrades

85th percentile speed
46-50km/h

After upgrades

61-65km/h

55-60km/h

Road40-45km/h

Risk worms: Figures 2 - 5 shows charts illustrating the Star Rating Scores (SRS) that underpin the Star
Ratings for each of the road users (the higher the SRS, the greater the risk). The charts help to illustrate therelative level of risk each type of road user experiences as they move along the road. The dark blue lines
illustrate risk before the road upgrade and the light blue lines illustrate risk after the road upgrade.

Figure 2. Vehicle occupant risk scores

Figure 3. Motorcyclist risk scores160

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines

Figure 4. Pedestrian risk scores

Figure 5. Bicyclist risk scores

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A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines
3 ECONOMIC ANALYSIS
Baseline number of deaths and serious injuries: As part of the iRAP model calibration, an estimate of thenumber of deaths and serious injuries that occur on the road, both in aggregate terms and by road user type, isrequired. It is noted these estimates only influence the economics component of the project, and not the risk
assessments (Star Ratings). As was noted in the baseline report, there is no information available on thenumber of deaths and serious injuries on the Wright-Taft-Guiuan Roads and so it was assumed that there wasa death rate of 0.5 deaths per km. For the Buray-Tinani Road in this report, a lower figure, 0.2 deaths per km,
has been assumed, reflecting the lower volumes and speeds on this section. On this basis, it is estimated that
0.2 x 16.3 = 3.3 deaths occur each year, or 65.6 deaths over 20 years.
In the baseline report, it was assumed that deaths are equally distributed among vehicle occupants,
motorcyclists, pedestrians and bicyclists. However, this assumption has been adjusted for this reportfollowing the observation that very few bicyclists use the road. Hence the distribution is as follows:Vehicle occupants: 33%
Motorcyclists: 33%
Pedestrians: 33%
Bicyclists: 1%

An estimate of the number of serious injuries was made by assuming that for each death, 10 serious injuries
occur. (McMahon and Dahdah 2008). Hence, it is estimated that 32.8 serious injuries occur on the road eachyear, or 655.8 serious injuries over 20 years. Combining this with the estimated number of fatalities gives anestimated 721 fatalities and serious injuries over 20 years.
Economic cost of deaths and serious injuries: iRAP uses a standard approach globally to estimate theeconomic cost of deaths and serious injuries, based on research undertaken by McMahon and Dahdah for theorganization (McMahon & Dahdah 2008). It is the approach preferred by the Global Road Safety Facility for
iRAP projects. It is noted that this approach may result in estimates that differ from those undertaken in thepast due to new methods for calculating economic costs and changes in technology.
The key equations used are:
 the economic cost of a death is estimated to be: 70 x Gross Domestic Product (GDP) per capita(current price) the economic cost of a serious injury is estimated to be: 0.25 x economic cost of a death.
 For the purposes of this assessment, the baseline report costs were used, namely:
 the economic cost of a death in the Philippines is estimated to be 70 x Php 97,840 = Php
6,848,800
 the economic cost of a serious injury is estimated to be: 0.25 x Php 6,848,800 = Php 1,712,200.
Overall, it is estimated that 721 deaths and serious injuries occurred on the road segment surveyed over a 20
year period before the upgrade.

4 SAFER ROADS INVESTMENT PLAN
iRAP considers more than 90 proven road improvement options to generate affordable andeconomically sound Safer Road Investment Plans (SRIP) that improve a road's Star Ratings and save
lives. Table 3 shows the safety countermeasures that could enhance safety and which are likely to beeconomically viable (with a benefit cost ratio greater than 1). The analysis indicates that if all thecountermeasures in the enhanced safety package were installed, 279 fatalities and serious injuries could be
prevented over 20 years, representing a 38% reduction. This would save approximately Php 226 million
in estimated costs associated with deaths and serious injuries.

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A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines

Table 3. Suggested Road Safety Countermeasures (20 years)
Countermeasure

Length /
Sites

FSIs
saved

Safety benefit(Php)

Estimated
Cost (Php)

Cost per FSI
saved (Php)

BCR

Improve curve delineation

7.80 km53

43,151,659

7,515,493

141,745

6

Roadside barriers - passengerside

5.40 km50

40,931,298

13,768,920

273,774

3

Roadside barriers - driver side

5.30 km49

40,272,062

13,513,940

273,103

3

Unsignalised crossings

30 sites

21

16,880,786

3,129,825

150,895

5

Clear roadside hazards passenger side

7.00 km18

14,590,809

1,238,300

69,071

12

Delineation and signing(intersection)

12 sites

16

12,741,072

4,600,054

293,836

3

Clear roadside hazards - driverside

6.70 km16

13,187,209

1,185,230

73,147

11

Traffic calming

2.10 km14

11,548,066

6,898,717

486,1912

Parking improvements

3.70 km12

9,712,267

5,550,000

465,0722

Upgrade pedestrian facility
quality

9 sites

10

7,906,919

1,189,776

122,4637

Pedestrian fencing

0.30 km4

3,437,169

450,000

106,552

8

Footpath provision driver side(adjacent to road)0.90 km4

3,285,158

2,880,000

713,484

1

Footpath provision passenger
side (adjacent to road)0.80 km3

2,630,770

2,560,000

791,964

1

Footpath provision passenger
side (informal path >1m)

1.90 km3

2,174,091

1,540,205

576,566

1

Footpath provision driver side
(informal path >1m)

2.00 km3

2,309,977

1,621,268

571,209

1

Skid Resistance (paved road)

0.20 km2

1,903,918

832,843

356,0112

279

226,663,230

68,474,571

245,865

3Total

5 CONCLUSION
The assessment shows in Table 4 that there has been an improvement in the Star Ratings for the BurayTinani Road, although a significant percentage of the road remains in the 1- and 2-star categories.
In summary:

the percentage of road rated 3-stars or better for vehicle occupants increased from 23% to 32%
the percentage of road rated 3-stars or better for motorcyclists increased from 10% to 30%
the percentage of road rated 3-stars or better for pedestrians increased from 8% to 36%
the percentage of road rated 3-stars or better for bicyclists increased from 20% to 75%.

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A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines

Table 4. Star Ratings: before upgrades (B) and after upgrades (A) and the difference (D)Vehicle occupants

Motorcyclists

Pedestrians

Bicyclists

Star Rating

B

A

D

B

A

D

B

A

D

B

A

D

5

0%

0%

0%

0%

0%

0%

0%

0%

0%

0%

0%

0%

4

0%

0%

0%

0%

0%

0%

0%

0%

0%

0%

2%

2%

3

23%

32%

9%

10%

30%

20%

8%

36%

28%

20%

75%

55%

2

66%

57%

-9%

35%

59%

24%

30%

44%

14%

66%

21%

-45%

1

12%

12%

0%

55%

12%

-43%

62%

20%

-42%

14%

1%

-13%

Total

100%

100%

0%

100%

100%

0%

100%

100%

0%

100%

100%

0%

The assessment in Table 5 shows that there have been modest improvements in the road safety Star Ratings
for the Buray-Tinani Road as a result of the upgrades, despite operating speeds increasing by an estimated
15km/h. It is further estimated that as a result of the road improvements, the level of road accidents will
decline by 70 deaths and serious injuries (10%) over 20 years, saving an estimated Php 57 million in costs
associated with road accidents.
Table 5
Improvement in Star-Rating
Percentage of road rated 3stars or better Road user
Vehicle occupants
Motorcyclists
Pedestrians
Bicyclists

Before upgrade

After upgrade

23%
10%
8%
20%

32%
30%
36%
77%

Road attributes on the upgraded road that have led to a reduction in accident risk include: improved
delineation, street lighting, paved shoulders, pedestrian crossings, sidewalks, pedestrian fences and increased
roadside clear zones. However, a number of serious road safety issues were identified during the assessments,
so numerous opportunities to enhance safety on the road remain. An economic analysis of safety
countermeasure options identified approximately Php 68 million of investments that could prevent a further
279 (38%) deaths and serious injuries, potentially saving Php 224 million in accident-related costs. This
investment would eliminate virtually all the 1- and 2-star sections of road. The improvements include: better
traffic management at the section of road where there has been a landslip; making adjustments at schools
such as extending sidewalks and reducing speeds; upgrading and extending safety barriers; improving
delineation at curves and intersections; and installing village ‘gateway’ treatments. DPWH has acknowledged
the proposed improvements are highly beneficial in further improving road safety condition and is willing toincorporate them to the maximum extent moving forward.
In addition to taking a more comprehensive approach to road safety engineering, significant benefits could
also be realised through coordinated targeting of risk factors for road users (such as speeding, seat belt use
and driving under the influence ) and vehicles. This would be consistent with taking a Safe System approachto the road project. To this end, the iRAP assessment was followed up with a joint DPWH and MCA-P led
public awareness campaign that aimed to communicate a message of road safety to both the travelling public
and to communities along the road. Particular attention was paid to engaging administrators, students andparents of students in schools along the road alignment in an effort to instil awareness of road safety practices
for not only drivers and users of vehicles, but for pedestrians as well. This engagement and awareness raisingof road safety roles and responsibilities among the road’s user community formed an essential
complementary socialization feature to the physical safety measures recommended by the iRAP assessment.

164

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines

6 BEFORE AND AFTER IMAGESThe following are images collected in the baseline survey (2011) and the post-construction survey (2015)
for selected locations.
KM831 (left = before upgrade; right = after upgrade)

KM832 (left = before upgrade; right = after upgrade)

KM833.4 (left = before upgrade; right = after upgrade)

KM834 (left = before upgrade; right = after upgrade)165

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines

KM837 (left = before upgrade; right = after upgrade)

KM838 (left = before upgrade; right = after upgrade)

KM840 (left = before upgrade; right = after upgrade)166

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines

KM842 (left = before upgrade; right = after upgrade)

KM843.1 (left = before upgrade; right = after upgrade)167

A Proactive and Systematic Approach to Investing in Road Safety Shows Measurable
Results – A Case Study of Road Upgrade Project in Samar, The Philippines
CITATIONS AND REFERENCES
iRAP Philippines : Wright-Taft-Guiuan Roads, Samar, Technical Report, iRAP, 2011.
Lantin, D. Road Safety in the Philippines, UN ESCAP, 2013. Accessed online at
http://www.unescap.org/sites/default/files/2.19.Philippines.pdf
McMahon, K. and Dahdah, S. The True Cost of Road Crashes – Valuing Life and the Cost of a Serious
Injury, iRAP, 2008. Accessed online at http://www.irap.net/en/about-irap-3/research-and-technical-papers
Bayuhay or Bagong Yugto ng Buhay, Millenium Challenge Account Philippines, 2016.
World Road Traffic Accident Report, 2014. World Health Organization, 2014. Accessed online at
http://www.worldlifeexpectancy.com/cause-of-death/road-traffic-accidents/by-country/

ACKNOWLEDGEMENTS
Sir Rodolfo Arias, Director, SNRDP, MCA Philippines
Ma’am Criste Navida, Director, ESGA, MCA Philippines
Mr. Burak Inanc, Deputy Resident Country Director, Philippines, MCC
Mr. Greg Smith, Regional Director, Asia Pacific, iRAP
Mr. Rob McInerny, iRAP

168

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Development of Development of Non-contact Wireless Power Supply Pavement

TRACK

Pavements or Mobility Management

AUTHOR(Capitalize Family
Name)NagatoABE
CO-AUTHOR(S)(Capitalize Family Name
Masaya
TSUKAMOTO
E-MAIL(for correspondence)

POSITION
Executive
Manager

GeneralORGANIZATIONTOAROADCORPORATION,
Technology Department

POSITION
Chief Manager

COUNTRYJAPAN

ORGANIZATIONTOA ROADCORPORATION,
Research Laboratory

COUNTRYJAPAN

n_abe@toadoro.co.jp

KEYWORDS:
Pavement, EV, Non-contact, Wireless power supply, shield

ABSTRACT:Electric vehicle (EV) is, no CO2 generation by the service, has been defined as the environmentally friendly car.
There is a can travel up to 200km in relation to the capacity of the battery mounted on a vehicle, for summer air
conditioning and the load of the winter heating is large, one can only travel a maximum of about 100km in charge.
For this reason, in addition to the charging stand to promote the spread of electric vehicles, it will need to charge inthe parking zone of the stopped or running.
To improve the efficiency of the power supply coil embedded in the pavement, it was decided to use magnetic
material sand generated during steelmaking slag purification. It decided to use the cement and asphalt emulsion
mortar (CAM) in order to protect the buried coils from loading due to the moving track. The structures of thepavement have developed two types of asphalt pavement structure and dish type concrete structure using the CAM.
In this paper, with respect to leakage radio waves at the time of the non-contact wireless power supply,
knowledge was obtained about the validity and the direction of the magnetic field at the time of the occurrence of analuminum plate. Future advances the study of the structure and buried depth of the coil at the time of high power
output.

169

Development of Non-contact Wireless Power Supply
PavementDr. Nagato Abe1
1

TOA ROAD CORPORATION, Technical Department,

Minato-ward, TOKYO, JAPAN, n_abe@toadoro.co.jp
2

TOA ROAD CORPORATION, Research Laboratory,

Tsukuba, Ibaragi Pref., JAPAN, m_tukamoto@toadoro.co.jp

1 CONCEPT AND CIRCUMSTANCES OF NON-CONTACT WIRELESS POWER SUPPLY
Environmentally friendly electric vehicles can run only up to approximately 100 km on one charge
due to the capacity of batteries installed in the vehicles. Therefore, the key for the promotion of electricvehicles is developing a charging infrastructure that allows batteries to be wirelessly charged while driving,as well as expanding charging stations. Measures need to be considered to prevent electromagnetic waves
from moving laterally without losing the efficiency of the battery charge from the supply coil installed
beneath the pavements of roads.
Furthermore, it is essential to install magnetic materials and a layer of shields under the coils, as themagnetic flux needs to expand upward for the coil installed on cars to efficiently receive electromagnetic
waves generated from the underground coil. (Figure 1).

Figure 1. Image of dispersion of magnetic flux due to the presence or absence of a magnetic material.

2 COIL AND ELECTRICAL CHARACTERISTICS
A 12mm-diameter Litz wire was used for the coil. The receiver coil – a circular sextuple coil 40 cm
in diameter – was, in principle, installed under the car.
The transmitting coil embedded in a pavement was a triple coil 1.6m in length and 30 cm in width,
as described in Figure 2 (Throngnumchai, K. & Hanamura, A. & Naruse, Y. & Takeda, K. 2013).
The embedded transmitting coil was designed in a way that the inductance (L), which indicates theelectromotive force generated in the coil, is 33μH under 40A current and the Q-factor (Quality factor)

170reaches the maximum value under 80-100kHz frequency (Figure 3). The Quality factor under 90kHz was
440.

Figure 2. Structure of coil embedded in pavement in this study.

Figure 3. Inductance and Q-factor of embedded coil.

Based on experience of installing equipment under road pavements, it was decided to have a loop
length of 1.6m and width of 300mm, and the electric field intensity was measured at a point 30m away while
increasing the current A (Power W). The test condition is described in Photo 1, and the result is described in
Figure 4.
This test result revealed that embedding the power supply coil in the ground mitigates the impact ofelectromagnetic waves to the surrounding areas. Following this result, we went on to study the structure that
ensures the shielding performance against the surrounding areas, and the electric field intensity to the car
driving above the embedded coil.

Photo 1. Measurement situation at a point 30m away.

171

Electric Field Intensity (μV/m)

Power (W)

Figure 4. Generated electromagnetic waves and electric field intensity at a point 30m away.

3 MATERIALS FOR WIRELESS POWER SUPPLY AND TEST PAVEMENT
Materials for a non-contact power supply pavement also need to have functions for collecting
electromagnetic waves generated from the coil and blocking the waves from traveling sideways anddownward.
Materials typically used for pavements are aggregates such as crushed stones and sands as well as
bonding materials such as asphalt and cement. Among those materials, we focused on slag, produced in theprocess of iron manufacturing, as the magnetic body. The elements of slag are described in Table 1, andaggregates we examined are described in Table 1. In comparison to crushed stones and sands of converterslag Agg. and steel slag (55) Agg., steel slag (75) sands have the highest level of Fe in their content (Photo2). Steel sands are used as iron sands as the main element is Fe.
Table 1. Main elements of steel slag aggregates examined.
Total Fe
(T-Fe)

Lime (CaO)Slica(SiO2 )

Alumina(Al2 O3 )Magnesiumoxide (MgO)

Converter slag Agg.

21.4

38.42

15.81

1.94

7.1

2.27

0.04

5.12

92.1

Steel slag (55) Agg.

43.5

22.54

7.17

1.63

4.07

1.25

0.05

2.34

82.55

Steel slag (75) Sand

67.4

16.85

3.8

1.05

2.2

0.85

0.02

1.3

93.47

Item

Phosphoric
Manganese
Sulfur (S)acid (P2 O5 )oxide (MnO)

Total

Converter slag Agg. Steel slag (55) Agg. Steel slag (75) Sand
Photo 2. Steel slag aggregates examined.
We measured the conductance (Q-factor) by securing a coil, wound into a circular form, to apermeability measurement specimen (Photo 3), built inside a room, to determine the permeability
characteristics.
The result is described in Figure 5. The Q-factor of converter slag is lower than others. This testshows that just 20 mm of magnetic sand or CAM with magnetic sand has higher permeability than just a coil.

172

The asphalt structure we used is described in Figure 6 (Abe, N., Manabe, K. (2013)). 20mm of CAM
including magnetic sands was laid under the coil.
We used deformed stainless rebar (SUS304), typically used as support members, in the concrete
trough structure to integrate it into the structure as described in Photo 4. Each block in the concrete troughstructure was 2m long. The flexural capacity and shear capacity were examined, and the stainless rebar
structure was built with D13 main bars and 9mm distributing bars so that the structure can withstand a heavy
vehicle driving over it (Figure 6).

Photo 3. Specimen for permeability measurement and with laid coil.

Coil only
Converter slag 20mm
Steel slag Sand 20mm

Q-factor

CAM(Fe-Sand100%)
CAM(Fe-Sand50%)

Frequency (kHz)

Figure 5. Q-factor against frequency of each specimen.
600

90

90

400
Asphalt Mixture（PMAⅡ)CAM Only

Coil Φ 8mm
Aluminum plate(2mm)
CAM(Slag sand)

Asphalt Mixture

Base course
Figure 6. Wireless power supply asphalt pavement.

173

Photo 4. Stainless rebar used for concrete trough.
Concrete trough(445mm×140mm)
445

115

75

Coil (Litz wire, three)

550

115

70

60

150

80

70

Injection of cement andasphalt emulsion mortar

Laid cement mortar

Milling wide (550mm)

Figure 6. Wireless power supply concrete trough pavement.
Table 2. General description of magnetic materials used for pavement.
Type
A
B
C
D
E

Magnetic Body Description
Silica sands in the CA mortar are replaced with magnetic bodyA
As composite (aggregate) is replaced with magnetic slag
Aluminum rebar, electrically more stable than regular deformed
rebar, is used for troughStainless rebar, electrically more stable and more resistant tocorrosion than regular deformed rebar, is used for troughAluminum plate

Figure 7. A plan view and a cross-sectional view of the test pavement.
The magnetic body used in this test pavement and each work area of the test installation of shieldmaterials are outlined in Table 2.
Type A is CA mortar (asphalt emulsions: cement: silica sand = 1.4: 1.0: 1.0), currently used as
buffer materials installed under slab tracks for the Shinkansen. As a replacement, magnetic sands are usedinstead of silica sands (aggregate) in the CA mortar. Magnetic sands are burned iron oxide, which is the main

174

component, and in powder form, of which the particle size is nearly the same as a silica sand. Type B is sandsof steel slag, which contains more than 65% iron oxide, being used as fine aggregate for asphalt composite.
Type C and Type D are secondary concrete products with stainless rebar and aluminium plates(1.2mm), which contain the shielding effect that reduces the amount of the magnetic flux diffusing laterally.
More accessible aluminium plates were used in Type E. Figure 7 describes the test pavement plan andsection. The pavement width of the power supply lane was decided to be approximately 450mm inconsideration of wheel distance of the car, and all coils were buried at a point where the distance from thepavement surface to the bottom of the coil is 50mm. Three coils were buried in this test.
Photo 5 describes the coil installation of each type. We adjusted the finished surface level ofmagnetic materials to maintain the 50mm depth to the buried coils, and the upper surface of the coils wassealed with the standard CA mortar that used silica sands as aggregate.

Type B, Coil installation;

Type C, Coil installation;

Type C, Re-embedding of coilPhoto 5. Coil installation in each type of the test pavement.

4 VERIFICATION OF
SUPPLY AND
OF MAGNETIC BODYWIRELESS POWER
MEASUREMENT TESTWe
measuredradio wave leakage to thesurrounding areas when
5A current (1kW) at
200V voltage is applied tothe power supply coilembeddedinthepavement.
Themeasuring conditions ofelectric and magnetic
fields are described in
Photo
5.
The
measurements of theelectric field by the loop
coil are described in Figure 8. The electric field intensity gradually decreases as the distance increases. It isinversely proportional to the cube of the distance in the direction perpendicular to the vehicle’s running
direction, and it is inversely proportional to the square of the distance in the direction parallel to the vehicle’s
running direction.

175

Electric field (dBμV/m)

Direction along the building(inversely proportional to
the square of the distance)

Measurement ofmagnetic field

Direction to the hospital(inversely proportional tothe cube of the distance)
Distance (m)Figure 8. Electric field value against distance.
The permissible value of radio wave leakage is specified as being less than 3.46mV/m at ameasurement distance of 30m. The results in this test indicate that the values are sufficiently small, and thecurrent structure is capable of supplying power from 6kW to 9kW, although there are issues for thepermissible value of the electric field intensity of the directions perpendicular and parallel to the vehicle’s
running direction.
LED lights were connected from the power receiving coil under the car (Photo 6) through thebatteries and installed inside the car (NISSAN New Mobility Concept). The LED lights are turned on when
receiving the power so that one can visually confirm while driving if the car is receiving the electromagnetic
waves from the embedded coil when current is being applied. Photo 7. shows the driving test being
conducted. The LED lights clearly lit up when the car ran in such a way that the power receiving coil stayed
within 450mm width of the power supply lane pavement, which indicates the power was being supplied
wirelessly (Photo 8). However, the LED lights blinked randomly when the car ran in such a way that thereceiving coil was off the supply lane by 150mm to the side, which indicates the power was not being
received efficiently.
Therefore, we measured the magnetic field when the coil is away from the lane, using an Exposure
Level Tester, ELT-400 (Narda) as indicated in Photo 9. The magnetic field, Tesla, in a case of the receiving
coil being offset by 150mm to the side was a half of the value of the coil directly above the lane, and it was
nearly impossible to measure the magnetic field in a case of the coil being offset by 300mm. Therefore, it isclear that minimizing lateral movement is necessary when driving electric vehicles during the wireless power
supply stage on the power supply pavement.

Coil under the car

Trough type(SUS rebar)

Photo 6. Power receiving coil
under the car

Current being supplied tothe batteries.

Photo 7. Driving test

Photo 8. LED lights are turned on

Distance fromthe coil (mm)388 nT
Photo 9. Magnetic field measurements when apart laterally from the coil.
(Exposure Level Tester, ELT-400 (Narda), Low frequency 1Hz-400kHz)
176

5 CONCLUSIONSThis test pavement construction and driving test are basic tests aimed for the practical use of a noncontact wireless power supply system, and there are many problems to be solved in our goal to develop theinfrastructure. However, we were able to achieve the second stage for practical use as we could verify thatthe coil can receive electromagnetic waves, transmitted from the underground-embedded coil when thecurrent is applied, installed in the car, and the batteries can be charged.
Our future tasks shall be optimizing the power supply system by designing more efficient switch
systems and shields for magnetic flux, and pursuing the practical use of a non-contact wireless power supply
for electric vehicles.

6 ACKNOWLEDGEMENTS
We would like to express our gratitude to Mr. Kraisorn Throngnumchai, Mr. Akihiro Hanamura, andMr. Kazuhiro Takeda of EV System Laboratory, Nissan Research Center, Nissan Motor Co., Ltd. for theirsupport in this research.

REFERENCES
Throngnumchai, K., Hanamura, A., Naruse, Y., Takeda, K. (2013). Design and Evaluation of a WirelessPower Transfer System with Road-Embedded Transmitter Coils for Dynamic Charging of Electric
Vehicles, EVS27, Barcelona, Spain, 2013.
Abe, N., Manabe, K. (2013). Construction for running a power supply system under road paving, Japan
Road Association, 30th Japan Road Conference, V.

177

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
PAPER TITLE

Development of the three-dimensional road surface measurement technology by thehigh-speed road surface measurement vehicle

TRACK

Shigeki Ando

E-MAIL(for correspondence)

Pavement Engineering
SectionCivil Engineering
Department

Central Nippon Highway
Engineering Tokyo
Company Limited

JAPANs.andoh.aa@c-nexco-het.jp

KEYWORDS:
Inertia Measurement Unit (IMU)
Global Positioning System (GPS)Three-dimensional
Non-Contact Measurement

ABSTRACT:Our Company has developed a vehicle to measure road surface of expressway. It is capable of measuring ruts,
cracks and IRI at high speed since 1984. We have developed technology which incorporates Inertia Measurement
Unit (IMU) and Global Positioning System (GPS) data with our high-speed road surface measurement vehicle
since 2004. This technology enables detailed measurements of extensive three-dimensional road surfaces at any
speed up to a maximum of 100 km/h (60 mph). The greatest advantage of this vehicle is that can measure roadsurfaces with non-contact measurement and allows smooth and safe measurement even though there are othervehicles traveling on the same road.
We can detect deteriorated road conditions very quickly such as rutting, impact and puddle of water. Thus, we canmake countermeasure in a timely manner and secure the safety driving and contribute to disaster prediction. We havemeasured 5,710 km of road surfaces and made repair plans for 263 areas.

178

Development of the three-dimensional road surface
measurement technology by the high-speed road surface
measurement vehicle
Shigeki Ando1
1

Central Nippon Highway Engineering Tokyo Company Limited,Tokyo,JAPAN
Email: s.andoh.aa@c-nexco-het.jp
Contact number: +81-3-5339-1321

1. Introduction
Expressways in Japan are periodically inspected to check their road surface properties (rutting, cracks,international roughness index (IRI), etc.) in order to maintain good surface conditions. Vehicles that can measure
the road surface while traveling at high speed have been developed and put into service to prevent causing
congestion and minimize the risk of accidents during inspection. In recent years, expressway corporations haveinvestigated a Pavement Management System (PMS) that takes into account various kinds of road surface
evaluation data, as well as the conventional control standards shown in Table 1, to draw up highly detailed
pavement repair plans.
Deformation of road surfaces, such as are caused by the road settlement at the boundary between a bridge andearthworks and between cut and embanked sections, becomes increasingly apparent the longer the roads are used.
Such deterioration not only makes the road uncomfortable to drive on, but may also aggravate damage to roadstructures and deterioration of the roadside environment. Poor longitudinal and cross-sectional profiles caused bysuch settlement may also inhibit the smooth discharge of rainwater, resulting in water remaining on the roadsurface, which destabilizes and endangers driving. Therefore, understanding the longitudinal and cross-sectional
profiles of the road surface is essential to construct an advanced PMS.
Deformation of road surfaces over relatively long distances has ordinarily been measured by restricting lanes.
Thus, measurement has been difficult on heavy traffic routes such as the Tomei and Meishin Expressways
because any lane restriction is likely to cause congestion, and on sections with temporary service, where thetraffic volume may be small but taking the measurements can be dangerous.
Against such a background, we developed a system that can measure the three-dimensional profiles of theroad surface while traveling at speeds of up to 100 km/h without needing to restrict lanes. This was achieved byadding a global positioning system (GPS) and an inertial measurement unit (IMU) to the vehicles previously
developed by us to measure road surfaces. This system has been used since 2003.
Similar road surface measuring vehicles equipped with GPS and IMU are available. No organization otherthan us, however, has used these measuring vehicles to conduct longitudinal and cross-sectional measurements
on expressways under the control of NEXCO group companies. The measurement technology has no compare
anywhere else in the world.
This paper gives an overview of the technologies used in the new road surface-measuring vehicle.
Table 1: Target values in road surface repairs adopted by expressway companies
Rutting (㎜)National expressways
Motorways

25

Level difference (㎜)Skid resistance Roughness (σ3m)
Joint to a traverse
coefficient (μV)
or IRI (㎜/m)
Joint to a bridge
structure
20

30

0.25

3.5

Cracking ratioa
(%)
20

a

We analyzed the road in one-meter* sections – a quarter of the lane width.
Then the cracking ratio was calculated as the number of sections with cracking divided by the number ofsections analyzed.

2. Overview of the technologies
2.1 Vehicle for measuring road surfaces (Road Tiger Ver.V)
In 1982, we developed the first version of the roadsurface-measuring vehicle, whose technology was assessed andapproved by the then Ministry of Construction (present-day
Ministry of Land, Infrastructure, Transport and Tourism) in 1983.
The vehicle has undergone various improvements ever since. The
vehicle used today can measure: 1) rutting, 2) cracking, 3)international roughness index (IRI), 4) flatness (σ3m), and 5)
Photo 1: New road surface-measuring vehicle “Road Tiger Ver. V”
179

longitudinal and cross-sectional profiles; all simultaneously while traveling at speeds of up to 100 km/h, and thus
does not cause traffic congestion. (Photo 1) (Table 2) (Figure 1)
Table 2: Basic specifications of the “Road Tiger Ver. V”
Measuring method

Cracking

Multiple-point displacement
measurement method
Continuous photographing

IRI

Double integration of acceleration

Flatness σ3 m

Non-contact 3-m profile meter

Longitudinal andcross section profiles

Global positioning data/
Inertial measurement unit

Rutting

Detecting device
CCD camera
Streak camera
Non-contactlaser
displacement meter
Non-contact laser
displacement meter
GPS/IMU

Range ofmeasurement
5.2 m(0.1-m intervals)
4.5 m
One survey line
(OWP)
One survey line
(OWP)
5.2ｍ
(0.1-m intervals)

Measurement intervals(longitudinal)

Precision of measurement

0.5ｍ、1ｍ、10ｍ、20ｍ

Not exceeding ± 2 mmContinuous

Width: 1 mm or larger

0.1ｍ

Within ± 15%

1.5ｍ

Within ± 15%0.5-m intervals

Mean vertical error: ± 11 ㎜

Figure 1: Schematic diagram of the “Road Tiger Ver. V”
2.2 Rut-measuring device
In the development of a three-dimensional road surface measurement system, the most critical of the existing
technologies was the multiple-point displacement measuring technique used in the rut-measuring device, which
has been used since our first road surface-measuring vehicle was developed in 1982. The technique requires adevice with a complicated structure, which is thus difficult to calibrate, but it was the only mean by which we
could obtain the correct vertical coordinate across the traveling direction at the necessary points, which isachieved by distance pulse control. Therefore, this technology was a prerequisite for the establishment of athree-dimensional road surface measurement system able to function at high speeds. The technology is described
below.
The rut-measuring device consists of two laser slit projectors at the front of the vehicle and line sensor
cameras. Each of the laser slit projectors projects 54 beams of light at 100-mm intervals across the road, with thetwo projectors combined covering a width of 5.2 meters. The light beams are projected diagonally toward theroad surface, and thus the resultant shadows due to unevenness in the road surface are cast left and right. Their
movement is detected by the line sensor cameras installed on the top of the vehicle. Because the positions fromwhich the laser light beams are projected, the projection angles, and the angle of the line sensor cameras aremechanically determined, the changes in the positions of the light beams are monitored as observed angles, andthe positions of the light beams (unevenness of the road surface) can be determined as intersections between
projection and observation lines using the following equations. (Figure 2)tan(θ1)•Y1 – tan(θm)•Yc + X1 – Xc
Ys=
(1)tan(θ1) - tan(θm)
Xs = -tan(θ1)•(Ys – Y1) + X1

(2)

where:Xs, Ys: coordinates of light beam,
Xc, Yc: central coordinates of the lens of line sensor camera,
X1, Y1: central coordinates of the light projected from laser slit projector,
θ1: projection angle of laser slit light, andθm: observation angle of light beam.
The observation angle is determined from the mapping position of the CCD (Charge Coupled Device) pixelsof the line sensor camera by the following equations.
Lc
Np- 1
×N
2
Np
lc
-1
θm=tanHc
where:
lc: mapping position, Lc: CCD length,
lc=

(3)
(4)

180

Np: total number of CCD pixels,
N: mapping position of pixel, and
Hc: distance between CCD and the lens.
Line sensor camera

CCD length Lc
Central coordinates ofthe lens (X0, Y0)

Position of pixel

Np-1

N

Np/2

Np/2-1

Total number of pixels Np
Coordinate system

CCD length Lc
Observation angleθm

Mapping position Ic

Observation
line

slit line

lens

Projection angle
θ1

CCD distance HcCentral coordinates ofthe laser slit projector(X1,Y1)

Observation angle
θmRoad surface
Coordinates of slit light(Xs, Ys)a) Principle of measurementb) Observation angle and mapping position of pixels
Figure 2: Principle of rutting measurement
High resolution is achieved by using a CCD that features as many as 5,150 pixels. Mechanical errors andoptical strain of the lens are corrected by the measuring control unit and host computer, and excellent overall
precision of ±2 mm is achieved.
In order to measure rutting, a measuring range of about ±100 mm
was considered necessary to deal with the unevenness of the roadsurface and vibration of the vehicle. Such a large measuring range
causes light beams projected at 100-mm intervals to interfere withthe adjacent beams. The system manages to achieve a measuring
range of ±100 mm while retaining the small cross-sectional
measuring intervals by emitting alternate beams of red (690 nm) andinfrared (780 nm) light and detecting the beams using line sensor
cameras with optical filters installed that preclude one of the
wavelengths. (Photo 2)
Photo 2: Exterior view of the vehicle in measurement mode
Note: Only the 26 red light beams are visible (690 nm @ 200 mm)
The system can determine the vertical coordinates of the road surface across the traveling direction
independently from the traveling speed by sampling 54 light beams simultaneously, which minimizes the effects
of vehicular vibration while traveling at high speeds.
2.3 Longitudinal and cross-sectional measuring technology using GPS and IMU
The basic technology for this measuring system is kinematic GPS under the interferometric positioning
method, which involves conducting measurements at unknown observation points using a traveling vehicle,
receiving signals from GPS satellites based on known fixed electronic datum points, movable ground stationsand virtual reference stations, and correcting errors using the phases of the carrier waves. Moreover, the inertial
measurement unit (IMU), which consists of a triaxial optical gyro and three silicon accelerometers, precisely
records the position and inclination of the vehicle at 200 Hz. The post-processing system combines the resultant
longitudinal and cross-sectional measurements, enabling the road surface to be precisely assessed in three
dimensions (at 0.5-meter intervals longitudinally and 0.1-meter intervals across the road) (Figure 3).
A prominent characteristic of the system is that the IMU technology enables the road surface to be measured
even in areas where GPS satellite signals are weak, such as in steeply sided sections, near tall noise barriers, andunderneath overhead bridges, as well as in places devoid of signals, such as in tunnels.
Artificial satellite

Movable ground station
Electronic datum point(Geographical Survey Institute) (To be set at an arbitrary position)
Longitudinal and crosssectional analysis

Road surface measuring vehicle(moving station)

Figure 3: Kinematic GPS measurement using the road surface-measuring vehicle
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Coordinates are determined by calculating the origin of measurement (X0, Y0, Z0) from the position of the
IMU in relation to the vehicle axis, which is determined from the position of the unit and the posture data of thevehicle (pitching, rolling and direction), adding the calculated rutting data (0, Yn, Zn) to the origin, andcomputing the position of each laser beam (Xi, Yi, Zi). From this position (Xi, Yi, Zi) and the data of the postureof the vehicle, the coordinates are converted into those of the North-East-Down coordinate system* to calculate
the absolute coordinates of the points. (three-dimensional data link; Figure 4)
GPS／IMU（Xi、Yi、Zi）

計測原点（X0、Y0、Z0）
Originof measurement(X0, Y0, Z0)*North-East-Down coordinate system
North axis: Line that passes through the origin, is on a plane
parallel to the tangent plane to a reference ellipse at the geographicalposition of the origin, and is positive towards true northEast axis: Line on the same plane as that of the North axis and ispositive toward the east
Down axis: Line that is positive vertically downward to the NE
plane

Figure 4: Schematic diagram of three-dimensional data link
The kinematic method is believed to be accurate to within about 2 to 3 cm. However, this measurement
system achieves vertical errors caused by relative displacement of only 11 mm on average with thepost-processing system and IMU correcting the GPS data and thus improving precision. The accuracy has been
confirmed on expressways in service. This degree of precision is likely to be adequate to understand changes inthe three-dimensional profile of road surfaces from the time of completion, but errors are further minimized byinstalling temporary benchmarks.
4. Conclusions
The three-dimensional road surface measurement system on a new measurement vehicle can measure andassess the present longitudinal and cross-sectional profiles of the road surface, and the measurements can be used
to improve designs (profile modification) when restoring road surfaces that have been deformed by settlement of
weak ground or earthquakes. The system is a completely new technology for measuring and designing roadsurfaces as it not only measures changes in road surface conditions, but can also use the measured coordinates as
design data – unlike conventional methods, which only compare road surface data, such as rutting, cracks and
IRI, with standard values.
The system has numerous advantages over leveling, which requires lane restrictions, including: 1) ensuringsafety while taking measurements, 2) maintaining traffic convenience by not restricting lanes while reducing therisk of congestion and traffic accidents, 3) improving the efficiency and reducing the costs of taking
measurements by enabling long sections to be measured quickly, 4) facilitating the work involved when ordering
improvement projects, and 5) increasing the precision of road maintenance technologies through comprehensive
assessment with conventional road control indices.
The system has already been developed and is in use on actual roads. With the original design modification aid
system, the system can estimate future ground surface conditions from its measurements and calculate the costs
for different profile designs freely. It has been used to measure the profiles of some 5,710 km of roadway, anddesign surface modifications for 262 sections.
The system still has several points to be improved, such as: 1) ranges outside the measurement width of 5.2 m
need to be designed using estimated values, 2) it is difficult to measure sections at low speeds, such as at ramps,
due to the properties of the measuring instruments, and 3) up and down lanes cannot be designed as a single
profile due to measurement properties. These topics will be actively investigated.
In addition, there are not the operation results out of Japan to date, but the operation in foreign countries wants
to let you accelerate the technology development that you put in the field of vision in future.

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Innovative improvement to restrooms in rest areas
Gaku SUZUKI
Business Planning Division, Central Nippon Highway Maintenance Nagoya Company Limited,Japan
Email for correspondence: g.suzuki@c-nexco-hmn.jp

1.

INTRODUCTION

This paper describes a program of restroom cleaning on expressways managed by Central Nippon
Highway Maintenance Nagoya (hereafter, “Central NEXCO HMN”). The program described hereincomprises the following five points. This five-point program changed the nature of this work from simply
cleaning to cleaning that provides hospitality to the customers. As part of this program, we changed the term
used for “cleaning staff” to “area cast” and created a high-motivation workplace where staff can enjoy
working, and we have succeeded in making expressway restrooms clean and attractive like those in a hotel.

1: Changing from conventional cleaning with water and detergent to cleaning with electrolyzed water
2: Use of a gum removal machine and floor washing machine
3: Hospitality provided to customers by the area cast
4: Improving the hospitality level through makeup training and customer service training
5: Restroom diagnosis, use of a cleaning manual, and use of a cleanliness level scoring system
6: Conclusion

1: Cleaning with electrolyzed water
The conventional way of cleaning expressway restrooms involved manual scrubbing using detergent,rinsing with large amounts of water, and allowing everything to dry naturally (Figure 1). This method had
the following problems.

Figure 1: Conventional cleaning method

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Problems(1) Because the entire floor became wet, there were instances when customers’ trousers became dirty, andaccidents when customers slipped and fell also occurred.
(2) Because time was required for cleaning, restrooms were often unavailable when buses or tour groups
arrived.
(3) Because large amounts of detergent and water were used, the environmental impact was large.
(4) Detergent foam and water puddles would remain behind after cleaning, and required much work forremoval.

In order to improve customer service and lessen the workloads on area cast, Central NEXCO HMN
introduced a new cleaning method using electrolyzed water.
Electrolyzed water is tap water that has been broken down by salt and electricity to produce two types ofwater: acidic electrolyzed water and alkaline electrolyzed water (Figure 2). Although there are three major
methods of producing electrolyzed water, Central NEXCO HMN uses the “3-chamber electrolyzer withdiaphragms” method. (Figure 3)
The 1-chamber electrolyzer method is not used because it requires dilute sulfuric acid in order to produce
the electrolyzed water, posing a risk to the staff who produce it. The 2-chamber electrolyzer method is not
used because it produces electrolyzed water with a high salt content that can corrode drainage pipes andother metal fixtures. The 3-chamber electrolyzer method was selected because the electrolyzed water does
not contain salt and because it is safe, since the only materials required to produce it are salt and water.

Figure 2: Production of alkaline water and acidic water

Figure 3: Formula for the 3-chamber electrolyzer production process

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Central NEXCO HMN introduced the use of electrolyzed water in 2011, and now uses it for the
restrooms of nearly all rest areas (92 locations).
Electrolyzed water is water that has been separated into acidic electrolyzed water and alkaline
electrolyzed water, each with unique characteristics.
The characteristics of acidic electrolyzed water include high disinfecting and deodorizing effects. A testcomparing the disinfecting effects of acidic water and the detergent previously used showed that theremaining bacteria count was 80% lower with acidic water than when detergent was used. Because of thepowerful disinfecting effects, the deodorizing effects of acidic water are also high and pouring it intodrainage pipes can prevent odors. The acidic water is hypochlorous acid, and is effective in disinfecting
pathogens such as E. coli, salmonella, and norovirus. Consequently it can contribute to preserving the healthof users and the area cast. (Figure 4) (Figure 5)

Figure 4: Graph of bacteria count reductions after the use of electrolyzed water

Figure 5: Sterilizing effects of electrolyzed water185

Alkaline electrolyzed water is characterized by high cleaning effects. It has the same effect as soap on theoil spots that frequently occur in places where people walk on the floor, and on the protein stains thatfrequently occur in places where people touch. However unlike soap, the slipperiness can be eliminatedsimply by wiping it away, reducing the time required for cleaning. (Figure 6)

Figure 6: Oil removal test using alkaline water

Central NEXCO HMN uses an electrolyzed water mixture of the two types of water. The ratio of acidic
electrolyzed water to alkaline electrolyzed water is 1:1. Even when mixed together, the water does not
become neutralized for approximately 8 hours, and each water type retains its individual characteristics. The
water is mixed just before the start of cleaning, and the electrolyzed water mixture is used in place ofdetergent as water with high disinfecting and cleaning abilities.
The acidity is around pH 3, and the alkalinity is around pH 11 – approximately the same as commerciallyavailable detergents.
The use of electrolyzed water mixture has resulted in a change from conventional wet cleaning withdetergent to dry cleaning with electrolyzed water. As a result, the acidic water reduces the growth of bacteria
and eliminates odors, while the alkaline electrolyzed water removes accumulated dirt and stains. It also
shortens work times and reduces workloads.
The cleaning procedure is extremely simple, and involves filling a hand-held sprayer with electrolyzed
water and applying it to the floor and toilets, then wiping it off. This has reduced work times byapproximately 60% compared with the conventional cleaning method. It has also increased the time that the
restrooms are available for customer use, and allows staff work on locations which could not be fully cleaned
before due to lack of time, increasing the cleaning quality. (Figure 7)
However because electrolyzed water is a strong acid or alkali, some caution is required when handling it.
Rules require that gloves be worn in order to prevent skin irritation, and that work areas be ventilated. Aslong as these rules are observed, electrolyzed water can be used for long periods without any adverse healtheffects.

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Figure 7: Dry cleaning with electrolyzed water (spraying and wiping off only)
2: Cleaning with a gum removal machine and floor washing machine
In order to improve cleaning efficiency, Central NEXCO HMN has introduced compact cleaningmachines that can be operated easily by anyone. This has changed conventional manual scrubbing work
using brushes to work that is mechanized and efficient. The machines were selected from the perspective of
the female area cast who would use them, and the selected products require little force to operate.
Replacement of consumable parts and charging can also be done easily. The use of electrolyzed water withthe machines has also improved the level of tile cleanliness. (Figure 8)

Figure 8: Cleaning with the machine
We also introduced a machine for efficient removal of discarded gum from rest area sidewalks. Thismachine discharges steam together with a special solvent that melts the gum, and then uses suction to pull off
the melted gum. A single piece of gum stuck to the floor can be removed in 2 – 5 seconds. The machine ispopular with the staff as it reduces the burden on the workers and shortens work time compared to theconventional work method of using a metal spatula. (Figure 9) (Figure 10)187

Figure 9: Using the gum removal machine

Figure 10: Work with the gum removal machine (Left: Before work, Right: After work)

3: Hospitality provided to customers by the area castCentral NEXCO HMN received positive evaluations from users and contracting agencies for the
improved cleaning quality resulting from cleaning with electrolyzed water and the use of machines. As aresult, this provided a motivation boost to the area cast, who began independently providing hospitality to thecustomers while cleaning. They began by placing seasonal flower decorations in the restrooms. At first, thesewere just small vases, but as customers commented on the beauty and relaxing effects of the flowers, thisfurther increased the motivation of the cast. (Figure 11)
Later they began using pieces of wood from trees cut during construction and other supplies to makedecorations at the entrances to the restrooms, and are working to provide hospitality that continues to delightthe customers today. (Figure 12) (Figure 13)
Word of these efforts spread, and the area cast has been interviewed by newspaper companies andreceived observational visits from overseas organizations. (Figure 14)

Figure 11: Flower arrangements in the restrooms

Figure 12: Decorations using by-product materials

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Figure 13: Decorations made from origami

Figure 14: Area cast being interviewed by anewspaper reporter

4: Improving the hospitality level through area cast makeup training and customer service training
The Central NEXCO HMN area cast now provides services to customers as they are cleaning. For thispurpose, we introduced customer service training so that they can learn the correct manners for interactingwith customers. Because more than 90% of the area cast members are women, we also included makeup
training for them.
For customer service training, we conduct a training session each year and invite an instructor who
previously conducted staff training at Disneyland. The training contents are not manual-based, but rather are
intended to create area cast who can think independently and provide services from the customers’
perspective on their own. This training was highly rated by the area cast who participated in it. (Figure 15)
They also learn the cleaning methods used at Disneyland, and learn how to provide hospitality to thecustomers while cleaning. In addition to the Disneyland instructor, we conduct manners training led byairline cabin attendants.
The makeup training for area cast has also been popular with the participants (Figure 16). For this training,
we invite a lecturer from a cosmetics manufacturer to teach the participants about makeup manners forcustomer service, and about how to apply makeup that will stay in place even when they perspire in thesummertime.
The area cast is composed primarily of older persons. The average age is 55 and the oldest member is 67.
The majority of the area cast previously would work without makeup, but as opportunities for contact withcustomers increased, the number using makeup has also increased. This makeup training has been wellreceived, with participants saying that it gives them confidence and is also useful in their private lives.

Figure 15: Training with a Disneyland instructor

Figure 16: Makeup training189

5: Restroom diagnosis, use of a cleaning manual, and use of a cleanliness level scoring system
Improvements are made to the level of our restroom cleaning every year. However it is true that not every
restroom is at the same level of cleanliness. Aiming to further improve these levels, the Central NEXCO
HMN restrooms undergo inspections by restroom consultants who are certified based on the in-housecertification system prescribed by the Japanese Ministry of Health, Labor and Welfare.
There are approximately 30 diagnostic items. Diagnosis is not only visual, and is also performed using
instruments such as an odor meter and concentration meter. Locations such as inside drain pipes and behindequipment where dirt can adhere and cause odors are also checked. The diagnosis results are quantified andreported to the area cast of each restroom facility, with scores indicating places where cleaning wasinadequate, and places that were cleaned well and worthy of praise. Because the restroom consultants
evaluate all the restrooms based on the same inspection level and diagnostic items, this diagnosis has enabledCentral NEXCO HMN to work for a consistent level of cleaning quality. (Figures 17, 18)

Figure 17: Diagnosis using a measuring instrument

Figure 18: Checking a drain for odor

The restroom consultants do more than just perform diagnosis. They also provide instruction in efficientcleaning methods that include methods of removing dirt that cannot be removed with electrolyzed water
alone, cleaning methods that will not harm porcelain toilets, and how to polish mirrors and stainless steel
products. Participants are also taught how to use a hand mirror to check places that are not directly visible inorder to improve the level of cleanliness. (Figures 19, 20)

Figure 19: Restroom cleaning instruction

Figure 20: Checking for cleanlinesswith a hand mirror

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A manual has also been created for new members of the area cast. It contains diagrams showing cleaning
methods and locations that are likely to become dirty. Because the manual also includes customer service
instruction as well as cleaning instruction, it can also be used for OJT of new employees. (Figures 21, 22)

Figure 21: Area cast manual (cleaning section)

Figure 22: Area cast manual (hospitality section)

5. Conclusion
Before the expressways were privatized around 10 years ago, the image of expressway restrooms was ofdark and dirty places. The area cast who worked there also had little knowledge of cleaning, and the turnoverrate of persons leaving the job was high. However the adoption of methods that make the facilities more
comfortable to the customers, and methods for efficient cleaning, has resulted in customer expressions ofgratitude and satisfaction reaching the area cast. This is a good example of employees who were able toimprove the level of their own work when their work was praised by the customers. Now the expressway
restrooms are featured in related pamphlets and other materials as model examples of clean restrooms.
Warm-water washing toilet seats and disinfecting cleansers have been installed at all expressway restrooms,
making them some of the top restrooms in Japan both in terms of cleanliness and equipment. As a result,supervisors of railway companies, park facilities, and theme parks have come to Central NEXCO HMN tolearn about our cleaning methods. We are working to train area cast personnel and are studying more
efficient cleaning methods, aiming for further improvements in the future.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Decision Support In Real-Time Traffic Management

TRACK
AUTHOR(Capitalize Family Name)
Johannes SCHLAICH

CO-AUTHOR(S)(Capitalize Family Name)POSITION
Director ProductManagement & Services Traffic Software
POSITIONORGANIZATIONPTV Group

COUNTRY
Germany

ORGANIZATIONCOUNTRY

Thomas OTTERSTÄTTER

Senior Product Manager
PTV Vision Online

PTV Group

Germany

Nate CHANCHAREON

Managing Director Traffic Software

PTV Asia-PacificSingapore

Luca PAONE

Solution Director forRealtime Products

PTV Group

Italy

E-MAIL(for correspondence)

Thomas.otterstaetter@ptvgroup.com

KEYWORDS:
Include up to 5 keywords
Real-Time
Traffic Management
Decision Support
Traffic State Prediction
Model-based

ABSTRACT:
Traffic managers know from experience what traffic is going to be like during a specific time and day of the week andcan therefore handle incidents that occur regularly. They use real-time information from detector data, floating car data
(FCD) and cameras. However, these data records only cover a certain part of the area. A daily challenge - because if
something unusual happens or if several unprecedented incidents occur at once, traffic managers will be stressed
quickly.
That is why they need support. Cities and regions are therefore increasingly making use of decision support tools for
traffic management, which support traffic state prediction and scenario evaluation. In this paper we want to discussdifferent approaches for this task (mostly statistical vs. simulation-based), the role of big data and traffic demand andshowcase a real-word application.

192

Decision Support in Real-Time Traffic Management
Dr.-Ing. Johannes Schlaich1
Dr.-Ing. Thomas Otterstätter2
Nate Chanchareon3
Luca Paone4
1

PTV Group, Karlsruhe, Germany
johannes.schlaich@ptvgroup.com
2

PTV Group, Karlsruhe, Germany
thomas.otterstaetter@ptvgroup.com
3

PTV Asia-Pacific, Singapore, Singapore
nate.chanchareon@ptvgroup.com
4

PTV Group, Rome, Italyluca.paone@ptvgroup.com
1. INTRODUCTION
Around 50 per cent of all Germans have a smartphone (Statista 2015). Three quarters of those access Internet
content on the go and 50 per cent use apps for different aspects of day-to-day life: and these numbers arerising. Transport-related applications are in the top five of the most-used apps (ARD/ZDF 2014). This
includes the latest traffic information, navigation and route planning tools and timetable information. The
current availability of real-time data is increasing people’s expectations. “Real-time” is no longer just a
buzzword but is part of the here and now, and modern traffic management can no longer shy away from it.
But how can data streams be processed smartly, what are the limits to big data and how can demandmodelling fill this gaping void? Worldwide, 2.5 Exabyte (or 2.5 billion bytes) of electronic data are produced
per day. It is hard to imagine, but entirely true, that 90 per cent of all electronic data has been produced in thepast two years (Barnes et al. 2014). And this statement will remain true in the future as the numbers of data
sources and the volumes of information they generate are set to grow exponentially. Data on mobility
behaviour make up a portion of this: With each piece of information on timetables and each route planningquery, travellers disclose information on their mobility behaviour and contribute to the rise in data volume.
And yet today this information is still often not available to transport managers. Their real-time information
is fed from data from detectors, floating car data (FCD), automatic number plate recognition systems(ANPR) and accident- and road works reports. This is how they obtain an overview of the current traffic
situation of the observed area and can react to regular disruptions thanks to their many years of experience.
2. METHODOLOGYSTATISTICAL VERSUS MODEL-BASED
Thanks to traffic forecasts, the transport manager is getting more and more room for manoeuvre for choosing
the best measure to take. Today there are two main distinct approaches in traffic forecasting: the statisticaland the model-based approach (FGSV 2012) (see Table 1). The statistical approach uses interpolation,interference, data collection, artificial intelligence and mathematical models to compare observed time
periods with historical patterns. The traffic flow and speed variables are analysed and predicted without
explaining and reproducing the underlying phenomena, i.e. the interaction between the vehicles and thedriver behaviour. Statistical techniques are suited to projecting low-volatility traffic measures or recurring
traffic patterns. They come up against their natural limits, however, if there is not enough historical data from
sufficiently similar situations. This happens in particular with unusual situations, when accidents occur orroad works are set up.

193

If someone wishes to react to these situations in real-time, model-based approaches can be used for theforecasting.
Table 1. Statistical and model- based approach in direct comparison

Objective
Traffic estimation“What is going on?”Traffic forecast

MethodStatistical
Approach

Model-based
Approach

Maybe, withextensivemeasures

Yes

Yes

No

Only “usual”
conditions

Yes

No

No

Yes

Observed Data

“What is going to happen?”
Scenario evaluation &decision support“What would happen if?”
“How should we act?”

MODEL-BASED TRAFFIC-MANAGEMENT IN REAL-TIME
In contrast to statistical processes, the model-based simulation approach relies on a physical interpretation of
the traffic network and conditions. This is added to the supply through an explicit simulation of the interplay
between travel demand and the transport network. model-based solutions such as PTV Optima, which can
output dynamic forecasts for a time horizon of up to 60 minutes, combine for proven off- line trafficmodelling with real-time data and algorithms.
On this basis, a traffic model created in the traffic planning software PTV Visum, for example, shows the“typical” day (e.g. workdays or week- ends) in the transport area under consideration. The transport supply
and demand are then represented in the form of demand matrices. Dynamic traffic assignments calculate thetime-dependent volumes and turn proportions on the network from the travel demand (for further information
see Bellei et al. 2005, Gentile et al. 2005, Gentile et al. 2007 or PTV Group 2015). PTV Visum passes all thisinformation on to PTV Optima (Figure 1).

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Figure 1. Logical architecture for model-based traffic management.
In PTV Optima, the online data therefore comes into play. The data is used in real time in PTV Optima toadjust base model capacities, speeds or volumes from PTV Visum locally to the latest circumstances. As
PTV Optima explicitly takes into account the network structure, traffic flow dynamics and travellers’ route
choice behaviour, it also reproduces the traffic situation for links on which no detectors have been installed(spatial distribution) and can furthermore predict the effects of planned and unexpected results (temporal
distribution) and then evaluate and compare different strategic measures.
OFFLINE METHODOLOGY
The offline part is devoted to the construction, calibration and update of the transport model, and to provide,by means of a dynamic assignment model, base estimations and forecasts of traffic behavior and travel time
conditions for typical non-disrupted days and/or for possible incident patterns.
Once the model and the base traffic conditions are available, the online part will use the latter combining
them with the measures coming continuously from the field into a real-time traffic model, that will basicallyadjust the traffic estimation and forecast to the measured traffic conditions of that particular day. The online
part is completely automatic and runs “continuously”: that is, a new traffic estimation and forecast is
produced every few minutes.
The base transport model relies on a PTV Visum transport model either new or already existing. This basetransport model is firstly calibrated and utilized off-line with the Traffic Real-time Equilibrium (TRE) add-inof PTV Visum in order to calculate a base traffic estimation. This is typically done for different day types,that are an a priori estimation of link flows, queues, travel times that reproduce average observed traffic
conditions for different typical days as well as base path choices, in the form of turn splitting rates at nodes
and represents how the travel demand will distribute on the different network for the same day type. Within
operational planning activities, TRE allows also to assess possible control and management strategies, which
can then be activated in real-time.

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TRAFFIC MANAGEMENT SCENARIOS
When disturbances are modelled into the forecasts on the network, it is necessary to react and rectify thesituation. Cities and regions have different objectives in this. Transport for London (TfL), for example,
measures its success by the reliability of the transport network (Transport for London 2012). PTV Optima is
flexible in its use of Key Performance Indicators (KPI) which deliver aggregated information on the overall
network status in addition to the graphical feedback, and displays the basis for a decision that can be assessed
quickly. The KPIs can be adjusted flexibly and it makes no difference whether the user has set the avoidanceof traffic, the minimising of travel time or the reduction of negative effects of planned or unpredictable
events as the main criteria. Typical tools for reacting to this include traffic light signals, the unblocking oftraffic lanes, variable message signs and traffic information reported on the radio and Internet.
To resolve traffic jams, these tools are often used directly “on the living object”. Through their experience,experienced employees in traffic management offices can of course already now choose effective strategies.
However, this way makes it impossible ever to find out whether a different strategy might not have been
better. Seen from this angle, is it not better to test these and their alternatives in a virtual world? offline, in
PTV Visum for example, strategies which have been developed can be introduced to the PTV Optima online
environment, assessed, compared and ranked on the basis of the current traffic situation, before they are thensent onto the streets. PTV Optima is therefore capable of calculating many combinations of strategies
simultaneously within a few minutes, including for large networks. This means that the best possible strategy
can be applied as soon as possible. Using this process, the transport manager builds up his wealth ofexperience with unforeseen circumstances, develops confidence about the different scenarios and can choose
from the optimal measures recommended by PTV Optima so that the traffic on the road network returns to“normal”.
ONLINE METHODOLOGY
Within the online part, real-time traffic data, representing measures of the road network state, are collected in
the form of: probe trajectories and Automatic Vehicle Location data, coming from single vehicles,
commercial fleets or public bus fleet
 travel time measures, derived from FCD trajectories from probe vehicles or comparable data
sources like e.g. Automatic Number Plate Recognition (ANPR) systems
 detector data, that is flow and occupancy measurements from detectors on links
The first two data sources are associated in real-time to the link graph by the Vehicle Tracker (Figure 1), bymeans of an on-line map-matching procedure, and will calculate observed average link speeds.
The Traffic State Harmonizer (Figure 1) will complete the traffic data pre-processing, merging all observed
measures (i.e. both traffic counts and FCD-derived speeds) into real-time traffic measures of vehicular flows,
speeds, densities and capacities on the links of the road graph.
In parallel to traffic data, also planned and unplanned events, such as road-works, congestions alerts,
accidents, but also current status of control devices like signal green and cycle times, are imported
continuously into the system, and their effect on the road network in terms of temporary speed and capacity
reductions is automatically calculated. Then, the simulation TRE is used in its real-time configuration, withina Rolling Horizon Dynamic Traffic Assignment procedure, the base transport model with the traffic measuresand event effects in order to produce every few minutes a new real-time traffic estimation and forecast, that is
the flows, queues and travel times on all network links, as well as their evolution over time in the next future.
Additionally, TRE is able to reproduce the effect of management scenarios, that is traffic management
strategies (e.g. different signal programs or activations of variable message signs), isolated or combined
together to represent complex scenarios. These strategies need to be prepared a priori, like the base model,
but can be combined in real-time in any combination and simulated in parallel to the base simulation asadditional scenarios. The comparison of the results of the different scenarios is assisted by the calculation of
Key Performance Indicators (KPI) like e.g. the total travel time in the network.

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TRE in its real-time configuration is aimed at reproducing as closely as possible the real operation of thewhole network in terms of current traffic state (density, speed and capacity of each link) and of its evolution
over time, producing every few minutes the estimation and forecast of the actual traffic flow condition on the
network.
To this end, TRE exploits an advanced methodology for modelling transport demand and vehicle congestion,
through which the behavior of drivers and the propagation of queues are explicitly represented. The
connection to current traffic conditions is guaranteed by field measures at discrete points (loop detectors,
speed radars, video cameras, probe vehicles) that are collected in real-time and sent to TRE, which is able toreconstruct the current and future traffic pattern on the entire network, hence extending the available data intime and space to provide useful information for driver navigation and transport optimization.
The modelling paradigm adopted within TRE, primarily based on the physical interpretation of the traffic
phenomena, differs substantially from the mere interpolation of field measures through artificial intelligence
methods. Most monitoring systems apply, in fact, data mining techniques to match the current time-series
with historical patterns, thus providing forecasts only on local and typical conditions. However, the statisticalinference alone may not allow to deduce the traffic state of unmonitored links from the observed data or toforecast the consequences of unpredictable atypical events such as road accidents.
PTV Optima is thus specifically conceived for metropolitan contexts, as said in Meschini and Gentile (2010),
where the congestion is strongest, while the day-to-day variability and the within-day fluctuation of vehicle
flows and travel times is not negligible; but it can also be installed in extra-urban frameworks, that are lesscomplex by their nature.
The mathematical model underlying TRE is based on an explicit representation of traffic phenomena, withparticular reference to flow and congestion propagation. In particular, this method adopts as its simulationengine the GLTM (Gentile 2008), which is a macroscopic dynamic network loading model based on the
Simplified Kinematic Wave Theory. Key features of the GLTM are: the possibility to adopt a fundamental
diagram with general shape; complete representation of general intersections, even signalized; no need for
spatial discretization of links (contrary, for example, to the Cell Transmission Model). Thus, the proposedmodelling approach is opposed to micro-simulation, in which individual vehicles are operated as separate
elements. Therefore, the GLTM is computational wise a lot faster than microscopic simulations - this in turnallows the simulation of larger or more detailed networks.
In order to obtain a continuous update of the traffic forecast, the GLTM is sequentially applied with a rolling
horizon schema, exploiting both the Base Transport Model and the traffic measures and events gathered frommonitored links.
Specifically, a continuously updated traffic flow forecast is achieved by performing a sequence of real-time
dynamic traffic propagations over the network in rolling horizon. In order to correctly implement the rolling
horizon context, each simulation will not start from empty network initial conditions, but instead will adopt
as initial conditions the traffic state calculated by the previous simulation in correspondence of its initialinstant; this way, the congestion situation will be “transmitted” from one simulation to the next one. Making
sure that previously calculated queues and/or measure-derived variations are inherited.
This concept is schematically depicted in the example provided in Figure 2: within this example, a new
simulation is launched every 5 min; each simulation has a simulation horizon of 35 min, spanning withrespect to the launch time, from 5 min in the past (this way the current simulation takes into account all themeasures and events arrived to the system between the launch time of the previous simulation and the launchtime of the current simulation) to 30 min in the future (in order to allow producing e.g. 15 and 30 min
forecasts).

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Figure 2. Example of a simulation timeline.
3. APPLICATIONITS Vienna Region is the joint traffic management project of the three Austrian provinces Vienna, Lower
Austria and Burgenland. After a very good experience with the old PTV product “Traffic Platform” the ITS
Vienna Region decided to go for an update with the brand new product for traffic monitoring and traffic
forecast: PTV Optima.
THE MODELThe base of this system in Vienna was a model with dynamic assignment built by PTV starting from thestatic model already existing for the old platform. The model covers an area of approximately 27,000 km(Vienna region). The selected network is a part of the national unified network GIP and was built in PTV
Visum using this reference network.
The total number of covered street links is 149,678 while the simulation runs on a simplified network(composed by all meaningful and major roads) of about 50,000 links. The study area was divided in 1,096
zones and the available historical data were used to build hourly O/D matrices for 3 typical days. Demand
was corrected by Fuzzy matrix correction methodology (PTV Visum 2015. A Dynamic user equilibrium(using the TRE add-in available in PTV Visum) was calculated offline until the typical flow and speed curves
were deemed to be satisfying with client requirements.
THE ITS INFRASTRUCTURE
ASFINAG, ÖBB, Wiener Linien (public transport operator in Vienna), the police, the traffic information
center of Austrian broadcaster Ö3, Carsharing and Citybike Wien and all services within the public
administration are all data partners of ITS Vienna Region (Figure 3). Over 3,500 taxis belonging to the taxi
companies continually send in their GPS data, including information on position as well as speed, which isused to draw up the real-time traffic report. All the available data (mainly data from 780 loop detectors
giving flow and speed, taxi trajectories and events generated by the third part systems mentioned above) are
given in real time to the PTV Optima system.

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Figure 3. ITS Vienna Region project partners and schematic data flow (ITS Vienna Region 2016).
DATA FUSION
The Data Fusion engine processes the traffic state data in order to normalize them and to filter what isunreliable. In some case detectors can deliver only partial lane information, and thus PTV Optima fills theremaining lanes with a similar value, other times only taxy trajectories are available and thus speed isreconstructed according to consolidated map-matching algorithms (see Marchal et. al 2004). Unreliable (likeunrealistic flow drops or flow raises) values are filtered. In case of multiple available data sources on thestreet link the system is able to weight the sources also according the number of samples (e.g. FCD speed
data are more reliable whenever more cars are passing through the observed link).
Events are forwarded to PTV Optima by partners like ASFINAG using the well-known DATEX2 (seewww.datex2.eu) European standard to exchange traffic information. PTV Optima then translates
automatically the impact of any events in terms of capacity or speed restrictions that will affect the runningsimulation. These events are then available not only to the simulation but to every system that uses PTV
Optima results.
THE ONLINE SIMULATION
Simulation is automatically recalculated every 5 min, in case of necessity it can triggered manually. Runtime
is about 90 s. Results forecast the next hour in time slices of 15 min.
RESULTS

The Transition to the new system was according to the client successful, with full and seamlessly
integration in the client IT architecture.
Estimation and forecast available in term of speed/flow for every main link of Vienna region.
These data are used by the client not only for traffic information but also for planning and offline
traffic estimation.
On a selection of 100 working detectors the accuracy of the model for the 15 min forecast wasmeasured. The comparison has been made between the current estimated out-flow from thesingle detector (which reflects the real-time data that are put inside the models as the inflow
value of that link) with respect to the predicted outflow calculated 15 min before. This showedthat for 80% of that detectors the mean daily GEH is 5.19 which is specifically for a real-time
application a very satisfying value (for GEH reference please refer to UK Highway Agency
1996).
PTV Optima results feed the national VAO journey planner for private transport where they areused to obtain more efficient routes for drivers, taking into account FUTURE short-term
formation of congestions and queues. The public website of the VAO project is
http://www.verkehrsauskunft.at.

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4. CONCLUSIONS AND OUTLOOK
Fusing Real-time models and transport algorithms with huge amounts of real time data is a modern way toanalyze, monitor and predict traffic. In fact this allows to reproduce dynamically emerging queues, speed
drops and thus react to planned and unplanned events. It has been demonstrated that starting from a dynamic
model it is possible to build a complete suite of functionalities that can help cities to plan, monitor, forecast
the traffic and to give the right advice to every driver at the right moment.
Travel demand is very often produced in the transport planning using a classic demand model. This covers
the trip generation (how many routes are done for each trip purpose?), the trip distribution (what destination
has been selected?) and the choice of transport (with which means of trans- port is the destination reached?).
By modelling the decision-making behaviour in this way, the model can be made more sensitive to measuresconnected with typical transport planning issues (Schlaich & Heidl 2016, Friedrich 2011). For traffic
management which emphasises private transport, on the other hand, purely empirical matrices can be used,such as those obtained with mobile data (Friedrich et al. 2011).
With the steady rise in the availability of real-time data, the demand matrix calculated in advance can be
replaced in the long run by real-time demand from data sources which actually come about by optimisingindividuals’ mobility (apps, navigation services, and so on). In this way, real-time data can detect not only
the current traffic situation, but also the current destinations of travellers who are potentially deviating fromtheir “typical” day. In this case too, a forecasting model is essential for predicting the traffic flow using fast
assignment procedures. These are processes that are currently used in real-time traffic management.
5. REFERENCES
ARD/ZDF (2014), ARD/ZDF-onlinestudie, [ARD/ZDF online study] www.ard-zdf-onlinestudie.de,Germany.
Barnes, J., Hitscherich, K., Koesling, S. (2014), How do you turn Big Data into intelligence? New data
sources for transport modelling, white paper of the PTV Group, Karlsruhe, Germany.
Bellei, G., Gentile, G., Papola, N. (2005), A within-day dynamic traffic assignment model for urban road
networks. Transportation Research B 39, S. 1-29., http://www.sciencedirect.com, Transportation
Research Board, Washington, D.C., USA.
FGSV (Road Traffic Research Association in Germany, 2012), Hinweise zur Verkehrsprognose inverkehrstechnischen Anwendungen [Instructions on traffic forecasts in traffic-related applications],
FGSV No. 382/1 (Information paper W1), FGSV publisher, Cologne, Germany.
Friedrich, M. (2011): Wie viele? Wohin? Womit? Was können uns Verkehrsnachfragemodelle wirklichsagen? [How many? Where to? What with? What can travel demand models really tell us?], Heureka 11
conference report, FGSV (Road Traffic Research Association in Germany) Verlag, Cologne, Germany.
Friedrich, M., Immisch, K., Jehlicka, P., Otterstätter, T., Schlaich, J. (2011), Generating originDestination matrices from mobile Phone Trajectories, Transportation Research Record, Issue 2196, pp.
93-101, Transportation Research Board, Washington, D.C., USA.
Gentile, G., Meschini, L., Papola, N. (2005), macroscopic arc performance models with capacity
constraints for within-day dynamic traffic assignment, Transportation Research B 39, 319-338, ISSN:
0191-2615, Transportation Research Board, Washington, D.C., USA.
Gentile, G., Meschini, L., Papola, N. (2007), Spillback congestion in dynamic traffic assignment: amacroscopic flow model with time- varying bottlenecks, Transportation Research B 41, 1114-1138,
ISSN: 0191-2615, Transportation Research Board, Washington, D.C., USA.
Gentile, G. (2008), The General Link Transmission Model for dynamic network loading and acomparison with the DUE algorithm, in Proceedings of the Second International Symposium on Dynamic
Traffic Assignment – DTA 2008, Leuven, Belgium.
ITS Vienna Region (2016), ITS Vienna Region Factsheet,
http://anachbvaocmsfiles.anachb.at/files/anachbvao/theme/ownuploads/ITS%20Vienna%20Region_Facts
heet_engl.pdf, Vienna, Austria.
Marchal, F., Hackney, J., & Axhausen, K. (2004). Efficient map-matching of large GPS data sets - Tests
on a speed monitoring experiment in Zurich. Arbeitsbericht Verkehrs- und Raumplanung, Institut fur
Verkehrsplanung und Transportsysteme, ETH Zurich, Zurich.
Meschini L., Gentile, G. (2010). Real-time traffic monitoring and forecast through OPTIMA – Optimal
Path Travel Information for Mobility Actions, in Proceedings of Models and Technologies for Intelligent

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Transportation Systems, International Conference Rome 2009, ed.s G. Fusco, Aracne, 113-121, ISBN
978-88-548-3025-7 – (MTITS2009), Rome, Italy.
PTV Group (2015), manual PTV Visum 15, Karlsruhe, Germany.
Schlaich, J., Heidl, U., Huan, L. (2016), State of the art of multimodal macroscopic transport modeling,
14th World Conference on Transport Research, Shanghai, China.
Statista (2015), Anzahl der Smartphone-Nutzer in Deutschland in den Jahren 2009 bis 2014,
http://de.statista.com/statistik/daten/studie/198959/umfrage/ anzahl-der-smartphonenutzer-indeutschland-seit-2010/, Deutschland [Number of smartphone users in Germany between 2009 and 2014].
Transport for London (2012), Travel in London, Report 5, http://www.tfl.gov.
uk/assets/downloads/corporate/travel-in-london-report-5.pdf.
UK HIGHWAY AGENCY (1996). Design Manual for Roads and Bridges (DMRB), Office of Official
Publications, Volume 12.

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PAPER TITLERESONANT RUBBLIZATION AS A METHOD TO REHABILITATECONCRETE PAVEMENTTRACKAUTHOR(Capitalize Family Name)
Richard KOCHPOSITION
President – East Asia

CO-AUTHOR(Capitalize Family Name)POSITION

E-MAIL(for correspondence)

ford.koch@rubblization.com

ORGANIZATION

Quasco LLC
ORGANIZATIONCOUNTRYUSA
COUNTRYKEYWORDS:
Resonant Rubblization
Quasco LLC

ABSTRACT:
Resonant rubblization is the leading technology for concrete rehabilitation and breaking. Utilizing the industry leading
resonant beam technology, resonant machines are able to fracture the concrete at a 40-degree shear plane, creating aninterlocking base material that allows the concrete to be recycled in place and used as the new base.
Resonant machines complete the rehabilitation of a roadway much faster than traditional methods, minimizing the costand energy needed for roadway repair. The rubblization process requires half the time of traditional concrete
replacement, thus significantly decreasing the disruption to the community.
The rubblization process using resonant machines is sustainable. Rubblization recycles the existing concrete in its place,turning it into a base and allowing for a new roadway surface to be directly overlaid. The process is “green” and greatly
reduces the impact to the environment.

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RESONANT RUBBLIZATION AS A METHOD TO REHABILITATE CONCRETE PAVEMENT
Richard Koch

ABSTRACT
Resonant rubblization is the leading technology for concrete rehabilitation and breaking. Utilizing theindustry leading resonant beam technology, resonant machines are able to fracture the concrete at a 40degree shear plane, creating an interlocking base material that allows the concrete to be recycled in place
and used as the new base.
Resonant machines complete the rehabilitation of a roadway much faster than traditional methods,
minimizing the cost and energy needed for roadway repair. The rubblization process requires half the time of
traditional concrete replacement, thus significantly decreasing the disruption to the community
The rubblization process using resonant machines is sustainable. Rubblization recycles the existing concretein its place, turning it into a base and allowing for a new roadway surface to be directly overlaid. The
process is “green” and greatly reduces the impact to the environment.

INTRODUCTION
Portland Cement Concrete (PCC) has played a crucial role in road construction around the world. It is
incredibly durable and has the ability to handle heavy traffic loads. However, PCC, like all materials,
eventually deteriorates. The question numerous countries have considered is how to effectively andefficiently deal with aging roads once they are nearing the end of their life cycle. The purpose of this paper
is to discuss resonant technology as applied to repairing concrete roads.
The use of PCC roads has expanded exponentially over the past few decades. From 1990, the portland
cement concrete used in China grew from 11,373 kilometers to 199,000 kilometers in 2003 (Chen et al.
2004a). Roughly 700 million tons of cement was manufactured in China in 2002 alone. That amount isroughly half of the world’s output for that year (Chen et al. 2004b). China has tried numerous rehabilitation
methods with varying success. In China, Full Depth Repairing (FDR) and under-sealing the voids arecommon for deteriorated slabs. This method, however, failed in many areas or adjacent slabs in less than
three years (Chen et al. 2004c). It is no wonder that China has adopted the resonant beam technology torehabilitate roads in numerous Provinces around the country. Quasco LLC has rubblized well over 6,000,000
square meters of concrete in China alone.
Various methods, including direct overlay, crack and seat, complete dig-out and removal, drop/multi-headhammers and rubblization have all been used to rehabilitate concrete roads nearing the end of their life span.
A study by (Witzak and Rada 1992) included a total of 454 field projects in 34 US states. The study tested
hot mix asphalt (HMA) overlays placed over various rehabilitation techniques. The techniques included
crack and seat, break and seat and rubblization. Rubblization was used on 19 sections of the test, crack andseat was used on 250 sections, 150 sections used break and seat, and the remaining 35 sections did not havecomplete data available. Several United States Federal and State organizations were involved, including the
National Asphalt Pavement Association (NAPA), Transportation Research Board (TRB), and the Asphalt
Institute (AI). Tests were used on the sections including a visual test based on the pavement condition index(PCI) highway methodology. In addition, non-destructive testing (NDT) using a falling weight deflectometer(FWD) was used. After extensive analysis, it was concluded the rubblization process performed the best
(Tim & Warren 2004).
All methods have advantages, but rubblization with resonant beam technology has proven to be an
inexpensive, quick, and long-term solution to concrete road rehabilitation. A properly executed rubblization
project can extend the life of a concrete road by over twenty years. The key is to choose rubblization at the
optimal time in the life cycle of the road. In some cases, it may be determined the concrete is beyond repair

203and must be completely removed. Failing to properly time the rehabilitation to a road can significantly raise
the cost, regardless of the method chosen.

Figure 1. A graph displaying the ideal time to use rubblization on a concrete road nearing the end of its
lifecycle.

RUBBLIZATION
Rubblization is the process of fracturing pavement of PCC into angular pieces for direct overlay. It destroys
the integrity of existing concrete to allow for immediate overlay. Rubblization involves breaking an existing
concrete slab in to various sized pieces, destroying any slab action, and overlaying with hot mix asphalt(APA 2002). Rubblization eliminates the problem of reflective cracking, since the technique is supposed tocompletely disintegrate the existing concrete slab (Recommendations 2013a). True rubblization, withresonant beam technology, does not damage or destroy the sub-base of roads. Unlike other methods,
including the drop hammer and multi-head hammer, the resonant beam fractures the concrete on a shear
plane, at a 40-degree angle. This method allows for an interlocking, angular fracturing pattern that provides
for a greater modulus as opposed to a vertical fracturing pattern from drop or multi-head hammers. The
angular fracturing pattern spreads the load over a larger area and allows for a greater modulus. The sizes ofbroken pieces usually range between 2 to 6 inches (Recommendations 2013b).
Rubblization with resonant beam technology was first used in the United States in 1986 as a method torehabilitate concrete roads nearing the end of the their life-cycle (Fitts 2006a). New York was the first state
to adopt the technology. Since then, rubblization has been used in 37 US states, two Canadian Provinces,and many countries around the world (Fitts 2006b).
The resonant energy involved in rubblization originates from the resonant beam. The beam is attached to apedestal and shoe that in unison strike the concrete 44 times per second (44Hz), at an amplitude of only 20
millimeters per strike (See Figure 2 on the following page). This high frequency, low amplitude impact
dissipates all breaking energy by the time the fracture spreads through the slab. The process causes thebottom of the slab to remain smooth and does not drive broken concrete pieces into the base. Rubblization
protects the integrity of the base as well as underground utilities. It also provides a base that is not only
durable, but also interlocked for greater strength. A study by the North American Pavement Association

204

shows that the strength of a rubblized layer of concrete is 1.5 to 3 times stronger than a high-quality dense
graded crushed stone base (NAPA 1994).

Figure 2. Graphic with the pedestal shown fracturing the concrete on a shear plane.

A demonstration of the entire rubblization process can be seen at http://www.rubblization.com/process.html.
Complete rehabilitation of a road section can be completed in one day. Once a project is selected, the area
should be closed to traffic. It is recommended to begin rubblization on the free edge, or shoulder of the roadand break towards the opposite edge or shoulder. If reinforcing steel bar is present, it will be completely debonded from the concrete once rubblization takes place as shown below.

Figure 3. De-bonded reinforcing bar after rubblization.

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The resonant machine works best, and is most effective, when 500 linear meters or more of concrete isclosed to traffic. This allows the machine to maximize each pass and provide the greatest amount of
production in a given workday. Each resonant machine is capable of breaking one linear kilometer of twolane road, or roughly 6,000 - 7,000 square meters in a given 8 hour workday.
Proper rehabilitation of PCC requires a high quality of rubblization and maintaining a strong base and/or
subgrade soil. In order to achieve this process, a correctly installed drainage system is essential. Poor
performance can occur when the underlying soils are saturated. Installation of edge drains prior to
rubblization has proven to be successful for this type of condition (Chen et al. 2004d).
Water intrusion into pavement structures is a major factor in reducing the service life of a road. The
principle drainage management procedures in the United States are still frequently based on the American
Association of State Highway and Transport Officials (AASHTO) Guide for Design of Pavement Structures.

Figure 4. A diagram of a retrofitted edge drain design for a rubblized roadway.

The edge drain allows water to effectively drain away from under the slab. Proper drainage results in a dry,
firm base and in consequence a higher modulus. Vibrations from traffic will allow previously trapped waterto escape. This process will only work if the base is not penetrated by broken concrete. Each place the baseis punctured is a potential water trap. Resonant technology allows the concrete slab to be fractured without
piercing the base. Once proper drainage is established, rubblization can be effectively carried out.
A study in Colorado by the state’s Department of Transportation tested rubblization with the resonant
breaker as well as the multi-head hammer. Half of the project, roughly 39,361 square yards, was rubblizedusing the resonant breaker (LeForce, Robert, P.E. 2006a). After rubblization, the study noted there was noreflective cracking from the old concrete in the five years since construction, and no base-related distresses
were seen on the project (LeForce, Robert, P.E. 2006b). The results of the study show the effectiveness ofresonant technology. As stated in the report, the use of rubblization and overlay with hot mix asphalt should
be incorporated into the Colorado Department of Transportation design manual (LeForce, Robert, P.E.
2006c).
Once rubblzation is complete on a given section, two or three passes with a vibratory roller are all that isneeded before paving of the road can begin. There is no need to apply a prime or tack coat before the HMA
overlay as no detrimental effects could be identified (Chen et al. 2004e). Traffic should not be allowed on
the rubblized concrete slab, due to the risk of “unseating” the particles of rubblized pavement (Decker &Hansen 2006a). If traffic is absolutely necessary, it should be kept at a minimum in order to maintain the
integrity of the rubblized slab. It is recommended that the HMA overlay over a properly compacted206

rubblized PCC pavement occur within a 24-hour period from the compaction process (Decker & Hansen
2006b).
In most cases, a hot-mix asphalt overlay is used on the rubblized concrete. HMA overlays have been used
for decades and provide an inexpensive and long-term solution to pavement rehabilitation. Different
countries have different standards when it comes to the depth of asphalt that is needed on a rubblized road.
A chart from the National Asphalt Paving Association (NAPA) shows the recommended overlay amounts
based on a number of different factors.

Figure 5. Provides the specifications as set forth by the National Asphalt Paving Association. The depth isbased on the existing thickness of the concrete, the structural number on the sub-base, and the amount oftraffic.

The biggest obstacle to HMA overlays is reflective cracking. The key is to completely fracture the slab
before adding the HMA overlay. Rubblization fractures the slab into fragmented interlocking pieces. This
process destroys the existing slab and eliminates reflective cracking. Rubblization is the only approach thatutilizes the existing concrete pavement and fully addresses slab movement responsible for reflective
cracking (Recommendations 2013c).

207

Figure 6. Demonstrates the reflective cracking issue as related to HMA overlays.

When the rubblized PCC modulus decreases by the slab being more intensely fractured, the likelihood ofreflective cracking from the HMA overlay is greatly reduced. The structural capacity of the PCC decreases
and requires a thicker HMA overlay. The ultimate goal is to reduce the rubblized slab modulus (EPCC)
value to a minimum to eliminate reflective cracking, but not so low that the rubblized slab requires anexcessive amount of HMA overlay.

NAPA IS-117

Fracture Modulus vs Reflective
Cracking

Probability of Failure

100

Structural Failure

Reflective Cracking

Target Zone

0
Low
Small

PCC Modulus
Nominal Fragment Size

High
Large

Figure 7. A graph from the National Asphalt Pavement Association shows the relationship of the rubblized
slab modulus (EPCC) to the functional distress caused by reflective cracking and the structural requirementsof the HMA overlay.

Resonant technology has consistently proven to retain the highest modulus, highest structural coefficient andan ability to distribute surface loading over a much wider base. The structural coefficient of a crushed stonebase is typically .14 and a stabilized base is .25. A slab supported by sand or an unconsolidated base material

208

will produce a structural coefficient between .16 and .25. The structural coefficient of a rubblized slab
ranges from .25 to .28. Rubblized pavement tested with a falling weight deflectometer (FWD) method haveshown the strength of the rubblized layer to be 150% to 300% of the effectiveness in load base distribution
compared to a high quality dense graded crushed stone base.
The strength of the rubblized PCC measured by a FWD in subsequent tests have improved year over year.
The small particle size on the top layer of the rubblized concrete is constantly being driven deeper into thefracture lines on the rubblized slab. It was concluded that rubblization using a resonant breaker was not
detrimental to the stiffness of the base, sub-base and subgrade. In addition, the modulus values would
increase with time until they reach equilibrium values (Chen et al. 2004f).
The resonant machine will not damage underlying utilities. In a study conducted in China, it was concluded
that the resonant machine yielded minimum disturbance during the rubblization process due to its low
impact and high frequency operation. In fact, there were no complaints during rubblization from businessowners and residents from Huqingping Highway and Kim Shan Broadway (Chen et al. 2004g). Bothprojects were in the greater Shanghai area. There was a priority to quickly and efficiently rehabilitate theroads with minimal disruption to the community. Underground utilities and buildings close to the road’s
edge were not damaged by the machine’s operation. In many cases, resonant machines are specifically usedin urban areas for this purpose. Other technologies, including drop and multi-head hammers, have been
known to break utility pipes and damage buildings.

SUSTAINABILITY
A major concern affecting the Earth is rapid industrialization. Pollution, resource depletion, climate change
and waste disposal are some of the major issues facing the entire human population. The world’s yearly
cement production of 1.6 billion tons accounts for about 7% of the global loading of carbon dioxide into theenvironment (Mehta, P. Kumar 2001a). Concrete ordinarily contains about 12% cement and 80% aggregate
by mass. Globally, for concrete making, the Earth is consuming gravel, sand and crushed rock at a rate of 10
to 11 billion tons every year (Mehta, P. Kumar 2001b). In North America, Europe, and Japan, about twothirds of the construction and demolition waste consists of masonry and old concrete rubble (Mehta, P.
Kumar 2001c).
Preservation is key in order to maintain and preserve the planet for future generations. Rubblization withresonant beam technology allows the concrete to be rehabilitated in its original place. The fact the concrete
can be reused allows an enormous amount of energy and resources to be conserved. Other methods require
the old concrete to be removed and transported to another location. Not only is this method expensive, it’salso incredibly harmful to the environment. The used concrete, if not recycled for other uses, is dumped into
landfills.

CONCLUSIONS
Rubblization using the resonant beam technology is the premier solution to concrete road rehabilitation. The
resonant machine can rehabilitate a concrete road five times as fast as alternative methods at half the total
cost. Resonant machines fracture the slab on a shear plane that eliminates reflective cracking. The highfrequency, low amplitude process will not damage underlying utility pipes or structures close to the road.
In addition to the speed and cost-savings, resonant technology is also sustainable. The concrete can berecycled in its place and used as the new base for the road as opposed to a complete dig out. Given the fastpace in which the world is changing, it only makes sense that resonant technology is the preferred method
for long-term repair of concrete roads.

209

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Chen, Dar-Hao, Huang Qinlong, Ling, Jianming. (2004). Shanghai’s experience in utilizing the rubblization
for jointed concrete pavement rehabilitation. Page 2 a.
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for jointed concrete pavement rehabilitation. Page 21 d.
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for jointed concrete pavement rehabilitation. Page 16 f.
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for jointed concrete pavement rehabilitation. Page 15 g.
Decker, Dale S., LLC and Hansen, Kent R. (2006) Design and construction of HMA overlays on rubblized
PCC pavements: state of practice. Transportation Research Circular, Number E-C087. Page 13 a.
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PCC pavements: state of practice. Transportation Research Circular, Number E-C087. Page 13 b.
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Number E-C087. Page 20 a.
Fitts, Gary L., (2006) Rubblization using resonant frequency equipment. Transportation Research Circular,
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LeForce, Robert, P.E. (2006) Performance of Colorado’s first rubblization project on I-76 near Sterling.
Colorado Department of Transportation Research Branch. Page 15 a.
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Colorado Department of Transportation Research Branch. Page 28 b.
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concrete pavement. TRR1374.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
STEINER, Viviana, Dr.
CO-AUTHOR(S)(Capitalize Family NameSCHAEFER, Benjamin
E-MAIL(for correspondence)Protecting Vulnerable Road Users: Traffic separation with colored pavement
markings
Road Safety
POSITION
Marketing Manager

POSITION
Technical Manager

ORGANIZATION
Evonik Resource Efficiency
GmbH
ORGANIZATION
Evonik Resource Efficiency
GmbH

COUNTRY
Germany

COUNTRY
Germany

Viviana.steiner@evonik.com

KEYWORDS:
Vulnerable road users
Traffic separation
Pavement markings
Bike lane
Pedestrian crossing

ABSTRACT:
According to the World Health Organization, almost half of the world’s road traffic deaths occur among vulnerable road
users. The provision of innovative and forgiving road infrastructure and significant change in the behavior of all road
users are two key factors to succeed in halving the number of traffic fatalities. Colored pavement markings are aneffective way to address both: They separate vulnerable road users from the other motorized traffic and raise theattention of road users through visual stimuli.
This presentation will look at practical case studies of colored pavement markings that separate different modes oftransportation and thereby contribute to the safety of vulnerable road users. They can be found all around the world:from advanced stop boxes for motorbikes in Indonesia, over separate bus lanes in Chile, bike lanes in Poland and theUnited States, to pedestrian crossings in Thailand and China.
Besides this paper reports the results of both lab and field tests on the performance of MMA cold plastic as one standard
material for colored pavement markings

212

Protecting Vulnerable Road Users: Traffic separation withcolored pavement markings
Dr Viviana Steiner1 Benjamin Schaefer1
1

Evonik Resource Efficiency GmbH, Germany
Email for correspondence viviana.steiner@evonik.com; Benjamin.schaefer@evonik.com

1 INTRODUCTION
Infrastructure development is a constant requirement for global challenges such as urbanization, growing
population and accident increases.
Today over half of the world’s population (54%) live in urban areas and urbanization is expected to increase
further in the upcoming decades (United Nations 2014). By 2050, 66% of the world’s population is expected to residein urban areas. Asia today is home of 53% per cent of the global urban population. And Asia is expected to urbanize
faster than other regions in the world over the next decades. While the number of mega-cities with more than 10 million
inhabitants is expected to increase from 28 today to 41 in 2030, the fastest growing urban areas will be cities mid-size
cities (with 500,000-1,000,000 inhabitants) located in Asia. Increased urbanization requires infrastructure development,
including adequate road infrastructure.
Luoma et al. 2010 examined the modes of transportation in megacities. Different modes of transportation coexist between each other: transport on foot and by bicycle co-exists besides private motorized traffic (car andmotorbike) and public transport. While transport on foot and by bicycle is currently dominant in Chinese megacities,
public transport dominates in Indian megacities. The authors predict a substantial increase in personal vehicle
ownership in these megacities until 2025, along with an increase in the number of road fatalities in these megacities.
Managing the co-existence of different modes of transportation and reducing the number of accidents, many
cities reacted with projects separating traffic: separating cyclists from motorized traffic by separate bike lanes,
separating pedestrians from motorized traffic by pedestrian zones and well-marked pedestrian crossings, separating
public from private motorized traffic by establishing bus lane networks, so-called BRTs (bus rapid transportation).
Separating traffic has become a widely used and accepted way to protect vulnerable road users (VRUs). VRUs
are typically defined as non-motorized road users, such as pedestrians and cyclists as well as motor-cyclists and persons
with disabilities or reduced mobility and orientation. VRUs typically are at greater risk for accidents and bear more
severe consequences from accidents. In 2015, 49% of the road traffic deaths around the world were pedestrians,
motorcyclists and cyclists. This figure is the same for South-East Asia with motorcyclists having the highest share with34% (WHO 2015). Although several countries have police in place to protect vulnerable road users, changing the
behavior of road users and the provision of innovative road infrastructure has become a key approach to decrease thenumber of these accidents.

2 EFFECT OF COLORED PAVEMENT MARKINGS ON VRU
The importance of horizontal road markings in reducing traffic accidents has been well recognized. Modern
road marking systems are providing various signal functionalities and safety features that make them a very efficient
tool to improve road safety. However, they must be clearly visible and stay in shape at all times and at all climaticconditions. Important safety features of a pavement marking system are visibility and skid resistance (to avoid
slipping), for instance.
Cities have tested separate bus/bike/pedestrian lanes and found a cost efficient solution to increase safety withcolored pavement markings. Exclusive lanes for buses, cyclists or pedestrians separate fast from slow moving transportand separate vulnerable road users from higher motorized traffic. Experience suggests that separating different modes oftransport, not only reduces travel times and makes transportation more efficient, but also increases road safety. Typicalapplications are:- Bus lanes- Bike lanes- Advanced stop lanes (ASL)- Pedestrian zones- Pedestrian crossings
Traffic separation by giving cyclists, pedestrians and public traffic their own space, can be achieved simply byusing (white) line markings. However, empirical research points out that applying color to these facilities has a much213

stronger positive effect on safety. Coloring these separate lanes different from general traffic generates greaterawareness and minimizes the encroachment of other traffic participants. Color improves the visibility of the facility,
encourages its use by the designated user group and discourages the use by other road users. In the end this leads to lesstraffic conflicts and increased safety.
Giving color to bike lanes increases the visibility of the facility. This is especially important at areas ofpotential conflict, e.g. it raises the awareness of both cyclists and motorists at intersections and at traffic lights. Hunter
et al. (2000) found that colored bike lanes increase the cyclists’ comfort as his space is clearly delineated. Color
discourages illegal parking on bike lanes and more motorists yield to cyclists at colored intersections. Similar researchand experience has led more and more countries to specify the use of color in their national guidelines on bike lane
design. E.g. the Manual for Uniform Traffic Control Devices (MUTCD) in the US and the ‘Recommendation on red
bike lanes’ from the German Research Association for Road Markings (DSGS) in Germany. In China, a working groupis currently elaborating on area marking standards.
A similar effect of color can be seen at Advanced Stop Lanes (ASL) or boxes: drivers are less likely toencroach on colored bicycle spaces than uncolored ones. (Koorey and Mangundu 2009). But color also encourages theuse of ASL by cyclists. Loskorn et al. (2010) found that cyclists are more likely to use ASLs when they are coloredcompared to uncolored.
Colored road markings also increase the visibility of bus lanes. Usually they are treated with a red color thatmakes sure other motorists are aware of the bus lane – and neither drive or park on it. Several studies showed that color
is effective in reducing the unauthorized use of bus lanes , including both illegal driving, standing and parking (Carryet al. 2012, Ney York City DOT 2011).

3

CASE STUDIES ON COLORED PAVEMENT MARKINGS

This section introduces case studies around the world, successfully contributing to the safety vulnerable road
users with colored pavement markings. The choice of material, the intention of the initiative and the effect on safety is
described. The design of these cases will be illustrated by pictures in the presentation.
3.1 Advances stop boxes in Bandung, Indonesia
The idea of ASL for bicycles has been adopted for motorcycles on several signalized intersections Indonesia,
among others in Bandung (Bali). Red boxes for motorcycles at signalized intersections designate a space formotorcyclists to wait at a red light. Motorcyclists stop in front of other types of vehicles and can proceed through theintersection first when the light turns green. This solution reduces conflict between motorcycle and other types ofvehicles and increases intersection performance. Traffic flows more orderly, safely and smoothly.
3.2 BRT in Santiago de Chile, Chile
By separating bus traffic from automobile traffic, the average bus speed increases, thereby reducing travel
times and making public transport more attractive to users. With the implementation of the Transantiago system, thecity of Santiago recogonized the need for a better infrastructure for the buses. This is why red colored „bus only“ lanes
requiring a high friction, durable and skid resistant surface were introduced. In September 2011, the transport ministerannounced plans to color the surface of Transantiago “bus only” lanes red, with the tacit warning to motorists being:“Do not use this lane.”
3.3 Bike lane in Syracuse, NY, US
Since 2000, many cities throughout the United States have reported a doubling or tripling in the number ofpeople using bicycles as a primary mode of travel for work, school and recreation. With bicycling accounting forroughly 2% of all traffic fatalities and 6.3% of all traffic injuries nationwide, many cities, like Syracuse, NY, haveestablished goals and master plans to decrease the number of crashes by adding safer infrastructure for bicyclists andpedestrians. As of today, Syracuse has incorporated new bicycle lanes as part of a new Connective Corridor project andplan to incorporate additional miles in the next two years. As part of this Connective Corridor project, the city of
Syracuse has applied green bike lanes, or “greenways”, usinsafer biking network for students and residents navigating through the city

3.4 Bike lane in Warsaw, Poland

214

The intersection of John Paul II Avenue, Prosta Street, and Swietokrzyska Street is a major junction in thecenter of Warsaw. At this location the six-lane thoroughfares in the Polish capital meet at the four-lane Rondo ONZ
traffic circle, which is also a hub for three commuter rail lines and one subway line. Approximately 450 cyclists alsopass by every hour. Making sure everyone stays safe here thus poses a major challenge. Indeed, the expansion of a safe
network of bike paths and lanes has become a top priority in Poland. The resins make road and other surface markings
last longer and also ensure a very good tire grip on wet surfaces. The red bike path markings increase safety for cyclists
because they ensure motorists can clearly see the bike lanes—it sort of sends a signal.
3.5 Bike lane in Poznan, Poland
The objective of this application was increasing safety of cyclists on a two-way bicycle path running along ahighly trafficked street. Especially at junctions, the visibility of the bicycle path had to be improved to reduce carbicycle conflicts. Since the red color had been applied, no serious accidents have been recorded in this place.
3.6 Pedestrian crossings in Denizli, Turkey
Due to increasing traffic density, the city of Denizli applied a new design at crosswalks all over the city, toensure increased safety for pedestrians, drivers, and cyclists. Different colors and warning signs were used in front ofcrosswalk lines to increase attention. Applications showed great results: the number of accidents reduced and the city
received positive feedback from citizens.
3.7 Pedestrian crossings at school zones in rural Thailand
The safety of children at school-zones along the rural roads in Thailand is critical, as often footpaths are notprovided. Colored anti-skid rumble stripes and zebra crossings have been applied on the road to help to reduce thespeed of vehicles, guide students, pedestrians, cyclists, cars and buses smoothly and safely through the school area.

3.8 Pedestrian crossing at school zones in Chongqing,China
Four red and white, anti-slip zebra crossings, covering a total area of about 400sqm were applied in front of the
Liyuan road primary school and two other schools in Chongquing city. Observation statistics showed that the rate ofroad accident is reduced more than 50% after using a colored zebra crossing.
3.9 Pedestrian crossing in Denver, Colorado
Cold Plastic (MMA, methacrylate resin based) area markings were recently applied at three intersections along
one of the busiest roads in Colorado to increase pedestrian safety. The color stability of the area markings and theretained retroreflectivity of the accent stripes are getting the attention of drivers passing by and are expected to reduce
the number of pedestrian vs. vehicle accidents at these locations. Known for their high durability, increased wet-nightvisibility, skid resistance and optimal color stability, contrast area markings based on cold plastic are increasingly being
used to apply bright crosswalks to high traffic areas.
3.10 Pedestrian zone in Graz, Austria
In the context of an urban development program, the city planners of Graz wanted to regenerate the Jakomini
district to attract residents and tourists once again, and to get craftspeople and artists to settle there. Since September
2010, a 750-meter running track with a methacrylate (MMA) cold plastic area marking has been ushering pedestrians,
cyclists, cars, trolley cars, and buses through the Jakomini district of Graz more safely and pleasantly than ever before.
Graz was named a UNESCO City of Design in March 2011.
4 PERFORMANCE OF COLORED PAVEMENT MARKINGS
The choice of road marking material has an impact on the performance of the pavement marking: its durability,
its visibility over time and its skid-resistance (i.e. non-slippery surface). The performance of pavement markings istypically measured by its skid resistance over time. This can be done by lab tests using wear simulators (advantage:equal conditions for all tests) or by field tests (advantage: real traffic and weather conditions).
Cold plastic MMA based pavement markings have been tested both in lab and field tests with excellent results.
Cold Plastic/MMA based pavement markings are characterized by great UV-stability and excellent color retention overtime. Besides, the durability of the cold plastic / MMA material helps to ensure a high skid resistance of the marking
over years.

2154.1 Lab test
Cold plastic MMA pavement markings based on DEGAROUTE resins have been tested at AETEC turntable.
Results show (Figure 1), that even after 8 Million wheel passages (simulating 8 years of traffic) – the double of thehighest category - SRT (Skid Resistance Tester) Values are still above the requirements of 45. Figure 1 shows the SRT
values for two samples over time.

Figure 1. SRT values of DEGAROUTE based pavement marking at AETEC turntable test
4.2 Field test
Cold plastic MMA pavement markings based on DEGAROUTE resins have been applied at a roundabout in
St. Martin, Austria. After 3 and 5 years, skid values still exceeded the minimum requirement of 45% (Figure 2).

Figure 2. Average SRT Values of DEGAROUTE based pavement marking at St. Martin roundabout

6 CONCLUSIONS
Vulnerable Road Users are in the focus, when it comes to reducing road traffic fatalities. Many cities approach
this issue with separating VRUs from other forms of traffic by installing bus lanes, bike lanes, ASLs, pedestrian zones
and crossings, etc. Research has shown that adding color to these separate lanes or areas improves their visibility andcontribution to road safety. Thus, colored traffic facilities should be used more frequently and be part of design
guidelines authorities and institutes demand.

216

When it comes to material choice for colored pavement markings, cold plastic MMA based markings showed
outstanding durability in both lab and field tests. Their practical application and positive effect on safety has been
demonstrated by several case studies around the world.

REFERENCES
Carry, W., Donnell, E., Rado, Z., Hartman, M., Scalici, S. (2012), Red bus lane treatment evaluation,
Koorey, G., Mangundu, E. (2009), Effects on motor vehicle behavior of color and width of bicycle facilities at
signalized intersections, University of Canterbury, Christchurch, New Zealand.
Loskorn, J., Mills, A., Brady, J., Duthie, J., Machemehl, R. (2010), Effects of bicylce boxes on bicyclist andmotorist behavior at intersections, The University of Texas at Austin.
Luoma, J., Sivak, M., Zielinski, S. (2010), The future of personal transportation in megacities of the world,
University of Michigan Transportation Research Institute, Report No. UMTRI-2010-2
Hunter, W.W., Harkey, D. L., Stewart, J. R., Birk, M.L. (2000). Evaluation of Blue Bike-Lane Treatment in
Portland, Oregon. Transportation Research Record, 1705, 107-115.
New York City DOT (2011), Report on the efficacy of red bus lanes as a traffic control device,
United Nations, Department of Economic and Social Affairs, Populations Division (2014). World urbanization
prospects: The 2014 revision, Highlights (ST/ESA/SER.A/352)
World Health Organization WHO (2015), Global status report on road safety 2015, ISBN 978 92 4 156506 6

217

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Asset Management on Main Cables of Suspension Bridges

TRACK
AUTHOR(Capitalize Family Name)
Masahiro TAKEGUCHI

CO-AUTHOR(S)(Capitalize Family Name
Muneo OKAWA

CO-AUTHOR(S)(Capitalize Family Name
Yoshiji OURA

E-MAIL(for correspondence)

POSITIONORGANIZATIONManager of First Bridge
Maintenance
Section,Sakaide Operation Center

Honshu-Shikoku
BridgeExpressway
Company
LimitedPOSITIONORGANIZATION

Directorof
BridgeMaintenance Division

Honshu-Shikoku
BridgeExpressway
Company
LimitedPOSITIONORGANIZATION

Engineer of MechanicalFacility Division

Honshu-Shikoku
BridgeExpressway
Company
Limitedmasahiro-takeguchi@jb-honshi.co.jp

COUNTRYJapan

COUNTRYJapan

COUNTRYJapan

KEYWORDS:
Include up to 5 keywords
Asset management, Dry air injection system, Main cable, Anti-corrosion, Monitoring

ABSTRACT:
Since a main cable is one of the most important members of a suspension bridge and its replacement work entails muchdifficulty, it is necessary to prolong the service life as long possible. This motivated the Honshu-Shikoku Bridge
Expressway Co. Ltd. (HSBE) to install a “Dry Air Injection System for main cables (DAIS)” in all HSBE’s suspension
bridges to improve humidity in the cable causing the rust of wires.
The maintenance management of the cable by DAIS is being carried out in a systematic manner with introducing athought of asset management; the humidity inside the cable of the suspension bridges is being continuously monitored,
the coating on the cable preventing a leakage of dry air is being regularly inspected, and consistent improvement isbeing done based on the results.
This paper describes consistent improvements of DAIS based on the results of humidity monitoring and coating
inspection of the main cables of the HSBE’s suspension bridges.

218

Asset Management on Main Cables of Suspension Bridges
Masahiro TAKEGUCH1, Muneo OKAWA1, Yoshiji OURA1
1

Honshu-Shikoku Bridge Expressway Company Limited, Kobe, Japanmasahiro-takeguchi@jb-honshi.co.jp

1 INTRODUCTION
The Honshu-Shikoku Bridge Expressway (HSBE) consists of three routes (total length of 172.9km) between
Honshu and Shikoku (Figure 1). It unifies the region of Seto Inland Sea and plays an important role as a part of thearterial high-standard highway network. The HSBE has 17 long-span bridges in total including the Akashi Kaikyo
Bridge that is proud of the world's biggest scale as a suspension bridge and the Tatara Bridge that is a world-leading
cable stayed bridge. These long-span bridges composed of ten suspension bridges, five cable-stayed bridges, one archbridge and one truss bridge, are gigantic structures constructed with utilizing the world-highest level technologies.
Implementing maintenance of these long-span bridges is based on the both concepts of preventive maintenance andasset management with a sustained effort to develop new technologies resolving several problems.
A main cable is one of the most important members of a suspension bridge. Therefore, protecting the cablefrom corrosion is an important task in maintenance and a “Dry Air Injection System for main cables (DAIS)” isinstalled in the ten suspension bridges as an anti-corrosion measure. This paper describes the maintenance of thesuspension bridges’ main cables, which is being implemented based on a concept of asset management.

Figure 1. Honshu-Shikoku Bridges(SB: suspension bridge, CSB: cable-stayed bridge, TB: truss bridge, AB: arch bridge)219

2. MAINTENANCE OF HONSHU-SHIKOKU BRIDGES(1) Features in Maintenance (HSBE 2015)
The HSBE’s long-span bridges have the following features in terms of maintenance.
1) Volume of the maintenance target is massive. Signature example is 4,000,000m2 of the external surface of the steel
structures that needs to be recoated multiple times during the life time of the structures.
2) For new materials or special structures utilized in the bridges, its maintenance experience is scarce and durability is
not fully known.
3) Since they are located over straits, they are in very harsh corrosive environment such that they are exposed to strong
wind that brings chloride particles from the sea. In addition, since the superstructures are in high location overstraits, they are not easily accessible and construction of scaffoldings required for inspection or repair works
becomes extensive work.
4) Since there are no alternative routes, repair works under traffic closure are not favorable.
5) Since the construction cost is huge, replacement and large-scale repair works are difficult.
Above-mentioned features motivate us to implement the maintenance management under a policy of
preventive maintenance, which is to conduct adequate measures before deterioration progresses become serious. The
preventive maintenance policy could realize safe and reliable structures, minimize the life cycle cost (LCC) and extend
the life time.
(2) Asset Management (HSBE 2015)
A basis of maintenance for the HSBE’s long-span bridges is to take periodical and scheduled actions in order toprevent the progress of deterioration with time and to maintain the bridges’ functions. One of the representative actions
is coating on concrete and steel structures. In order to secure implementation of the preventive maintenance, we arepromoting a concept of asset management as shown in a flow of Figure 2.
Procedures involved in the asset management need to perform bridge inspections and surveys according to aprescribed plan, to evaluate the bridge’s overall state, to predict the deterioration and to take a proper action at an
optimum time. Then, this cycle is appraised and its feedback is incorporated into the plan. This would enable
implementation of effective maintenance, which could lead to realize the bridges’ service life of more than 200 years.
It can be said that a key element in the flow would be inspection, which grasps the state of all structuralmembers precisely. Furthermore, in order to secure implementation of the flow, so-called PDCA (Plan, Do, Check andAction) cycle, accumulation of the inspection data, appropriate evaluation and deterioration prediction based on
analyses of the data would become important as well. It is believed that establishment of repair plans and its
implementation would result in effective maintenance management and minimization of the LCC.

Figure 2. Flow of Asset Management220

3. DEVELOPMENT AND INSTALLATION OF DAIS
3.1 Background for Development of DAIS (Fujikawa et al. 2000)
A conventional anti-corrosion measure is composed of paste, wrapping wire and coating as shown in Figure 3,
which aims to prevent water from penetrating into the cable from the surface. In 1989, an investigation of the cables of
the Innoshima Bridge, the first HSBE’s suspension bridge, was conducted. In the investigation, it was found that thedeteriorated paste retained water and that induced corrosion of the cable wires within a few layers from surface asshown in Figure 4. This indicated that the conventional measure was insufficient for corrosion protection of the main
cables of suspension bridges. Following the investigation, we initiated the development of a new anti-corrosion measure,
DAIS, which will improve corrosive environment inside the cable by injecting dry air into the cable, in addition topreventing water penetration.

Figure 3. Conventional corrosion protection system for cable

Figure 4. Unwrapped Cable at Innoshima Bridge

3.2 Outline of DAIS (Fujikawa et al. 2000)
The DAIS consists of filter unit, dehumidifier, roots blower, piping, injection cover and exhaust cover asshown in Figure 5. A salt-removal filter is also installed because injecting dry air with chloride ion would make salt
accumulate inside the cable with time, which is unfavorable in terms of corrosion protection. The filter has the capacity
to eliminate 99.7% of particles with the size of more than 0.3m (typical chloride particle size: 0.3-30m).

Figure 5. Dry Air Injection System (DAIS)

3.3 Installation of DAIS (Ogihara et al. 2013)
The DAIS was developed in parallel with the construction of the Akashi Kaikyo and Kurushima Kaikyo
Bridges and installed in the bridges during its construction stages in 1997 and 1999, respectively. It was also installed in
the remaining eight suspension bridges between 1997 and 2002. Since it was found that the system had notdehumidified inside of the cables well and the relative humidity (RH) inside the cable had remained high even after its
installation in some brides, an additional injection cover was installed to shorten the air blowing length as shown in
Table 1.

221

Table 1. DAIS in HSBE’s suspension bridges
CentralSpan
Length(m)

BridgelengthAkashi-Kaikyo

1,991

3,911

1998

Ohnaruto

940

1,629

1985

Shimotui-Seto

940

1,400

1988

Kita Bisan-Seto

990

1,538

1988

Minami Bisan-Seto

1,100

1,648

Innoshima

770

OhshimaBridge Name

OpenedYear

Location(m)

Number of
Injection Points

Number of Units

Original

Present

Original

Present

32

32

8

6

13

27

2

2

6

12

3

3

Kagawa

6

12

3

3

1988

Kagawa

6

12

3

3

1,270

1983

Hiroshima

8

8

2

2

560

840

1988

Hiroshima

8

8

2

2

1st Kurushima Kaikyo

600

960

1999

Ehime

8

8

2

2

2st Kurushima Kaikyo

1,020

1,515

1999

Ehime

12

8

3

2

3rd Kurushima Kaikyo

1,030

1,570

1999

Ehime

12

8

3

2

Hyogo
Hyogo
Tokushima
Okayama
Kagawa4. MAINTENANCE OF MAIN CABLE
4.1 Setting of Target Value of RH (Fujikawa et al. 2000)
Since it is necessary to set a target value of RH inside the cable in order to properly operate the DAIS, several
studies were carried out. As a result, it was found that a galvanized wire with a tiny amount of adherent salt (less than
0.1g/m2) doesn’t corrode in a dry air environment with RH of less than 60% RH as shown in Figure 6. Given the fact,
the target value inside the cable was set to be 40% RH taking into account unevenness of RH along the cable and otherunknown factors. On the other hand, the target value inside a spray chamber in an anchorage was set to be 50% RH,
because the cable condition can be easily identified by visual inspection.

Corrosion mass
mass ofof galvanizedgalvanized wireg/m2)
Corrosion
wire ((g/m2)

80
quantity of adherent salt
10.0g/m2
0.1g/m2
0.0g/m2

70
60
50
40
30

20
10
0
0

20

40

60

80

100

Relative humidity (%RH)

Figure 6. Relationship between RH and corrosion

222

4.2 Continuous Improvement of DAIS based on PDCA Cycle(a) PDCA Cycle
Maintenance management of the cable is being implemented based on PDCA cycles as shown in Figure 7,
which incorporates a concept of asset management. The outer cycle corresponds to a concept level, which is to make abasic policy for the cable maintenance, to prepare a maintenance manual and a long-term maintenance plan, to perform
inspection and monitoring according to the plan, and to periodically evaluate the cable’s condition. Then, the cycle isappraised and its feedback is incorporated into the manual or plan. The middles cycle corresponds to a strategy level,
which is to draw up a 3-year maintenance plan, to secure the airtight cable, and to improve the system for more reliable
and economical operation. The inner cycle corresponds to an implementation level, which involves annual activities as
described below;
 Monitoring Securing an airtight cable Installing a pre-cooler
 Installing an additional injection point
 Performing an economical operation test
These activities allow us to accumulate data, which is indispensable to do “Check” and “Action” in the cycles.

Make a basic policy for cable maintenance

Plan

Prepare a manual for design, execution andmaintenance (inc. monitoring) for DAISDo Draw up a 3-year maintenance plan

Plan

Improve DAIS for more reliable andeconomical operation

Do

C&A
Evaluation of DAIS’s
Current Status based on
Inspection andMonitoring Results

Plan

C &A
C&A
Evaluation ofInspection andMonitoring Results

Review ofInspection,
Monitoring andRepair Results

Implement an inspection and monitoring
Draw up a repair planDo

• Inspection and Monitoring• Measures against Air Leakage• Installation of Pre-Coolers• Installation of Additional
Injection Points• Tests for More Economical
Operational Method

Figure 7. Asset Management Cycle for Cable Maintenance(b) Monitoring
An operating status of the DAIS in the HSBE’s suspension bridges is being continuously monitored byautomatically measuring both temperature and RH of exhausted air at the cover. In addition, a manual measurement isperiodically made to compensate the automatic measurement, because automatic measuring points in some bridges arecoarse and malfunction of sensors for the automatic measurement sometimes happens. Especially in summer, whenoutside air humidity is normally high and RH inside the cable increases in proportion to outside air humidity, themanual measurement is mainly made by an inspector on a day of good weather. Items of the manual measurements areboth temperature and RH of injected and exhausted air at the covers, as well as of produced air at the dehumidifier, andblowing pressure at injection points.
(c) Improvement of DAIS (Kusuhara et al. 2015)
The monitoring data showed that the system had not dehumidified inside of the cable well and RH in some
portions of the cable had remained higher than the target value, 40% RH. The causes were considered as the following.
 Air leakage at defects of sealing of the cable band, injection and exhaust covers
 Air leakage at cracks of the cable coating Air leakage at cracks of piping defect or at loosened joints of the pipe
 Malfunction of the DAIS’s mechanical equipment
 Malfunction of the monitoring devices
 Lack of the DAIS capacity
In order to solve the problem, two countermeasures has been mainly implemented; improvement of the DAIS
and securing an airtight cable. As for the former measure, machinery improvements for more efficient dehumidificationand installation of additional injection/exhaust covers to shorten the blowing length have been employed. As for the223

latter one, measures for the deterioration of cable coating and the defects of sealing of the cable bands have been
applied. Examples of the system repairs and improvements are described in the following section.
5 Improvement of DAIS
5.1 Example at Seto-Ohashi Bridges(1) Installation of Additional Injection Points
Original installation arrangement of injection points at the Seto-Ohashi Bridges (three suspension bridges) was
set as shown in Table 2 based on the experience in other bridges and the result of preliminary air flow tests performedat the sites. The system, however, had not dehumidified inside of the cables well and the relative humidity in the most
portions of the cables had remained high even after the installation of the system. Since the blowing lengths of the SetoOhashi Bridges were over 200m and high humidity portions in the cables were found to be limited to vicinities of theexhaust points, this fact seemed to be responsible for the insufficient blowing capacity of dry air up to the exhaust
points. Therefore, additional injection points were installed to shorten the blowing length. Changes of the blowing
lengths by installation of additional injection points are also shown in Table 2.
Effects of the installation of additional injection points in the Kita Bisan-Seto Bridge are shown in Figure 8. It
was found that RH at all three points were drastically reduced owing to the installation, although RH in front of theanchorage has been occasionally over the target value, 40% RH. The cable in front of the anchorage was confirmed to
be in sound condition and is being periodically monitored by visual inspection. Also, a pre-cooler was installed to
improve capability of producing dry air especially during summer seasons, and its effectiveness was confirmed.

Table 2. Changes of Blowing Lengths by Installation of Additional Injection Points( Seto-Ohashi Bridges, after 2005)

224

87/8858/59

Tower height

58

Center
span

59

68/69

78

Anchorage

西ケーブル

1A

100

2P

Before installation of additional injection points(2011.7-2012.6)

Relative humidity（%RH）

Anchorage

Outside

60

40

20

100

2011/8/31

2011/10/31

2011/12/31

2012/3/1

2012/5/1

After installation of additional injection points(2014.7-2015.6)
Anchorage

Relative humidity（%RH）

Center span

8002011/7/1

Tower height

Center span

Outside

80

60

40

20

0
2014/7/1

2014/8/31

2014/10/31

2014/12/31

2015/3/2

Before installation of additional points（2011.7～2012.6）

2015/5/2

After installation of additional points（2014.7～2015.6）

100%

100%

80%
60%

60%-

40%

40%-60%

20%

-40%

0%
Anchorage Tower height Center span

Probability of RH

Probability of RH

Tower height

80%
60%

60%-

40%

40%-60%

20%

-40%

0%
Anchorage Tower height Center span

Figure 8. Effects of Installation of Additional Injection Point at Kita Bisan-Seto Bridge(West Cable)

225

79

3

100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%

Probability of RH

Probability of RH(2) Improvement of Humidity inside Spray Chamber
It is necessary to dehumidify not only inside the cable but inside a spray chamber. This chapter shows the
improvement of humidity inside a spray chamber.
(a) Installation of Additional Fans
It is difficult to dehumidify inside a spray chamber installing only a dehumidifier because a dehumidified
volume is big. Therefore, two improvements were implemented installation of additional fans to circulate air inside aspray chamber, effective running of fans by installation of the sensor to high humidity portions. These installations
enabled RH in a spray chamber to be almost below control target value of 50% expect bigger volume of 4A anchorage
as shown in Figure 9.

Upper

Middle50～60%RH

Lower

40～50%RH

Upper

Before (2009)

Shimotsui-Seto Bridge 1A (WEST)-40%RH

MiddleAfter (2011)

Lower

Upper

Middle

Lower

Upper

MiddleLower

Before (2009)

100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%

After (2011)

Kita and Minami Bisan-Seto Bridge 4A (EAST)
60%RH--40%RH

40～50%RH

50～60%RH

60%RH-

Figure 9. Comparison of RH before and after Installation of Fans(b) Installation of Membrane Structure
It is obvious that less spatial volume in a spray chamber
would contribute to higher efficiency of dehumidification. In orderto decrease a spatial volume and to prevent the strands fromleakage of water from ceiling, membrane structures covering
strands were installed in the 1A and 7A anchorages of the Kita andMinami Bisan-Seto bridges. Table 3 shows the comparison of a
spatial volume in a spray chamber in the Seto-Ohashi Bridges.
Since the 4A anchorage bilaterally used for the twosuspension bridges where configuration of strands crossing eachother is complicated, the membrane structures, which covers only
strands above the crossing portion to decrease a spatial volume ofchamber, was installed in 2013 to 2014. Figure 10 shows theinstallation of membrane structure in 4A anchorage of the Kita andMinami Bisan-Seto bridges, and Figure 11 shows the photo ofmembrane structure. The spatial volume decreased from 21,400m3
to 15,400m3 by installation of the membrane structure.

Figure 10. Installation of Membrane Structure in
4A Anchorage of Bisan-Seto Bridges

Table 3. Comparison of Spatial Volume in
Spray Chamber

Figure 11. Membrane Structure226

5.2 Case at Akashi Kaikyo Bridge(1) Installation of Pre-Cooler and Reduction of Running Cost(a) Operational Status
The DAIS’s specification installed in the Akashi Kaikyo Bridge was designed to dehumidify moisture intruded
inside of the cable during its construction within one year. It was confirmed that the system successfully dehumidify
inside of the cable below the target value of 40% RH by approximately 150 days after its operation was initiated. Then,it was also confirmed that RH inside the cable occasionally exceeded the target value, especially during summer season
with high-temperature and humidity.
In order to improve this situation, the system was altered so that extra dry air was recirculated and its cost- andperformance-effectiveness was confirmed in 2001. Although the system has been in stable operation since the alteration,exceeding the target value of RH inside the cable was occasionally observed during summer season.
In response to this, a pre-cooler was installed in a dehumidifier in one circulation line on a trial basis in 2015
and the installation has soundly kept RH below the target value. The installation will be discussed more in (b).
(b) Cost Reduction aiming to Economical Operation for a Long Term (More Than 200 Years)
As part of our efforts to reduce the operation cost, we changed the operational method by reducing blowing air
and optimizing the output of the system unit in 2007, when the system became to be in stable operation. Blowing air
was cut by half and the power consumption of a root blower was reduced by changing the number of a motor pole fromfour to six as shown in Table 4. The change saved approximately 27 million JPY on the operation cost during the lastten years.
Table 4. Cost Reduction by Measure Implemented in 2007 at Akashi Kaikyo Bridge
MeasureImplemented Content

Reduction of blowing air ・Halve blowing air
andoptimizationof ・Reduce the power consumption of aoperationroot blower by changing the numberof a motor pole from 4 to 6
・Reduce the number of operating units
at the towers from 4 to 2

Investment for
Equipment\3.2 million

Cost-Saving Benefit\2.7 million/year\27 million saving is expected in 10
years, which is the mechanical life

In addition to the measure implemented in 2007, two additional measures were taken in a trial basis in 2015;
one is installation of a pre-cooler, whose effectiveness was verified at the Kurushima Kaikyo Bridge, the other isreduction of heating temperature for drying a silica gel rotor in a dehumidifier. Cost-saving benefit based on the result
during the last six months’ operation is tabulated in Table 5.
Table 5. Cost Reduction by Measure implemented in 2015 at Akashi Kaikyo Bridge
MeasureInstallation of pre-cooler
and reduction of heating
temperature for silica gel
rotor

Implemented Content

Investment for
Equipment
2.1 million
・Install a pre-cooler in one circulation
JPY/lineline out of eight lines as shown in(12.6 JPY/6
Figure 3
・Reduce heating temperature for lines)
drying a silica gel rotor from 140 to
70 degree

Cost-Saving Benefit
0.4 million JPY/year, line (370>270 kwh/day)
24 million JPY saving by 6 lines is
expected in 10 years, which is themechanical life.

The Seto-Inland Sea region where the Honshu-Shikoku Bridges including the Akashi Kaikyo Bridge arelocated has a warm climate. Figure 12 shows an annual RH data recorded at Kobe in every hour in 2015 (8760=24*365
data). It indicates that data with RH more than 40% and 60% account for 96% and 63%, respectively. Besides, anannual temperature data in every hour in 2015 shows that data with temperature more than 19 degree and less than 18
degree account for 55% and 45%, respectively. These imply that the region is under high humidity and wide-range
temperature environment for wire corrosion.
As described earlier, since exceeding the target value of RH inside the cable was occasionally observed during
summer season, a pre-cooler was installed in a dehumidifier in one circulation line on a trial basis. Advantageous pointsof the pre-cooler are; it enables to efficiently dehumidify air in high humid and temperature with temperature of morethan 19 degree, and it is composed of small-sized instruments which can fit into the existing dehumidifier. As shown
Figure 13, humid outside air is firstly dehumidified at the pre-cooler by getting cool the air in a cooling coil anddraining liquefied water to outside, then secondly dehumidified at the silica gel rotor. The pre-cooler will not be able todehumidify air with temperature of less than 18 degree because of frost getting stuck at the cooling coil. Accordingly,
the pre-cooler is set to halt when temperature of outside air becomes less than 18 degree. It was verified that the
hybridization of a dehumidifier and a pre-cooler successfully dehumidifies outside air throughout the year, even during
summer season with high-temperature and humidity.

227

Silica Gel RoterHeater300

Frequency(# of Occurrence)

250

Outside Air

RH>40% (96% of Total)

200

Cooling Coil

150

Cable

Outside Air

100
50

OutsideDry Air

Dry Air

RH>60%(63% of Total)

Dehumidifier

Roots Blower

00 10 20 30 40 50 60 70 80 90 100

Relative Humidity (%RH)

Figure 12. Annual RH Data Recorded at
Kobe in 2015

Drain Pipe
OutsideFigure 13. Dehumidifying Process

In addition, heating temperature for drying a silica gel rotor in one circulation line was experimentally reduced
from 140 to 70 degree in the period of August 2015 through February 2016 in order to save electricity consumption
increased by the hybridization. As a result, electricity consumption was decreased to 70%, from 370 to 270kwh/day,and RH inside the cable was almost kept below the target value of 40% RH under wide-range temperature variation,from -2.5 to 27 degree.
The additional two measures have been taken for all six circulation lines from this year. Although it costs 12.6
million JPY, it is expected to save 24 million JPY during the next ten years.
6 CONCLUSIONS
After installation of the DAIS in all HSBE’s suspension bridges, improvements of the DAIS have been
consistently implemented based on inspection or monitoring results. These efforts have made RH inside the cable to be
kept below the target value, and thus the cables seem to be is in sound condition at this moment. In order to maintainthe cables for a long time, improvements of the DAIS will be continued based on a PDCA cycle, which incorporates aconcept of asset management. Besides, further studies in terms of material of the wrapping system with higher
durability and economical way of operation are going to be performed.
REFERENCES
Fujikawa, H., Kashima, S.& Kawakami, Y. (2000). Corrosion Protection for Suspension Bridge Cables, 2ndInternational Suspension Bridge Operators’ Conference, New York.
Honshu-Shikoku Bridge Expressway Co., Ltd (2015) Disclosure Book of Honshu-Shikoku Bridge Expressway Co.,
Ltd, pp 18- 25.
Kusuhara, S., Moriyama, A., Toyama, N., Kagawa, A.& Yamamoto, M. (2015). Current Condition and
Improvement of Dry Air Injection System for main cables, 2015 New York City Bridge Conference, New York.
Ogihara, K., Sakai, K., Masada, K. (2013). Present Situation of Dry Air Injection System for Main Cables in Japan,
8th International Cable Supported Bridge Operators Conference, Edinburgh.

228

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

INFLUENCE OF ROADSIDE VEGETATION ON ROUGHNESSPROGRESSION FOR PAVEMENTS FOUNDED ON EXPANSIVESOILSASSET MANAGEMENTTRACKAUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

AHMED, Md Yeasin

PhD Student, Department
of Civil and Construction
Engineering

Swinburne University ofTechnology

Australia

POSITIONORGANIZATIONCOUNTRY

Senior Lecturer,
Department of Civil andConstruction Engineering
Associate Professor,
Department of Civil andConstruction Engineering

Swinburne University ofTechnology

Australia

Swinburne University ofTechnology

Australia

CO-AUTHOR(S)
EVANS, Robert

IMTEAZ, Monzur Alam

E-MAIL(for correspondence)

mdyeasinahmed@swin.edu.au

KEYWORDS:
Expansive soils, Gilgai, roadside vegetation, waveband roughness, pavement deterioration

ABSTRACT:

Non-uniform ground movement due to moisture variation in an expansive soil subgrade often results
in increased pavement roughness that effects ride quality and causes passenger discomfort. It is acommon belief that the presence of roadside vegetation can contribute to increased roughness levels
and progression rates, but this has not yet been quantified in any published literature. In order toevaluate the influence of roadside vegetation on roughness progression, roadside vegetation datasuch as number of roadside trees, size of tree canopy area, height of tree, relative distance between
tree and pavement seal, and a density rating for any grass present in the unsealed shoulder wasdeveloped. This data was collected using satellite imagery for a rural highway in North-Western
Victoria, Australia, which was then analyzed against historical road roughness data to develop amodel to quantify the influence of vegetation on road roughness progression rates.

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INFLUENCE OF ROADSIDE VEGETATION ON
ROUGHNESS PROGRESSION FOR PAVEMENTS
FOUNDED ON EXPANSIVE SOILS
Md Yeasin Ahmed1, Dr Robert Evans1, Dr Monzur Alam Imteaz1
1

Swinburne University of Technology, Melbourne, Australia
Email for correspondence, mdyeasinahmed@swin.edu.au

1 INTRODUCTION
In Australia, it is quite common for pavements founded on expansive soils to experience extensive
roughness, premature distresses and structural deformation due to non-uniform ground movements. Overall,six out of the eight Australian capital cities and surrounding areas are affected by such geological conditions.
All light structures, such as road pavements, parking lots, residential dwellings, light commercial buildings,
etc. are all vulnerable to such ground movements associated with expansive soil behavior (Delaney et al.,2005, Fityus et al., 2004, Krohn and Slosson, 1980). Expansive soils are defined as those that shrink andswell significantly when subjected to variations in moisture. They are typically clay type soils that yield highliquid limits and levels of plasticity. More specifically, it is the presence of “active” clay minerals (i.e.
montmorrilonite) within the soil that creates the greatest potential for expansion and contraction. Literaturesuggests that factors responsible for expansive behavior can be classified as either intrinsic factors or driving
factors. The intrinsic factors include clay content (Anderson et al., 1973, Franzmeier and Ross, 1968,
Komornik and Zeitlen, 1965, Russell, 2002), organic content (Davidson and Page, 1956), cation exchange
capacity(Franzmeier and Ross, 1968, Gill and Reaves, 1957), type of adsorbed cation (Anderson et al., 1973),
charge density (Komornik and Zeitlen, 1965), amount and type of clay minerals present (Anderson et al.,1973, Komornik and Zeitlen, 1965), and bulk density (Finn and Strom, 1958, Komornik and Zeitlen, 1965).
The driving factors that act to instigate expansive behavior of a soil includes climate (Krohn and Slosson,
1980, Lambe, 1960), site drainage (topography) (Mathewson et al., 1975) and vegetation (Hammer andThompson, 1966). Any of these factors or their combination can initiate expansion and contraction of thesubgrade, which may result in increased roughness levels (loss of shape) and longitudinal cracking.
Longitudinal cracking usually initiates due to the desiccation and shrinkage of soil beneath the edge of thepavement, while road roughness can be attributed to non-uniform volume changes and associated movements
beneath the pavement. Such non-uniform volume changes often occur due to development of Gilgai.
Gilgai is a topographical feature that comprises of a series of mounds and depressions (i.e.
undulating surface terrain). Gilgai is an Aboriginal (Australian) word that means “small waterhole”, whichrefers to the water captured in the depression of the undulating ground. Aitchison (1953) was the first torecognize and introduce the principles of Gilgai formation in Australia. Many others, namely:Knight (1980),
Maxwell (1994), Paton (1974) have all since proposed slightly different theories about Gilgai formation.
Nevertheless, the best and most complete description of Gilgai and its formation can be found in theAustralian Handbook of Soils (Hallsworth, 1968). In brief, it is the presence of an expansive soil deposit thatis responsible for Gilgai formation. As deep shrinkage cracks allows water to penetrate deep into the ground,deep seated swelling occurs and initiates the formation of the mound. This mound then slowly grows eachclimatic drying and wetting cycle.
At present, approximately 30 per cent of all Australian dwellings and approximately 50 per cent ofVictoria’s surface area is covered by moderate to highly expansive soils (Holland and Richards, 1982,
Richards, 1965). Moreover, a considerable amount of Victorian soil deposits have shown significant trends indeveloping Gilgai characteristics. In this specific area, Gilgai formations have been measured successfullyusing road profile data and associated waveband analysis (Evans et al., 2015). As the variation in moistureplays a major role in expansive soil behavior and the formation of Gilgai, the presence of roadside vegetation
should influence the ground moisture and thus influence the development of Gilgai and associated pavement
roughness development. Current literature suggests that trees do significantly affect subsurface moisture

230

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levels and variations (Blight, 2005, Snethen, 2001). The influence has been measured vertically up to 10 m
below the ground surface and horizontally up to 1.5 to 2 times the height of the tree (Richards et al., 1983).
However, no studies have ever quantified the relationship between presence of roadside trees and roughnesslevels. This paper aims to develop relationships between various tree parameters and roughness progression
rates.
2 SITE DESCRIPTION
The Borung highway is located in North-Western Victoria and runs from St Arnaud to Litchfield to
Warracknabeal to Dimboola. This highway was selected as the test site for this study based on the following
criteria: (i) distribution of expansive soil deposits, (ii) presence and possible development of Gilgai insurrounding areas, (iii) favorable climate condition that promotes significant shrink-swell behavior, (iv)
typical populations of roadside trees present in road reserve, and (v) availability of quality historicalpavement roughness data. Among hundreds of sections along the Borung Highway, a total of 109 sections(each 100 m in length) were selected to evaluate the influence of vegetation on pavement roughness levels.
All selected sections are rural highway sections between the township of Litchfield and Dimboola(approximate 80 kms in length) which have shown a wide variation of roughness progression, as shown in
Fig. 1. In this figure, the white region is considered to represent geology that is non-expansive. The yellow todark orange regions represent alluvial expansive soils, and the pink regions represent residual expansive typesoils (i.e. weathered basalt). Most importantly, the darker the color in this figure, the more expansive the soil.

Figure 1. Distribution of expansive soil in Victoria (Australia) and location of test site (Evans, 2013)
3. DATA COLLECTION AND METHODOLOGY
The data collection of this study comprised of two parts: (a) pavement roughness data and (b)roadside vegetation data. The raw pavement roughness data was provided by VicRoads (the State Road
Authority of Victoria, Australia) and the roadside vegetation data was collected using satellite imagery
software. The roughness data was collected every two years using a vehicle-mounted laser profilometer

231

`

device to measure the raw longitudinal road profiles. These road profiles were then used to calculate theInternational Roughness Index (IRI) via the quarter car model at 100 m intervals. The IRI is the most popularand acceptable way of interpreting pavement roughness. In general, the higher the IRI value, the lower the
ride quality and the higher the passenger discomfort. The quarter car model used to calculate the IRI
theoretically responds to wavelengths between 0.5 m and 100 m, but it is mostly influenced by wavelengths
between 1.2 m and 30 m and is most sensitive at 2.4 m and 15.4 m. These two wavelengths are known for
their characteristics of causing high passenger discomfort. Although the IRI represents a summary of theoverall pavement roughness level within a pavement, it may become necessary to distinguish between longand short wavelength roughness content (i.e. the type of roughness present in the pavement). It is believedthat the influence of short wavelength roughness is limited to deformation of the upper layers of thepavement, while roughness within the lower layers (i.e. subgrade) is represented by long wavelengthroughness. In order to evaluate the cause of roughness within the pavement, waveband analysis was
performed to determine the contribution of each waveband in terms of roughness. To calculate the waveband
roughness contribution, the raw longitudinal road profile data was passed through various band pass filters(namely the four-pole Butterworth filter using Mean Absolute Values (MAV) in this study). The RoadRufsoftware package was used for these calculations. The waveband intervals were setup based on double octave
bandwidths. The Double Octave Bands (DOBs) were classified into seven categories to cover the fulldefinition of roughness (i.e. 0.5 m to 100 m). However, indices DOB3, DOB4 and DOB5 were considered tobest match the wavebands similar to the IRI. These octave bands (DOB1 to DOB7) with their respective
lower and upper wavebands have been defined in Table 1.
Table 1. Definition of Butterworth (MAV) double octave waveband indicesProfile Name
Butterworth (MAV)- DOB1
Butterworth (MAV)- DOB2
Butterworth (MAV)- DOB3
Butterworth (MAV)- DOB4
Butterworth (MAV)- DOB5
Butterworth (MAV)- DOB6
Butterworth (MAV)- DOB7

λlower
0.354
0.707
1.414
2.828
5.657
11.31422.627λcentre
0.707
1.414
2.828
5.657
11.31422.62745.255λupper
1.414
2.828
5.657
11.31422.62745.25590.51

Google Earth Pro was used to collect the roadside vegetation data as it offers recent satellite imagery
with acceptable precision and accuracy. Tree data was collected using both satellite view and street view.
Distance and canopy area measurements were taken from the satellite view option within Google Earth Pro,
while the street view option was used to determine elevations.
(a) PAVEMENT ROUGHNESS DATA COLLECTION AND MANAGEMENT
VicRoads usually conduct detailed road surveys once every two years for rural highways across theState of Victoria, which consists of measuring longitudinal road profiles and calculating the IRI at 100 mintervals. For the Borung highway, consecutive road roughness data was available from 1995 to 2009, withthe exception in 2003. From the 80 kms of potential Borung highway to select, 150 sections (each 100 m inlength) were initially selected as they contained abnormally high levels of roughness. However, to maintain agood distribution of roughness levels, only 109 sections were finally selected and used in this study. The
selected test sites were identified according to Victoria’s State Road Referencing System (SRRS), which isbased on chainages. This was essential for the proper identification and management of the test site data.
Roughness progression rates (for all indices) were calculated for each selected test site. Theseroughness progression rates were also separated into pre-maintenance and post maintenance rates. This was
to increase the actual accuracy of the deterioration. Maintenance activity can easily be identified from theroughness data over cumulative years from any sudden drop in level. This approach was used to determine
the pre-maintenance and post-maintenance roughness progression rates.
(b) ROADSIDE VEGETATION DATA COLLECTION
In order to determine the influence of roadside trees on pavement roughness, vegetation data wascollected for the selected sections. This data included: (i) number of trees present on each side of the

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pavement, (ii) location of individual trees along the pavement, (iii) offset distance between individual trees
and centre-line of the pavement, (iv) canopy area of each tree, (v) height of each tree, and (vi) density ratingof grass present in the shoulder. Figure 2 depicts some of the data collected for the roadside trees database.

(a)

(b)
Figure 2. Identification of tree data measurements (a) distance (offset) and height, and (b) an example ofcanopy area and distance (offset)

233

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From satellite imagery, the number of trees present on each side of the pavement section has been tabulated.
Only trees located within the road reserve were considered. All types of trees including mature trees, young
trees, bushes and even trees with no canopy were considered. For large groups of trees, street view imagery
was used to identify and tabulate these individual trees.
The offset distance between individual trees and center-line of the pavement were measured using
the “Ruler” tab available in Google Earth Pro. Any two dimensional measurement is possible using thisoption and any desired scale can be chosen. The procedure of taking measurements in Google Earth Pro has
been illustrated in Figure 3. In Figure 3 (a) the tree has been identified as DTLR104783 as it is located on left
side of the pavement at a chainage of 104783 m and has an offset distance of 17.6 m from the centre-line ofthe pavement. In Figure 3 (b) the canopy area of tree (TR104783) has been measured using a polygon. Here,the area of the polygon measures 47.1 m2.

(a)

(b)

Figure 3. Example measurements (a) offset distance between tree and center-line of pavement, and (b) tree
canopy area using polygon method
The measurement of tree height was performed using both satellite and street view type images in
Google Earth Pro. First, satellite imagery was used to position a small polygon near the base of the tree(using 3D Polygon tab). A narrow or slender polygon is preferable as it is easier to position. The sides of thepolygon then need to be extended to the ground using the scale, and the height of the polygon adjusted. The
style and color of the polygon can be modified for better visibility depending on the image. Street view isthen used to adjust or fine-tune the height (if required) of the polygon to match the height of the tree (seeFigure 4). The accuracy of this approach may depend on the initial positioning of the polygon and visualadjustment of the height. The closer the position of the polygon to the base of the tree, the greater the level ofaccuracy will be achieved. Figure 4 (a) shows the positioning of the 3D polygon near the tree base and Figure
4 (b) shows the adjustment and fine tuning of established polygon to determine tree height. The height of thetree was measured as 9 m.

234

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Figure 4 (a) Positioning of 3D polygon near the tree base, and (b) Adjustment and fine tuning of 3D polygon
to measure the heightAs the grass density within each pavement shoulder may influence pavement roughness, a rating
system (using values between 0 and 5) was employed. A zero rating indicated no grass present while a ratingof 5 indicated a shoulder fully occupied by grass. The rating system was necessary as it converted theapproximate density of grass into a metric scale. The rating of shoulder vegetation was performed using
Google Earth street view. The scrolling function within Google Earth street view allowed each shoulder to be
rated with a reasonable degree of accuracy. Figure 5 presents an example of the density rating system. Here,the density rating for the left and right shoulders was recorded as 2 and 1 respectively. This is because thegrass started to encroach into the left shoulder, while nearly no grass was present on the right shoulder.

Figure 5. An example of grass density rating for the left and right shoulder using Google Earth street view

235

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DATA ANALYSIS AND RESULTS
As the objective of this study was to evaluate the influence of roadside vegetation (namely trees) onroughness levels, all roadside vegetation variables and road roughness indices were statistically evaluated. To
achieve this, all roadside tree parameters were set as independent variables and the roughness indices wereset as the dependent variable. Unfortunately, no statistical correlation was evident between the roadside tree
variables and the individual roughness levels. This was most likely due to the fact that road pavements
naturally deteriorate over time due to a number of different factors and pavement age was not considered inthis analysis. Thus, to remove pavement age (or time factor) from this analysis, we evaluated the roadsidetree and vegetation variables against roughness progression rates for both IRI and Butterworth waveband
roughness indices instead. Roughness progression rates (RPRs) are average change in roughness level per
year and represents the deterioration of pavement. The RPRs were divided into pre-maintenance and post
maintenance rates.
The independent roadside tree and vegetation variables evaluated in this study were (i) Number ofTrees (NoT), (ii) Average Distance between Tree and center-line of Pavement (AvDTrPv), (iii) Average
Canopy Area (ACA), (iv) Average Tree Height (ATH), and (v) Average Grass Density (AGD) rating. Trees
were considered up to a distance of 51.5 m from the center-line of the pavement, and tree height ranged from
0.5 to 24 m. In addition, the statistical analysis was performed in three modes. First, only the roadside tree
population on the “near” side adjacent to the surveyed lane was considered. Then, only roadside trees on thefar (opposite) side were evaluated. Finally, all roadside trees (both sides of the surveyed lane) wereconsidered and evaluated with the lane roughness progression rates. The results of the statistical analysis
using roughness progression rates for IRI and Butterworth indices (DOB3, DOB4, and DOB5) yielded muchbetter correlations than roughness levels, which is presented in Tables 2 and 3. It is important to note that thestatistical correlation between roadside trees and roughness progression rates was greatest when laneroughness indices were used rather than individual wheel paths indices.
Table 2. List of independent roadside vegetation variables and associated correlations with overall laneroughness progression rates (for IRI) as well as relevant prediction equations

IRI

Near
Side
Trees
Only
Far
Side
Trees
Only
All
Trees
(Both
Sides)

Ind. Variables
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
AvDTrPv, ATH

p
0.222
0.227
0.101
0.175
0.142
0.392
0.835
0.634
0.513
0.625
0.111
0.015
0.198
0.02
0.17
0.006

(r)
0.118
0.117
0.158
0.131
0.141
0.083
0.02
0.046
0.063
0.047
0.154
0.233
0.124
0.223
0.132
0.302

Prediction Equations

RPRIRI,LANE = 0.241 – 0.006AvDTrPv
RPRIRI,LANE = 0.219 – 0.012ATH
RPRIRI,LANE = 0.321 – 0.005AvDTrPv – 0.1ATH

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Table 3. List of independent roadside vegetation variables and associated correlations with overall laneroughness progression rates (for DOB3, DOB4 and DOB5) as well as relevant prediction equations

DOB3 Near
Side
Trees
Only
Far
Side
Trees
Only
All
Trees
(Both
Sides)

DOB4 Near
Side
Trees
Only
Far
Side
Trees
Only
All
Trees
(Both
Sides)

DOB5 Near
Side
Trees
Only
Far
Side
Trees
Only
All
Trees
(Both
Sides)

Ind. Variables
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
AvDTrPv, ATH
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
AvDTrPv, ATH
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
NoT
AvDTrPv
ACA
ATH
AGD
AvDTrPv, ATH

p
0.202
0.155
0.095
0.095
0.288
0.398
0.599
0.646
0.851
0.526
0.104
0.015
0.087
0.009
0.249
0.003
0.28
0.298
0.094
0.148
0.13
0.515
0.798
0.861
0.988
0.545
0.184
0.031
0.144
0.01
0.147
0.007
0.314
0.417
0.124
0.227
0.055
0.404
0.694
0.598
0.498
0.671
0.157
0.029
0.252
0.014
0.092
0.008

(r)
0.123
0.137
0.161
0.161
0.103
0.082
0.051
0.045
0.018
0.061
0.157
0.233
0.165
0.251
0.111
0.32
0.104
0.101
0.161
0.14
0.146
0.063
0.025
0.017
0.001
0.059
0.128
0.207
0.141
0.246
0.14
0.3
0.097
0.079
0.148
0.117
0.184
0.081
0.038
0.051
0.066
0.041
0.136
0.209
0.111
0.234
0.162
0.294

Prediction Equations

RPRDOB3, LANE = 0.106 – 0.003AvDTrPv
RPRDOB3,LANE = 0.102 – 0.006ATH
RPRDOB3,LANE = 0.147 – 0.005AvDTrPv – 0.002ATH

RPRDOB4, LANE = 0.13 – 0.003AvDTrPv
RPRDOB4,LANE = 0.132 – 0.007ATH
RPRDOB4,LANE = 0.18 – 0.002AvDTrPv – 0.006ATH

RPR DOB5, LANE = 0.135 – 0.003AvDTrPv
RPR DOB5, LANE = 0.133 – 0.007ATH
RPR DOB5, LANE = 0.186 – 0.003AvDTrPv – 0.007ATH

The statistical results showed that when we consider only the near side tree population or far sidetree population alone, the relationship with lane roughness progression rate is not significant for any of the
independent vegetation variables. However, when the total tree population (on both sides) was considered,

237

`

the significance in correlation improved and became significant. The greatest correlations were recorded for
AvDTrPv and ATH against the lane RPR. It was observed that in all cases, AvDTrPv and ATH produced thebest correlation with lane RPR regardless of the type of indices used (IRI or Butterworth waveband indices).
The Pearson r value for all these correlations was between 0.2 and 0.32, which indicated a small to medium
effect (Field, 2009). But, these correlations were found as being significant with p values less than 0.05
achieved. This is a clear indication that a relationship exists between lane roughness progression rates androadside tree variables like AvDTrPv and ATH. All prediction equations developed to predict RPR withrespect to AvDTrPv and ATH have also been tabulated and recorded in Tables 2 and 3.
All RPR prediction equations based on AvDTrPv and ATH all show a negative relationship, whichis common for both IRI and Butterworth waveband indices. These negative relationships indicate that: (i) the
further the position of tree from pavement, the lower the expected roughness progression rate, and (ii) the
greater the height of the tree, the lower the roughness progression rates. The first finding supports the current
belief in the literature that the closer the tree the greater the moisture variation in the ground will occur andthe greater the ground movement. However, the second finding goes against current literature as it iscommonly believed that the bigger the tree, the more widespread and established the root system, and thus
the greater the influence in moisture variation and the greater the ground movement. This was a surprising
result, which could be explained by the fact that the smaller trees (being younger trees) need greater moisture
to establish their growth cycles and cell development. Thus, the smaller trees contribute more to roughness
progression within the nearby pavement.

CONCLUSIONSThe overall results obtained in this study proved that trees contribute to pavement roughness
progression for those founded on expansive soils. A weak to medium correlation relationship was found toexist between roadside tree variables and roughness progression rates. The best correlations were foundbetween roughness progression rates and (i) relative distance between the tree and center-line of thepavement, and (ii) the height of the trees. In both these cases the correlation was found to be negative andwas common for both IRI and individual Butterworth waveband indices. Even though the correlations
attained were not convincing, this might have occurred as other variables such as pavement age, annual
average daily traffic (AADT) and pavement distress features such as cracking, rut depth, climate, topography
and geological origin were not considered in this model. Moreover, many parts of the Borung highway havebeen found to be affected by Gilgai development, and the undulating pattern of such geological formation is
expected to influence the growth of roughness progression rates. As a weak to medium relationship wasestablished between tree variables and roughness development, the overall roughness progression rates could
have resulted from the combined effect of many variables. Thus, in the future, it is intended to merge thisdatabase with the abovementioned “traditional” pavement deterioration variables to enhance current
pavement deterioration models in areas of expansive soils with roadside tree plantations.

ACKNOWLEDGEMENT
The authors acknowledge the support offered by VicRoads in providing the raw longitudinal roadprofile measurements, which was used to calculate the roughness indices.

REFERENCES
AITCHISON, G. (1953). The mechanics of gilgai formation. Proc. of Conf. on Soil Science, Adelaide. 1-3.
ANDERSON, J., FADUL, K. E. & O'CONNOR, G. (1973). Factors affecting the coefficient of linear
extensibility in Vertisols. Soil Science Society of America Journal, 37, 296-299.
BLIGHT, G. E. (2005). Desiccation of a clay by grass, bushes and trees. Geotechnical & GeologicalEngineering, 23, 697-720.
DAVIDSON, S. E. & PAGE, J. (1956). Factors influencing swelling and shrinking in soils. Soil Science
Society of America Journal, 20, 320-324.
DELANEY, M., LI, J. & FITYUS, S. (2005). Field monitoring of expansive soil behaviour in the newcastlehunter region. Journal of Australian Geomechanics, 40, 3-14.

238

`

EVANS, R. (2013). Synchronisation of road profile data and the assessment of road roughness using
waveband analysis. PhD Thesis, Swinburne University of Technology.
EVANS, R. P., ARULRAJAH, A. & HORPIBULSUK, S. (2015). Detecting gilgai relief beneath sealed
flexible pavements using road profile and road roughness measurements. Indian Geotechnical
Journal, 45, 431-440.
FIELD, A. (2009). Discovering statistics using SPSS, Sage publications.
FINN, W. & STROM, B. (1958). Nature and magnitude of swell pressure. Highway Research Board
Proceedings.
FITYUS, S., SMITH, D. & ALLMAN, M. (2004). Expansive soil test site near Newcastle. Journal of
Geotechnical and Geoenvironmental Engineering, 130, 686-695.
FRANZMEIER, D. & ROSS, S. (1968). Soil swelling: laboratory measurement and relation to other soil
properties. Soil Science Society of America Journal, 32, 573-577.
GILL, W. R. & REAVES, C. A. (1957). Relationships of Atterberg limits and cation-exchange capacity tosome physical properties of soil. Soil Science Society of America Journal, 21, 491-494.
HALLSWORTH, E. (1968). A handbook of Australian soils. Rellim Public., Adelaide, South.
HAMMER, M. & THOMPSON, O. (1966). Foundation clay shrinkage caused by large trees. Journal of Soil
Mechanics & Foundations Div, 92.
HOLLAND, J. & RICHARDS, J. (1982). Road pavements on expansive clays. Australian Road Research,
12.
KNIGHT, M. (1980). Structural analysis and mechanical origins of gilgai at Boorook, Victoria, Australia.
Geoderma, 23, 245-283.
KOMORNIK, A. & ZEITLEN, J. (1965). An apparatus for measuring lateral soil swelling pressure in thelaboratory. Proceedings of the 6 th International Conference on Soil Mechanics and Foundation
Engineering, 278-281.
KROHN, J. P. & SLOSSON, J. E. (1980). Assessment of expansive soils in the United States. Expansive
Soils, ASCE, 596-608.
LAMBE, T. (1960). The character and identification of expansive soils, soil PVC meter. Federal housing
administration, technical studies program, FHA, 701.
MATHEWSON, C. C., CASTLEBERRY, J. & LYTTON, R. (1975). Analysis and modeling of theperformance of home foundations on expansive soils in central Texas. BuUetm of the Association ofEngmeering Geologists. Yol, 12, 275-302.
MAXWELL, B. (1994). Influence of horizontal stresses on gilgai landforms. Journal of geotechnicalengineering, 120, 1437-1444.
PATON, T. (1974). Origin and terminology for gilgai in Australia. Geoderma, 11, 221-242.
RICHARDS, B. (1965). An analysis of subgrade conditions at the Horsham experimental road site using thetwo-dimensional diffusion equation on a high-speed digital computer, Division of Soil Mechanics,
CSIRO.
RICHARDS, B., PETER, P. & EMERSON, W. (1983). The effects of vegetation on the swelling andshrinking of soils in Australia. Geotechnique, 33, 127-139.
RUSSELL, J. E. (2002). Soil conditions and plants growth, Daya Books.
SNETHEN, D. R. (2001). Influence of local tree species on shrink/swell behavior of Permian clays in central
Oklahoma. GEOTECHNICAL SPECIAL PUBLICATION, 158-171.

239

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Asset Management to Highway: Soil-Cement Stabilization TechniqueTRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Norehsan ABU BAKAR

Region Manager

Opus International (M) Ltd.
NMM-NRO

Malaysia

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Zulkhairi HASAN

Project Director

Mohd Mustaqim MOHDNORDIN

Lecturer

E-MAIL(for correspondence)

Opus International (M) Ltd.
NMM
Faculty of Civil Engineering
Universiti Teknologi
MARA (Pulau Pinang)

Malaysia
Malaysia

norehsan.bakar@opusbhd.uemnet.com

KEYWORDS:
Soil-cement Stabilization; Soft Ground Treatment; Roadbase.

ABSTRACT:The North South Expressway section in Kedah was partly built on an overlying soft clay formation. The groundstabilization technique, namely stone column piles, was implemented to construct denser roadbase layer. However,consolidation and creeping processes had resulted in uneven settlement on treated layer thus undulating the pavement
surface or creating an effect known as “mushroom”. The common pavement treatment of regulating, mill and pave tothe undulated surface proves to be short term measures. In this paper, an innovative treatment method using alkaline
compound was introduced to alleviate these issues at the Alor Setar Selatan Interchange ramps. Utilizing mostly alkaline
earth elements, this technique recycles existing roadbase material by mixing it with cement additive to stimulate direct
hydration processes to form a stiffer roadbase foundation. After curing it with adequate moisture content, upper layers ofbinder and wearing course are then applied. This treatment has effectively improvised roadbase compressive strengthand bearing capacity.

240

Asset Management to Highway: Soil-Cement Stabilization
Techniquea*Norehsan Abu Bakar; bZulkhairi Hasan; cMohd Mustaqim Mohd-NordinaOpus International (M) Berhad
Network Maintenance Management, Northern Region Office,No.10 & 11, 1st Floor, Jln Dagangan 2, Pusat Bandar Bertam Perdana,
13200 Kepala Batas, Pulau Pinang, MalaysiabOpus International (M) Berhad
Network Maintenance Management,
Level 17, Menara UEM, Tower 1, Avenue 7, The Horizon, Bangsar South City,
No. 8, Jalan Kerinchi, 59200 Kuala Lumpur, MalaysiacFaculty of Civil Engineering
Universiti Teknologi MARA (Pulau Pinang),
13500 Permatang Pauh, Pulau Pinang, Malaysia*Email for correspondence,
norehsan.bakar@opusbhd.uemnet.com

1. INTRODUCTION
The northern part of North-South Expressway that traverses the state of Kedah is mostly rested on the paddy field plain.
Since its construction back in 1986, several locations have experienced uneven ground settlement and caused
undulation, depression and cracks on the pavement surface. This condition may endanger the highway users during
heavy rain due to hydroplaning effects as a result of water lying stagnant within the settlement area.
Undulation and uneven ground settlement on the highway surface is significantly influenced by soft groundcondition with low compression and stiffness characteristics. Conventionally, for the ground stabilization technique,stone column piles were applied to construct denser road base layer. However, consolidation and creeping processes
had resulted in uneven settlement on treated layer thus undulating the pavement surface or creating an effect known as“mushroom”. The highway pavement rehabilitation by applying the Cement-Bound Material (CBM) was introduced toextend the life span of the pavement structure by recycling the existing roadbase material (Chai et al., 2005). From thisstabilization technique, the cement effect significantly improves the stiffness properties of unbound layer, thus
providing better load transfer to the pavement foundation.
The factors that influence the physicochemical reactions of soil-cement hydration and the interactions of peatsoil-cementation process are the amount of solid particles, the water-soil ratio, the quantity of binder, the presence of
humic and/or fulvic acids, the soil pH and the amount of organic matter in the peat (Zulkifley et al., 2014). According to
Wu et al. (2016), the applicability and the effectiveness of soil-cement stabilization technique in soft ground
improvement are mainly evaluated by the compactability and strength performance.
2. DESIGN CRITERION
2.1 Existing Roadbase Identification
Prior to the determination of the design mix, samples of the existing roadbase was taken for identification andlaboratory identification tests. The respective tests being conducted were Particle Size Distribution (PSD) for coarse
and fine grained soils (BS 1377: Part 2: 1990: 9), moisture content determination (BS 1377: Part 2: 1990: 3) and Proctor
test (BS 1377: Part 4: 1990) to determine the maximum dry density and optimum moisture content.
From the PSD qualification result, the existing roadbase material had mixed with subgrade material whereby asignificant amount of silt and sand had been identified with the percentage of fine material (i.e. less than 0.8mm) not
exceeding 10% (Figure 1), conforming to Arahan Teknik Jalan 5/85 (2013). While, the result for proctor test on thesame existing roadbase was recorded 2.08 Mg/m3 of maximum dry density (Figure 2) which surpassed the minimum
requirement of 1.3 Mg/m3 thus showing a very good material as a soil-cement stabilization medium. Hence, thepreliminary stage for existing roadbase condition had found that additional fine material (i.e. quarry dust) shall be
combined to improve the PSD curve grading. Furthermore, a minimum of 8% cement and 2% alkaline compound as thestabilizing agent shall act as a basis for the proposed mix design to display higher stiffness and strength properties.

241

Figure 1. Grading characteristic for existing roadbase

Figure 2. Proctor test result for existing roadbase

2.2 Design Application
The thickness of the layer to be treated by soil-cement stabilization is determined by the traffic category andequivalent standard axles as tabulated in Table 1. The stabilization thickness of 300 mm is determined in accordancewith T4 traffic category. The recommended mix design then refers to Qualification test as per Soil Cement
Specification, i.e. relationship between mix design and soil classification. This relationship then introduces thecomposition of Ordinary Portland Cement (OPC) mixed with alkaline compound that promotes cement hydration
process, thus inhibiting the actions of fulvic acids and carbonic acids. Technically, this compound result in roadbase
structural changes and the formation of minerals occurring during cement hydration greatly increases the compressive
strength, the static and dynamic stiffness modulus, the tensile bending strength, besides stabilizing humus-rich soils(Suddath and Thompson, 1975; Wu et al., 2016).

242

Table 1. Relationship table between traffic categories with roadbase stabilization thickness (Arahan Teknik
Jalan 5/85, 2013)
Traffic
Category
T1
T2
T3
T4
T5

Design Traffic(ESAL X 106)
≤1.0
1.1 to 2.0
2.1 to 10.0
10.1 to 30.0
>30.0Depth Stabilization
Thickness
200 mm
250 mm
275 mm
300 mm≥300 mm

The amount of OPC and alkaline compound to be added to the mixture for stabilization was decided based on
soil matrix classification (Table 2) that leads to the design of initial water content and amount of OPC and alkaline
compound. This amount highly influences the rate of pozzolanic reaction that progressively depends on mineralogy ofthe soil and pH level. According to Little et al. (2009), sufficient high pH is maintained to solubilize silicates andaluminates from the clay matrix or fine silt soil. This reaction then forms calcium-silicate-hydrates and calcium
aluminate-hydrates, a similar compound produced during the strength development in the hydration of Portland cement.
This non-binding material type of soil requires the amount of OPC and alkaline compound in the range of 140 kg/m3
to 180 kg/m3. For confirmation, the proposed mix design will be assessed by the seventh day Unconfined Compressive
Strength (UCS) test (BS 1377: Part 7:1990) for bearing capacity.
Table 2. Soil matrix classification relation to mix design
Soil Class
GW
SW
NonBinding

GP
GM

Silty Gravels, gravel-sand-silt mixtures

GC

Clayey Gravels, gravel-sand-clay mixtures

SW
SP
Mixed
Grains

Silty Sands, sand-silt mixtures

SC

Clayey Sands, sand clay mixtures

CLOL
BindingMH

Normal Amount of
OPC + Alkaline
Compound

From 0 to 1520%

From 140 kg/m3
to
180 kg/m3

From 0 to 3035%

From 160 kg/m3
to
190 kg/m3

From 0 to 1530%

From 170 kg/m3
to
220 kg/m3

Well Graded Sand and gravelly sands, little
or no finePoorly Graded Sand and gravelly sands,
little or no fineSM

ML

Organic

Well Graded gravels and gravel-sandmixture, little or no fineWell Graded sand and gravelly sand, little
or no finePoorly Graded gravels and gravel-sandmixtures, little or no fineInitial Water
Content

In organic silts, very fine sands, rocks, silty
or clayey fine sandInorganic clays of low to medium plasticity,
gravelly/ sandy/ silty/ lean clays
Organic silts and organic silty clays of low
plasticity
Inorganic silts, micaceous or diatomaceous
fine sands or silts, elastic silts

CH

Inorganic clays or high plasticity, fat clays

OH

Organic clays of medium to high plasticity

Pt

Peat, muck and other highly organic soils

Import material recommended to beinstalled before stabilization

2432.3 Seventh Day Unconfined Compressive Strength (UCS) Test
This test was carried out to estimate and certify the bearing capacity of the proposed mix design and to choose
the final mix design. The intended sample was prepared by mixing the existing material based on the ratio
predetermined with 8% OPC and 2% alkaline compound. Cylinder of this mix of materials was prepared and cured for
7 days prior to the execution of the UCS test. Based on the results obtained (Table 3), the proposed mix design had
surpassed the minimum strength of 2.5 MPa that has been set by JKR/SPJ/2008-S4, hence the ratio proportion for OPC
and alkaline compound is satisfied.
Table 3. Summary results of UCS test after 7 days of curing
Age
Maximum Load
Compressive Strength
Sample No.
(days)
(kN)
(MPa)
1
2
3

7
7
7

70.80
77.00
66.30

3.15
3.42
2.95

3. CONSTRUCTION APPLICATION
The pavement roadbase rehabilitation construction works by applying soil-cement stabilization technique was
successfully completed at the respective ramp from Alor Setar Utara to Alor Star Selatan toll plaza. In this projectworks, the rehabilitation phases started from milling-off the existing pavement surface not exceeding 150 mm ofthickness (Figure 3). Prior to stabilization works by mixing the existing roadbase material with OPC and alkaline
compound (i.e. Geocrete), quarry dust was spread equally over the stabilized area (Figure 4). The mixing work wasdone by special rotary mixer machine, CAT RM500 that has the capability of ensuring a uniform blend of stabilizationmaterial with the set of 300 mm depth. Water was then spread uniformly over the mixed soil-cement-alkaline
compound to start the chemical reaction for this stabilization process (Figure 5). Then, the mixture was compacted with10 tonnes drum roller without vibration for two passes, followed by another compaction using three passes of vibrationroller with the speed of not more than 3 km per hour (Figure 6).
Finally, before laying the bituminous layers, the curing process was performed by spraying water uniformly on
the stabilized soil periodically for every three to four hours in three days. This is a process to ensure that no prematurecracking is formed by controlling hydration during the stabilization process.

Figure 3. Milling process to scrape-off the existing asphalt layers

244

(a)
(b)
Figure 4. (a) Spread layer of quarry dust; and (b) positioning of cement and alkaline compound packaging toensure an evenly distribution over the stabilized area

Figure 5. Mixing process of mixed soil-OPC-alkaline compound by special rotary mixer machine, CAT RM500

Figure 6. Compaction process by a 10 tonnes drum roller without and with vibration
4. POST-CONSTRUCTION RESULTS
Two types of monitoring test procedures were conducted after the completion of construction works, i.e. UCS
test after 28 days and Light Falling Weight Deflectometer (LFWD) test. As tabulated in Table 4, results confirmed thatthe application of soil-cement stabilization technique has achieved the expected strength and the project objective bycomplying with the requirement greater than 2.5 MPa.

245

Table 4. Summary for UCS test results after 28 days
Diameter
Length Sample Mass
Density
Maximum
(mm)
(mm)
(g)
(kg/m3)Force (kN)
94.0
323
1338.9
2113
73.0
94.0
318
1378.9
2094
105.0
94.0
334
1346.42098
106.0

Sample
No.
1
2
3

UCS
(MPa)
10.5
15.1
15.3

LFWD tests were performed according to ASTM E2835 - 11(2015) to monitor the bearing capacity and thestrength behaviour of unbound pavement material by using Light Drop Weight Tester ZFG2000 (Figure 7). This quick
and cost effective method is to evaluate the dynamic deflection modulus, E vd in MN/m2. This modulus is an index forthe bearing capacity of roadbase layer, and calculated from the measured settlement(s) which equivalent to the results
obtained from static plate bearing test (BS 1377 Part 9: 1990) recorded for existing pavement; i.e. 46.03 MN/m2.
Figure 8 shows an illustration for the summary average results of LFWD up to 28 days after the construction
had been completed. For comparison purposes, the data of the 1st, 3rd, 7th and 28th days after stabilization werecompared again with the result of existing roadbase surface. The readings recorded after stabilization on the 1st, 3rd, 7th
and 28th days age were 109.08 MN/m2, 140.45 MN/m2, 159.46 MN/m2 and 182.39 MN/m2 respectively. It evidently
shows an increase of 237% from the 1st day up to 396% on the 28th day, a significant improvement in roadbase bearing
capacity index which was achieved in the post construction.

Figure 7. In-situ practical of Light Falling Weight Deflectometer (LFWD) test
200

182.39Stabilized Pavement

159.46140.45150
109.08(MN/m2)

Dynamic Deflection Modulus, E vd

Existing Pavement

100

50

46.03

46.03

46.03

46.03

0
1

3
7
Age of Stabilization (day)28

Figure 8. Summary of result for dynamic deflection modulus with respect to age of stabilization

246

5. CONCLUSIONS
The application of soil-cement stabilization technique with the incorporation of quarry dust and alkaline
compound (e.g. Geocrete) with designated proportion has resulted in high value bearing capacity and is more effective
than the conventional regulating during the mill and pave of the undulated surface of highway pavement. In tandemwith soil-cement-alkaline stabilization design approach, a high performance of roadbase in term of compressive
strength and high resilient modulus can be expected as a solution for unstable pavement.
From the mix design of 8% and 2% for OPC and alkaline compound respectively, the average results of 13.63
MPa for compressive strength and 396% increment in bearing capacity as compared to existing roadbase reading of
LFWD for after 28 days were achieved. Subsequently, this stabilization technique can lessen the frequency ofmaintenance cycles, which makes it an effective and practical engineering solution especially for highway maintenance.

ACKNOWLEDGEMENTS
The authors wish to thank PLUS (Projek Lebuhraya Usahasama Berhad) for granting the permission to publish the data
presented in this paper. Technical contributions from GeoCrete Specialist Sdn. Bhd., and PROPEL Bhd are greatly
appreciated.

REFERENCES
Arahan Teknik Jalan 5/85 (2013). Manual for the structural design of flexible pavement. Jabatan Kerja Raya Malaysia.
ASTM E2835 - 11(2015) Standard test method for measuring deflections using a portable impulse plate load test device
BS 1377 Part 9 : 1990 In-situ plate bearing test
BS 1377: Part 2: 1990: 3 Moisture content determination
BS 1377: Part 2: 1990: 9 Particle size distribution for coarse and fine grained soils
BS 1377: Part 4: 1990 Modified proctor test
BS 1377: Part 7:1990 Methods of test for soils for civil engineering purposes. Shear strength tests (total stress)
Chai G.W.K., Oh E.Y.N. and Balasubramaniam A.S. (2005). In-situ stabilization of road base using cement - A casestudy in Malaysia. The fifteenth international offshore and polar engineering conference, 19-24 June, Seoul, Korea.
International Society of Offshore and Polar Engineers.
JKR/SPJ/2008-S4 Standard specification for road works, Jabatan Kerja Raya Malaysia
Little, D. and S. Nair (2009). Recommended practice for stabilization of subgrade soils and base materials.” NCHRP
Project 20-07.
Suddath L.P. and Thompson M.R. (1975). Load-deflection behaviour of lime stabilized layers. Technical report
4A664717D895-04-002 (U.S. Army Construction Engineering Research Laboratory (CERL)).
Wu Zilong, Deng Yongfeng, Liu Songyu, Liu Qianwen, Chen Yonggui, Zha Fusheng (2016). Strength and microstructure evolution of compacted soils modified by admixtures of cement and metakaolin. Applied Clay ScienceVol. 127-128: 44-51.
Zulkifley M.T.M., Ng TF, Raj JK, Bakar AFA, Ashraf MA, Hashim R and Paramanthan S. (2014). A review of thestabilization of tropical lowland peats. Bulletin of Engineering Geology and the Environment Vol. 73:733–746.

247

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Removal method for ceiling board of the Hanshin Expressway’s tunnels

TRACK
AUTHOR(Capitalize Family Name)
Masahide TAKAHASHI
CO-AUTHOR(S)(Capitalize Family NamePOSITION
StructuralGroup

RepairORGANIZATIONWorkPOSITION

Hanshin
Expressway
Company Limited

COUNTRYJapan

ORGANIZATIONCOUNTRY

Shotaro HIRAYAMA

StructuralGroup

RepairWork

Hanshin
Expressway
Company Limited

Japan

Hideki TAKADA

StructuralGroup

RepairWork

Hanshin
Expressway
Company Limited

Japan

E-MAIL(for correspondence)masahide-takahashi@hanshin-exp.co.jp

KEYWORDS:
Hanshin Expressway
ceiling board of tunnel
removal works
Kobe Nagata tunnel
Shin-Kobe tunnel

ABSTRACT:In December 2012, a traffic accident caused by fall of the ceiling board occurred inside a tunnel in Japan. We checked
the tunnel in the Hanshin Expressway network where a similar type of ceiling board was installed. As the result of safety
evaluation, we made a judgement that the ceiling board would be able to serve sufficiently for some more years.
However, we decided to remove the ceiling board in consideration of risks assumed in the course of operation andmaintenance. In order to minimize inconvenience to users, the removal works was carried out during a limited days.
This paper introduces the outline of the removal works.

248

Removal method for ceiling board of the Hanshin
Expressway’s tunnels
Masahide TAKAHASHI1・Shotaro HIRAYAMA1・Hideki TAKADA1
1

Hanshin Expressway Company Limited Osaka, JPN
Email ：masahide-takahashi@hanshin-exp.co.jp

1 INTRODUCTIONIn December 2012, a traffic accident caused by fall of the ceiling board occurred inside a tunnel in Japan.
Following this incident in Sasago tunnel, we checked the tunnel in the Hanshin Expressway network where a similar
type of ceiling board was installed. As the result of safety evaluation, we made a judgement that the ceiling board
would be able to serve sufficiently for some more years.
However, we decided to remove the ceiling board in consideration of risks assumed in the course of operationand maintenance. In order to minimize inconvenience to users, the removal works was carried out during a limited days.
This paper presents the methods of removal of the ceiling boards.

2 KOBE NAGATA TUNNEL AND SHIN-KOBE TUNNEL
Hanshin Expressway Co. Ltd. is in charge of the administration of expressways of 259.1 km in total length(Figure 1), which consists of elevated structures of 209.1 km, underground structures of 28.1 km and others of 21.9 km.
Of these, Kobe Nagata Tunnel and Shin-Kobe Tunnel (northbound) had ceiling boards installed.

Figure 1. Hanshin Expressway network.

249

Shin-Kobe Tunnel (northbound) is a two-lane one-way tunnel with a length of 6,910 m. When it was firstbrought into service in 1976, it was a two-way tunnel with one lane for each direction, which is one factor that led to theemployment of a transverse ventilation system, and ceiling boards were installed at the top of the tunnel cross section toensure space for supply and discharge of air. Subsequently in 1988, the southbound tunnel was opened and therespective tunnels are now in service as one-way northbound and southbound tunnels.
Kobe Nagata Tunnel is composed of two tunnels of 3,906 m northbound and 3,364 m southbound, each ofwhich is a two-lane one-way tunnel. For the Tunnel, a transverse ventilation system was employed from the fist
construction and the structure included suspended ceiling boards to ensure space for supply and discharge of air.

3 STRUCTURE OF CEILING BOARDS OF KOBE NAGATA TUNNEL
The ceiling boards of Kobe Nagata Tunnel were structurally supported by metal fittings suspended from thetunnel lining using post-construction anchor bolts and the ceiling boards were installed by inserting at the lower end of
the metal fittings (Figure 2). For these ceiling boards, extruded cement panels containing asbestos (non-scattering) weremainly used. For preventing falling of the ceiling boards, a backup structure using fall prevention wires was installed.
On these metal fittings for suspension at the center (hereafter referred to as "central metal fittings"), ALC
panels were installed as partitions between the air supply duct and air discharge duct. The partitions were installed on
the central metal fittings by using M12 hexagon head bolts.
At the side ends of the ceiling boards, mortar was poured for filling the gap between the lining and ceilingboards.

Figure 2. Structure of ceiling boards of Kobe Nagata Tunnel.

4 STRUCTURE OF CEILING BOARDS OF SHIN-KOBE TUNNEL
Unlike the suspended structure using post-construction anchor bolts of Sasago Tunnel, the ceiling boards of ShinKobe Tunnel have a structure self-supported by arched reinforced concrete (t = 150 mm) as shown in Figure 2 and theinside was divided by partitions into the air supply and discharge spaces. The emergency stopping lane had the structure
supported by the suspension members embedded in the lining, as shown in Figure 3.

250

Figure 3. Structure of ceiling boards of Shin-Kobe Tunnel.

5 CEILING BOARD REMOVAL METHOD FOR KOBE NAGATA TUNNEL
Plans for the removal of the ceiling boards of Kobe Nagata Tunnel were made mainly including complete
closure of the Tunnel for all days. Closure for 14 days was required for completing the removal of all ceiling boards.
For removing the ceiling boards, the works were conducted by assigning the operations to different work teams
mainly for the ceiling boards, partitions and metal fittings for suspension (central and end) in this order to complete theremoval. The following describes the procedure.

(1) Removal of ceiling boards
Ceiling boards were removed by using a handling machine equipped with a special device on the backhoe.
This device is capable of rotating the tips of the arms that grip an object, which can be used to avoid the mounting
metal fittings to remove ceiling boards as shown in Figure 4. The ceiling boards were installed separately for thedriving lane and passing lane sides bordering the central metal fittings and, to maintain the stability of the ceilingboards during the removal, two boards were removed each time while alternating the sides. The ceiling boards
removed by the handling machine were transferred onto a forklift for temporary placement and carried outside.

Figure 4. Removal by using handling machine.

251

(2) Removal of central metal fittings and partitions
After the removal of the ceiling boards, the partitions were removed by using a high place work vehicle toremove the mounting bolts of the partitions (ALC panels) and bringing the ALC panels down into the widened
bucket of a wheel loader. Then the metal fittings for suspension (central) were removed.
For removal of the metal fittings for suspension (central), a jig for removing the central metal fittings was
mounted on the forklift and, after removing the central metal fittings, a crane was used to lift them from the forklift
to temporarily place them on the road surface, where the central metal fittings were disassembled. In view of theoverall work process, some of the partitions were removed inside the ceiling boards before the removal of theceiling boards(Figure 5 and Figure 6).

Figure 5. Removal of the central metal fittings.

Figure 6. Removal of partitions.

(3) Removal of metal fittings for suspension (side ends)
The pedestals at the both side ends were found to be filled with mortal, and a standard approach based uponthis plan was designed to removal of the filling mortar by complete chipping. However, it was also revealed that thefilling mortar was shrinkage-compensating type and its removal by complete chipping was difficult. Accordingly,
the removal method was changed to simultaneous removal of the filling mortar and steel plates by using a special jig
mounted on the forklift to grip the filling mortar and steel plates together.

252

5 CEILING BOARD REMOVAL METHOD FOR SHIN-KOBE TUNNEL
Ceiling board removal works by complete closure were preferable also for Shin-Kobe Tunnel (northbound).
However, unlike Kobe Nagata Tunnel, it is on a principal road used by buses on regular routes and works by complete
closure was assumed to cause significant impact on the users. For this reason, the removal of the ceiling boards of ShinKobe Tunnel was planned based on implementation of works by closure only during the nighttime and completion of
the removal of all ceiling boards required nighttime closure for 40 days.
The hours of the nighttime closure were determined to be 6 hours and 30 minutes from 23:30, which is after
the last bus on a regular route passes, to 6:30 in the next morning before the first bus passes. It included the time forpreparation and clearing up for lane opening (lifting of the closure) and the time that could be used for the actual
removal works was very short at about 4 to 5 hours. Accordingly, how efficiently the removal cycle could be scheduled
was an important point. The following describes the removal procedure.

(1) Support and cutting of ceiling boards
The ceiling boards were cut in the transverse direction in advance from the inside of the ceiling boards.
Then, a multi-axle carriage was placed at the location of the ceiling board removal, the deck lift was jacked up to
support the ceiling boards at the center and the ceiling boards were cut in the longitudinal direction by using a
concrete cutter for detaching the central part (Figure 7).

Figure 7. Ceiling board cutting and support by using multi-axle carriage.

(2) Jacking down and moving of multi-axle carriage
The maximum length of a ceiling board that can be supported by the multi-axle carriage at one time is 12
m. The first span to be removed, after its cutting was finished, was placed on the deck, and jack-downed. After then,the carriage was moved to the next span (Figure 8). The next 12 m of the board was supported in such a way that it
was placed on top of the ceiling board removed first and cut in the same way. This process was repeated three times
and a stack consisting of three ceiling boards each 12 meters, or 36 meters in total was loaded onto the carriage.

Figure 8. Moving of multi-axle carriage.

253

(3）Transshipment of ceiling boards from multi-axle carriage to trailer
The multi-axle carriage loaded with the ceiling boards having a total length of 36 m (12 m ceiling boards inthree tiers) was moved to the transshipment area and the electric hoist installed on the crown in advance was used totransfer the boards to the trailer for carrying out (Figure 9). The ceiling board, after it had been cut in the traversal
direction into panels, were grouped in units of three panels each having the size of 5.4 m x 2.4 m; then this unit, in astate suspended, was turned 90 degrees, and loaded onto the trailer for carrying.

Figure 9. Transshipment of ceiling boards.

(4) Removal of ceiling board side ends
The remaining side ends of the ceiling boards were removed by using a forklift. On the forklift, a special
platform was installed and, with a ceiling board end supported from the bottom, the fall prevention (suspending)metal fittings were cut for removal (Figure 10). By carrying out the end removal in parallel with the removal of thecentral part using the multi-axle carriage, the cycle time was reduced.

Figure 10. Removal of ceiling board side ends.

254

6 CONCLUSIONSOf the tunnels on Hanshin Expressway, Shin-Kobe Tunnel and Kobe Nagata Tunnel had ceiling boards
installed and the removal of the ceiling boards was completed in 2016 for Kobe Nagata Tunnel and in 2014 for
Shin-Kobe Tunnel (northbound).
For the removal of the ceiling boards, it was necessary to take into account the structure and material of therespective ceiling boards and the restrictions on the work time in view of the impact on the road users. To deal withthese issues, we selected appropriate methods with the various conditions taken into consideration and studied
removal methods capable of realizing an efficient cycle time of the removal works, which resulted in the successful
completion of the ceiling board removal as initially scheduled.
These ceiling board removal works, which were determined in view of long-term safety, leads to the safety,
security and comfort of Hanshin Expressway.

255

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

EFFECT OF LONG-TERM AGING ON PROPERTIES OF APHALTTRACK
AUTHOR(Capitalize Family Name)TOSHIAKI HIRATO

POSITIONMANAGERORGANIZATIONTOACORPORATION

ROAD

CO-AUTHOR(S)(Capitalize Family NamePOSITION

MAI KOBAYASHIRESEARCHERTOACORPORATIONROADMASATO MURAYAMA

Director

TOA
CORPORATIONROADSHIGEKI TAKAHASHIDIVISION Chief

E-MAIL(for correspondence)

ORGANIZATION

Nippon Expressway
Research Institute Company
Limited

COUNTRYJAPAN
COUNTRY
JAPAN
JAPAN

JAPAN

T_hirato@toadoro.co.jp

KEYWORDS:
asphalt pavement, aging, FT-IR, stiffness, Dynamic Shear Rheometer256

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
ABSTRACT:The properties of asphalt are important in the characteristics of pavement used for long periods. Damage toasphalt pavement is caused by fatigue due to cyclic traffic loads and hardening of asphalt due to oxidative aging. East
Nippon Expressway Co., Ltd. has carried out excavation investigation of asphalt pavement on the expressways. In thisstudy, we have collected sample blocks from asphalt pavement under long-term use from expressways. Ten samples
were obtained from the following four locations: On the Joshin-Etsu Expressway between the Nagano andSuzakanagano East interchanges (both away from and toward Tokyo), on the Nagano expressway between the
Toyoshina and Omi interchanges (away from Tokyo), and on the Nagano expressway between the Omi and Kousyoku
interchanges (away from Tokyo). These samples are recorded about the traffic volume and repair history. The samples
were then classified based on the damage level, years of service, wheel path location, asphalt mixture type, and otherparameters.
This study investigates the effects of traffic and environmental factors on the aging of the asphalt. The
objectives of this research were (1) to achieve a better understanding of the aged state of the asphalt mixtures inpavements after long-term use and (2) to simulate the aged state in laboratory tests in order to identify the factors
affecting aging. We surveyed the asphalt extracted from the surface course to base course in each blocks.
Characterizations were performed on the extracted asphalts to determine how the specimens had aged. Next, the samecharacterizations were performed on the asphalt, which were subjected to accelerated aging under various conditions.
The results revealed that aging affects not only the surface course of asphalt pavement but also the base course,
and the penetration of asphalt in porous asphalt mixture decreased more rapidly than that of dense-graded asphalt
mixture.
Moreover Stiffness of asphalt was calculated with a nomograph and measured using a dynamic shear rheometer (DSR).
The findings showed a very high correlation between stiffness calculated by nomograph and complex modulus
measured by DSR regardless of the loading time and measurement temperature, as well as a very high correlation
between complex modulus and loss modulus regardless of loading time, temperature, type of binder, field sample andaccelerated aging sample. The relationship between damaged asphalt pavement and the rheological properties of asphalt
is discussed.

257

Effect of Long-term Aging on Properties of Asphalt
Toshiaki Hirato1, Mai Kobayashi1, Masato Murayama1, Shigeki Takahashi2
1

2

TOA ROAD CORPORATION, Tsukuba, Ibaraki, JAPANNippon Expressway Research Institute Company Limited Pavement Division, Tokyo , Japan
Email for correspondence, e.g. t_hirato@toadoro.co.jp

1 INTRODUCTION
Damage to asphalt pavement is caused by fatigue resulting from cyclic traffic loads and asphalt hardening due
to oxidative aging (Kasahara et al. 1975; Iijima et al. 1982; Steiner et al. 2015). Previous research (Hofko et al. 2015;
Yumura et al. 1980; Abe et al. 1985) has shown that oxidative aging progresses not only on the surface, but also in the
downward direction. However, there have been no previous studies presenting detailed surveys of the binder course (orlower courses).
In this study, we extracted sample blocks from asphalt pavement under long-term use from expressways thathave extensive traffic volume and repair history records. The samples were then classified based on the damage level,
years of service, wheel path locations, asphalt mixture type, and other parameters. Next, we examined asphalt extracted
from the surface course, binder course, and asphalt stabilized base course of the each block. Moreover, asphalt stiffness
was calculated with a nomograph and measured using a dynamic shear rheometer (DSR). The findings showed a very
high correlation between the stiffness calculated by nomograph and the complex modulus measured by DSR, regardlessof the loading time and measurement temperature, as well as a very high correlation between complex modulus and loss
modulus, regardless of loading time, temperature, binder type, field sample, and accelerated aging sample.
This report presents the results of the investigations described above. The study was carried out as a part of asurvey conducted by East Nippon Expressway Co., Ltd. (Takahashi et al. 2013, 2014).

2 OBJECTIVE AND METHODSThe objectives of this research were (1) to achieve a better understanding of the aged state of various asphalt
mixtures in pavements after long-term use, and (2) to simulate age states in laboratory tests in order to identify factorsthat affect aging.
Characterizations were performed on the extracted asphalts in order to determine how the specimens had aged.
Next, the same characterizations were performed on the asphalt samples that were subjected to accelerated aging undervarious conditions.

3 RESULTS OF THE FIELD INVESTIGATION
3.1 TEST LOCATIONS
Ten samples were obtained from the following four locations: the Joshin-Etsu Expressway between the
Nagano and Suzakanagano East interchanges (both away from and toward Tokyo), the Nagano expressway between the
Toyoshina and Omi interchanges (away from Tokyo), and the Nagano expressway between the Omi and Kousyoku
interchanges (away from Tokyo) (Takahashi et al. 2013). Table 1 provides a summary of the sites from which thesamples were taken.
Both the damaged and undamaged portions indicated in the table were distinguished by the cracking present on
the surface course. The traffic volume on the expressways is approximately 14,000–15,000 vehicles/day in eachdirection, and large vehicles account for 19%–22% of this total. The section of the Joshin-Etsu Expressway between the
Suzakanagano East interchange and the Nagano interchange was opened in November 1995, while the sections on the
Nagano expressway were opened in March 1993. Subsequently, repairs were made on the Nagano expressway to thesurface, binder, or asphalt stabilized base course of these roads. Dense graded asphalt mixtures (DGA) or porous
asphalt mixtures (PA) were used, as shown in the table 1.

258

Table 1. Summary of the investigation sites
Site

#121
#72
#39
Nagano IC –Toyoshina IC – Omi
Location
Suzakanagano east Suzakanagano east IC – Nagano IC
ICICDenseType of surface
Dense-graded
Dense-graded
PorousgradedOpen
March 1995
March 1995
March 1993
Repair2005 a)1998 a)
No.
1
2
3
4
5
6
7
8
NonNonWheel Wheel Wheel Wheel
Wheel
Wheel
Location
wheel
wheel
path
path
path
path
path
path
path
path
Damage
A
A
A
D
C
C
D
D
Level c)a) Surface course and binder course were repaired.
b) Surface course, binder course, and a portion of asphalt stabilized base course were repaired.
c) A: non-damaged, C: slight cracking, D: much cracking on the surface of the pavement.

ObasuteOmi IC – Kousyoku
ICPorousPorousMarch 19932005 b)
9
10
Wheel
path

Wheel
path

A

D

3.2 DESCRIPTION OF SPECIMENS
Block samples (45 cm × 45 cm × 18 cm) of asphalt mixtures were retrieved from the expressways. The asphalt
mixtures were then sliced into sections with the dimensions shown in Figure 1(a) representing the surface, binder, andasphalt stabilized base courses. Asphalt samples were then extracted from each section.
The specimens taken from undamaged expressway sections were well formed, but the specimens retrieved
from damaged pavement tended to fragment during the cutting process. Additionally, some specimens showed cracking
in the asphalt stabilized base course layer, as shown in Figure 1(b).
According to the construction records, straight-run asphalt (stAs) was used for the asphalt mixtures. However,
the asphalt used in the repaired sections was not recorded. Tests for the presence of a modifier were conducted incompliance with “Quantitative Test Method A058 for SBR Incorporated in Polymer-Modified Asphalts” published in
the Book of Standards for Surveys and Tests of Pavement. Absorption at 965 cm-1, which is typical for styrenebutadiene-styrene (SBS) block copolymer, was observed in all of the PA samples. Additionally, the softening
temperature was around 80°C, which provides further evidence that high content polymer-modified asphalt (Type H)
had been used.

2.5 cm

6 cm

7. Second layer

8. Third layer

8 cm

2 cm

(a)

2 cm

5.Third layer

2.5 cm2 cm

4. Second layer

6. First layer

2.5 cm

3. First layer
4cm

2. Second layer

3 cm

1. First layer

Asphalt stabilizedbase course

Binder course

1 cm

Surface course(b)

Figure 1. (a) Sliced layers of the samples (b) Cracking in the asphalt stabilized base course layer

3.3 EVALUATION METHOD
Asphalt was extracted from the blocks using Abson method (ASTM 1856-95a) in Table 2. The properties testsummarized in Table 3 were conducted. Infrared spectroscopic analysis followed “The Handbook of Pavement
investigation and examination method (2007)”. Infrared spectroscopic analysis was conducted by attenuated total

259

reflectance Fourier transform infrared (ATR-FTIR) spectroscopy (Shimadzu), which enabled direct observation of theasphalt without the use of solvents. Asphalt aging was previously investigated over the range of wavelengths describedin Puello et al. 2008. In this comparative investigation, we focused on the increase in absorbance at the carbonyl peak
(1700 cm-1) that is expected with the progression of oxidative aging using the approach outlined in Figure 2.
Table 2. Abson test conditions
Items
Flow value of inactive gas at 135°C
Flow value of inactive gas at 160°C
Hold time at 160°C
Extractant

Contents
200ml/min
1600ml/min
30min
n- propyl bromide

Table 3. Characterizations performed in this study
Test

Temperature

MethodPenetration

25 °C

ASTM D5

Softening point
Ductility

15 °C

ASTM D36
ASTM D113

Infrared spectroscopic analysis

-

A058

0.05

Absorbance %

0.04
0.03

0.02
0.01
0.00
1800

baseline

1700

1600

1500

Wavenumber cm⁻¹

Figure 2. Method for calculating absorbance using carbonyl absorption at 1700 cm-1

3.4 TEST RESULTS
3.4.1 PENETRATION OF ASPHALT IN THE DEPTH DIRECTION
Figures 3(a)–3(d) show the results of penetration tests from the surface to the asphalt stabilized base course
taken from each investigation site. Since there were no clear distinctions from the first to third layers for any of thebinder course and asphalt stabilized base course samples, the averages of the first, second, and third layers are shown.
The undamaged and damaged portions are indicated by solid and dashed lines, respectively, while the DGA and PA are
indicated with solid and open symbols, respectively.
For site #121, the first layer penetration in the surface course was the lowest value for all layers, and the levelof penetration was higher as the distance from the surface of the block increased.
For site #72, cracking was found to have occurred at the bottom surface of all blocks. Low-level penetration
was found in the asphalt stabilized layer, as well as the surface course. The level of asphalt penetration in the damaged
section (No. 4 in the figure) was especially notable, although low-level penetration was found in all layers.
The surface course from investigation site #39 was classified into 7-year-old PA and 14-year-old DGA. Bothsets were taken from the damaged portions of wheel paths. Penetration into the 7-year-old PA (No. 7 in the figure) was
clearly lower than that into the 14-year-old DGA (No. 8 in the figure).

260

The surface course in the Obasute site was replaced with PA during repair work in 2005. Specimens weretaken from both undamaged and damaged portions. While no cracking was found in the upper surface, both theundamaged and damaged specimens showed cracking at the bottom surface. Penetration was lower at the upper surface,
and increased with depth, as seen at the site #121.
Focusing on the damage level, it was found that when the asphalt pavement was undamaged, asphalt
penetration was lower at the surface course, and increased with depth from the block surface. The DGA and PA results
were similar. When the damage was seen in the asphalt pavement, no difference in penetration was seen between thesurface course and the asphalt stabilized base course. It is presumed that the damage occurring in asphalt pavement
caused the oxidative aging progression.
Regarding differences between wheel path and non-wheel paths locations, non-wheel path penetration was
found to be lower than the levels found in wheel paths, as described in previous papers (Kasahara et al. 1975; Tateishi
et al. 1998).
40

40
35

30

Penetration 1/10 mm

Penetration 1/10 mm

35

No. 2

25
20

No. 1

15

10
5

30

No. 3

20
15

No. 4

No. 5

10
5

0

0
SurfaceFirst layer

SurfaceSecond layer

BindercourseAsphalt
stabilizedbase course

SurfaceFirst layer(a) #121 (DGA)

SurfaceSecond layer

BindercourseAsphalt
stabilizedbase course

BindercourseAsphalt stabilizedbase course(b) #72 (DGA)
40

40

35

35

No. 8

30

Penetration 1/10 mm

Penetration 1/10 mm

No. 6

25

25
20

15

No. 7

10

5

No. 10

30

25
20
15

No. 9

10
5

0

0

SurfaceFirst layer

SurfaceSecond layer

BindercourseAsphalt stabilizedbase course

SurfaceFirst layer(c) #39 (No. 7 : PA, No. 8 : DGA)

SurfaceSecond layer(d) Obasute (PA)Figure 3. Penetration of asphalt extracted from surface to asphalt stabilized base course in each investigation site

3.4.2 VARIATIONS IN PENETRATION WITH LENGTH OF SERVICE
Figure 4(a) provides the results of the tests and shows comparisons between years of service and penetration of
the surface course. Penetration of asphalt extracted from PA with 7 years of service was 11–24 (1/10 mm), and that of
DGA with 19 years of service was 13–29 (1/10 mm). Although there was a more than 10-year difference in the service
periods, these specimens showed similar penetration levels. The asphalt including PA tends to deteriorate more rapidly
in comparison with that of DGA.
Figure 4(b) shows the relationship between length of service and penetration in the binder course and asphalt
stabilized base course. As expected, penetration into the undamaged pavements was not significantly lower, although it
was clearly lower in those of the damaged pavements. This indicates that the progression of asphalt aging is affected by
the presence of damage to the asphalt mixture.

261

50
First layer at DGA
Second layer at DGA
First layer at PA
Second layer at PA

40

30

Penetration 1/10mm

Penetration 1/10mm

50

29

24

20
10

30
20

10

13

11

Non-damaged section
Damaged section

40

0

0
0

5

10

15

20

0

5

Service period years

10

15

20

Service period year

Figure 4. Relationship between Service period and penetration (a) surface course and (b) binder course and asphalt
stabilized base course.

3.4.3 RELATIONSHIP BETWEEN PENETRATION AND OTHER PROPERTIES
Figure 5 shows information on absorbance by infrared spectroscopic analysis, ductility, softening point, andpenetration. First, the infrared spectroscopic analysis clearly shows that the absorbance increased as the penetration
decreased, which indicates that the asphalt hardened as oxidative aging progressed. The absorbance of TypeH extracted
from PA was lower than that of stAs for the same penetration values. It was also found that the service period for thePA was shorter than that for the stAs, which suggests that the service period has an impact on absorbance.
The softening point increased and ductility decreased as the penetration decreased. The ductility of TypeH wasfound to be somewhat higher than that of stAs with identical penetration, which suggests that the modifiers included in
TypeH maintain the ductile properties of asphalt.
100
Duc. (stAs)
Duc. (typeH)
S.P. (stAs)
S.P. (typeH)

20

0.015

Ductility at 15 °C cm

Absorbance %

stAs
TypeH

0.010

0.005

15

60

10

40

5

20

0

0.000

0

10

20
30
Penetration 1/10mm

4080Softening Point °C

25

0.020

0
0

10

20
30
Penetration 1/10mm

40

50

Figure 5. Variation in penetration with (a) absorbance and (b) ductility and softening point.

4 EVALUATION OF RHEOLOGICAL PROPERTIES OF ASPHALT
4.1 ACCELERATED AGING TESTS OF ASPHALT
Next, to determine the viscoelastic properties of field-aged asphalt, test specimens were examined over atemperture range of room temperature to the high-temperature region. The influence of aging was observed inlaboratory tests, specimens subjected to accelerated aging were compared with asphalt taken from expressways, andmethods for evaluating the viscoelastic properties of aged asphalt were investigated.
An accelerated aging test was conducted using stAs. After a rolling thin film oven test (RTFOT: ASTM D
2872), specimens were aged for 20, 40, and 60 hours with a pressurized aging vessel (PAV: ASTM D 6521).
4.2 METHODS OF EVALUATION
The penetration test and the softening point test were used to estimate the stiffness of the specimens taken frompavement, and the DSR test was used to measure each modulus of the asphalts. Table 4 shows the DSR test conditions.

262

Van der Poel proposed a nomograph for estimating asphalt stiffness using penetration, a softening point
penetration index (PI), and any available loading time and temperature information (Van der Poel 1954). Himeno
presented software he had developed in “Estimation of Sbit and Smix using Van der Poel's nomograph and Heukelom's
equation (SbitSmix)”, based on Van der Poel’s nomograph, in which asphalt stiffness was calculated upon input of each
property. That software was used to calculate the asphalt stiffness in this study.
Table 4. DSR test conditions
Items
Test Temperature
Frequency
Radius of plate
Thickness
StrainContents
20°C,40°C,60°C
0.1-100rad/s
8mm
1mm
10%

4.3 RESULTS OF PROPERTY TESTS
4.3.1 Results of accelerated aging test
Table 5 presents the test results. It can be seen that accelerated aging reduced the penetration and raised thesoftening point, and that the PI of stAs was increased by these changes. Additionally, while ductility did not change
significantly after the RTFOT, it was found to fall quickly after the PAV test.
Figure 6 shows how the value for Sbit of stAs, calculated by the program using penetration, softening point, andPI, varied with several parameters identified in the DSR test. A significantly high correlation was found between
Sbit and the complex modulus indicated by the DSR test, and the relationship is linear on a log-log
graph (Figure 6(a)). Examination of the relationships among each modulus shows that these all fell with an increasein the measured temperature or a lengthening of load time. Comparing the complex modulus, loss modulus, and storage
modulus, we see that a storage modulus decreased most (Figure 6(b)).
Table 5. Physical properties of stAs after accelerated aging
Test
Penetration
Softening Point
Ductility
PI

25°C
15°C

1/10mm°Ccm-

Original

RTFOT

PAV20hPAV40hPAV60h

61
48.0
100+
-1.3

42
51
100+
-1.3

30
57
7
-0.7

25
60
5
-0.5

18
62.5
4
-0.6

1.E+01

original

Storage modulus/Loss modulus MPa

1.E+02

1.E+02

1.E+01

RTFOT

Storage modulus

Loss modulus

1.E+00

Sbit MPa

1.E+00

PAV20hPAV40h

1.E-01
PAV60h
1.E-02

1.E-03

1.E-04(a)1.E-05
1.E-05

1.E-04

1.E-03

1.E-02

1.E-01

1.E+00 1.E+01 1.E+02

Complex modulus MPa

1.E-01

1.E-02
1.E-03
1.E-04
1.E-05(b)
1.E-06
1.E-06 1.E-05 1.E-04 1.E-03 1.E-02 1.E-01 1.E+00 1.E+01 1.E+02

Complex modulus MPa

Figure 6. Sbit, complex modulus, storage modulus, loss modulus and phase angle of straight asphalt after accelerated
aging
4.3.2 Comparison between field-aged asphalt and accelerated-aged asphalt
Figure 7 shows the values for the stiffness of the extracted asphalts predicted by the nomograph and each
modulus found by the DSR test. Here, the parameters were abstracted from the DSR results under loading times of 0.1,263

1, and 10 s, and the results were compared with the stiffness results provided by the nomograph. The parameters in the
figure representing asphalt extracted from visibly damaged specimens were measured at 20°C after loading for 0.1 s.
By the results except type H, the complex modulus indicated by the DSR test showed excellent correlation
with the stiffness of the extracted asphalt estimated using the nomograph, regardless of use age, load time, or test
temperature. From these results, for stAs, the stiffness can be estimated using the nomograph with penetration andsoftening point. We can see that this represents the viscoelastic properties of asphalt with high accuracy.
These specimens had been in use for 20 years and comprised different asphalts, but they provided results thatwere nearly identical to the stAs specimens used in the laboratory accelerated aging test. These findings suggest thatasphalts subjected to accelerated aging in the laboratory can provide some estimates of the stiffness and changes in
stiffness occurring after aging in the field. However, the stiffness found the nomograph did not match the results forcomplex modulus measured by the DSR test on a one-to-one basis. This discrepancy is probably for two reasons: thestiffness predicted by the nomograph is based on the penetration and the softening point, that is, observations in static
tests, while the DSR test is a dynamic test; and the nomograph estimate is based on two temperature measurements,
while the DSR test is conducted at numerous different temperatures.
Polymer modified asphalts have high complex modulus at high temperatures, so they exhibit behaviors
different from those of straight asphalts. In the future, accelerated aging tests must be conducted with polymer modified
asphalts in order to obtain a better understanding of the behaviors of these mixes as well.
Examination of the relationship between the storage modulus and the complex modulus revealed slightdifferences in the specimens subjected to accelerated aging in the laboratory and the specimens extracted fromroadways. In contrast, the same comparison between the loss modulus and the complex modulus revealed a linear
relationship between the two on a log-log chart, regardless of changes in test temperature, loading time, or material, that
is, accelerated-aged asphalt versus road-aged asphalt.
The stiffness, complex modulus, storage modulus, and loss modulus of damaged asphalt were examined at thetest temperature of 20°C and a loading time of 0.1 s. The stiffness was at least 10 MPa, the complex modulus and loss
modulus were at least 5 MPa, and the storage modulus was at least 3 MPa. It is especially notable (see Figure 7(c)) thatthe relationship between complex modulus and loss modulus can be viewed as a straight line in the materials subjectedto accelerated aging in the laboratory, as well as in the asphalt and the modified Type H asphalt extracted fromroadways, and thus can be treated as a single index for the degree of aging. The Strategic Highway Research Program(SHRP) has set a standard of 5 MPa or less for the asphalt subjected to accelerated aging of loss modulus |G*|·sin δ; thetest conditions in the SHRP differ from those in the present study, but their results have generally been the same.
1.E+03

1.E+03(a)1.E+02(b)

Approximate curve is calculated using all data
except field sample(typeH).

10.0MPa

1.E+02y = 0.8896x1.3348
R² = 0.97

1.E+01

1.E+01

Sbit MPa

1.E+00

1.E-015.0MPa1.E-02

1.E-03

Field sample(Extracted stAs)

Storage Modulus MPa

3.0MPa1.E+00

1.E-015.0MPa1.E-02

1.E-03

Field sample(Extracted stAs)
Field sample(Extracted type H)

Field sample(Extracted type H)
1.E-04

1.E-05
1.0E-05

Accelerated test(stAs)
Field sample(stAs) having beendamaged (at 20°C, loading time:0.1s)
1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00 1.0E+01 1.0E+02 1.0E+03

Complex Modulus MPa

1.E-04

1.E-05
1.0E-05

Accelerated test(stAs)

Field sample(stAs) having beendamaged (at 20°C, loading time:0.1s)
1.0E-04

1.0E-03

1.0E-02

1.0E-01

1.0E+00 1.0E+01 1.0E+02 1.0E+03

Complex modulus MPa264

1.E+03(c)

Approximate curve iscalculated using all data.

1.E+02

Loss Modulus MPa

1.E+01

Y=0.8585X0.9691
R2=0.99
5.0MPa1.E+005.0MPa1.E-01

1.E-02

Field sample(Extracted stAs)

1.E-03

Field sample(Extracted type H)
Accelerated test(stAs)

1.E-04

1.E-05
1.0E-05

Field sample(stAs) having beendamaged (at 20°C, loading time:0.1s)
1.0E-04

1.0E-03

1.0E-02

1.0E-01 1.0E+00 1.0E+01 1.0E+02 1.0E+03

Complex modulus MPa

Figure 7. Sbit, complex modulus, storage modulus and loss modulus of field-aged asphalt compared to asphalt after
accelerated aging
5 SUMMARY
The following findings were obtained in this study:









Aging decreases the rheological properties in the interior courses of asphalt, as well as the surface course. The
degree of aging depends on the type of the asphalt mixture and the extent of damage.
A study of the relationships between penetration, ductility, and softening point indicated that the ductility decreases
and the softening point increases as penetration decreases. Additionally, Type H used for PA has higher ductility
than stAs, even though its penetration is lower.
Type H used for PA with 7 years of service and DGA with 19 years of service showed the same level ofpenetration, even though penetration between stAs and Type H were different at the original construction.
In order to simulate the properties of actual aged asphalt pavement, it is necessary to consider the composition of
the asphalt mixture.
The stiffness of asphalt subjected to accelerated aging in the laboratory and that of field-aged asphalt show similar
trends, in spite of loading time and test temperature differences. This suggests that the stiffness of field-aged
asphalt can be reproduced by accelerated aging.
There is an extremely high correlation between the complex modulus obtained in the DSR test and the asphalt
stiffness estimated using the nomograph.
The complex modulus obtained in the DSR test was found to show a linear relationship with the loss modulus on alog-log graph, regardless of test temperature, load time, asphalt type, and source of specimens, whether laboratory
specimens subjected to accelerated aging or specimens from roadways.
The stiffness of damaged asphalt was at least 10 MPa, the complex modulus and loss modulus were at least 5 MPa,and the storage modulus was at least 3 MPa. Since the complex modulus showed a relationship with loss modulus
that could be considered linear, regardless of whether the specimens had been subjected to accelerated aging in thelaboratory or recovered from roadways, whether stAs or Type H asphalt, this relationship can be expressed as asingle index of the degree of aging.

265

REFERENCES
Abe Y., Kozai T. (1985). Changes in Performances and Material Properties of Runway Pavements over a Period ofTime. Sekiyugakkaishi (J. Jpn. Petrol. Inst.).
The Committee on Pavement Engineering. (2012). Fundamental Pavement Engineering, Pavement Engineering Library7.
B. Hofko, F. Handle, L. Eberhardsteiner, M. Hospodka, R. Blab, J. Füssl, H. Grothe.(2015). Alternative Approach
Toward the Aging of Asphalt Binder. Journal of the Transportation Research Board.
Iijima H., Kojima I., Terashi K.(1982). A research on Mix Design of Asphalt Mixture Pavement Failure Results of
Makuhari Test Road. Civil Engineering Journal.
Kasahara Y., Uemura T., Ushijima K.(1975). A Study of the Aging of Asphalt Recovered from Pavement in Service –The influence of Depth below Pavement Surface on Hardening-. Sekiyugakkaishi (J. Jpn. Petrol. Inst.)
J. Puello, N. Afanasjeva, Malvarez. (2008). COLOMBIAN BITUMENS: RHEOLOGICAL AND FTIR ANALYSISDURING THEIR ACCELERATED AGING. 4th Euroasphalt & Eurobitume.
D. Steiner, B. Hofko, M. Hospodka, F. Handle, H. Grothe, J. Füssl, L. (2015). Eberhardsteiner, R. Blab: Towards an
optimised lab procedure for long-term oxidative ageing of asphalt mix specimen. International Journal of pavement
engineering.
Takahashi S., Yoshino K., Hayakawa Y., Harada S., Isago K. (2013) "KAITAI SHINSHO(New Book of Anatomy)"
project of Asphalt Pavement in the Expressway. Japan Society of Civil Engineers Annual Meeting.
Takahashi S., Tateoka Y., Yoshino K. (2014) "KAITAI SHINSHO (New Book of Anatomy)" project of Asphalt
Pavement in the Expressway -Main Knowledge-. Japan Society of Civil Engineers Annual Meeting.
Japan Road Association. (2007) Handbook of Pavement investigation and examination method No.2. Maruzen Co., Ltd.
Tateishi D., Nitta H., Sasaki I., Sakamoto H. (1998). Properties of Long-term Aged Asphalt and Evaluation of
Accelerated Aging Test. Civil Engineering Journal.
VAN DER POEL C. (1954). Journal of Applied. Chemistry.
Yumura T. (1980). A CASE STUDY: The method for constructing a surface course on the binder course unserviced fora long time. DOUROKENSTSU.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
Olga ALVAREZ MOLINA

New Integrated System to support the London
Streets Tunnels Operations Control Centre (LSTOC)
Intelligent Transportation Systems
POSITION

Product Manager

ORGANIZATIONCOUNTRY

INDRA

SPAIN

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Joaquín PONZ MACHO DE
QUEVEDOArea Manager

INDRA

SPAIN

E-MAIL(for correspondence)jgomezr@indra.es
jmedeiros@indra.es

KEYWORDS:“HORUS” is a SCADA (Supervisory Control And Data Acquisition) product developed by Indra that not only
integrates different devices and systems into a complete software application to monitor and control interurban traffic
and tunnels, but also manages the equipment maintenance.
“London Streets Tunnels Operations Centre (LSTOC)” means the London Streets Tunnels Operation Centre whichis responsible for the management of traffic and safety of the London road tunnels and designated approach roads“Minimum Operating Requirements (MOR)” means, in respect of each Tunnel, the lowest number of End-Point
Devices connected to the System which the Users need to be able to view and/or control in order to keep a Tunnel open
“Rule” is a set of fundamental rules for the control of End-Point Devices which cannot be contravened by either a Useror the System, primarily to ensure the safety of road users“Sequence” is a series of End-Point Device actions which must be implemented in a defined order with appropriate
time delays and confirmation points;

ABSTRACT:In 2015, HORUS was the new integrated system to support the London Streets Tunnels Operations Control Centre(LSTOC).
The HORUS platform is the solution to modernize the technology for the control and operation of the 12 roadtunnels in London and 90 km of approach roads. These tunnels are critical for the mobility across London, some ofwhich are more than 100 years old and others which have special requirements (A2 Eltham, A12 Eastway, George
Green and GreenMan, A13 Limehouse Link and East India Dock, A101 Rotherhithe, A102 Blackwall Northbound andSouthbound, Hanger Lane, Upper Thames Street and A406 Fore Street Tunnels).
The HORUS solution provides the LSTOC operator with real-time information, helping in decision-making andfacilitating quick and accurate management of everything that happens in the tunnels. Due to the intelligent incident
management system operation is simple and predictable, even in exceptional situations, as the system guides theoperator through the correct response in each case.
By collecting current and historical traffic data, the Horus solution also facilitates the analysis, reporting andconsolidation of information for decision making regarding mobility.

267

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
Therefore, the new system:- provides a unique solution- integrates multiple traffic control systems- manages emergencies to keep the city moving safely and efficiently- helps to manage maintenance services- provides the real-time information about incidents in the tunnels and minimise the impact on London’s streets- is designed to incorporate new systems in the future
The aim object of this paper is to provide you an introduction for the solution and the operational management.
Firstly, It includes specific sections to introduce you in the project:- A leader in technology and innovation ( Who is Indra?, What does it do?, Our experience )- Our client (What is Transport for London?, What does it do?, What TfL is requesting?)
The transport and traffic solution (HORUS. Transport and Traffic solution, How did Indra do it?)Secondly, It provides specific sections to introduction you in the general solution:- The system architecture and integrations- Main features of the platform (all in one philosophy, flexibility, scalability, customization )- The advanced incident management system (IMS) and asset management- Expert systems ( Rules , sequences and MOR)
- Configuration tools- Reporting, validation and simulation tools
And finally, the remaining sections introduces you the conclusions and acknowledgements.
In summary, Indra provides a single and intelligent traffic system with state-of-the-art technology to manage the city'stunnels in an integrated manner.

268

New Integrated System to support the London Streets Tunnels
Operations Control Centre (LSTOC)
Olga ALVAREZ MOLINA
Joaquín PONZ MACHO DE QUEVEDO

Email for correspondence, jgomezr@indra.es, jmedeiros@indra.es
1 INTRODUCTION
Indra is delighted to have been accepted to this congress and we are confident that we are able to contribute ourknowledge and years of technical expertise to all of the participants.
Throughout this paper we will have the chance to share our experiences. In particular, we will present thereader with the technical solution for the London Streets Tunnels Operation Centre (LSTOC) project.
In the following chapters, the reader will have the opportunity to enjoy this approach to the project. Indrahopes that the reader finds this paper useful.
2 INDRA, A LEADER IN TECHNOLOGY AND INNOVATION
Who is Indra?
Indra is a global consulting, technology, innovation and talent company headquartered in Madrid. It is on the
cutting edge of high value-added solutions and services for the Transport and Traffic, Energy and Industry, Public
Administration and Healthcare, Financial Services, Security and Defence and Telecom and Media sectors. The
multinational is one of the top European companies in its sector in terms of Research & Development & Innovation.
Additional company information about Indra can be found by following the links below:
http://www.indracompany.com
http://www.indracompany.com/en/tunnels
What does it do?
The company operates in 128 countries, with more than 42,000 employees worldwide focusing on
developing innovative solutions that meet the needs of the most demanding clients.
Our experience
The Transport and Traffic sector accounts for 23% of the company’s overall business and is the largest, andfastest growing, area within Indra. Our priority is to design more secure, ecological, economical and efficienttechnologies and we supply solutions and services for Air Traffic Management (ATM); Communications, Navigationand Surveillance (CNS); Airports; Rail Traffic Management; Intelligent Traffic Systems (ITS); Vessel Traffic
Management (VTMS); CAD/AVL Systems; Ticketing and Tolling.
We are proud to boast that more than 100 cities in the world rely on Indra for the management, security anddevelopment of their transport networks and that we have supplied 1,200 air traffic management facilities in more than
90 countries.
HORUS. Transport and Traffic solution
Specifically in the Road Tunnel Management field, we are a world leader and our Horus platform has beenused in more than 50 large traffic infrastructure projects around the world over the last 10 years, about half of thesebeing complex multi-tunnel environments.
More than 30 countries control the traffic on their highways, tunnels, airports and roads with Indra’s systems.
3 BACKGROUND INFORMATION

269

What is Transport for London?
Transport for London (TfL) is the integrated body responsible for London’s transport system.
What does it do?
TfL is responsible for London's network of principal road routes, for various rail networks including theLondon Underground, London Overground, Docklands Light Railway and TfL Rail, for London's trams, buses andtaxis, for cycling provision, and for river services. It is accountable for both the planning and management of transport
services across London.
What is London Streets Tunnels Operations Centre (LSTOC)?
LSTOC is responsible for the management of traffic and safety of the London road tunnels and designatedapproach roads.
The key LSTOC responsibilities are:
- Monitor and control tunnel environments and systems- Control Traffic Using the Tunnels and Approaches- Co-ordinate “First Response” Incident Management- Co-ordinate Internal Communication, Incident Logging and Report System Management
4 GENERAL PURPOSE OF THE LSTOC PROJECTHORUS is the new integrated system to support the London Streets Tunnels Operations Control Centre(LSTOC).
What was TfL requesting?
Before the migration, LSTOC used multiple control systems to operate and control safety and traffic control
systems, communicate with road users, emergency and maintenance services people and to manage safety and minimize
disruption.
According to this, the new system should be able to provide:- A fully integrated solution- A multi-system interface- A multi-operator platform- A solution that monitors and controls all the existing sub-systems and end-point devices in the 12
urban tunnels- A solution that monitors and controls all the existing sub-systems and end-point devices in the
LTRACS traffic systems on 90km of Road Networks.
- Primary and disaster recovery operator user interfaces in two separate central London facilities.
- Hosting in two high quality data centers.

Figure 1. HORUS platform
What does Indra provide?
The HORUS platform is able to carry out the following functions:- Tunnels’ monitoring and control- Asset Management and Fault Handling- Incident and Alarm management
270-Performance Reporting
Decision Support
Integrated Human Machine Interface (HMI)

Therefore, the upgrade solution for the LSTOC is based on the HORUS platform. This new management
system has the following technical capabilities:- A new software platform with a single interface that communicates with, monitors and controls all theexisting systems in the 12 tunnels and 90km of surface roads operated by TfL from the London
Streets Tunnels Operations Control Centre (LSTOC).
- An open, highly flexible and configurable solution, which can incorporate any new system.
- A high level of automation of operations, which provides the operator with real-time information,
helping in decision-making and facilitating quick and accurate management of everything that
happens in the tunnels.
- An intelligent incident management system whose operation is simple and predictable, even in
exceptional situations, as the system guides the operator through the correct response in each case.
- By collecting current and historical traffic data, the Horus solution also facilitates the analysis,
reporting and consolidation of information for decision-making in terms of mobility.
How does Indra do it?
The HORUS platform is able to monitor and control the following sub-systems:- Public Address and Emergency Telephones- Road traffic signs, signals and barriers- Over-height vehicle detection- Tunnel closure system- Tunnel emergency signage system- Integration with other SCADA systems (floodgate, electrical supplies, etc)
- CCTV system (including video wall)- Video Automatic Incident Detection (VAID) system- Drainage system- Pump system- Fire detection- Tunnel ventilation system- Tunnel lighting system- Fire detections and suppression system

Figure 2. System & Integration Protocols
The HORUS platform is able to exchange data with external systems like
- TIMS means “Traffic Information Management Systems”- NAMS means “Asset Management System for Highway, Drainage and Electrical Assets on theTransport for London Road Network”- SFM means “Site Fault Management”

271

5 TECHNICAL SOLUTIONS & INTEGRATIONS
Flexibility & scalability
The HORUS system has been designed as a modular, distributed application, its tasks executed in
distributed systems allowing each module to be expanded or reconfigured without affecting the others.
As a result of this modularity, the large library of standard interfaces and the integration tools available, thesystem is highly expandable. This has allowed many of our customers to seamlessly grow the system adding newtunnels to their network or new features to the system.
Systems Architecture
The HORUS application uses a distributed process architecture that allows the system to scale in performanceand functionality. The process communications are service oriented and performed through the Active Interface
Communications library JMS.
HORUS Platform: “all in one” philosophy
The HORUS Platform has been designed with an “All-in-one” philosophy, aiming to simplify the work to be
performed by the operator, both in their daily routine and in emergency situations. To achieve this goal the system has
been designed to:- Be consistent and easy to use in terms of system operation.
- Use summary windows and present the relevant information, highlighting where the operator’s
attention is required.
- Unify tools (Alarms, Sequences, summary windows...) of different types of elements, to avoid having
to navigate between multiple windows and simplifying complex tasks.
The HORUS platform is designed for the consistent representation and management of traffic and tunnels’
elements, regardless of the type of equipment. The aim is that ,once the operator knows how to manage one type ofequipment, they will know the basics of how to manage all system equipment. This consistent representation of any
item ensures the operator will easily see, with just a glance, the status of any item and without the need to consult
multiple detailed information screens. The navigation has been optimised to minimise the number of steps required toperform the basic actions of daily work. It is also a highly integrated platform allowing a single user interface tomanage all the systems under the operators’ control.

Figure 3. HORUS Platform: “all in one” philosophy
Customization & Configuration tools
The HORUS system is fully customizable. The HORUS system allows configuration of parameter settings
related with alarms, procedures, incidents, resources, user profiles, road maps, etc.
The administrator could modify existing equipment, add new equipment, new equipment types and even newtunnels into the platform.

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6 THE ADVANCED INCIDENT MANAGEMENT SYSTEM (IMS) AND ASSET MANAGEMENT
Advanced incident management system (IMS)
One of the major strengths of HORUS is its powerful and flexible Incident Management System (HORUS
IMS), which coordinates all subsystems and performs an integral management of the incident and incident recording.
HORUS goes beyond the required functionality through a high level subsystem that automates the detection ofoperational incidents and maintenance incidents, and automates the response to these, guiding the users through thoseactions that the system cannot do automatically.
This HORUS IMS subsystem carries out complex analysis and management of concurrent situations handling
multiple alarms intelligently. It manages the response to an incident based on the severity of the incident, its impact on
the network impact and if there are other active incidents nearby.
HORUS IMS helps LSTOC maximize security and minimize risks; reduce reaction time to a road incident;
guarantee a consistent response time and ensure that the incident management follows the operation manual.
Reporting tools (IMS)
All the actions, automatic or manual are registered in the system. It is possible to query this information
through specific reports.
Workflow and Incident life Cycle
An incident has the following workflow:- Detection: An incident can be automatically generated through an alarm sent by equipment via theControl Centre Software or manually by the user. At this stage, and to facilitate the verification of theincident, the IMS will automatically preposition a camera located near the incident, and show this on
the relevant control centre monitor.
- Confirmation: When an incident is automatically detected, the user must confirm or discard it. In
order to verify the incident, the user can use the live feed image situated in the monitor which thesystem has previously prepositioned along with any other relevant information which will bepresented to the operator.
- Response: On confirming the Incident, the IMS will provide the operator with a series of optional andmandatory actions. These will be used in order to resolve the Incident as defined in the Operation
Manual. These actions can be automatic or manual:- Automatic actions: Many of the actions defined in the Operation Manual can be automatically
performed through the IMS, these include actions such as: signalling, lighting, public address,
Ventilation, etc. or any other action implemented in the IMS. Some of these may require operator
intervention to authorize the execution.
- Manual actions: All those reserved for the user because they are not automated.
- Restoration: After the resolution of the incident, it is necessary to restore the initial conditions of theroad. The IMS is also capable of automating this restoration.
- Incident Reporting: The IMS allows information and documentation to be attached to the incidents
file. As the Incident is managed the required data is collected and stored in the database.

273

Figure 5. IMS: Management for the whole Incident life Cycle
Benefits of using the IMS
The benefits of using the IMS are many:- Maximize security and minimize risks- Reduce reaction time towards road incidents.
- Guarantee that the response time towards one same incident in different periods of time ishomogenous and follows the Operation Manual.
- Facilitate the Operation of Control Centre- Register all operations carried out, both normal operations described in the road management plan,and those carried out to solve an incident as described in the emergency plan.
- Allow the information registered to be used, not only at a statistical level, but also based in actions
carried out during the resolution of a specific incident.
- Provide a high level of service. The high level execution of the objectives is essential to provide all
the road users with an adequate level of comfort and their subsequent satisfaction.
- Optimize costs - both those derived from the operation itself and those that come from having the roadshut down.

Figure 6. IMS: Automatic management of Stakeholders & end-point-devices
Asset Management

274

The HORUS platform, being an incident management platform, has implicit facilities which can be used for
asset management without the need for additional software for TfL.
Using the power of the HORUS platform, the operators can control and monitor the facilities, and analyse all
the information that flows within the system, included information coming from other systems like SFM or NAMS or
the MOR tracking.
This module manages the whole life cycle of asset faults (i.e. detection, monitoring of the actions taken andtheir resolution). These faults are treated as maintenance incidents, taking advantage of the benefits of the incident
management features of the HORUS IMS.
As a result, this tool is able to reduce failure detection time improving the response to the faults, with the aimof ensuring the optimum maintenance conditions of both facilities and equipment.
Reporting tools
Horus also has a powerful tool for reporting. New reports can be added or modified to fit client requirements.
The system is designed to know what has happened and what action has been taken, as well as information that willassist in applying responsibilities, detection of procedural failures, detection of unsafe points on the road, procedures for
improvement or evaluating the suitability and number of resources. The system also allows extensive customization of
the forms for reports.

Figure 4. HORUS Platform: Report System & Configuration tools
7 EXPERT SYSTEMAt this point, we would like to highlight the trend of automating scheduled actions using business logic. In thisway, the HORUS Platform has a set of tools to increase the reliability of operations carried out on the devices,automating actions and guiding the operation in order to have a safer environment road and tunnel operation.
There are three expert systems available in LSTOC:- the rules management- the sequences management- the MOR management
All these modules are configurable and they allow subsequent reconfigurations of the system in order toguarantee its scalability.
Rules management
The rules management is a set of fundamental rules for the control of End-Point Devices which cannot be
contravened by either a User or the System, primarily to ensure the safety of road users.

275

This tool provides LSTOC with autonomy and LSTOC is therefore capable of automatically managing systems
such as:-ventilation system,
lighting system,
energy savings system,
roadway management,
detour notifications, etc

In particular, the traffic rules are available for evaluation of traffic conditions. For example:- Logic required and condition for evaluation- Logic required for developing device management scenarios of the traffic system
After this validation, the traffic rules are able to set signaling in matrix signal gantryes or carriageway.

Figure 7. Traffic Rules
In addition, and before the activation of the signaling, there is a proposal layer. This proposal summary is
updated with the aspect of the primary signals and the aspects of secondary signals affected.

Figure 8. Off Proposal layer vs. On Proposal layer
Interlock rules
The HORUS system disposes of interlock rules that do not allow the incompatibles states or aspects of thesignals. For example, on the reversible lane the HORUS system defines incompatibilities between two signals whichhave a special location relationship. In order to manage the reversible lane when there are two signals on the same
location, one in one direction and the other in the opposite direction, the system blocks the lane open aspect in the two
signals at the same time. This incompatible command orders are blocked and it shows a message indicating that thiscommand is not executed because of non-compliance with the interlock rules.
Sequences management276

A sequence is a series of End-Point Device actions which must be implemented in a defined order withappropriate time delays and confirmation points. In this context, a sequence is a set of instructions capable of changing
the state of part of the traffic system.
In LSTOC, the new system provides TFL with a library of available orders to perform an action over any typeof device:- VMS,- Traffic Lights,- Fans, ...
The new system provides TFL with a library of commands or logical types of orders. For example, these areavailable for use:
- Send warning messages to users.
- Ask confirmation to a user.
- Wait a fixed time.
- Execute another plan, …
HORUS has a powerful graphic tool that allows the user to define new business logic by creating sequenceswith automatic, manual or scheduled execution. This execution of complex sequences is transparent to the user.

Figure 9. Expert System
MOR Fault management & diagnostics
The Minimum Operating Requirements (MOR) means, in respect of each Tunnel, the lowest number of EndPoint Devices connected to the System which the Users need to be able to view and/or control in order to keep a Tunnel
open.
The new system, HORUS platform, detects faults of end-point devices, either because the device reports its
own failure or by applying detection thresholds or correlation alerts.
The MOR can be loaded into HORUS in order to anticipate a MOR breach and initiate tunnel closure before
MOR limits are surpassed.
According to this, the new system HORUS:- manages the whole life cycle of asset faults- carries out statistical studies of faults- it filters false faults and fault avalanches- has implemented a rating matrix whose criticality conditions are: 25,50,75 or 100%
- has access to all the information:
 state alarms
 parameter data events277

Figure 10. MOR Fault management & diagnostics
8 SIMULATION TOOLSFAT Testing & pilot availability
The main objective of the simulation environment in the HORUS platform is to enable the practice of theavailable tools and to become familiar with the environment and devices installed in tunnels and roads.
In particular, for training / test purposes, the platform has been used for TFL as:- Platform of training and continuous improvement (Training).
- FAT and Test bench of the control system (Test).
The tool allows simulating the conditions to be controlled and managed in a tunnel. The architecture consistsof a model that recreates the installations and on which the operators will be trained.
For the second functionality, the tool allows the performance of offline tests. The following tasks have been
performed with TfL:
- Conceptualization Validation: On the environment, it allows the validation of incidents, automatisms,
sequences and logic associated with automatic actions.
- Functionality Validation: On the same environment it allows the validation of the state logic, alarm
generation, faults and malfunctions.
And finally, the tool is also used for internal TfL validation of new system configurations and version
validation after the changes have been made from the preproduction environment during the current operation phase.

Figure 11. FAT Testing & pilot availability278

9 CONCLUSIONSThe HORUS platform is the solution to modernize the technology for the control and operation of the 12 roadtunnels in London and 90 km of surface roads operated by TfL from the London Streets Tunnels Operations Control
Centre (LSTOC).
The updated system has the following functionalities:- Design, installation, commissioning and maintenance of a new hardware and software platform with asingle interface that communicates with, monitors and controls all the existing systems in the 12
tunnels- As an open, highly flexible and configurable solution, it can incorporate any new system.
- With a high level of automation of operations, the solution provides the operator with real-time
information, helping in decision-making and facilitating quick and accurate management of
everything that happens in the tunnels. Due to the intelligent incident management system, operation
is simple and predictable, even in exceptional situations, as the system guides the operator through thecorrect response in each case.
- By collecting current and historical traffic data, the Horus solution also facilitates the analysis,
reporting and consolidation of information for decision making regarding mobility.

10 CITATIONS AND REFERENCES
Bonet, Eduardo (9-15 March 2015) - “Smart Mobility”, IIIth Civil Engineering Week (SICMA), MadridPonz, Joaquín, Álvarez, Olga (11-13 March, 2015) – “Technology for tunnels”, VIth The Spanish Tunnels
Congress, Technical Association of Road (ATC), Zaragoza
Martín Crisenti, Antonio (26-30 September, 2011) – “Poster: The technological implementation for the Traffic
Management Plan”, XXIVth World Road Congress, Permanent International Association of Road Congresses(PIARC), Mexico279

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
Carlos VIDAL
CO-AUTHOR(S)(Capitalize Family Name

Kuala Lumpur Integrated Control Centre - Monorail, LRT, BRT,
High Speed and Mass Rapid Transit systems
Intelligent Transportation Systems
POSITION
Programme Director
POSITIONORGANIZATIONINDRAORGANIZATIONCOUNTRYSPAIN
COUNTRY

Shahanas YUSOFF

Project Manager

INDRA

MALAYSIA

Javier F. GOMEZ

Project Manager

INDRA

SPAIN

E-MAIL(for correspondence)jgomezr@indra.es
jmedeiros@indra.es

KEYWORDS:“Integrated”“Prasarana”“Multi-modal”“Transit”“Indra”

ABSTRACT:In 2017-2018 Indra will unveil the new Kuala Lumpur Integrated Control Centre, from where all operation, control andmanagement of the Monorail and two Light Rapid Transit lines will take place. These three transport lines are currently
managed from three different control centres; the new Integrated Control Centre will allow their operation from one
location and will involve the integration of various different systems, including but not limited to Traffic Management
Systems, SCADA for Energy Remote Control, SCADA for Fixed Facilities, Communications, CCTV and AccessControl Systems. Furthermore, the new Integrated Control Centre will have the capacity and capability of integrating theoperation of Bus Rapid Transit, High-Speed trains and Mass Rapid Transit systems in the future.
Indra previously achieved the successful integration of Prasarana's ticketing system; through the Automatic Fare
Collection (AFC) all rail networks now use the MyRapid Card as a common ticketing mode.

280

KL Integrated Control Centre - Monorail, LRT, BRT, High
Speed and Mass Rapid Transit systems
Carlos VIDAL
Shahanas YUSOFF
Javier F. GOMEZ
Email for correspondence, jgomezr@indra.es, jmedeiros@indra.es

1. INTRODUCTION
In 2017-2018 Indra will unveil the new Kuala Lumpur Integrated Control Centre (ICC), from where all
operation, control and management of the Monorail and two Light Rapid Transit (LRT) lines will take place.
This paper will firstly introduce the background and context of the ICC, including a brief description of
Prasarana, the owner of the ICC, and Indra, the contractor for this project. The main features and benefits of
the ICC will then be outlined and explained. Finally, this paper will conclude with a summary of what has
been presented and with the relevancy of the ICC to the Transportation industry in Asia.

2. BACKGROUND
The ICC was commissioned by Prasarana (Prasarana Malaysia Berhad), a 100% government-owned
company. Established in 1998 and operational since 2002, Prasarana is the asset owner and operator of
Malaysia’s two LRT networks and the KL Monorail, in addition to the bus services of RapidKL, RapidPenang
and RapidKuantan. Prasarana has been undertaking a modernisation and expansion of its multi-modaltransport offering in the past years, with for example the fleet expansion of the KL Monorail and RapidBus,
and the line extensions of the Light Rapid Transit lines of KL.
Indra was awarded the ICC project in 2012, after Prasarana saw the need for a control centre from which
the operations of its 3 metro lines in Kuala Lumpur could be managed. This innovative and ambitious project
consolidates Indra as one of Prasarana’s technological partners. Indra has previously successfully integrated
Prasarana’s ticketing system, so that through the Automatic Fare Collection, all rail networks now use the
MyRapid Card as a common ticketing mode.
Indra is a multinational leader in consulting and technology, present in 138 countries and with a strong
presence in Asia Pacific. It is now present in India, Bangladesh, China, Vietnam, the Philippines, Indonesia,
Thailand, Australia and of course, in Malaysia. Indra offers technological solutions and services in various
different sectors, from Transport & Traffic to Security & Defence, passing through Energy & Industry andPublic Administration.
Within the Transport & Traffic division, the offering varies from urban traffic systems, airport
management, traffic control systems for highways, tunnels and toll systems and port and waterways
management. Indra has been an active player in the global railroad traffic industry for many years now, withprojects in Saudi Arabia (Mecca-Medina High-Speed Train), Spain, Morocco, Lithuania, China and Brazil for
example, and subway systems projects in Madrid, Mumbai, Delhi, Shanghai, Saint Louis and Cairo, to namebut a few. The company has one of the most advanced railroad traffic control systems in the world, and has
developed an integration platform which allows integrating systems from many different providers into one
single control centre. For example, in Lithuania Indra has integrated interlockings from Siemens, Bombardier,
AZD, Ex-Soviet technology and electromechanical in one Traffic Management System.
In short, Indra provides integrated solutions for software, systems, control rooms, data centres, crisis
management and training rooms in rail environment.

281

The main aim of the ICC is to integrate the operations of the Ampang and Kelana Jaya lines, as well as
the Monorail Line of Kuala Lumpur. The operating control centres of these 3 lines will remain as back-ups to
the ICC. Indra will also be responsible for the implementation of a new data centre in the ICC which will
support the control centre’s activities and provide all the technology required for this.
However, it will also have the capability and capacity of integrating the operations of more transportlines. Prasarana and Indra foresee that the ICC will integrate the Mass Rapid Transit (MRT) and KTM
Komuter lines in the future, and will have the potential for the planned High-Speed Rail from KL to
Singapore to be operated from it. Furthermore, the operation of non-rail transportation systems, such as thebus network of Kuala Lumpur, could also be carried out from the ICC.

3. ICC INTEGRATED SYSTEMS
Focusing on the current aim of this project, the technological solution designed and deployed by Indra
will include the integration of the following main systems:
Traffic Management System
This will include the Scheduling Subsystem and the Real-Time Subsystem, which will jointly organise
the train timetables and regulate, control and monitor the train traffic in real –time. Indra’s system is morethan a control system; it is a complete operation management system from traffic planning to vehicle
scheduling including statistics and key performance indicators monitoring. Indra has previously integrated
systems in other projects from different providers such as Thales, Invensys, Siemens and Bombardier.
SCADA for Fixed Facilities
Indra’s SCADA for Fixed Facilities system (HORUS) is designed to control/monitor the fixed facilities
installed in the existing Kelana Jaya Line, Ampang Line and Monorail Line, providing a common graphicalinterface. In addition, it can centralise the alarms received and collected from all the lines.
SCADA for Energy Remote Control
It involves the control and management of all elements related to power supply for both the traction train
and the operation of other equipment or facilities that exist along the way.
Security and CCTV Monitoring
The integrated CCTV System will provide a platform designed to integrate multiple unconnected
security applications and devices and control them through one comprehensive and unique user interface. It
will collect and correlate events from existing different security devices and information systems to empower
Prasarana’s personnel to identify and proactively resolve situations.
The CCTV system in the ICC will integrate the systems of 2 different providers into one user-friendly
interface created for Prasarana’s operators.

Radio and Telecommunication systems
Indra’s technological solution to integrate the different radio and telecommunication systems in the 3
different lines is the iConnect Rail Voice Coordination System. iConnect Rail will enable an operator-train
and operator-station communications as well as communication through the Administrative and public
Telephony. The iConnect Rail system designed for Prasarana will enable a dispatcher operator to access thedifferent communication systems currently operating in each line (QS2, TETRA and WIFI) from one single
dispatcher. Indra’s iConnect Dispatcher which will be deployed in the ICC will integrate the QS2 systems of 2
different providers, the TETRA communication system and the WIFI system, into one easy-to-use, sleek
interface.

282

Card Access System (CAS)The ICC CAS will be integrated with the new Prasarana CAS Infrastructure as a common CAS Solution.
Operators in the ICC will be able to monitor and control the CAS in any of the 3 lines as well as in the ICC.
On top of the integration of these systems, Indra will implement the following systems in the ICC in
order to improve and enhance the performance of the three metro lines:
Topology Management System
This system will allow modelling different versions of the network infrastructure and performing
capacity analysis of the network for the different modelled versions. TOPMS is a simulator system which will
enable the optimisation of rail traffic capacity, both for rolling stock and personnel.
Remote Monitoring System
It allows monitoring of railway components in real time within a working framework with web access.
This data can be shown in 3 different views: geographical, synoptic, and time-distance view.
Dashboard and Decision Support System
This system makes use of Business Intelligence technology to collect and make an effective use of
information in order to improve business effectiveness. It can be defined as a set of methodologies, processes,
architectures and technologies that change raw data into meaningful and useful information. This information
will then be used by Prasarana to gain more effective strategic, tactical, and operational insights and better
decision-making.
All of these operational systems will be supported by the Authentication and Authorisation
Infrastructure, which will control and verify the user permissions to enter the ICC systems and offer a Single
Sign-On platform to access the integrated applications. Many of the systems mentioned above will beaccessed from a common human-machine interface: the ICC launcher. Users in the ICC will be able to log-in
to use different systems from this interface. Based on their roles and permissions (administrators or users)
they will be able to access different functions and the train line they are operating.
The Equipment Control and Monitoring System will monitor and supervise the integrated architecture in
the ICC. Furthermore, the ICC will be integrated with Prasarana’s existing Automatic Fare Collection systems(provided by Indra) in order to collect data on revenues and ridership.
The following figures show some examples of the systems that will be integrated in the ICC and whatthese will look like.
Indra’s iConnect Dispatcher which will be deployed in the ICC will integrate the QS2 systems of 2
different providers, the TETRA communication system and WIFI, into one easy-to-use, sleek interface.

283

Figure 1. iConnect Rail Dispatcher Frontal View

Figure 2. iConnect Rail Dispatcher Rear View
As another example, the CCTV system in the ICC will integrate the systems of 2 different providers into
one user-friendly interface created for Prasarana’s operators. This will look similar to the figure below, whichshows some of the different functionalities that will be available for the operators of the 3 lines:

284

Configuration

Users

Roles

Permission

Layout Manager

Download Request

Login

Main Window(Preview, Viewers, Playback Control and Tree)

Downloads

Download Viewer

Filters
GroupsPlan Manager

AlarmsFigure 3. Indra Integrated CCTV system – example
Many of these systems will be accessed from a common human-machine interface: the ICC launcher.
(The images shown below are a render of the ICC launcher and are subject to change according to thesystem’s final look & feel designed for Prasarana).

Figure 4. ICC launcher initial screen

285

Users in the ICC will be able to log-in to use different systems from this interface. Based on their roles
and permissions (administrators or users) they will be able to access different functions and the train line they
are operating.

Figure 5. Launcher operational screen

In summary, Indra’s technological solution for the ICC will create an open framework for the integrationof any third party technology. However, what will differentiate the ICC from other control centres will be thefact that 3 different metro lines will be operated in the same control centre, under the same roof, metres apartfrom each other. And herein lies the ICC’s strength and Indra’s specialty: the integration, into one common
working environment, of the systems of different providers with different features and functionalities.
In fact, the integration in the ICC is especially complex since Prasarana is currently undergoing theextension of the Ampang and Kelana Jaya lines, and the fleet expansion of the Monorail line. These works
imply the re-haul of many of the existing systems and the involvement of many new parties and providers into
the integration required for the successful operation of the ICC.

4. ICC BUILDINGThe building of the ICC, also awarded to Indra and located in Cheras, KL, has been designed to become asymbol of Prasarana and even Kuala Lumpur. It will hold a control centre with an initial 22 operating posts,
with the capacity of expanding this number in the future to include more operating posts based on the
additional transport lines integrated within the ICC. The control centre will also hold a continuous videowall
where the operation of the lines will be displayed, also with future expansion capacity.

The control room has been ergonomically designed to provide an environment which blends
functionality with comfort and ease of use.
Furthermore, the ICC will include a Crisis Management room with a direct view to the control centre,
Security and CCTV Monitoring Room, Operation and Maintenance Planning Centre and Press Conference
Room.

286

The ICC will be connected to the Operating Control Centres of the Kelana Jaya and Ampang lines, andMonorail, through a communication link, also provided by Indra. This communication link will include fiber
optic cabling as well as the digital transmission backbone network.

5. IMPACT OF ICC
Operations from the ICC will allow Prasarana to benefit from more control in real time of its
transportation systems, achieving increased efficiency levels and reducing operation costs by integrating themanagement of the different lines into only one centre. Indra’s reliability in this field will bring about thehighest level of automation avoiding human errors and increasing safety and punctuality.
On the other hand, Prasarana’s customers and users of its transport systems will enjoy a higher quality
and safer service, where interconnection between the different lines will be favoured. The integration of the
ICC systems will aid Prasarana in its strategic decision-making, which will allow it to obtain service-levelindicators with the aim of adjusting this to the real demand of KL’s citizens, increasing performance andreducing costs.

6. CONCLUSION
Prasarana’s Integrated Control Centre has been designed to become a landmark of Kuala Lumpur city andwill offer Indra’s cutting edge technology for the integration of the operation of 3 different transportationlines. Indra will provide the ICC with a solution which will allow the integration of all the elements of control
and management of the metro systems and a higher degree of automation.
The potential of the ICC lies in its versatility and ability to integrate different public transportation
systems under one roof, including buses and high-speed lines, in order for each one, Prasarana, and thegeneral public, to benefit from the synergies and knowledge transfer created.
In view of all this, it becomes clear that the ICC will become a turning point in the way that theoperations of the public transportation system in KL, and the rest of Asia in the future, are handled. Indra is
proud to be at the forefront of such prominent technology and the leader of this influential multi-modal
project, with far-reaching implications for the Intelligent Transportation Systems industry worldwide.

287

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Geocells for Affordable Low Volume Pavements

TRACK
AUTHOR(Capitalize Family
Name)
Oliver WHALLEYPOSITIONORGANIZATIONCOUNTRY

Transport
AnalystThe World Bank

Sydney,Australia

CO-AUTHOR(S)(Capitalize Family
Name

POSITIONORGANIZATIONCOUNTRY

owhalley@worldbank.org

E-MAIL(forcorrespondence)

KEYWORDS:
Pavement, access, flexible, concrete, affordable

ABSTRACT:
Developing countries are often faced with a need to extend paved road networks into remote rural areas. Paved
roads significantly enhance accessibility but also come with higher capital and maintenance costs than unpaved roads.
One novel solution to address the need for paving roads with low traffic volumes are concrete geocell pavements.
Consisting of an interlocking set of unreinforced concrete blocks formed by a thin high density polyethylene lattice, theresulting flexible concrete surface reduces the need for granular pavement layers, resulting in significantly lower
construction and maintenance costs. The objective of this paper is to present this novel pavement system and an
application in the Pacific Islands. The paper summarizes the theory behind geocell pavements, presenting a simplified
design method which takes into account two parameters of traffic loading and subgrade stiffness. Construction
methodology is then discussed including equipment and material supply issues. Finally a case study presents successful
application of geocell pavements to a road rehabilitation project in Kiribati. Conclusions reveal that concrete geocell
pavements offer an affordable alternative to conventional bituminous surfacing and should be considered in the designof rural road projects.

288Geocells for Affordable Low Volume Pavements
Oliver Whalley1
1

The World Bank, Sydney, Australia, owhalley@worldbank.org

1 INTRODUCTION
1.1 BACKGROUND
Developing countries are often faced with a need to extend paved road networks into remote rural areas. Paved
roads significantly enhance accessibility and quality of life, providing all weather access and reducing the burden ofroutine maintenance inherent with unsealed roads. However an issue often faced is the capital cost of conventional
pavement technology. Typically consisting of layers of aggregate surfaced with either concrete, asphalt or chip seal,
constructing and maintaining these designs is costly and requires significant maintenance capability. As a result, traffic
volumes need to be high enough to justify the investment, which can be rare in rural areas where traffic is light.
One novel solution to address the need for paving roads with low traffic volumes are concrete geocell pavements.
Consisting of flexible interlocking concrete blocks, they can make extensive use of local labor, while reducing the needfor granular pavement layers. Road maintenance is greatly reduced compared with other types of surfacing. Used in
Africa, Australia and now in the Pacific, these geocells should be considered in any low volume road project as a costeffective way of delivering improved accessibility.
1.2 DEVELOPMENT NEED
Governments often request support from development institutions for improving accessibility for their ruralcommunities which despite trends of urbanization still represent approximately 46% of the world’s population, some
3.4 billion people (United Nations, 2015). Based on surveys of accessibility, the Rural Access Index (RAI) estimatesthat 1 billion of these rural dwellers are without access to reliable all-weather transport (World Bank, 2013).
Strong links have been drawn between low RAI ratings and the failure to achieve millennium development goals
including poverty, maternal mortality and gender equity. Rural areas are also the source of inequality when comparedwith urban dwellers who have access to the services of larger settlements. By providing all weather access with asmooth running surface, rural dwellers are provided access to economic opportunities. For example, they can sell
agricultural produce consistently and with less damage, and also access essential services such as healthcare andeducation.
While the needs are clear, the investments in rural roads need to be economically justified, which can often cause
tension between Governments and Donor organizations. When traffic volumes are low the savings in road user costs do
not justify the investment in conventional pavement technology. In a number of countries roads which were previously
paved with bituminous surfaces have deteriorated to unpaved condition due to unsustainable maintenance costs.
The main advantage offered by geocell pavements is that they provide this access at lower cost, making extensionof the sealed road network into rural areas more economically viable, as well as offering reduced long-term
maintenance costs.
1.3 GEOCELL TECHNOLOGY
Geocell pavements consist of an interlocking set of unreinforced concrete blocks formed by thin plastic lattice, withthe resulting composite structure serving as a flexible but impermeable pavement surface. Ranging from 75 to 150 mm
thick with plan dimensions from 150 mm to 300 mm square, the cells are shaped by a high density polyethylene(HDPE) sacrificial formwork which remains in the final pavement. This plastic mold forms concrete blocks into aninterlocking shape, which allows mechanical transfer of load from one block to those surrounding it, and thus provides
the surfacing with an enhanced ability to resist loads– refer289

Figure 1. Diagram showing expanded geocell formwork (Hyson Geocells)
Geocells differ from conventional block paving due to a mechanical keying which occurs as a result of the distorted
face of the cells. Protrusions in one block key in to cavities in adjacent blocks, creating a joint which is better able totransfer loads. This interlocking effect means that geocell pavements are effective in spreading load and can do without
the aggregate base course and subbase layers of traditional pavements, relying instead on load transfer between blocks.
Doing away with these layers gives a lower cost solution for low volume roads which makes extending sealed networks
more affordable.
While geocells with aggregate or concrete fill have a range of applications for example as waterproof channel
liners, and for slope stabilization, they have not been widely used for pavements outside South Africa where they weredeveloped despite offering significant benefits.
The objective of this paper is to present this novel pavement system and an application in the Pacific Islands.
Firstly the paper will summarize the theory behind geocells pavements before describing the design approach andconstruction methodology. Finally a case study will be presented describing the application of geocell pavements on a
project in the Republic of Kiribati, an equatorial Pacific Island.

290

2

GEOCELL PAVEMENT SYSTEM

2.1 ENGINEERING THEORYA deeper understanding of the application of Portland cement concrete filled geocells can be formed by considering
the engineering theory which underlies the technology. The use of flexible concrete pavements formed by geocells was
documented by Visser and Hall (1999). Their initial approach required base and subbase layer works, with the resulting
requirement for extensive roller compaction effort proving to be a constraint in some developing countries where such
equipment is scarce. In subsequent work (Visser and Hall 2003), their approach evolved to include the consideration of
remote rural areas with a structural design approach developed to be congisant of equipment, terrain and labour
conditions.
In this work they stated that a pavement’s primary purpose is to protect underlying weak layers of soil, which canbe composed of fine grained or clayey soils. According to mechanistic design methods of South Africa (Theyse et al.
1996) and Australia and New Zealand (Austroads, 2008), the critical pavement design parameter is the verticalcompressive strain of the subgrade, or the amount the underlying soil deforms in the direction of the applied trafficload.
By constructing instrumented experimental sections from concrete filled geocells, Visser and Hall’s analysis
revealed that stiffness of the geocell pavements depended on the stiffness of the subgrade layers. Therefore increased
subgrade stiffness resulted in increased geocell layer stiffness, while thicker cells also increased stiffness. Note that due
to the inherent flexibility of of the concrete geocell layer (esepcially thin ones), the cells themselves provide little
additional stiffness. Instead, stiffness gains come from two areas. Firstly the lock-up which occurs during large
deflections, where the load on a single block is distributed to surrounding blocks, with this effect more prominent on
thicker geocells. A linear relationship was subsequently identified between geocell thickness and the logarithim of
geocell stiffness. Secondly, the impermable geocell layer enhances pavement stiffness by preventing saturation ofunderlying subgrade which can become plastic when moisture content is high. Once protected these soils are much
more able to resist traffic loads.
Using a transfer function provided by Theyse et al (1996) which relates the number of repetitions of an equivalent
standard 80 kN axle (ESA) load for a rut depth of 20mm to the allowable vertical compressive strain, equation (1) was
developed.
−𝑙𝑜𝑔10(𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝐸𝑆𝐴 𝑟𝑒𝑝𝑒𝑡𝑖𝑡𝑖𝑜𝑛𝑠)+36.7
10

𝐴𝑙𝑙𝑜𝑤𝑎𝑏𝑙𝑒 𝑣𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑐𝑜𝑚𝑝𝑟𝑒𝑠𝑠𝑖𝑣𝑒 𝑠𝑡𝑟𝑎𝑖𝑛 ( 𝜇∈) = 10

(1)

Finally, using ELSYM5 linear elastic layer software, the vertical compressive strains at the top of the subgrade
layer were calculated, with results presented in Figure 2 for a range of geocell pavement thicknesses.

Figure 2.Computed vertical compressive strains applied by an ESA load on subgrade for a range of geocell
thicknesses (Visser & Hall, 2003)
This theory provides a sound basis for design of concrete geocells pavements by following the methodology
described below.
2.2 DESIGN METHODOLOGYPerhaps the most valuable aspect of the Visser and Hall (2003) work is the simplified design approach theypresented. The approach takes into account inputs of traffic and loading and subgrade stiffness, and provides
practitioners with guidance on a geocell pavement layer thickness.
To apply the theory they developed, the first step is to calculate the pavement traffic loading using conventional
methodology including traffic counts and or estimation. Average daily traffic should be adjusted to yearly traffic, then291

annual traffic growth added for each year, before summing the traffic over the design life of the pavement. Any trafficloading must be converted to ESA loading, which can then be used in equation (1) to arrive at an allowable verticalcompressive strain.
The next step is to determine subgrade stiffness. In many cases in developing countries, this information is notreadily available, with a dearth of information for basic subgrade material properties like California bearing ratio(CBR). Fortunately, an estimate of in situ CBR can be obtained using a dynamic cone penetrometer (DCP), a ubiquitouspiece of soil test equipment. The Shell relationship (2) (Heukelom & Klomp, 1964) can then be used to determine
subgrade stiffness, noting that there is some variation in the factor used. Visser & Hall (2003) suggested that where
subgrade conditions are poor (CBR < 3), a factor of 3 can be used, while for CBR > 10 a factor of 10 is a good starting
point. A linear relationship between CBR and factor can be assumed between these values.
𝑆𝑢𝑏𝑔𝑟𝑎𝑑𝑒 𝑠𝑡𝑖𝑓𝑓𝑛𝑒𝑠𝑠 (𝑀𝑃𝑎) = 𝑍 × 𝐶𝐵𝑅(2)

𝑊ℎ𝑒𝑟𝑒 1 ≤ 𝑍 ≤ 100
𝐴𝑠 𝑎 𝑔𝑢𝑖𝑑𝑒: 𝑍 = 3 𝑓𝑜𝑟 𝐶𝐵𝑅 < 3,

𝑍 = 𝐶𝐵𝑅 𝑓𝑜𝑟 3 ≤ 𝑍 ≤ 10 ,𝑍 = 10 𝑓𝑜𝑟 𝐶𝐵𝑅 > 10

Armed with these two inputs of allowable vertical strain and subgrade stiffness, practitioners can use Figure 2 to
calculate the required geocells pavement thickness. By drawing a vertical line up from corresponding support stiffness
value, and noting where it intercepts with a horizontal line matching the allowable compressive strain, a point can beplotted. Identifying the charted line which lies closest to this point from the legend, the required cell thickness isprovided. If a conservative design is required, the thickness corresponding with the line below the plotted point can beselected.
For example shown in Figure 3, for an allowable strain of 6000 µƐ and a subgrade stiffness of 50 MPa, a geocell
thickness of 75mm is required (or 100mm for a conservative design).

Figure 3. Application of Figure 2 to example case (Subgrade stiffness 50 MPa, Allowable vertical strain 6000 µƐ)This simple design methodology can be readily applied and thus makes the approach accessible for the developing
country context where the resources for complex pavement modeling are limited.
2.3 CONSTRUCTION METHODOLOGYWith the design thickness established, discussion can now turn to the construction methodology. Much of thephysical work required can be completed by either labor or equipment based methods, for example edge beam or
geocell or tuck-in areas can be excavated by hand, or with mechanical excavators. This can provide work for laborers
which assist with poverty reduction goals. Geocells also have the advantage of being able to be constructed in very
constrained alignments—including curves—where large paving equipment would have difficulties in operating or indensely populated urban areas which prohibit street closures.
The first step to construct the geocells pavement is preparation of the subgrade. This can include filling in low
spots with select fill, and shaping the surface to achieve fall. Excavation for edge beams is also required. These beams
provide horizontal restraint to the geocells and prevent water ingress. Wooden formwork is required to form the beams,
and is removed after concrete has reached sufficient strength. Secondly, it is necessary for the subgrade to becompacted, using either small rollers (refer Figure 4 ) or hand operated plate compactors.

292

Figure 4. Compaction of subgrade with mechanical roller. Note edge beam formwork in place.
Thirdly the HDPE geocell formwork can be anchored in place and tensioned with steel reinforcing pegs, then
expanded to the full width and length of the road section (refer Figure 5). Once expanded and tensioned, the geocells
will be ready for placement of high-slump concrete. This is mixed, poured and spread into the cells before broomfinishing and curing. The modular nature of the geocells means it can be constructed using small mixers, oralternatively for large areas if concrete agitator trucks are available.

Figure 5. Geocell formwork expanded and tensioned and ready for placement of concrete.
After curing of concrete, edge beam formwork can be removed and edges of pavement backfilled, with pavement
usable as soon as concrete strength of 15 MPa is reached, probably within one week, although the mix design would
have a strength of 30 MPa for durability.
2.4 MATERIALS REQUIREDIn order to construct a geocell pavements, a range of materials are required. Perhaps the most difficult to source isthe HDPE geocell formwork. At present, only one supplier produces the thin (0.2mm thick) formwork which the theory
described above is applicable for, but as the technology is adopted more widely other suppliers are more likely to
produce equivalent products. Conventional materials required include Portland cement from local suppliers if available,293

or imported if no such supply exists. The sand and aggregate required for the concrete should be supplied fromsustainable local sources, and can be of a quality which might otherwise be unsuitable as pavement or surfacing
materials. A target concrete mix strength of 30MPa is typically specified, and the workability required for placing in thegeocells means that a high slump mix of 120 to 150mm is needed. This slump can be difficult for contractors to achieve
and a superplasticizer can assist with achieving a sufficiently workable mix.
2.5 PERFORMANCE AND MAINTENANCE
Given that geo-cells rely on the subgrade layer for strength, they are typically less able to withstand the heavy loads
and traffic of traditional designs. Despite this, vehicle loads are transferred to surrounding blocks in a way which
doesn’t occur with traditional block paving, which results in good pavement performance despite the absence ofgranular pavement layers. Thin geocells pavements are clearly well suited to applications where traffic loading is light.
For a 20mm rut to form in a 100mm thick geocell pavement (assuming a subgrade CBR of 10) it would take 2000 ESA
passes which is equivalent to a typical truck loading, but 124 million passes for a small vehicle with a 50 kN axle load.
Thicker geocells should therefore be used for pavements with truck traffic, as well as considering granular base courseand subbase layers. By applying the theory described above with proper supporting pavement layers the system has
been successfully used for container terminal pavements where axle loads of 100 kN are applied by heavy loading
equipment.
Because geocells are typically installed without granular pavement layers, the subgrade is less protected fromexcessive loads, and this can lead to a significantly shorter pavement life compared with granular pavements. This
problem may be exacerbated where high water tables or weak subgrades exist, the latter may require stabilizing which
may offset any cost savings from omission of granular layers.
The modular nature of geocells also allows for individual blocks to be removed for pothole repair and service
installation without the more extensive reinstatement required for traditional pavements. Geocell pavements also havebenefits in difficult geographic and climatic conditions. In mountainous terrain, the steepness of longitudinal drainage
channels can lead to scour and eventual pavement failure, however geocells can be placed with drainage integrated into
the road surfacing at center or edge of the road. This effectively armors the channel and prevents a common failuremode. Performance of geocells has not been observed in situations where frost heave is an issue, as application has so
far been restricted to warm climates.
In thin thickness and with no granular support layers, geocell pavements are well suited to light traffic and difficult
terrain and spatial conditions for both rural and urban roads, offering an affordable pavement solution in theseapplications.
2.6 CASE STUDY
Geocells have recently been used on the Kiribati’s Road Rehabilitation Project (KRRP) being undertaken by theGovernment of Kiribati with support of the World Bank. With a development objective of improving the condition ofSouth Tarawa's roads and strengthening road financing and maintenance capacity (World Bank, 2011), the ambitious
project is due for completion in November 2016. Included in the project is rehabilitation of 6.8 km of pothole ridden
feeder roads with geocell pavements – refer Figure 6. As a remote coral atoll, material supply was an issue for the
project with some pavement materials needing to be imported by barge from Fiji, some 2000km of open ocean away. In
this context, 5m wide geocell pavements of 75mm thickness cost AU$140,000 per kilometer, 72% of the cost for chipseal surfacing, and 53% of asphalt.

294

Figure 6. Before (left) and after (right) on a KRRP project feeder road in Kiribati
While these pavements have only been installed for a short time, pavements in South Africa have demonstrated
service lives of more than 10 years without periodic maintenance. That said, additional research is required to document
the long-term performance of geocells and establish whole of life costs (including maintenance) to allow for better
comparison with traditional pavements.
While the contractor in Kiribati noted long lead times for geocell formwork and issues with getting a concrete mix
with a sufficiently high slump, the geocell feeder roads are now considered one of the project’s success stories. No
complaints were received from adjacent residents despite the need for complete road closure to vehicles until thegeocell pavement had cured. The geocell pavements have significantly enhanced the amenity and accessibility of thecommunities they serve. The success in Kiribati prompted geocells to be considered for paving sections of road in theneighboring Pacific nations of Samoa, Tuvalu and Papua New Guinea.
3

CONCLUSIONS
Geocell pavements represent an attractive solution for paving low volume roads. With significantly lower costs
compared with traditional pavements due to a reduced need for granular pavement layers, and the potential for a labor
intensive construction approach which assists with poverty alleviation goals, the benefits are numerous.
While the rewards of increased accessibility are clear, expanding the sealed network can often lead to capital andmaintenance costs which are difficult to justify economically. Geocell pavements represent a novel way of addressing
the need for all weather accessibility at a significantly lower initial construction cost as well as reduced routine andperiodic maintenance requirements. All projects involving low volume roads should consider concrete geocells as apavement option.
4

ACKNOWLEDGEMENTS
This paper was prepared with the guidance and review input of Dr Alex Visser and Dr Chris Bennett who have bothsupported the wider adoption of geocells pavements on development roadprojects in the Pacific.

5 REFERENCES
Austroads. (2008). Guide to pavement technology part 2: Pavement structural design. Sydney: Austroads.
Heukelom, W., & Klomp, A. J. (1964). Road design and dynamic loading. Proceedings of the Association of Asphalt
Paving Technologists, Technical Sessions, Vol. 33, (pp. 92-125). Minneaoplis, MN.
Theyse, H. L., de Beer, M., & Rust, F. C. (1996). Overview of the SA mechanistic pavement design and analysis
method. Pretoria: Council for Scientific and Industrial Research.
United Nations. (2015). World urbanization prospects: The 2014 revision (ST/ESA/SER.A/366). New York: Departmentof Economic and Social Affairs, Population Division .
Visser, A. T., & Hall, S. (1999). Flexible Portland cement conrete pavement for low-volume roads. Transportation
Research Record 1652 (pp. 121-127). Washington DC: Transportation Research Board.
Visser, A. T., & Hall, S. (2003). Innovative and cost effective solutions for roads in rural areas and difficult terrain.
Transportation Research Record No. 1819 (Vol. 1) (pp. 169-173). Washington DC: Transportation Research
Board.
World Bank. (2011). Project apprasial document: Kiribati Road Rehabilition Project. Washington D.C.
World
Bank.
(2013).
Rural
Access.
Retrieved
fromTransport
Results:
http://www.worldbank.org/transport/transportresults/headline/rural-access.html

295

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Status of Electronic Toll Collection (ETC) and the Development of a New ETCbased Traffic Information Service in Korea

TRACKIntelligent Transportation Systems

AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Hwanpil LEE

Senior Researcher

Korea Expressway
Corporation ResearchInstitute

Korea, Republic of

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Sangmin PARK

Graduate Student

Ajou University

Korea, Republic of

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Ilsoo YUN

Associate Professor

Ajou University

Korea, Republic of

E-MAIL(for correspondence)ilsooyun@ajou.ac.kr

KEYWORDS:
Electronic Toll Collection, ETC, Expressway, Traffic Information, Vehicle Trajectory, DSRC, Section-based Detection

ABSTRACT:Hi-pass system is the brand name of the electronic toll collection (ETC) system of the Korea Expressway Corporation.
Since 2004, the Hi-pass system has been employed to collect toll fares on expressways throughout the country.
Recently, the share of the vehicles equipped with the onboard unit (OBU) for the Hi-pass system exceeded 65% of thetotal registered vehicles in Korea. In addition, the Hi-pass system has been used to collect data on the section travel timeof traveling vehicles equipped with the OBU; this was achieved by installing antennas along the main lines of
expressways. The antennas can read the ID of passing vehicles with OBUs by means of dedicated short-range
communication (DSRC). This study was initiated to utilize the travel time data collected using DSRC to develop a new
ETC-based traffic information service. First, an algorithm to estimate the path travel time using ETC-based individualvehicle trajectories was developed in this study. This algorithm was used to estimate the path travel times between two
major cities in Korea. Second, the behaviors of vehicles parked in service areas were analyzed using the travel time datacollected using the DSRC.

296

Current Status of Electronic Toll Collection (ETC) and theDevelopment of a New ETC-based Traffic Information Service
in Korea
Hwanpil Lee1

Sangmin Park2

Ilsoo YUN3

1

Korea Expressway Corporation Research Institute, Gimcheon-si, Gyeongsangbuk-do, Korea
pogijay@ex.co.kr
2Ajou University, Suwon-si, Gyeonggi-do, Korea
stylecap@ajou.ac.kr

3

Ajou University, Suwon-si, Gyeonggi-do, Korea
ilsooyun@ajou.ac.kr

1 INTRODUCTION
Most of the expressways in Korea have closed-type toll collection system(TCS). In such a system, the driver
pays toll fare based on the distance traveled on expressways. The Korea Expressway Corporation (KEC) is the biggest
government-run company operating expressways in Korea. The KEC is using a TCS for collecting toll fare. For theconvenience of drivers using expressways, KEC has employed an ETC system referred to as “High-pass” system since2004. This Hi-pass system is now the brand name of KEC's ETC system. The share of the vehicles equipped withonboard unit (OBU) for the Hi-pass system exceeds 65% of the total registered vehicles in Korea. In addition, the sharehas been continuously increasing since 4.5 ton or heavier trucks were allowed to use the Hi-pass system and since lowcost OBUs were made available for the Hi-pass system. Accordingly, the share of vehicles with OBUs is expected toreach 80% of the total registered vehicles in the near future.
The KEC developed the Freeway Traffic Management System (FTMS) for better traffic operations. In the
FTMS, the basic traffic data, including speed and volume, are collected through a vehicle detection system (VDS),
which consists of loop detectors and image sensors. The VDS is utilized to collect point-based traffic data. However,
because of the limitations of point-based traffic data, an additional step is performed to estimate section-based traffic
information, including a segment travel time, using the point-based traffic data. In general, the values estimated bymeans of point detection are usually less precise than the directly observed values obtained via section detection.
Hence, the KEC decided to use the data collected through the TCS and the Hi-pass system in order to increase theaccuracy of traffic data for segments or routes.
Using the data collected from the TCS, the travel time between major cities was estimated; this was possible
because the TCS records the entry tollgate, exit tollgate, entry time, and exit time of every trip via the expressway
network operated in the closed-type TCS. However, the travel time determined based on the TCS data have someshortcomings. When the TCS data are used, the actual route of an individual trip cannot be identified. This is because
the TCS only records the entry tollgate, exit tollgate, entry time, and exit time even if multiple routes exist between an
entry tollgate and an exit tollgate. In addition, screening the vehicles parked or rested at a service area is difficult, andthis may increase the estimated travel time as an outlier. Moreover, the available sample size dramatically decreases in
the case of a long distance trip. Therefore, acquiring sufficient sample size and guaranteeing the reliability of theestimated travel time are technically difficult, especially in the case of long-distance trips.
In order to overcome the aforementioned shortcomings, the Hi-pass system was used to collect data on thesection travel time of traveling vehicles equipped with OBUs. For this purpose, Hi-pass system’s antennas were
installed along the main lines of expressways. The antennas can read the ID of passing vehicles with OBUs by means ofdedicated short-range communication (DSRC).
This study was initiated to utilize the travel time data collected using the DSRC in order to develop a new
ETC-based traffic information service. To this end, first, an algorithm to estimate the path travel time using the ETCbased individual vehicle trajectories was developed in this study. Using the algorithm, the path travel times between
two major cities in Korea were estimated. In addition, the behaviors of vehicles parked in service areas were analyzed
using the travel time data collected via DSRC.

297

2 LITERATURE REVIEW
Dixon and Rilett (2002) and Chun et al. (2005) suggested that a travel trajectory may be applied to verify the
relationships among links. In addition, they claimed that the trajectory data might be useful for estimating travel speed
in a section. According to a survey conducted by Guillaume, the traditional data collection method employing sensors
on the road is necessary but not sufficient. Travel trajectories obtained using the Global Positioning System (GPS) or
cellular phones have become more important in the development of Intelligent Transport System. Such trajectories canprovide significant information such as traffic conditions and alternative routes to users (Guillaume 2008).
Park et al. (2009) and Im et al. (2009) proposed the concept of calculating the representative value for link
travel time using vehicle trajectories based on wireless communication. However, the trajectory data applied in thesesurveys were simulation data. Hence, there were limitations in the application of this concept to real systems. Lee et al.
(2011) surveyed the establishment of the dynamic origin-destination (OD) using vehicle trajectory; OD was expected tofacilitate data collection during the deployment of SMART Highway's 1 Wireless Access in Vehicular Environment(WAVE) communication. However, as in the case of Park et al.'s research, this survey too had a shortcoming in thatsimulation data were used.
Jing et al. (2010) developed the optimal route algorithm for designated departure time using 30,000 probe cars
with GPS in Beijing. The field test results showed an average travel time reduction of 16%. Kwon and Pravin (2005)
developed a method for computing partial trip trajectory and estimating real-time OD based on FasTrak ETC system.
3 CURRENT STATUS OF ELECTRONIC COLLECTION SYSTEM IN KOREA
The primary function of the Hi-pass system is to enable payment without stopping at a tollgate. The KEC uses
these payment data for generating traffic information. The Hi-pass system provides data on travel time and frequency
between the entry and exit tollgates. However, the derived travel time differs from the actual travel time owing to route
diversity and service area's rested vehicles. The Hi-pass utilization ratio is approximately 64% of the total expressway
trips, and this value corresponds to 70 million trips annually. The KEC currently operates the Hi-pass system for 709 of
970 entry lanes and 428 of 1412 exit lanes nationwide. As shown in figure 1, two types of OBUs—infra red (IR) andradio frequency (RF) OBUs—are adopted. When a Hi-pass OBU-equipped car enters the entry tollgate, the TCS will
issue the entry statement. This statement includes the entry tollgate number, time, and vehicle class. The exit statement
will be issued when this car passes the exit tollgate. The exit statement comprises the exit tollgate number, time, travel
distance, travel time, and fare in addition to the elements mentioned in the entry statement.

Figure 1. Configuration of the KEC Hi-pass system
The Hi-pass traffic information system is derived from the Hi-pass system. This system comprises roadsideequipment (RSE) and RF-type OBUs. This system generates the segment travel time of the main line by means of the
RF-type OBU. Each RSE collects the encrypted OBU ID, communication time, OBU type, and vehicle class. The
traffic information center first searches for a specific OBU ID in the data collected by numerous RSEs within theindicated time duration. If the same OBU ID is detected at different RSEs, the trip is considered a partial trip. Then, thecenter searches for other partial trips with the same OBU ID until no more partial trips are found. Thereafter, the center
estimates the section and path travel time from each trajectory. Figure 2 shows the configuration of the Hi-pass traffic
information system.
1

SMART Highway is the brand name of the KEC’s super highway that includes C-ITS service.
298

Figure 2. Configuration and function of the Hi-pass traffic information system

Data on each criterion such as segment and path are collected. Finally, the representative travel time
will be determined by screening each trip’s travel time. At present, the KEC operates 967 RSEs nationwide.
4 ALGORITHM DEVELOPMENT FOR TRAVEL TRAJECTORY
If the obtained data are perfect, the travel time and trajectory can be produced easily. However, actual data
always have imperfections. Hence, additional preprocessing is necessary to guarantee reliability of the obtained value.
The imperfections reason may be attributed to various reasons such as operation failure of RSEs, interruption by OBUequipped cars on frontage roads beside expressways, the OBU power getting turned off when driving, duplicate
communication, and overstaying of vehicles in service or parking area. Table 1 lists these abnormal data cases.
Table 1. Abnormal data cases and their influence on information
Abnormal data caseRe-detection of an exit vehicle on an expressway
Overstaying of a vehicle in service or parking area
Interruption by an OBU-equipped car on a frontage road
beside an expressway
Turning off of OBU power when driving
Operation failure or breakdown of an RSE

Influence on traffic information
Abnormal travel time
Abnormal travel time
Reversal and discrete travel trajectory
Reversal and discrete travel trajectory
Discrete travel trajectory

When these imperfection factors cannot be filtered out, they may cause various abnormalities in the traffic
information, such as excessive travel time, re-detection of a vehicle that has already exited the expressway, and a
momentary reversal progression on the opposite side of the trajectory. Thus, the travel trajectory generation algorithm
developed in this study reflects various abnormalities.
Sorting each RSE ID by communication time with same OBU ID is a simple method to create travel
trajectories. Nevertheless, some problems may occur. First, the TCS and Hi-pass traffic information system operate
independently. Therefore, mutual data transaction between the systems is impossible. Therefore, the whole travel time
for the entry tollgate-mainline-exit tollgate route cannot be determined in the current system environment of the KEC.
Hence, the vehicle that exited through the Interchange (IC) and re-entered from the same IC on the same day cannot be
distinguished for each trip and trajectory. Second, detection of the re-entered car by the simple sorting method is
impossible because of missing data and communication failure.
Trajectory tracking is the process of connecting points that are revealed as the target vehicle's detected
locations. Using the section-based detection method, the traffic information center gathers the individual vehicle's
location, and then combines every vehicle's detected location by matching the license plate or specific ID structure in
the upstream and downstream data. This is a transparent process to check whether the target vehicle sequentially passedalong the pre-defined RSE's spatial and temporal arrangement. The target vehicle’s OBU ID may be missed in a certain
section even though the ID exists in the RSE's communication log for the upstream and downstream sections. Thismeans that the target vehicle exited, detoured, and re-entered the expressway. Therefore, trajectory’s continuity has tobe terminated and re-created.

299

The simplest method to establish a travel trajectory, which only comprises the communicated RSEs according
to the communication time, frequently leads to discontinuities in the trajectory owing to various reasons. In this study,
the concept of “Conzone”, which does not include entry and exit ICs in the section, was designed to solve these
problems. If a vehicle has one RSE communication log at least once within a Conzone, the vehicle has passed the whole
section of the Conzone. This concept expands the required basic spatial unit from point-based to section-based units.
Figure 3 shows the relation between Conzone and RSE composition.

Figure 3. Expansion of the tracking of spatial units and the concept of Conzone
As can be seen from figure 3, if RSE #1, 2, and 5 have the target vehicle's communication log, but RSE #3 and
4 do not, the trajectory will be terminated at RSE #2 and restarted at RSE #5 in the RSE-based tracking method.
Consequently, two discrete trajectories will be created. On the contrary, as the basic spatial unit on Conzone, thetrajectory in the above case will be continuous from RSE #1 to #5 because three Conzones (upstream of Suwon IC,
Suwon IC-Kiheungdongtan IC, and downstream of Kiheungdongtan IC) can satisfy the minimum requirement of atleast one communication log within one Conzone.
The time coverage of the developed algorithm for matching OBU IDs is from D-1 to D+1 day to minimize theloss of late departure and early arrival of vehicles of a target day (e.g., a vehicle departs at 11 P.M. on day D-1 or
arrives at 2 A.M. on day D+1). The travel sequence for the commuting or regular route bus, which has to be considered
to detect repetitive trips along the same routes, is also introduced. The feature of the RSE that one RSE simultaneously
contacts both up-bound and down-bound vehicles cannot be used to assign the direction for the collected data. Further,
the reversal progression step is avoided by checking the RSE sequential master data. Table 2 presents the travel
trajectory algorithm for filtering abnormal patterns in the collected data.
Table 2. Abnormal data cases and their influence on information
Step
1
2
3
4
5
6
7
8
9

Description
Get 72 h (D-1, D, D+1) data including those for the target day
Remove duplicate data in 30 min
Classify by vehicle type
Select by origin and destination
Sort RSE data by communication time with RSE for each vehicle
Compute travel time and travel sequence for each vehicle
Check direction of RSE data
Match RSE attribute Conzone master data
Connect Conzones that were matched in the previous step

The developed algorithm was implemented by a database query to produce a travel trajectory. The datacomprise all RSE data from September 17 to 19, 2013. In this survey, the analysis range is set as long distance trips
between major cities. The analysis results show that the average ideal trajectory ratio of total actual trips confirmed by
the TCS data among particular OD is approximately 42%. Table 3 lists the analysis results.

300

Table 3. Analysis results of ideal trajectory’s sample size and detected ratio
OriginDestin.
GangreungGwangju

Seoul

Daegu

Daejeon

Busan

Date
Sep. 17
Sep. 18
Sep. 19
Sep. 17
Sep. 18
Sep. 19
Sep. 17
Sep. 18
Sep. 19
Sep. 17
Sep. 18
Sep. 19
Sep. 17
Sep. 18
Sep. 19

Total trips2(vehicles)
740
753
684
2,748
2,902
1,628
2,906
2,783
1,604
4,280
5,579
3,658
436
415
216

Cars passing
OD3 (vehicles)
613
632
561
2,478
2,521
1,504
2,581
2,310
1,401
3,931
4,982
3,348
370
337
184

Ideal trajectories4(vehicles)
253
182
170
1,272
937
700
1,173
972
627
2,709
3,162
1,956
170
148
70

Ideal
trajectory ratio
34.2%
24.2%
24.9%
46.3%
32.3%
43.0%
40.4%
34.9%
39.1%
63.3%
56.7%
53.5%
39.0%
35.7%
32.4%

5 TRAJECTORY ANALYSIS RESULTS
In this survey, the long-distance path travel time and path distribution ratio within the complete trajectory were
determined. The confidence interval method is often applied to screen outliers in travel time pre-processing (Ki et al.,2010). In this survey, the confidence interval is set as 1σ. The target route was from the Seoul tollgate to Daegu
tollgate; there are numerous routes connecting these tollgates, and samples can be easily obtained.
Figure 3 presents the network diagram of the paths between Seoul and Daegu tollgates. Path 1 is a single
Gyeongbu line. Path 2 is a combination of lines along Gyeongbu-Yeongdong-Jungbunaeryuk-Gyeongbu. The last line
is a combination of lines along Gyeongbu-Cheongwonsangju-Jungbunaeryuk-Gyeongbu. The TCS will produce therepresentative travel time between Seoul and Daegu as path #1 in KEC’s system environment in spite of the existenceof other paths.

Figure 4. Network diagram showing the paths between Seoul TG and Daegu TG
Table 4 lists an analysis example corresponding to September 17, 2013. The distribution ratio is the ratio of thenumber of vehicles along each path to the total number of sample vehicles. Congestion length is the summation of thesection congestion length of each path.5 The congestion ratio is the ratio of the total congestion length of each path andthe path length.

2

The number of total vehicles between the origin and destination. This is a true value based on the TCS.
The number of total vehicles that are detected at the origin and destination RSEs. This value does not mean that eachvehicle has a perfect trajectory.
4
The number of vehicles that have ideal trajectories, and were detected at the origin and destination.
5
KEC’s congestion criteria is the Conzone’s spatial mean speed below than 40km/h.
3

301

Time
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23

Table 4. Travel time analysis example of Seoul–Daegu on Sep. 17, 2013 (partial example)
Congestion length
Travel time (min)Distribution ratio
Congestion ratio
(km)
#1
#2
#3
TCS
#1
#2
#3
#1
#2
#3
#1
#2
#3
162
171
195
210 17% 63% 21%
0
0
0
0%
0%
0%
151
188
166
191 14% 71% 14%
0
0
0
0%
0%
0%
152
163
0
201 17% 83% 0%
0
0
0
0%
0%
0%
0
183
243
191
0%
67% 33%
1
0
1
0%
0%
0%
255
175
183
183 24% 65% 12%
0
1
0
0%
0%
0%
165
181
195
181 12% 85% 4%
0
0
0
0%
0%
0%
175
178
208
176 21% 59% 21%
0
0
0
0%
0%
0%
253
191
183
183 26% 48% 26%
0
0
0
0%
0%
0%
195
206
181
178 31% 49% 20%
0
1
0
0%
0%
0%
187
184
175
181 26% 66% 8%
0
1
0
0%
0%
0%
214
221
195
188 20% 54% 25%
0
0
0
0%
0%
0%
232
271
207
228 38% 56% 6%
2
1
2
1%
1%
1%
210
256
192
234 44% 34% 21%
1
3
1
0%
1%
0%
204
349
253
217 60%8% 32%
1
1
1
0%
0%
0%
232
329
314
239 62% 25% 13%
2
4
5
1%
2%
2%
241
332
242
268 54% 34% 12%
11
13
18
4%
5%
7%
264
347
324
254 64% 24% 12%
15
17
22
6%
7%
8%
261
351
276
274 66% 27% 7%
28
19
32
11% 8%
12%
251
358
277
287 58% 30% 12%
3826
37
14% 11% 14%
270
390
284
295 58% 27% 15%3737
38
14% 16% 15%
280
323
278
296 63% 25% 12%
2732
30
10% 13% 12%
253
332
256
288 51% 30% 19%
2129
24
8% 12%
9%
224
319
320
283 62% 23% 15%
1827
21
7% 11%
8%
233
304
247
305 52% 32% 16%
1225
18
5% 11%
7%

Figure 5. An example of travel time analysis for Seoul–Daegu for Sep. 17, 2013302

Figure 6. Relationship between distribution ratio and congestion length (Sep. 17, 2013)

Figure 7. The relationship between distribution ratio and congestion ratio (Sep. 17, 2013)
According to abovementioned results for the Seoul–Daegu trip, the main path, which has the highest distribution
ratio within the non-congestion condition, may be path #2. The main path's distribution ratio declines, and that of path
#1 relatively escalates as the congestion increases. Meanwhile, the distribution ratio of path #3 is steadily low and is notaffected by congestion. Under the assumption that users are aware of the traffic condition in their route, the congestion
length is considered to influence the route choice from among the activated paths.
A correlation analysis was performed to determine the factors—from among congestion length, congestion ratio,
and VDS-based path travel time6—that influence route decision. Table 5 lists the results of correlation analysis. The
correlation coefficients of paths #1 and 2 are higher than 0.5; this result implies that a positive and negative correlation
exist between traffic information on a route and route decision.
Table 5. Correlation analysis results
Distribution ratio of
path #1

Distribution ratioof path #2
Distribution ratio
6

Congestion length 1
0.502
Congestion length 2-0.624
Congestion length 3

Congestion ratio 1
0.501
Congestion ratio 2-0.624
Congestion ratio 3

VDS path travel time 1
0.557
VDS path travel time 2-0.683
VDS path travel time 3

VDS-based travel time was used in this study to satisfy the sample size requirements for correlation analysis.
303

of path #3

0.163

0.163

0.109

6 ANALYSIS RESULTS OF SERVICE AREA USAGE
The KEC also operates RSEs in service areas to avoid overestimating the travel time when considering mainline
travel time. If an OBU-equipped vehicle stops in a service area, this vehicle communicates with the service area RSE;
the vehicle is then filtered as an outlier. Using this system configuration, the service area usage behavior was analyzed
based on travel trajectory. The criterion for screening of the parked vehicle in a service area is a time difference of morethan 5 min between the service area RSE and the next mainline RSE.
The completed travel trajectory of RF-type OBU vehicles is approximately 1.2 million per day; this value is
33% of the total day trips on the nationwide expressway.78 Vehicle class 1, which includes passenger cars, vans (lessthan 16-seaters), and trucks (less than 2.5-ton maximum load capacity), represents the highest portion among total trips,
but the service area visit ratio is not high in comparison with the occupancy of total trips. Vehicle class 2 includes buses(16–35 seaters) and trucks (maximum load capacity 2.5–5 tons) and has the lowest visit ratio. Vehicle class 3 comprises
buses (more than 36 seaters) and trucks (maximum load capacity over 5 tons) and have a visit ratio approximately equal
to that of vehicle class 1. Table 6 lists the fraction of the total number of vehicles visiting the service areas.
Table 6. Analysis of the service area visits of vehicles

1,162,245
6,309

Number of vehicles
visiting a service area
60,388220

Percentage of vehicles
visiting a service area
5.2
3.5

41,864
1,210,418

2,152
62,7605.1
5.2

Vehicle class

Total number of travels

1
2
3
Total

In this study, the service area usage pattern was analyzed depending on travel distance. According to theanalysis results for the travel distance distribution of population, short distance travel of less than 50 km contributed
most of the proportion of the total trips. Further, the trip frequency was found to decrease as travel distance increased.
The results for service area use ratio showed behavior opposite to that of the results for travel frequency. That is, theservice area use ratio increases as the travel distance increases. In the case of trips of more than 50 km for a class 1
vehicle, the use proportion of each interval especially increases by two times. Table 7 presents the analysis results for
total trip and service area usage ratio depending on the travel distance.

Table 7. Analysis results for total trip and service area usage ratio depending on the travel distance
Distance<50 km50–100 km

100–200 km> 200 km

Total

Classification
Total trips
SA9 visit frequency
Ratio
Total trips
SA visit frequency
Ratio
Total trips
SA visit frequency
Ratio
Total trips
SA visit frequency
Ratio
Total trips
SA visit frequency

1764,352
9,607
1.3%
188,988
14,806
7.8%
152,534
21,09313.8%
56,371
14,88226.4%
1,162,245
60,388

Vehicle Class
2
4,316
54
1.3%
1,159
70
6.0%
633
45
7.1%
201
51
25.4%
6,309
220

3
19,341
117
0.6%
8,321
214
2.6%
8,257
606
7.3%
5,945
1,215
20.4%
41,864
2,152

Total
788,009
9,778
1.2%
198,468
15,0907.6%
161,424
21,744
13.5%
62,517
16,14825.8%
1,210,418
62,7607

The source data for August 10, 2014, were used for this analysis. This analysis differs from previous trajectory
analysis for several reasons.
8
The entire allowance for the truck Hi-pass over than 4.5 ton began on March 29, 2016. So, Trucks that weigh over 4.5
tons are not included in this population.
9
SA is an abbreviation of service area
304

Ratio
5.2%
3.5%
5.1%
5.2%
Analysis results of usage frequency depending on travel distance show that the usage frequency for trips of lessthan 50 km is 0.01 on an average. This observation can be interpreted as follows: drivers rarely use service areas on
short distance trips. The usage frequency for class 1 vehicles for trips longer than 200 km is 0.29, which is the highest
value among vehicles of all classes. The average for all the vehicles of the total distance was 0.13. Table 8 presents theanalysis result of usage frequency for service area depending on trip distance.
Table 8. Analysis results for usage frequency depending on travel distance
Travel distance
Vehicle class<50 km50–100 km

100–200 km>200 kmAverage

1

0.01

0.08

0.15

0.29

0.13

2

0.01

0.06

0.08

0.28

0.11

3

0.01

0.03

0.08

0.21

0.08

Total

0.01

0.08

0.15

0.28

0.13

The results for travel distance depending on departure time show that vehicles that departed during daytime
cover longer travel distances than those that departed during nighttime with regard to average travel distance depending
on departure time. The primary purpose of class 3 vehicles is transport of passengers or cargo, and these vehicles
traveled longer than class 1 vehicles, which are mainly used for commuting or visits.
Table 9. Analysis results for travel distance depending on departure time
Departure time

20–06

06–09

09–17

17–20

Average

1

51 km

59 km

57 km

51 km

55 km

2

49 km

45 km

50 km

54 km

50 km

3

76 km

92 km

96 km

93 km

89 km

Total

51 km

61 km

58 km

53 km

56 km

Vehicle class

Further, analysis of service area visit frequency depending on departure time showed that vehicles departing
during daytime have much higher visit frequency than those that depart in the nighttime. However, vehicles departing in
the morning peak hours of 6:00–9:00 AM have the lowest service area visit frequency. This behavior may be attributed
to the characteristics of commuting trips. Table 10 presents an analysis summary for service area visit frequency withregard to departure time.
Table 10. Analysis results for service area visit frequency depending on departure time
Departure time
Vehicle class
1
2
3
Total

20–06

06–09

09–17

17–20

Average

9,787
79
209
10,075

6,704
44
481
7,229

37,88275
1,083
39,040

9,823
33
476
10,33264,196231
2,249
66,676

7 CONCLUSIONSIn this study, the current status of the ETC employed in expressways in Korea was introduced. Using the ETC
data, an algorithm for estimating travel trajectory was developed in order to build a new traffic information service.
After preprocessing the vehicle trajectory data obtained from the RSEs of the Hi-pass system, a tracking method wasdeveloped to estimate the path travel time between major cities. The developed algorithm allowed estimation of theactual path travel time and path distribution, which could not be obtained using the TCS data. Using the path travel
time data, the congestion length, path travel time, and path distribution ratio were correlated. The path distribution ratio
was found to be directly related to the traffic congestion. The distribution of the main path was found to be high under305

non-congested conditions, and then, the route decision tended to shift to an alternative route with increase incongestion.
In addition, the behavior of vehicles parked in service areas was analyzed using ETC data. Traditionally, thebehaviors of vehicles parked in service areas were analyzed via interviews and surveys, and were not subjected to datadriven analysis. Data-driven analysis can provide information on the number of vehicles parked in service areas and thefrequency of parking by vehicle classes, travel distances, and departure times.
Diverse and innovative traffic information services such as estimation of detour rates on rural roads andincident detection can be considered in future study using the ETC data. This study may contribute to the developmentof the core algorithm and different applications for new services. The use of data from RF-type OBUs has shortcomings
because the penetration rate is approximately 45% of the total OBUs. For using these results, an additional process to
expand the data for the total number of trips is necessary. This problem can be solved by obtaining the population data
through the SMART Tolling System10 until 2020.

ACKNOWLEDGMENT
This work was supported by the National Research Foundation of Korea grant funded by the Korean
government (MEST) (NRF-2010-0028693, 2015R1A1A1A05028008).

REFERENCES
Ahn, K. H., Rakha, H., and Hill, D., Data Quality White Paper, FHWA, 2008
Chun, S. H. and Kim, H. M., "Application Method for Car Navigation Data in Transportation Field", Monthlytransportation, vol. 183, pp. 54-59, 2005
Dixon, M. P. and Rilett, L. R., "Real‐Time OD Estimation Using Automatic Vehicle Identification and Traffic
Count Data", Computer‐Aided Civil and Infrastructure Engineering, vol. 17, No. 1, pp. 7-21. 2002
Guillaume, L., Road traffic data: Collection methods and applications. Working Papers on Energy, Transport andClimate Change 1, European Commission Joint Research Centre Institute for Prospective Technological Studies,
2008
Jing, Y., Zheng, Y., Zhang, C. and Xie, W., "T-drive: driving directions based on taxi trajectories." Proceedings ofthe 18th SIGSPATIAL International Conference on Advances in Geographic Information Systems, ACM, 2010.
Ki, Y. G. Ahn, G. H., Kim, E. J., Cheong, J. H., Bae, G. S., and Lee, C. K., "Error Filtering Algorithm for Accurate
Travel Speed Measurement Using UTIS", The Journal of Korean Institute of Intelligent Transport Systems, vol. 9,
No. 6, pp. 33-42, Dec. 2010.
Kwon, J., and Pravin, V., "Real-time estimation of origin-destination matrices with partial trajectories fromelectronic toll collection tag data." Transportation Research Record: Journal of the Transportation Research Board,
pp.119-126, 2005
Lee, J. W., Choi, K. J., Park, S. W., and Son, B. S. “A Dynamic OD Construction Methodology using Vehicle
Trajectory in Ideal C&R Communication Environment”, Journal of the Korean Society of Civil Engineers, vol. 31,
No. 3, pp. 355-361, May. 2011.
Park, J. H., Hong, S. P., Oh, C., Kim, T. H., and Kim, W. K., "Estimation of Predictive Travel Times Using
Ubiquitous Traffic Environment under Incident Condition", The Journal of Korean Institute of Intelligent Transport
Systems, vol. 8, No. 2, pp. 14-26, Apr. 2009.
Rim, H. S., Oh, C., and Kang, K. P., "A Novel Method for Estimating Representative Section Travel Times Using
Individual Vehicle Trajectory Data", The Journal of Korean Institute of Intelligent Transport Systems, vol. 8, No. 6,
pp. 23-35, Dec. 2009.

10

The SMART Tolling system is an advanced tolling system of KEC. This system allows to charge and pay on theexpress mainline without stopping. KEC is planning to operate nationwide until 2020.
306

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Review of Estimation Method of Crack Depth in Asphalt Paving

TRACK
AUTHOR(Capitalize Family Name)
Jin HATAKEYAMAPOSITIONORGANIZATION

Deputy manager

CO-AUTHOR(S)(Capitalize Family NamePOSITION

COUNTRYJAPAN

ORGANIZATION

Toshiharu CHISAKACOUNTRYJAPAN

Manabu KOUHEIDeputy manager

JAPAN

Motoo TAKAHASHI

Chief

JAPAN

E-MAIL(for correspondence)j.hatakeyama.aa@e-nexco.co.jp

KEYWORDS:
asphalt pavement, crack, crack depth estimation, crack characteristic value

ABSTRACT:

Among the pavement repair work conducted by NEXCO using high-functionality pavement (porous
asphalt pavement), there is an increasing number of cases where the base layer is exposed to roadsurface water and even the roadbed needs to be replaced. When the repair depth has to be changed
during work, it greatly affects the work period, and so it is desirable to precisely estimate thedamage depth. General methods of determining damage depth include measuring cracks by core
boring or with the falling weight deflectometer. However, it takes time and cost to achieve precision
with these point-based survey methods, and traffic control is necessary. Considering thesedrawbacks as well as the focus on the importance of customer service, these methods are notrecommended. This paper describes an evaluation of a crack depth estimation method that analyzes
crack characteristics based on crack data obtained by a measurement technique that requires notraffic control..

307

Review of Estimation Method of Crack Depthin Asphalt Paving
Jin Hatakeyama1
1

East Nippon Expressway Co., Ltd.

1 INTRODUCTION
Among the pavement repair work conducted by NEXCO using high-functionality pavement (porous
asphalt pavement), there is an increasing number of cases where the base layer is exposed to road surface
water and even the roadbed needs to be replaced. When the repair depth has to be changed during work, it
greatly affects the work period, and so it is desirable to precisely estimate the damage depth. General
methods of determining damage depth include measuring cracks by core boring or with the falling weightdeflectometer. However, it takes time and cost to achieve precision with these point-based survey methods,
and traffic control is necessary. Considering these drawbacks as well as the focus on the importance ofcustomer service, these methods are not recommended. This paper describes an evaluation of a crack depth
estimation method that analyzes crack characteristics based on crack data obtained by a measurement
technique that requires no restriction control..

2. Crack Measurement System using a Laser
Since images taken by an ordinary road surface survey vehicle (line sensor camera) fail to clearlyshow cracks in a type I high-function pavement that is not continuously graded, a crack measurement systemusing a laser (LCMS: Laser Crack Measurement System) was used instead. This system, developed byPavemetrics, Canada, is capable of obtaining coordinate positions and dimensions in a 5-meter long lane
section as crack data and digitizing appearance characteristic values, based on which we can estimate thecrack depth.

3. Selection of Crack Characteristic Values and Estimation Method
12 characteristic values were obtained from identification and analysis of the crack characteristics
based on the obtained crack data (Table 1). The Random forest algorithm was selected from the proposedmachine learning algorithms as the method to estimate the crack depth based on those characteristic values.
Table 1. List of crack characteristic values
No. of vertexes
Average crack width
Total crack length
Most angles
Average width of the longest cracks
Angle histogram
Average length of the cracks
Length of the longest crack
Angle of the longest crack
No. of cracks
Average measured depth
Average measured depth of the longest cracks308

4. Learning with Random Forest and Procedure of Crack Depth Estimation
Random forest is a machine learning algorithm proposed in 2001. It has various features including
the capability of running at high speeds even with a large amount of data and can evaluate the extent to which
each characteristic value is effective for classification in the form of a contribution rate. A conceptual
diagram of a random forest decision tree is shown in Fig. 1, while an estimation based on many decision trees
is shown in Fig. 2.
The procedure of learning and crack depth estimation by the random forest algorithm is (1)preparing many decision trees with a branch structure (flow chart) based on a randomly adopted crack
characteristic values and two or more judgment criteria in each characteristic value and (2) learning by giving
right answers to the goals reached by applying the randomly selected crack data (sets of characteristic values)
to each decision tree (actual crack depth, which is hereinafter “damage level”) then, (3) incorporating thecrack data about which we want to estimate the damage level, to all decision trees, total the damage levels
given to the goals of the reached decision trees, and estimate by majority vote.

5. Review of Estimation of Crack Depth
To review estimations of the crack depth, the crack data for each mesh are obtained, the actual
damage level of each mesh (damage level A: crack having reached the upper base course; damage level B:
crack having reached the binder course; and damage level C: crack remaining inside the surface course) ischecked, and 723 datasets containing the crack characteristic values and actual damage levels are prepared.
However, since a large bias is determined to occur in the damage level, data from an area with arelatively good balance is doubled and data from areas with serious biases are randomly deleted so as to keepa balance. Eventually 617 sets were prepared. Of them, 447 sets (70%) were randomly extracted, and thosesets were used (learned) to prepare 500 decision trees.

Figure 1. Conceptual diagram of decision trees in the random forest algorithm

6. Result of Crack Depth Estimation
The crack data of the remaining 170 sets (30%) not used in preparing the decision trees were given
as tasks to experimentally estimate the damage level. The results of crack depth estimation are shown in Fig.
2. The overall match ratio is 88%, and the match ratio of each damage level is 93% for level A, 67% for B,
and 85% for C, which are good results (Fig. 3) (Table 2). There are four characteristic values with higher
contribution rate, namely “the number of crack peaks,” “the total length of cracks,” “the number of cracks,”
and “the length of the longest crack.” It is thus revealed that the “depth” of a crack is proportional to its“length.”

309

・
・
・

The judgment results
The damage level
Estimation result：Total
damage level A
A
B
C
400
70
50
500
Figure 2. Conceptual diagram of estimation with many decision tree

7. Summary
The review made by the authors as reported in this paper confirmed that the damage level (crack
depth) can be estimated by using the “crack characteristic values” (such as length) obtained from the laserbased measurement system (LCMS). Instead of the ordinary road surface survey vehicle using line sensor
camera, “crack measuring” using said method can simultaneously “estimate crack depth.” This is considered
to contribute to a reduced need of traffic restrictions for advance surveys or improve work efficiency by
reducing plan changes. Tasks requiring further study include the non-uniform area coverage of the samples
used in this review and the extremely small sample size of damage level B data. The authors intend toincrease the amount of data (to reduce biases) and promote study toward establishment of this highly
versatile crack depth estimation method.

■Estimation results level A■Estimation results level B■Estimation results level C

The actual
damage level A

The actual
damage level B

The actual
damage level C

Figure . Result of crack depth estimation310

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

A Basic Study on Comparison of Lane Width Measured with Sensors

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Jaehong PARK

Research Specialist

Korea Institute of Civil
Engineering and Building
Technology

KOREA

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Dukgeun YUN

Senior Researcher

Korea Institute of Civil
Engineering and Building
Technology

KOREA

Chunjoo YOON

Senior Researcher

Korea Institute of Civil
Engineering and Building
Technology

KOREA

E-MAIL(for correspondence)dkyun@kict.re.kr

KEYWORDS:
LiDAR, Camera, Lane width, Road Safety

ABSTRACT:This study has selected lanes and widths of the lanes as the object for recognition among the road factors whichshould be recognized necessarily by the unmanned vehicle and compared the results of the accuracy measured undervarious conditions. To proceed the research, the National Highway which was relatively recently and thus of which theroad condition is favorable was selected and as the equipment to measure and recognize the width of the lane throughthe actual measurement, the CCD camera and 3D LiDAR were used. According to the analysis result, the after thesunrise, the averages of the widths of the lane using the image or LiDAR were 3.34m and 3.21m and the RMSE was
0.19 and 0.34 and thus it was shown that the measurement of width of the lane using the image was more favourable in
the phase of the accuracy. However, before the sunrise, the width of the lane was not detected in the image and in thecase of the measurement of the width of the lane using the LiDAR, the average was 3.23m and the RMSE was 0.33 andthus the limitation of the measurement of the width of the lane using the image was proposed.

311

A Basic Study on Comparison of Lane Width Measured with Sensors
Jaehong Park1, Dukgeun Yun2, Chunjoo Yoon3
1,2,3

Korea Institute of Civil Engineering and Building Technology, KOREA
Email for correspondence, dkyun@kict.re.kr

1. INTRODUCTION
Various studies and technologies have been developed and proceeded in order to improve the safety of the roaddomestically and internationally and especially, the development of the technologies to decrease accidents due tohuman factors among traffic accident triggers is being proceeded. According to the actual analysis of the main causes of
the Road Traffic Accidents, it is being reported that over 90% of the traffic accidents are occurring due to humanfactors. Lane Departure Warning System(LDWS), Smart Parking Assist System(SPAS) and Advanced Driver
Assistance Systems(ADAS) as the various methods to reduce accidents due to human factors are being developed andused actually, which focus on supplementing the safe driving of the driver. Recently, being developed from the simple
system which helps the safety driving of the driver, the vehicle in which the driver does not manipulate the steering
wheel, but which drives mindlessly through the object recognition by the vehicle itself has passed the test driving and isdriving actually on the road. For this unmanned vehicle to drive, the recognition of street structure technology for theactual section that the vehicle drives and the positioning technology are required necessarily, through which the street
furniture should be recognized on-line which exists on the road. The median barriers, curbs and lanes and so forthwhich compose the basic elements of the road among the facilities existing in the road are the objects which should berecognized necessarily for safe driving of the unmanned vehicle. Especially, the recognition of the street furniture
should be possible under various conditions which reflect the actual driving environment and an accuracy of over acertain level should be guaranteed as well. Especially, in case of the lanes, they are the element which should berecognized necessarily to secure the driving safety of the vehicle and to ensure safe driving by differentiating thevehicle groups and up to now, the lanes are detected and width of the lane is measured using the image recognition or
LiDAR.
Thus, this study has selected lanes and widths of the lanes as the object for recognition among the road factors
which should be recognized necessarily by the unmanned vehicle and compared the results of the accuracy measured
under various conditions. To proceed the research, the National Highway which was relatively recently and thus ofwhich the road condition is favorable was selected and as the equipment to measure and recognize the width of the lane
through the actual measurement, the CCD camera and 3D LiDAR were used.
2. LITERATURE REVIEWThis chapter reviewed the existing studies which focus on recognizing the road information using various
sensors.
Choi et al. (2012) have studied on the visual Odometry to presume the location of the vehicle driving in theroad environment. For the position recognition, the stereo camera to acquire the 3 dimensional information in the frontof the vehicle and the single camera to acquire images from the back of the camera were used. An experiment was
performed about two long-distance routes acquired under the actual driving environment, and according to its result,over 97% of the matching success rate was showed, which proposed the conclusion that the methodology used in thisstudy can presume correct position. Jang (2005) used the digital video camera and shot and analyzed the road paved inasphalt concrete and extracted the information on the road. He has compared the result with the outcome by way of themeasurement of the base point and analyzed them and proposed the average errors of 0.0427m for the X axis, 0.0527m
for the Y axis and 0.1539m for the Z axis. Also, the cracking rate, plastic deformation and longitudinal roughness, theroad surface evaluation factors were able to be obtained through the processed image, through which the commonality
index and maintenance index were calculated and the road evaluation was performed in the object road. Kim & Lee(2008) has performed the study of creating 3 dimensional geometric model of the road automatically by using the
LiDAR data and numerical map. They have identified the points measured in the road surface through the division andgrouping process of the Data Cloud inside the road section and have extracted the linear and surface information of theroad. Yun et al. (2006) have proposed the way of measuring the cross slope of the road by using the vehicle for analysisof road safety. They have developed the algorithm which measures the cross slope during driving, using the vehicle
which is equipped with the GPS-IMU and laser scanner and compared it with the actual data and verified statistically.
Mun & Seo (2008) have developed the image analysis model which can measure swiftly using the line scan camera for
the facilities of which the installation interval and heights are regularized according to the design(operation) speed andgeometric structure among various road safety facilities. They have applied the developed model on the site andproposed the measurement results of the sizes and installation intervals of the facility. Jung et al. (2011) have
performed the study of using the vehicle in which GPS-INS is installed and collecting the geometric structure312information. They have used the Genetic Algorithm and developed the algorithm to analyze the horizontal alignmentand differentiated the direct line, curve and easement curve and so forth. The algorithm was evaluated using the freeway
and national highway data and it was analyzed that each showed 90.48% and 88.24% of classification accuracy. Jang etal. (2015) have used the fact that the lanes are brighter than the road and extracted the characteristics of being strong to
the illumination using the difference between the lanes and the surface of the road and the width of the lane and byusing the extraction result of the characteristics, detected the straight lanes. By using the detected straight line andcamera information, candidate curve groups were created in the 3 dimensional road and curve lanes among which thecurve lanes were determined. Also, the speed and accuracy were improved using the detection information of theprevious frame so that curve lanes can be traced swiftly in continuous frames. Kim et al. (2013) created a few putative
factors for tracing through the combination of the characteristics of the Background Subtraction, LK-Optical Flow andcommunity-based histogram, through which they proposed the tracing method which is relatively strong to the objects
with change and noise. In other words, they have proposed the method of reliable tracing for external environment also
through the verification method of the characteristic points traced by the optical flow which is strong to the change ofthe color and illumination, verification based on the regional histogram and the mixing method of these trackings. The
laser distance sensor was used to propose the method of swift recognizing of the surrounding environment in urban
environment made for an unmanned vehicle. Data was collected using the laser sensor and continuous points
classification was performed, and detection and removal of the ground, object division and object classification tasks
were performed. The conclusion was proposed that the realtime of the surrounding environment recognition algorithmof the unmanned vehicle was secured through the methods proposed in this study. Kim et al. (2013) have proposed themethod of recognizing the obstacles real time in the actual road condition using the LiDAR. They have classified thescanned data into the date inside the road and data outside the road and the data inside the road was clustered suing the
Euclidean Distance. They also have obtained the location and size of the detected obstacles and calculated the speed
and distance. The effectiveness of the algorithm has been verified using the LiDAR installed in the front bumper of theunmanned vehicle and the result of a swift 2ms of performance time has been proposed.
3. OVERVIEW OF ANALYSISThe GPS-IMU to measure the location information and the image equipment or LiDAR to measure the objects
are needed for the recognition of the lane and the measurement of the width of the lane. Information on each sensor
used in this study is as follows.
3.1 3D LiDAR
The LiDAR sensor used in this study is the PUCK(16 channels) by Velodyne. The PUCK(16 channels) of
Velodyne detects the scope of 360° horizontally and recognizes objects using 16 LiDARs per each 2° at 30° angle
vertically. The points cloud can be measured up to 100m maximum and the table 1. has proposed the main specificationof the Velodyne sensor used in this study.
Table 1. Specification of 3D LiDAR
Channel

16 channels

Accuracy± 3 cm (typical)

Field of view (horizontal/azimuth)

360°

Rotation rates:

5 - 20 Hz

Wave Length

903 nm (min/max range 896/910nm)

Operating range

up to 100 m

Max altitude of operation

200 m

Angular resolution (vertical)

2°

Angular resolution(horizontal/azimuth)

0.1° - 0.4°

3.2 3D CCD Camera
This study has selected the Manta-G 125 in order to measure the width of the lane using the images. The
CCD(Charge Coupled Device) camera was installed to collect the image of the section driven and the resolutions of the313

camera installed were 1936 X 1456, 40 FPS(Frame Per Second) and CCD Progressive shape for the shooting. Table 2.
has proposed the specification of the video equipment.
Table 2. Specification of CCD Camera
Resolution

1292 x 964

Max frame rate at full resolution

30 fpsType

CCD Progressive

Interface

IEEE 802.3 1000baseT

A/D

14 bitOutput8-12 bit

Sensor Size

Type 1/3

SensorSony ICX445

Cell size

3.75 μm

3.3 Data Acquisition System
The investigation equipment for road inspection was used as the data acquisition system in this study. The
vehicles in which each sensor was installed was used and the data collected through the sensors were synchronizedbased on the GPS-IMU location. The installation of sensors was showed Figure 1.

Figure 1. The installation of Sensors
3.4 Summary of the experiment
Result measured in the National Highway No.37 sector was proposed for the comparison of the widths oflanes. The detection was made for 1.6km road and the driving speed was 80km/h on the average. The object sectionused for the analysis of the width of the lane was a section which was constructed 15 years ago and is relatively goodcondition and the width of the lane of the object section was measured through actual measurement. As therepresentative time for the comparison between night and day, the measurement was made before and after the sunrise
based on the sunrise time (5:12AM).

4. METHODOLOGY FOR ANALYSISThis study has used the LiDAR and the image equipment in order to recognize the lane for an unmanned
vehicle to drive and measure the width of the lane to drive along and this chapter proposed the process for themeasurement of the width of the lane.
4.1 Detection of width of the lane using the LiDAR
The 3 dimensional LiDAR used in this study can measure the 3 dimensional coordinate values(x, y, z) from thesensor to the point and intensity reflected in the object. The lanes were recognized through the intensity measured by
the LiDAR and reflected and for the detection of the width of the lane, the plane coordinates were extracted among the314

3 dimensional coordinates and reflected into the X-Y axis coordinates and the threshold that the lanes are detected werededucted. The ROI was configured to improve the accuracy and detection of the lane and was set to be 5m in the rearand 5m in the right and left from the center of the LiDAR installed in the vehicle. Also, the 180° needed in the rear was
set to be FOV(Field of View) and the data acquisition cycle was set to be 10Hz. The scope of intensity acquired in the
Velodyne was 0 ~ 255, the average intensity of the road paved in asphalt was under 20 and the intensity about the lane
was under 60. As the result of the analysis result through the pilot test performed in this study, the case that intensity
was detected to be over 45 was used as the threshold about the detection of the width of the lane. The intensity of over
the threshold was detected through the Velodyne and the lane was detected and the right and left side from the center
axis of the vehicle was searched and the width of the lane was calculated. Figure2 proposed the lane detection screen
using the LiDAR.

Figure 2. The process of lane detection
4.2 Detection of the width of the lane using the image
The camera installed in the front of the vehicle was used in the measurement of the width of the lane whichuses the image. Calibration has been performed for correct measurement of the width of the lane and as in the figure 2,
focus boards were installed in 2m intervals for the calibration and the image was acquired and the actually measured
distance information was matched to the pixel coordinates of the image.

Figure 3. Image acquisition for the calibration

315

This study has used the IPM(Inverse Perspective Mapping) about the data acquired through the image
equipment and detected the width of the lane. IPM conversion is the method of configuring the ROI(Region of Interest)of the object scope to be observed, removing the perspective effects, reflecting each pixel to other locations and creatingnew 2 dimensional pixel arrangement. 20m of the scope observed was set to be the ROI for the detection of the width ofthe lane and after binarizing the color image of the acquired data, the left and right from the center of the vehicle(centerof the image) was searched and the pixel coordinates of the image with lanes are found. Convert the calibrated data of
the pixel coordinates of the lanes acquired into the actual coordinates and the width of the lane is calculated using theactual coordinates of the lane.
5. ANLYSIS RESULT
Measurement result of the width of the lane through the measurement, image and LiDAR of the section of the
National Highway No. 37 for the comparison of the width of the lane and the compared errors were proposed. In the
result of the measurement before the sunrise, in case of having used the image, the width of the lane was not measured
and in case of having used the LiDAR, the minimum width of the lane was 2.4m, maximum width of the lane was
3.79m and the average width of the lane was 3.23. After the sunrise, in case that the LiDAR was used, the minimum
width of the lane was 2.61m, maximum width of the lane 3.79m and the average width of the lane was 3.34m. The
summary result of the width of the lane using the measurement, image and LiDAR is proposed in the table 3.
Table 3. Comparison of descriptive statistics

Before the sunrise

After the sunrise

Measurement
Image

LiDAR

Image

LiDAR

Minimum(m)

3.5

None

2.40

2.61

2.40

Maximum(m)

3.5

None

3.79

3.79

3.79

Average(m)

3.5

None

3.23

3.34

3.21

The result of analysis through the absolute values comparison of the results measured using the image and
LiDAR with the measurement values is proposed in the table 4. The RMSE of the measurement result of the width ofthe lane using the LiDAR before sunrise was 0.33, RMSE of the measurement result of the width of the lane using theimage after the sunrise was 0.19 and the RMSE of the measurement result of the width of the lane using the LiDAR was
0.34. According to the analysis result, a difference about image recognition result existed for during the day.
Table 4. Comparison of RMSE of analysis result

Before the sunrise

After the sunrise

Image

LiDAR

Image

LiDAR

Minimum
absolute error(m)

None

0.00

0.00

0.00

Maximum
absolute error(m)

None

1.29

0.78

1.10

Averageabsolute error(m)

None

0.07

0.04

0.09

RMSE

None

0.33

0.19

0.34

316

6. CONCLUSION AND FUTHER STUDYThis study has selected lanes and widths of the lanes as the object for recognition among the road factors
which should be recognized necessarily by the unmanned vehicle and compared the results of the accuracy measured
under various conditions. According to the analysis result, the after the sunrise, the averages of the widths of the laneusing the image or LiDAR were 3.34m and 3.21m and the RMSE was 0.19 and 0.34 and thus it was shown that themeasurement of width of the lane using the image was more favourable in the phase of the accuracy. However, before
the sunrise, the width of the lane was not detected in the image and in the case of the measurement of the width of thelane using the LiDAR, the average was 3.23m and the RMSE was 0.33 and thus the limitation of the measurement of
the width of the lane using the image was proposed.
The following study is needed for the development of this study. First, collection of a large amount of data isneeded for various sections. More objective results should be approached by expanding the analysis scope and object
section. Second, Improvement of the comparison, verification and recognition method of various sensors is needed.
Accuracy of measurement should be able to be enhanced through this. Lastly, a study is needed in which technology
which recognizes other street furniture other than the width of the lane which was the object of this study can be
developed and analyzed.
It is expected that the result of this study can become a basic study which can help the unmanned vehicle torecognize the street furniture and drive.
7. ACKNOWLEDGEMENTS
This research was supported by a grant from Industrial Innovation Research Project (Standard open DB
establishment and evaluation system for intelligent vehicle awareness technology support, N0.10052941) funded by the
Ministry of Trade, Industry and Energy of Korea.
8. CITATIONS AND REFERENCES
Ahn, S., Choe, Y. and Chung, M.J. (2012), Fast Scene Understanding in Urban Environments for an Autonomous
Vehicle equipped with 2D Laser Scaners’, Journal of Korea Robotics Society, Vol.7, No.2, pp.92~100
Choi, S.I. and Park, S.Y. (2013), Localization of A Moving Vehicle using Backward-looking Camera and 3D Road
Map, Journal of The Institute of Electronics Engineers of Korea, Vol.50, No.3, pp. 682~695
Jang, H.S. (2005), Extraction of Information on Road Surface Using Digital Video Camera, Korean Journal of
Geometric, Vol.23, No.1, pp.9~17
Jang, H.J., Jang, S.H. and Park, S.Y. (2015), Model-based Curved Lane Detection using Geometric Relation between
Camera and Road Plane, Journal of Institute of Control Robotics and Systems, Vol.21, No.2, pp.130~136
Jung, E., Joo, S., Oh,C., Yun, D., and Park, J. (2011), Algorithm for Identifying Highway Horizontal Alignment using
GPS/INS Sensor Data, Journal of the Korean Society of Road Engineers, Vol.13, No.2, pp.175~185
Kim, J., Lee, J., Kang, T., Min, K., Byun, Y., and Kim, Y. (2013), LiDAR based Obstacle Recognition for Autonomous
Vehicle, The Korean Institute of Electrical Engineers, Information and Control Symposium, pp.127~128
Kim, S.J. and Lee, I. (2008), 3D Road Modeling using LiDAR Data and a Digital Map, Korean Journal of Geometric,
Vol.26, No.2, pp.165~173
Kim, Y.H., Park, S.Y., Oh, W.I., and Choi, K.H. (2013), Background and Local Histogram-Based Object Tracking
Approach, Journal of Korea Spatial Information Society, Vol.21, No.3, pp.11~19
Moon, H.C. and Suh, Y.C. (2008), System Development and Field Application for Measuring installation Interval andHeight of Road safety Facilities using a Line Scanning Camera, Journal of the Korean Society of Road Engineers,
Vol.10, No.3, pp.231~237
Yun, D.G., Jeong, D.H., Sung, J.G. and Lee, S.H. (2006), A Study for Measuring of Cross Slope using Instrument
Vehicle with Multiple Sensors, Journal of the Korean Society of Road Engineers, Vol.8, No.2, pp.105~116317

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)

The Needs of Life Cycle Cost Application for Malaysia Green Highway Projects

Project Delivery, Road Financing
POSITIONORGANIZATIONCOUNTRYPhD Candidate

Universiti Teknologi
Malaysia

Malaysia

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Rozana Zakaria

Assoc. Prof.

Universiti Teknologi
Malaysia

Malaysia

Muhammad Faiz A.Rahman

E-MAIL(for correspondence)

mfaiz83@live.utm.my

KEYWORDS:Life Cycle Costing; decision making application; green highway; sustainability

ABSTRACT:In the journey towards preserving highway infrastructures in a sustainable manner, Performance-Based planning andasset management are important to efficiently preserve and rejuvenate at its life cycle stages. There are many methods
and efforts to integrate the current practices, however, there are many gaps to be considered between the ideal theory
and real-time measures. The highway components asset life-cycle cost will have an impact in terms of larger costinvestment due to the fact that systematic assessment is rarely applied. The total cost of different highway projects
should be evaluated based on the life cycle cost (LCC), which includes all expenses and incomes during the lifetime of
the construction until post-construction. This paper focuses on the importance of the LCC application to highway
project and it also responds to the sustainability of highway infrastructure development. This paper also utilized andreviewed related literatures concerning life cycle cost (LCC) application for the green highway in order to spark thesignificance of this research. Then, this paper also highlights the expected findings, which lead to identifying importantfactors in developing real-time decision making application using LCC. The outcome of this paper will inspire the
Malaysia’s highway builders to respond to green highway development and make LCC as a tool of decision making.

318

The Needs of Life Cycle Cost Application for Malaysia
Green Highway Projects
Muhammad Faiz A.Rahman1, Rozana Zakaria1, Nur Nadhira A.Rasid1
1

Universiti Teknologi Malaysia, Skudai, Johor Bharu, Malaysia.
Email for correspondence, mfaiz83@utm.live.my.

1 INTRODUCTION
The construction industry has a significant impact on the environment, economy, and society.
Surface transportation systems are one of the biggest contributors to greenhouse gas emissions, for which
they are responsible for 38% of all CO2 emissions (Tatari, O. et al. 2011). Increased awareness of theenormous ecological footprint of the infrastructure environment has substantially increased the importanceand popularity of various green highway initiatives as a possible solution to remediate the damages incurredon the planet.
Many of these initiatives focus on enhancing biodiversity, improving air and water quality, reducing
solid waste generation, and conserving natural resources of buildings. Therefore, being green, or sustainable,
is the pressing issue coming from both internal and external drivers for construction and engineering
companies. To assess how green or sustainable the highway is, several green rating systems, protocols,
guidelines and standards have been developed in the past that respond to the need to evaluate and benchmark
levels of building achievement in the green revolution (Yudelson, J. 2008a), Yudelson, J. 2010b).
The first green highway manual was established in 1998 by the US Green Building Council(USGBC). Leadership in Energy and Environmental Design (LEED) adopted a checklist approach whichemphasizes on sustainability development. In 2008, New York State Department of Transportation
established their Green Leadership in Transportation Environmental Sustainability (GreenLITES) (New YorkState Department of Transportation 2010). It is a transportation specific checklist with 4 levels ofcertification. A year later, University of Washington produced Green road assessment model (University ofWashington 2011). In 2010, three green highway assessment tools have been established. Recycled Materials
Resource Center and University of Wisconsin-Madison, Portland (Oregon) Bureau of Transportation; Santa
Cruz County Regional Transportation Commission and Illinois Department of Transportation have formed
Building Environmentally and Economically Sustainable Transportation Infrastructure Highways (BE2ST in
Highways), Sustainable Transportation Access Rating System (STARS) and Liveable and Sustainable
Transportation Rating System and Guide (I-LAST) respectively (Lee, J. et al. 2010, The North American
Sustainable Transportation Council 2010, Illinois Department of Transportation 2010). On 2012, Federal
Highway Administration produced FHWA Infrastructure Voluntary Evaluation Sustainability Tool
(INVEST), and Institute for Sustainable Infrastructure Ranking System/Harvard Zofnass Program for
Sustainable Infrastructure have established Envision (U. S. DOT, Federal Highway Administration 2012,
Harvard University Graduate School of Design & the Institute for Sustainable Infrastructure. 2012).
Today’s evaluation of cost mainly focuses on the investment costs with only little regard to future
costs. For highway users, the expense of using this infrastructure is a result of the accumulated costs during
the highway’s lifetime. Initiatives that reduce the future costs (e.g. Energy savings, improved durability ofhighway components) often result in larger investment costs, (e.g. the addition of thermal insulation, more
durable pavement materials etc.). If future costs are not included in the evaluation, these initiatives will not
be implemented. Therefore, the total cost of different highway designs should be evaluated based on the life
cycle cost (LCC), which includes all expenses and incomes during the lifetime of the construction. In order toobtain total cost, the measureable variable in the stage of life cycle costing should be identified andcorrelation between them should be established first.

319

This paper will review the related literatures which may bring the sense of the importance of life
cycle cost (LCC) application for green highway. Besides, the steps to identify important factors in developing
real-time decision making application using LCC will also be highlighted in this research.
2 LITERATURE REVIEWA green highway can be defined as a roadway design based on a relatively new concept for roadway
design that integrates transportation functionality and ecological sustainability (UTM-LLM 2014). An
environmental approach is used throughout the planning, design, and construction stages. This green highway
will give benefit towards transportation, the ecosystem, urban growth, public health, and surrounding
communities. Awareness of the highway users and stakeholders is essential in order to ensure the equilibrium
between development and sustainability. When built to the standards of the concept, green highways haveinvaluable benefits to the environment. A green highway needs more consideration of all parties from top to
down. The government as a policy maker, will provide the rules and regulation to be practised by theconcession company and highway users (UTM-LLM 2014).
The need for promoting sustainability and green highway construction requires a green highway
assessment system. Therefore, Malaysia Green Highway Index manual was designed as a performancebaseline standard in order to measure the level of greenness for current highway in Malaysia. This manual
intends to come out with several fundamental elements of green highway development that is suitable to
Malaysia’s condition. Five (5) specific activities which are Sustainable Design And Construction Activies(SDCA), Energy Efficiency (EE), Environmental And Water Management (EWM), Material And
Technology (MT) and Social And Safety (SS) form the key featues in the Malayia Green Highway Index
Manual that suitable to Malaysia condition with Platinum level are the highest among four (4) certificationlevels. In the other hand, many parties in highway industry will get the benefit and courtesy by developing
the sustainable green roads, pathways, and expressways by following developed Green Highway certification(UTM-LLM 2014).
Life-Cycle Cost Analysis (LCCA) was legislatively defined in Section 303, Quality Improvement,of the National Highway System NHS Designation Act of 1995. The definition as modified by TEA-21, is“[it is] a process for evaluating the total economic worth of a usable project segment by analysing initial costs
and discounted future cost, such as maintenance, user, reconstruction, rehabilitation, restoring, andresurfacing costs, over the life of the project segment.” A usable project segment is defined as a portion of ahighway that, when completed, could be opened to traffic independent of some larger overall project (Walls
III, J. et al. 1998).
Similarly, in simpler terms, LCCA is an analysis technique that supports more informed and, it ishoped, better investment decisions. LCCA is an analysis technique that builds on the well-founded principles
of economic analysis to evaluate the over-all-long-term economic efficiency between competing alternative
investment options. It does not address equity issues. It incorporates initial and discounted future agency,
user, and other relevant costs over the life of alternative investments. It attempts to identify the best value(the lowest long-term cost that satisfies the performance objective being sought) for investment expenditures.
Life Cycle Cost (LCC) analysis should be conducted as early as possible in the project development cycle(Walls III, J. et al. 1998).
Cost and schedule are two of the most important project components in the construction industry.
Major research efforts have focused on the improvement of the effectiveness of cost and schedule control,
cost and schedule integration and cost-schedule trade-off in construction. A survey indicates that about 33%
of architecture/engineering projects do not meet cost and schedule targets (Bayraktar, M. E. 2006). A casestudy indicates that costs increased 9.2% and schedules increased 23.3% on average for four environmental
and engineering projects. A report indicates that the median cost increase for design projects is about 10%(Bayraktar, M. E. 2006). Bayraktar (2006) also finds out that project costs were underestimated in 90% of the
258 infrastructure projects completed in the past 70 years.
Gao et al. (2002) find the project cost as the highest ranked factor that determines the success of theconstruction projects (Gao Z. L. et al. 2002). Hastak et al. (1996) present a prototype decision support systemcalled COMPASS (Cost Management Planning Support System) for project cost control strategy andplanning. The proposed methodology helps management evaluate potential degree of cost escalation for the320

project under consideration and take proactive measures by identifying attributes that might be the reason forcost escalation including management errors, regulatory approval, and rework (Hastak, M., et al. 1996).
Dunston and Reed (2000) present the effectiveness of the Small Projects Team Initiative (SPTI)
developed and used by the Seattle district of the U.S. Army Corps of Engineers. The SPTI’s objective is tolower the design costs on construction projects where the design scope is simple. The study statisticallyconfirms that SPTI leads to reduced design costs and reduced schedule growth (Dunston & Reed 2000).
Barraza et al. (2000) present probabilistic monitoring of project performance using stochastic S-curves as apotential method to develop a better project control system (Barraza, G.A. et al. 2000). Similarly, Chang(2001) identifies cost/schedule performance indices and their values for design projects (Chang, A. S. 2001).
3 METHODOLOGY
In order to identify important factors in developing real-time decision making application using
LCC, the methodology of the research is as follows:
1.
At the beginning, literature review had been conducted in order to gather the information
about the green highway &life cycle costing from journal, books, conference paper, internet and etc. Fromthe literature review, the factor of green highway, which is relevant to the life cycle costing were identified.
The factors in concern were the measurable variable which is cost item.
2.
Then is the discussion on the criteria of cost items and confirming the cost item with theexpert. After the measurable variables in green highway had been identified, the research continued with theliterature review on the correlation between variable and Life cycle costing. Based on the literature and thefocus group method, a preliminary table which illustrates the item cost and each stage of life cycle costing
had been developed. There are 2 stages of life cycle costing involved, which are the initial cost and future
cost. For initial cost, there are capital; construction cost (installation); and management cost. While for future
cost, there are operation; maintenance/service; replacement; demolition; contingencies cost/risk andmanagement cost.
3.
Then is the survey questionnaire development with Decision Matrix (see Table 1). The
purpose of the survey questionnaire is to identify the relevant cost item which best suit in each stage of theLife cycle costing & the correlation between them. The questionnaire sheets consist of two (2) sections asfollows:
4.
Section A: Respondents’ Profile. This is to know the background of the respondents. . It is
important to know the experiences and individual preferences of those who are involved with the highway
construction.
5.
Section B: Selection of the correlation between green highway variables and life cycle cost
(LCC). There are five categories in the Section B where each category has its own Decision cross-matrix
between cost item and life cycle cost (LCC). Respondents were request to indicate No relevance=1, least
relevance=2, moderately relevance=3, strongly relevance=4, very strongly relevance=5 in the appropriate
blank box provided alongside each statement.
6.
The questionnaires will be distributed to the 10 targeted respondents, which consists ofexperts in highway construction industry, especially those who are involved in the development of green
highway and life cycle costing. The survey will be conducted using face-to-face interview with the
respondents in order to help them to fill the questionnaire survey form based on their expertise.
7.
The findings from the questionnaire survey will be analyzed by using IBM SPSS Statistics
22. Spearman correlation coefficient will be obtained in order to show the strength of correlation between
Energy efficiency cost items and life cycle costing.
8.
By referring to Dr Weir, L. from University of the West of England, Spearman’s
correlation coefficient is a statistical measure of the strength of a monotonic relationship between paired data
(Weir, L. 2015). In a sample, it is denoted by and is by rs design constrained as -1< rs < +1 and its
interpretation is similar to that of Pearsons, e.g. the closer rs is to ±1 the stronger the monotonic relationship.

321

Correlation is an effect size and so we can verbally describe the strength of the correlation using thefollowing guide for the absolute value of rs:•.00-.19 “very weak”•.20-.39 “weak”•.40-.59 “moderate”•.60-.79 “strong”•.80-1.0 “very strong”
9.
Spearman’s correlation coefficient which will be fell under “strong” and “very strong”
category are the important factors in developing real-time decision making application using LCC in green
highway.
4 RESULTS AND DISCUSSION
After going through the introduction and literature review, we noticed that many of the assessment
tools in green highway do not consider life cycle costing significantly. For our case study in Malaysia, theassessment tool in green highway is Malaysia Green Highway Index. This index also does not consider life
cycle costing in their manual.
Many studies have shown that project cost is the highest ranked factor that determines the success ofthe construction projects. Thus, in order to apply green element in highway development successfully, it isimportant and urgent to undergo the LCC in the assessment.
Besides, Table 1 has been proposed in order to identify the important factors of green highway
which will be used to develop real- time decision making application using LCC. This table will be used in
the design of questionnaire survey form in the phase of data collection.
Table 1. Sample of questionnaire

Management Cost

Contingency Cost / Risks

Demolition

Replacement

Operation

Maintenance / Service

Criteria

Future Cost
Management Cost

ID

Construction cost (Installation)

Life Cycle
Costing

Capital

Initial Cost

Cost Item

5. CONCLUSION
From extensive literature review, the importance of the LCC application to highway project has
been addressed. A sample of table of measurable variables (cost item) of energy efficiency in green highway
index was formulated, as presented in Table 1. The format of the table will be used to identify the importantfactors (cost items) of green highway which have significant contribution towards the establishment of realtime decision making application using LCC. Finally, the results of the questionnaire will be analyzed andwill lead to the addition of LCCA in the Green Highway Design Manual as shown in research framework(see Figure 1).

322

Figure 1. Research Framework
6. ACKNOWLEDGEMENTS
The authors wish to acknowledge the financial support provided by Ministry of Education (MOE)and Universiti Teknologi Malaysia (UTM), Research University Grant (RUG); Q.J130000.2522.4F680 for
supporting the financial for research works.
REFERENCES
Bayraktar, M. E. (2006). A decision model to determine the optimal time-cost tradeoff in highway work zone
projects. Purdue University.
Barraza, G.A., Back, E., and Mata, F. (2000) “Probabilistic monitoring of project performance using SScurves” Journal of Construction Engineering and Management. ASCE. Vol. 126(2), 142-148.
Chang, A. S. (2001). “Defining cost-schedule performance indices and their ranges for design projects.”
Journal of Management in Engineering. ASCE, Vol. 17(2), 122-130.
Dunston, P.S., and Reed, A.G. (2000). ‘‘Benefits of small projects team initiative.’’ J. Constr. Eng. Manage.,126(1), 22–28.
Gao Z. L., Smith G. R., and Minchin, R., E. (2002). “Budget and schedule success for small capital-facility
projects.” Journal of Management in Engineering,18(4), 186-193.
Hastak, M., Halpin, D.W., and Vanegas, J. (1996). “COMPASS – New paradigm for project cost control
strategy and planning.” Journal of Construction Engineering and Management. ASCE. Vol. 122, No. 3, 254264.
Harvard University Graduate School of Design and the Institute for Sustainable Infrastructure. 2012. A
Rating System for Sustainable Infrastructure. EnvisionTM Guidance Manual. USA .Version 2.
Illinois Department of Transportation (2010). Illinois-Livable and Sustainable Transportation. I-LAST Rating
System and Guide. Version 1.0.
Lee, J., Edil, T. B., Benson, C. H., &Tinjum, J. M. (2010). Use of BE2ST in-Highways for Green Highway
Construction Rating in Wisconsin.InProc., 1stT&DI Green Streets and Highway Conference.
New York State Department of Transportation (2010). Green Leadership in Transportation andEnvironmental Sustainability. GreenLITES Project Design Certification Program. New York. Version 2.1.0.

323

Tatari, O., & Kucukvar, M. (2011). Cost premium prediction of certified green buildings: A neural network
approach. Building and Environment, 46(5), 1081–1086. doi:10.1016/j.buildenv.2010.11.009
The North American Sustainable Transportation Council (2010). Sustainable Transportation Access Rating
System.
University of Washington (2011). Greenroads Abridged Manual. Washington. Greenroads Manual. Version
1.5.
U. S. Department of Transportation, Federal Highway Administration (2012). Infrastructure Voluntary
Evaluation Sustainability Tool.
UTM-LLM. (2014). Manual Malaysia Green Highway Index (MyGHI).
Walls III, J., & Smith, M. R. (1998). Life-cycle cost analysis in pavement design interim technical bulletin.
Weir,L.
(2015).
Spearman’s
correlation,
http://www.statstutor.ac.uk/resources/uploaded/spearmans.pdf

retrieved

on

13/7,

from:

Yudelson, J. (2008a). Marketing Green Building Services: Strategies for Success. Routledge.
Yudelson, J. (2010b). What Is a Green Building? Sustainable Retail Development, 41– 65.Risk Analysis andSimulation Add-In for Microsoft Excel ®, 2013, Palisade Corporation.

324

2nd IRF Asia Regional Congress Abstract Submission
October 16-20 2016
Kuala Lumpur, Malaysia

PAPER TITLE(90 Characters Max)APPLICATION OF MICRO-SURFACING SYSTEM –PLUS Experience along North South Expressway (NSE)

TRACK
AUTHOR(Capitalize Family
Name)

POSITIONORGANIZATIONCOUNTRYABDUL RAHIM
Mohd Shafie

Region Manager

Opus International (M) Sdn
Bhd

Malaysia

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Ir ZULKHAIRI Hasan

Project Director

Opus International (M) Sdn
Bhd

Malaysia

E-MAIL(for correspondence)arahim.mshafie@opusbhd.uemnet.com

KEYWORDS: Micro-surfacing, Distresses, QA/QC

ABSTRACT:Micro-surfacing is a polymer modified cold-applied paving system and it has been used as one of thepreventive maintenance options to the pavement along the North South Expressway (NSE) since1993.
For the past 10 years, micro surfacing has been widely used by Highway Concessions in Malaysia andits use has increased significantly especially in southern part of the NSE.
Project selection in determining suitable candidate is critical as the main use of micro-surfacing
materials is for pavement preservation before distresses appear. The main criteria for project selection
are sound and well drained bases, surface and shoulder. Any localized defects must be repaired before
application of micro-surfacing.
Findings from the micro-surfacing during construction indicated that the equipment, materials,
application conditions, skill operators and safety as well as traffic control are the most importantfactors contributed to the success of the micro-surfacing work. A strict QA/QC is important to guide
project personnel on the important aspects of micro-surfacing.

325

INTRODUCTION
Micro Surfacing is a mixture of asphalt emulsion, graded crushed mineral aggregate, mineral filler, water andother additives. The mixture is made and applied to existing pavement by specialized application machinethat carry all necessary components, mixed them on site, and spread the mixture onto the road surface
through an agitated spreader box. The typical mixing order is aggregate followed by cement, water, additive
and the emulsion.

Figure 1. Schematic of a Micro-Surfacing machine

Micro surfacing is a thin surfacing and does not add any structural capacity to an existing pavement. Primary
use of micro surfacing is to prevent future road surface distress in good pavement and as a corrective action
in older and ageing pavement. Typically, it offers alternative option to prevent and/or reduce
ageing/oxidation of asphalt, infiltration of surface runoff besides addressing surface raveling, weathering andloss of friction properties as well as provide better aesthetic view of overall completed section.
The completed micro surfacing works though proper quality control and correct selection of the materials
will give the following results: Increased stability at high temperature; Maximum, long lasting skid resistance; and Resistance against deformation, bleeding and raveling.

History
The use of a micro surfacing along the North South Expressway (NSE) was first introduced in year 1993
between KM23.00 and KM21.00 of the Senai Johor Bahru Highway. The two lanes dual carriageway was
overlaid using micro surfacing system, operated by the local contractor i.e ACP-DMT Sdn Bhd, based on
proven German technology.
Since completion of the first location, micro surfacing has been widely considered in the road maintenanceoption as it offers a cost-effective maintenance technique in addressing a broad range of common pavement
surfacing problems. In addition, availability of well- trained operator equipped with special machine allow
better implementation with minimal amount of inconvenience to the Engineer and road users.

326

Table 1 indicated the yearly consumption and coverage of micro surfacing system along the NSE for the pastten years. Increasing of the usage were recorded with the highest consumption was in year 2008 where morethan six hundred thousand square meter areas were applied along the NSE.
Table 1. Yearly Consumption of a Micro-Surfacing from 2006 to 2015

Year
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015

Quantity (sq.m)
32,660.00
58,730.00
628,489.00
599,876.50
255,095.00
Nil
253,024.00
238,318.00
478,397.00
442,893.00

Project Selection
Selection of project location is critical as the primary use of micro surfacing is for pavement preservation.
Generally, pre-treatment such as pothole patching and localized mill and pave are required to address
localized surface distress before application of micro-surfacing. Micro surfacing has been used along themainline of the NSE on the slow lane, fast lane and emergency lane but not on the slip road and toll plaza
areas.
Distress mode that can be addressed using micro surfacing include raveling, hairline cracks, polishedasphalt/concrete surface, as well as low skid resistance. However, micro-surfacing may not be suitable toaddress rutting, cracking or any kind of pavement base failures.

Construction Process
The construction process shall include the following components:







Traffic Management and Safety
Equipment
Stockpile
Surface preparation
Application
Quality issues
Post construction

Traffic Management and Safety
Traffic management is necessary for both safety of road users and the workers performing the work. Traffic
management control comprising construction signs, construction cones, and flagman should be in place
before entry into work zone. Traffic management requirements shall comply with the Client’s standard
requirement.
Traffic management control is also required to ensure adequate time of micro surfacing to cure priorreopening to traffic. The curing time for micro surfacing will vary depending on the weather condition andpavement surface conditions at the time of application.

327

Equipment
All equipment, tools and machine used shall be maintained in satisfactory condition at all times to ensure ahigh quality product. The machine must have sufficient storage capacity for aggregate, emulsion, mineral
filler, additive and water to maintain adequacy supply to the proportioning controls.
The mixture will be spread uniformly by means of a conventional augured surfacing spreader box attached tothe mixer.
Stockpile
Stockpile should be as close as possible to the construction site to ensure operation run as smoothly as
possible and provide good traffic flow through the construction area. In normal cases, area at the nearest toll
plaza or layby will be selected as a stockpile area.

Surface preparation
The area to be covered with micro surfacing shall be thoroughly cleaned from loose material, vegetation, silt
spot and other objectionable materials. Area with base failure must be rectified accordingly. Thermoplastic
road markings must also be removed prior to placing a micro surfacing.

Application
Micro surfacing is produced and placed by a purpose-design machine, which carries all the material
components. The machine will proportion these components on a continuous basis and applies it onto theroad surface through an agitated spreader box. A sufficient amount of material shall be carried in all parts ofthe spreader box at all times so that a complete coverage is obtained.

Quality issues
Quality control is very important during construction to achieve a uniform surface finish and ensure
successful of the work. The main areas of concerned are:1.
2.
3.
4.
5.

Longitudinal Joints
Transverse Joints
Excessive binder
Dragging line
Damaged due to early opening to traffic and raining

328

The longitudinal joint should be straight or curve with the traffic lane and overlaps should not be inwheel paths. Construction of longitudinal joints along the acceleration and deceleration lanes
approaching interchanges should be done carefully and must be butt joints. Overlaps should be kept
to a minimum to control free flow of surface water. Figure 2a and 2b indicates good quality andpoor quality of joints.

Figure 2a. Good quality longitudinal joint.

Figure 2b. Longitudinal joint on wheel path and excessive binder on joint.

329

Transverse joints are unavoidable as every time a truck is emptied a transverse joint is required.
Transitions at these joint is critical and must be smooth to avoid creating bump in the surface. The
main difficulty in obtaining a smooth joint occurs as the micro surfacing that is difficult to work byhand and breaks quickly. In some cases, excessive binder occurs at the joint as the contractor tend toover wet the mix. The operator shall be well trained and experienced in handling and getting used tothe application machine. Figure 3a and 3b indicates good quality and poor quality transverse joints.

Figure 3a. Good quality transverse joint

Figure 3b. Poor quality transverse joint

330

Excessive binder may occur due to poorly designed micro surfacing mixture or mix with too highwater content. This leads to a black and flush looking of completed surface with poor texture. Figure
4a and 4b indicates good and poor surface texture.

Figure 4a. Good surface texture

Figure 4b. Poor surface texture331

Dragging line on the micro surfacing occurs due to presence of oversize aggregate or could be due
to improper cleaning of spreader box. Therefore, spreader box must be cleaned properly before
starting of works and all new delivery of aggregate must be tested to comply with the requirements.
Figure 5 indicates dragging line on completed micro surfacing.

Figure 5. Dragging line on micro surfacing surface.

Heavy rain coupled with heavy traffic will likely lead to surface damaged especially on climbing
location. However, light rain 2 or 3 hours after placing of micro surfacing seems acceptable. In
some cases, sudden increase of traffic volume caused traffic congestion, thus require the lanes toreopen early and will also damage the newly laid micro surfacing. Figure 6 indicates raveling causedby rain and early opening to traffics.

Figure 6. Ravel off micro surfacing surface

332

Conclusion
Micro surfacing offers a cost effective technique in pavement maintenance options. It suitable to prevent
and/or reduce ageing/oxidation of asphalt, infiltration of surface runoff besides addressing surface raveling,
weathering and loss of friction properties.
Findings from the micro-surfacing during construction indicated that the equipment, materials, application
conditions, skill operators and safety as well as traffic control are the most important factors contributed tothe success of the micro-surfacing work.

333

REFERENCES
1.

Opus International (M) Berhad (2016), Work Order Database Report on Pavement Repair Worksfrom 2006 to 2015.

2.

PROJEK LEBUHRAYA USAHASAMA (PLUS) BERHAD (2015), Work Order Document for
Proposed Pavement Rehabilitation, Resurfacing Using Micro-Surfacing System And AssociatedWorks From Km172.00 To Km175.75 North Bound, Section S2, North South Expressway

3.

ASPHALT INOVATION SDN BHD (2016), Post Mortem Report on Completed Micro Surfacing
Works Between Tangkak to Ayer Keroh.

4.

ACP-DMT SDN BHD (2008), Micro Surfacing – Pamphlet

5.

Jabatan Kerja Raya Malaysia (2008), JKR/SPJ/2008 section 4.13 Surface Treatment 2 – Micro
Surfacing334

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Engineering Properties of PAC Thin Surfacing for Pavement Rehabilitation

TRACK
AUTHOR(Capitalize Family Name)
LIAO, Min-Chih

CO-AUTHOR(S)(Capitalize Family Name
LIN, Yen-Yu
E-MAIL(for correspondence)

POSITION
Assistant Professor

ORGANIZATION
National Taiwan Universityof Science and Technology

POSITION
Project Manager

ORGANIZATION
Sinotech Engineering
Consultants Ltd.

COUNTRY
TaiwanCOUNTRY
Taiwanminchih.liao@mail.ntust.edu.tw

KEYWORDS:
Porous asphalt concrete; Thin asphalt overlay

ABSTRACT:
Thin asphalt overlays have been used in mill-fill operations to surface badly cracked pavements simply because funding
may not be available to add additional structure. With respect to the limitation of lift thickness and minimizing closures
to traffic, the porous asphalt concrete (PAC) thin layer could be more durable and economical than dense-graded layers
in terms of the engineering properties and functionality. However, concerns are raised regarding the effect of aggregate
size on mechanical properties and performance of the PAC materials for thin overlays. The objective of thisinvestigation is to have a better understanding of the use of PAC thin overlays for asphalt pavement rehabilitation. This
will be accomplished by conducting a series of experimental works. Test results showed that the aged PAC mixtures
were found to have the better performance in tensile strength and rutting resistance as compared to the unaged PACs,
but the aging had the detrimental influence on the raveling resistance and moisture susceptibility. The long-term aging
procedure led to a considerable reduction in tensile strength ratio for the PAC mixtures irrespective of binder type andgradation. In addition, the values of resilient modulus and tensile strength for the fine-graded PACs appeared to behigher than those for the coarser graded PAC mixture. Based on the results obtained from the wheel track testing, theuse of premium asphalt enhanced the cohesive strength and adhesion, thereby reducing the proportional rut depth of
PAC. In terms of the overall performance evaluation, the fine-graded PAC with the highly modified asphalt binder canbe used without compromising engineering properties.

335

Engineering Properties of PAC Thin Surfacing for
Pavement Rehabilitation
Dr Min-Chih Liao1
Dr Yen-Yu Lin2
1

The National Taiwan University of Science and Technology, Taipei, Taiwan
minchih.liao@mail.ntust.edu.tw
2

Sinotech Engineering Consultants Ltd., Taipei, Taiwan

1 INTRODUCTION
Asphalt thin layer has been utilized in mill-fill operations to resurface badly distressed pavements simply
because funding may not be available to add additional structure. With respect to the limitation of lift thickness andminimizing closures to traffic, the porous asphalt concrete (PAC) thin layer could be a viable option for the high-speed
surface layer rehabilitation. The use of PAC with fine gradation is desirable owing to the potential to be placed thinnerand smoother layers. Although the PAC with a nominal maximum aggregate size (NMAS) of 19 mm has gained
acceptance after a couple of research study and filed validation in Taiwan [Coleri et al., 2013; Moriyoshi et al., 2014;
Putman and Kline, 2012], the engineering properties of finer gradation PAC are not know in great detail. In addition,
the large portion of void contents would result in an increased potential for accelerating aging. Rapid oxidation of theasphalt binder films has an adverse impact on the cohesion and adhesion within the PAC mixtures [Mo et al., 2009; Mo
et al., 2010; Molenaar et al., 2010].
In comparison with conventional dense graded asphalt concrete, the PAC differs from contains insufficient
fines to fill all of the voids between the coarse aggregate particles. The air void content, ranging between 15 and 25
percent of the volume of an asphalt mixture, are designed to be interconnected, allowing the surface water drain
vertically down to an impermeable layer. The water then travels laterally to the exposed edges of the PAC surface
course. PAC also provides a highly skid resistance, reduces headlight glare and absorbs tire noise because of having amacrotexture on the pavement surface. The void content would affect the stone-on-stone contact structure andmechanical properties of PACs [Alvarez et al., 2010; Alvarez et al., 2011a; Alvarez et al., 2011b]. It was known thatusing device such as Corelock® to conduct the bulk density analysis. The dimensional analysis method was also
recommended to compute the densities of the compacted mixtures and corresponding total air void content to obtainrepresentative void content [Alvarez et al., 2009].
Due to the relatively lager amount of air voids, the PAC is designed to possess the stone-on-stone contact inorder to offer a stable surface course structure. To quantify the stone-on-stone contact achieved in the mixtures, themaximum value of the voids in coarse aggregate (VCA) ratio of 0.9 was recommended to ensure adequate mixture
durability. The VCA ratio compares the VCA of compacted mix (VCAmix) to the VCA of the coarse aggregate fractionin the dry-rodded condition (VCADRC) to evaluate the existence of stone-on-stone contact [Alvarez et al., 2010b]. In
addition to the issue regarding aggregate skeleton of porous mixtures, the Cantabro abrasion test was suggested to be
useful for selecting material combinations and determining the optimum asphalt content [Alvarez et al., 2010c]. The
proper asphalt grade and asphalt content are also selected to have desired sufficient film thickness of asphalt binder inorder to provide good durability.
A number of studies related to PAC materials have been made over the past few years. Generally, finer
mixtures had higher indirect tensile strength and better moisture resistance because the aggregate particles packed moreclosely together, while the coarser gradation had lower rut depth [Xiao et al., 2015; Mansour and Putman 2013]. The
aggregate gradation also had significant effect on the porosity of the aggregate structure, which in turn controlled themacro texture and permeability of the porous asphalt mixtures [Martin et al., 2014]. Additionally, there had a few
studies regarding the re-use of reclaimed materials added in virgin porous asphalt mixtures. Basically, these results
showed that the mechanical properties and performance of the recycled porous asphalt mixtures were similar or better
compared with the virgin open-graded asphalt mixtures in some cases [Chen and Wong 2015; Frigio et al., 2013; Frigio
et al., 2015; Goh and You 2012].

336

Most research into porous asphalt mixtures has focused attention on mix design and mechanical properties.
Little research is conducted on characterizing the aging on the engineering properties of porous asphalt concretematerials over a period of time. The primary objective of this investigation was to:characterize the stiffness of PAC,
determine the resistance to ravelling of PAC,
assess the resistance to rutting of PACs, andevaluate the moisture susceptibility of PAC.

2 MATERIALS AND METHODS
2.1 Materials
The experimental design included the use of three types of asphalt binders as shown in Table 1. The
unmodified binder (UA) had a penetration value of 48. The two polymer modified binders were prepared using theproper content of SBS to achieve the desired viscosity requirements in accordance with the Public Construction
Commission (2010). The SBS was slowly added into the heated base asphalt at 170 oC and blended with a high-shear
asphalt mixer at 3000 rpm for 60 minutes. It is noted that the modified asphalt (MA) contained 5% SBS polymer of
60/70 penetration grade asphalt (base asphalt), while the highly modified asphalt (HA) contained 12% SBS polymer ofthe same base asphalt. The viscosity values of each asphalt binder at unaged and aged conditions were measured using a
Brookfield viscometer. The aging procedure was conducted on the asphalt binders by means of the thin film oven test
(TFOT) over the aging periods.
One source of limestone aggregate and ordinary Portland cement were used for the aggregate and mineral filler,
respectively. The basic properties of the limestone aggregate are tabulated in Table 2.
Table 1. Properties of asphalt binders

Properties
Penetration @ 25oC (dmm)
Viscosity @ 60oC (fresh) (Pa·s)
Viscosity @ 60oC (aged for 4 Hrs) (Pa·s)
Viscosity @ 60oC (aged for 48 Hrs) (Pa·s)
Viscosity @ 60oC (aged for 96 Hrs) (Pa·s)
Modification

UA
48
368
568
917
1,034
Unmodified

Asphalt Binders
MA
55
1,410
2,055
2,855
3,320
Modified

HA
50
48,00059,50083,500100,000
Highlymodified

Table 2. Properties of aggregate

Property
LA abrasion value (%)
Flat and elongated 1:3 (%)
Flat and elongated 1:5 (%)
Absorption (%)
Soundness (%)
One broken surface (%)
Two broken surfaces (%)
Sand equivalent value (%)

Coarse aggregate
19.7
6.4
2.1
1.0
5.7
100
97.3
-

Fine aggregate
1.5
3.1
81

2.2 Mix Design
The mixture design was performed in accordance with the Public Construction Commission (2010) for the two
distinct gradations. The coarse aggregate gradation had a NMAS of 19 mm, while the NMAS of 12.5 mm was selected
for the fine aggregate gradation. Both coarse and fine aggregate gradations had the same break-point (BP) sieve of 2.36
mm. A target air void content of 20% was selected for manufacturing the PAC specimens. The two types of gradations
are shown in Table 3.

337

Table 3. Design gradation and specification
Sieve Size
(mm)
25
19
12.5
9.5
4.75
2.36
1.18
0.600
0.300
0.150
0.075

19 mm Gradation
(%)
100
95
64
38
18
10
8
7
6
5
4

19 mm Spec.
(%)
100
95-100
64-84
10-31
10-20
3-7

12.5 mm Gradation
(%)
100
100
95
59
23
14
13
11
8
5
3

12.5 mm Spec.
(%)
100
100
90-100
11-35
10-20
3-7

The job mix formula was determined by conducting traditional Marshall mixture design method. The
allowable asphalt content range was determined according to the results of the Cantabro abrasion and asphalt
draindown tests. The various properties of mixtures at the optimum asphalt contents complied with the specification.
The PAC specimens were then fabricated at optimum asphalt content for further mechanical testing as required. Table 4shows the designations and various properties of the PAC mixtures.

Table 4. Results of PAC mixture design
Mix Designation
NMAS (%)
Stability (kgf)
Flow (mm)Cantabro weight loss (%)
Draindown (%)
Optimum asphalt content (%)
Void content

19/UA
19
508
2.5
19.1
0.008
5.1
20

12.5/UA
12.5
658
3.5
16.1
0.037
5.0
18

12.5/MA
12.5
651
3.3
11.9
0.020
5.0
18.5

12.5/HA
12.5
741
3.8
8.1
0.016
5.0
19

2.3 Preparation of PAC Mixtures
For the preparation of the PAC, the aggregate mix was heated and then the asphalt binder was added to the mix
to provide workability. To ensure that the aggregate was properly coated, the determination of mixing temperature wasdependent on the viscosity of the asphalt binders. The mixing temperatures were selected to be 152oC, 158oC and 166oC for the PAC with UA, MA and HA binders, respectively. The mixing time was 60 seconds.
In order to simulate the mixing process in the plant and filed construction effects on the PAC, the 4-hour aging
procedure was performed on loose mixture in accordance with AASHTO R30. The loose mixture was placed to an eventhickness ranging between 25 and 50 mm in a pan, followed by being conditioned in a forced-draft oven for 4 hours at
135oC. The loose mixture after the short-term condition was then removed from the oven for compaction.
A compaction effort of 50 blows was applied on each side at compaction temperatures for the PACs. The
compaction temperatures, depending on the viscosity of the asphalt binders, were selected to be 148oC, 154oC and 163oC for the PAC with UA, MA and HA binders, respectively.
After the compaction effort, the specimens were allowed to cool at room for 24 hours prior to being extruded
from molds. After extruding the specimens from the compaction molds, the compacted specimens were allowed to coolat room temperature for 16 hours before being subjected to the long-term aging process. The long-term aging procedure
was then applied to compacted PAC that had been subjected to the short-term conditioning according to AASHTO R30.
A compacted mixture of aggregate and asphalt binder was conditioned at 85oC in a forced-draft oven for 48 or 96 hours
in order for simulating the aging that occurred over the service life of a PAC pavement.
2.4 Test Methods
2.4.1 Resilient Modulus Test

338

The resilient modulus (MR) test was conducted at 25oC to evaluate the stiffness modulus of the PAC mixturesin accordance with ASTM D7369. The load was applied for 0.1 seconds along with a rest period of 0.9 seconds. The
Poisson’s ratio was assumed to be 0.35. The equation derived to calculate the M R is listed as:
𝑀𝑅 =

𝑃
𝐻𝑡

(0.27 + 𝜇)(1)

where MR is the resilient modulus (MPa), P is the repeated load (N), H is the horizontal deformation (mm), t is the
specimen thickness (mm) and μ is the Poisson’s ratio.
2.4.2 Cantabro Abrasion Test
The Cantabro abrasion test was performed at 25 oC to evaluate the resistance to raveling of the PAC mixtures.
The compacted PAC specimen was placed in a Los Angeles machine without the charge of steel balls. The Los Angeles
machine was operated for 300 revolutions at 30 rpm. The percentage of weight loss during this abrasion process wasused to represent the raveling resistance of the PACs. The percentage of weight loss is shown as:
mass loss (%) =𝑖𝑛𝑖𝑡𝑖𝑎𝑙 𝑠𝑝𝑒𝑐𝑖𝑚𝑒𝑛 𝑤𝑒𝑖𝑔ℎ𝑡(𝑔)−𝑓𝑖𝑛𝑎𝑙 𝑠𝑝𝑒𝑐𝑖𝑚𝑒𝑛 𝑤𝑒𝑖𝑔ℎ𝑡(𝑔)𝑖𝑛𝑖𝑡𝑖𝑎𝑙 𝑠𝑝𝑒𝑐𝑖𝑚𝑒𝑛 𝑤𝑒𝑖𝑔ℎ𝑡(𝑔)

× 100

(2)

2.4.3 Wheel Tracking Test
The wheel tracking test was conducted at 60oC in a temperature controlled chamber to evaluate the resistanceto permanent deformation of the PACs. The compacted PAC slab, housed in a 300 by 300 by 50-mm deep steel mold,
was trafficked by a solid steel wheel at a frequency of 42 passes per minute under a loading pressure of 700 kPa for 1
hour. The vertical deformation induced at the middle of the specimen was recorded. In accordance with BS EN 1269722, the deformation parameter of proportional rut depth was used to characterize the rutting resistance of the PACs, as
shown in the following equation:
Proportional Rut Depth (%) =𝑇𝑜𝑝 𝑠𝑢𝑟𝑓𝑎𝑐𝑒 𝑠𝑒𝑡𝑡𝑙𝑒𝑚𝑒𝑛𝑡 (𝑚𝑚)𝑇𝑜𝑡𝑎𝑙 𝑡ℎ𝑖𝑐𝑘𝑛𝑒𝑠𝑠 𝑎𝑠𝑝ℎ𝑎𝑙𝑡 𝑚𝑖𝑥𝑡𝑢𝑟𝑒 𝑠𝑙𝑎𝑏 (𝑚𝑚)

× 100

(3)

2.4.4 Indirect Tensile Test
The indirect tensile (IDT) test was used to evaluate the strength of the PACs in accordance with ASTM D6931[30]. The test was conducted on the PAC specimen at a deformation rate of 50.8 mm/minute and a temperature of 25 oC.
The equation for the indirect tensile strength at failure is provided as:
𝑆𝑡 =

2000𝑃

(4)

𝜋𝑡𝐷

where St is tensile strength (kPa), p is maximum load (N), t is thickness of the specimen (mm) and D is diameter of thespecimen (mm).
To evaluate moisture susceptibility of PACs, the tensile strength was measured before and after waterconditioning of specimens. The tensile strength ratio was defined as the retained tensile strength as a percent of theoriginal tensile strength.

3 RESULTS AND DISCUSSION
3.1 Stiffness of PAC Mixtures
The test results of the resilient modulus testing for the PAC mixtures are given in Figure 1. The MR values
showed an increase as the aging period increases, reflecting that given repeated loads resulted in lower strain for theaged PACs. For the fine PAC mixtures (NMAS 12.5 mm), the deviations are a result of different asphalt binders. The
12.5/HA had the higher MR. The 12.5/HA can carry and transfer loads efficiently compared to the other PACs. The
12.5/MA and 12.5/UA showed a little difference in stiffness modulus although the viscosity of the modified asphalt was
higher than that of the unmodified asphalt. The fact can be interpreted that the highly modified asphalt binder canincrease the MR of the PAC. With respect to the aggregate size on the stiffness modulus of PACs, the MR value for the339

12.5/UA appeared to be slightly higher than that for the 19/UA. The finer aggregate gradation was more cohesive due toslightly lower air void, as compared with the coarser aggregate gradation. M R is generally a function of the asphalt
binder properties in an asphalt mixture and this value can be increase with a stiffer binder. A higher resilient modulus
indicates that a given applied load results in lower horizontal strain in the mix.

Figure 1. Resilient modulus for PAC mixtures with increasing aging periods.
3.2 Resistance to Reveling of PAC Mixtures
The test results of Cantabro abrasion testing for the PAC mixtures are shown in Figure 2. The results indicatethat abrasion resistance was influenced by the gradation. The 19/UA had higher abrasion loss compared to the otherfine-graded mixes, reflecting the coarser gradation had the susceptibility to raveling. An increase in abrasion loss in thecoarser gradation when compared to the finer gradation was caused by the reduction in cohesion and adhesion within
the coarser mixture. In addition, the Cantabro loss results showed that the percentage of weight loss increased withincreasing the aging period. The aged PACs showed worse performance in resisting disintegration, indicating theweaker bonding between aggregate particles. The server disintegration for the long-term aged PAC specimens wascaused by the oxidation of the asphalt binder. The movements of aggregate particles, caused by the abrasive action,
developed sufficient tensile stress and strain which exceeded the cohesive strength of the mixes. The 12.5/HA had theleast weight loss, followed by the 12.5/MA and 12.5/UA. The use of highly modified asphalt binder resulted in a
reduction in percentage of the loss weight. It can be inferred that the asphalt binder with higher viscosity appears tocontribute to the cohesion and enhance the resistance to raveling for the PACs.

Figure 2. Cantabro abrasion resistance for PAC mixtures with increasing aging periods.

3.3 Resistance to Rutting of PAC Mixtures
The results of rut depth obtained from wheel track testing for each PAC mix are exhibited in Figure 3. The
19/UA had the smaller proportional rut depth as compared with the 12.5/UA. It is interesting to note that the 2-day and4-day aging PAC mixtures for the 19/UA had the better performance in rutting resistance as compared to those for the
12.5/MA. It can be inferred that the use of coarse aggregate can improve the deformation resistance for the PAC if theasphalt viscosity was not high. When the highly modified asphalt binder was used, the proportional rut depth for thefiner graded PAC was smaller than that for the coarser graded PAC. It can be interpreted that the finer graded PAC withhighly modified asphalt has the potential of better resistance to rutting as compared to the coarser graded PAC with the340unmodified asphalt. In addition, the proportional rut depth for the PAC mixtures reduced with increasing aging period.
The best performance in rutting was observed for the 4-day aging PAC mixes. For the finer gradation, the 12.5/HA wasresistant to the permanent deformation, followed by the 12.5/MA and 12.5/UA. It reflected the asphalt binder withhigher viscosity can improve the rutting resistance. Although the aggregate interlocking for the PAC is designed to havecapacity to resist rutting, the binder viscosity can contribute to the cohesion, thereby enhancing resistance todeformation.

Figure 3. Rutting resistance for PAC mixtures with increasing aging periods.

3.4 Resistance to Moisture Susceptibility of PAC Mixtures
The test results of the indirect tensile strength for each PAC mix are presented in Figure 4. The 12.5/UA
exhibited the better performance in strength as compared to the 19/UA. It demonstrated the cohesion for the finer
graded PAC is higher than that for the coarser graded PAC. It also can be interpret that the fine-graded PAC mix had
higher tensile strength because its particles packed more closely together than the coarse-graded PAC mix. The coarser
gradation was more susceptible to breaking. In addition, there was an increase in indirect tensile strength withincreasing the aging period. It indicated that the indirect tensile strength was influenced by aging of the mix. It alsoinferred that the rapid oxidation of the asphalt binder film significantly increased the indirect tensile strength of thecompacted PAC mixtures. The long-term aging results in an increase in the tensile strength for the PACs. Among the
NMAS 12.5 mm PAC mixes, the 12.5/HA was found to have the best performance in the indirect tensile strength test. It
is noted that due to the percentage of air void in PAC being much higher than in dense graded asphalt concrete, thePAC generally has less support from surrounding particles and thus has relatively lower strength compared to the dense
graded asphalt mixture. Using the highly modified binder appears to enhance the adhesion between aggregate particles
within the PAC mixes, thereby improving the indirect tensile strength values.

Figure 4. Indirect tensile strength for PAC mixtures with increasing aging periods.
The moisture susceptibility for the PAC mixtures in terms of the tensile strength ratio (TSR) is depicted in
Figure 5. In regard to the aggregate size effect on the moisture-induced damage, it is found that a little difference in
TSR between 19/UA and 12.5/UA. The finer aggregate gradation was shown to improve moisture susceptibility of PAC
mixture. In addition, it can be seen that the TSR value decreased with increasing the aging period, reflecting the aged
PAC mixture was susceptible to moisture-induced damage. The 12.5/HA had the highest TSR value among the341

mixtures. This could be attributed to the use of highly modified asphalt binder, improving the resistance to moisturesensitivity. The long-term aged PAC mixtures were found to have a reduction in TSR value. This is due to the open
nature of PAC mix which caused the rapid oxidation of asphalt binder together with the water retention in the voids.

Figure 5. Tensile strength ratio for PAC mixtures with increasing aging periods.

4 CONCLUSIONSThis paper characterizes the influence of aging on the stiffness modulus, resistance to raveling,rutting resistance and moisture susceptibility of the PACs. It should be noted that the results of the laboratory
tests described in this paper are confined to the material combinations, test procedures and equipment used inthis study. The following conclusions based on test results can be drawn:
The values of resilient modulus for the finer graded PAC appeared to be higher than that for thecoarse graded PAC. The PAC with highly modified asphalt binder can increase the MR of the
PAC, thereby carrying and transferring loads efficiently.

The coarse-graded PAC mixtures reflected the susceptibility to raveling. The use of highly
modified asphalt binder appeared to contribute the cohesion and adhesion, thereby enhancing theraveling resistance for the PACs.

The long-term aged PAC mixtures were found to have a considerably reduction in TSR value forthe four types of the mixes. The fine-graded PACs was found to have better resistance tomoisture-induced damage.

The wheel tracking test results indicated that the finer gradation with the highly modified asphalt
binder can improve the resistance to rutting for the PACs.

In terms of the overall laboratory evaluation, the finer gradation PAC with the highly modified asphalt is a
viable option without compromising engineering properties

5 ACKNOWLEDGEMENTS
The authors are grateful for the Ministry of Science and Technology (MOST 104-2218-E-011-019) and National
Taiwan University of Science and Technology (Taiwan Tech) providing financial supports to complete thisinvestigation.

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Coleri, E., Harvey, J.T., Yang, K. and Boone, J.M. (2013). Micromechanical investigation of open-graded asphalt
friction courses’ rutting mechanisms. Construction and Building Materials, Vol. 44, pp. 25-34.
Frigio, F., Pasquini, E., Ferrotti, G. and Canestrari, F. (2013). Improved durability of recycled porous asphalt.
Construction and Building Materials, Vol. 48, pp. 755-763.
Frigio, F., Pasquini, E., Partl, M.N. and Canestrari, F. (2015). Use of reclaimed asphalt in porous asphalt mixtures:
laboratory and field evaluations. Journal of Materials in Civil Engineering, Vol. 27, No. 7.
Goh, S.W, and You Z. (2012). Mechanical properties of porous asphalt pavement materials with warm mix asphalt and
RAP. Journal of Transportation Engineering., Vol. 138, No. 1, pp. 90-97.
Mansour, T.N. and Putman, B.J. (2013). Influence of aggregate gradation on the performance properties of porous
asphalt mixtures. Journal of Materials in Civil Engineering, Vol. 25, No.2, pp. 281-288.
Martin, W.D., Putman, B.J. and Neptune, A.I. (2014). Influence of aggregate gradation on clogging characteristics ofporous asphalt mixtures. Journal of Materials in Civil Engineering, Vol. 26, No. 7.
Mo, L., Huurman, M., Wu, S. and Molenaar, A.A.A. (2009). Raveling investigation of porous asphalt concrete based on
fatigue characteristics of bitumen-stone adhesion and mortar. Materials and Design., Vol. 30, pp. 170-179.
Mo, L., Huurman, M., Woldekidan, M.F., Wu, S. and Molenaar, A.A.A. (2010). Investigation into material
optimization and development for improved raveling resistant porous asphalt concrete. Materials and Design., Vol.
31, pp. 3194-3206.
Molenaar, A.A.A., Hagos, E.T. and van de Ven, M.F.C. (2010). Effects of aging on the mechanical characteristics ofbituminous binders in PAC. Journal of Materials in Civil Engineering, Vol. 22, No. 8, pp. 779-87.
Moriyoshi, A., Jin, T., Nakai, T., Ishikawa, H., Tokumitsu, K. and Kasahara, A. (2014). Construction and pavement
properties after seven years in porous asphalt with long life,” Construction and Building Materials, Vol.50, pp. 401413.
Public Construction Commission (2010). Porous asphalt concrete pavement, Item 02798, Taipei, Taiwan.
Putman, B.J. and Kline, C.L. (2012). Comparison of mix design methods for porous asphalt mixtures,” Journal of
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343

2nd IRF Asia Regional Congress & Exhibition
October 16‐20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
Naoki Meyama

CO-AUTHOR(S)(Capitalize Family Name

E-MAIL(for correspondence)

STUDY ON CHANGES OF RISK AWARENESS, SAFTYBEHAVIOR AND POSITION IN THE WALK WAY, THROUGH
THE ROAD SAFETY EDUCATION FOR CHILDREN OF PRIMARYSCHOOL AND JUNIOR HIGH SCHOOLROAD SAFETYPOSITION
Associate Professor

POSITIONORGANIZATION
National Institute ofTechnology,
Tokuyama College
ORGANIZATIONCOUNTRYJAPAN

COUNTRY

meyama@tokuyama.ac.jp

KEYWORDS:
school zone
road safety education
walkway
bicycle userquestionnaire survey

ABSTRACT:The purpose of this paper was to provide a road safety education to primary school and junior high school
students. Through questionnaire surveys implemented before and after lectures as well as actual measurement, the study
aimed to grasp the changes in students’ risk awareness, behavioral intention and passing position, and encourage them toobserve proper traffic behavior. The research area was a regional city in Japan, a primary school district in thesuburban residential area of Shunan City. The primary school was Katsuma Primary School and the number of students
was. Most of these students subsequently attend one junior high school, Kumage Junior High School.
From the results of research, following were clarified:
The higher grade students had higher risk awareness of the route to and from school. However, it is often
observed that when they proceeded to junior high school, their risk awareness fell.
The lecture on the seven road safety rules and the five rules for safe bicycle use provided to students of primaryschool and junior high school could make their traffic behavior safer.
Their risk awareness maintained the same level into the next grade year.
To conclude, it was confirmed that in order to encourage compliance with the rules of the road, theimplementation of road safety education to both primary school and junior high school is beneficial.

344

Study on Changes in Risk Awareness, Safety Behavior andPosition in the Walkway, through the Road Safety Education
for Children of Primary School and Junior High School in
Shunan City, JAPANNaoki Meyama1
1

National Institute of Technology, Tokuyama College, Shunan, Yamaguchi, JAPAN
Email meyama@tokuyama.ac.jp

1 INTRODUCTIONIn April 2012, a traffic accident occurred on a prefectural road of Kameoka City, Kyoto where a light car
crashed into rows of students going to primary school together with parents leading them. Ten of them were hit by thecar; three died and seven sustained minor and serious injuries. Since this accident, accidents on the routes to and fromschool have become recognized as a social problem. Therefore security measures on the route to and from school havebeen advanced on a national level.
As the first step, in August 2012, safety inspections of the routes to and from school were implemented
nationwide under the coordination of those concerned with schools, traffic police and road administrators. In July 2013,
the “School Route Safety Measure Advisory” system was institutionalized as a project of the Ministry of Education,
Culture, Sports, Science and Technology, and began its activities by deploying traffic specialists nationwide.
Since July 3013, the author has been appointed a school route safety measure advisor by the Department of
Education of Yamaguchi Prefecture. Since then, the author engaged in instructing proper traffic rules to the students ofprimary schools and junior high school in accordance with road safety education as well as improving traffic space incooperation with road administrators. It is common in Japan that primary school students go to school within walking
distance. Therefore, as a result, they have to share the same traffic space on the road with other pedestrians, bicycles
and cars. A greater percentage of junior high school students tend to commute by bicycle because of a greatercommuting distance from home.
In this research, their changes of risk awareness and behavioral intention on the traffic space for primaryschool students on foot and junior high school students on bicycles while commuting to and from school were discussed.
In particular, this research focused on accidental contracts by pedestrians and bicycles on the routes to and from schools.
The purpose of this paper was to provide a road safety education to primary school and junior high school
students. Through questionnaire surveys implemented before and after lectures as well as actual measurement, the study
aimed to grasp the changes in students’ risk awareness, behavioral intention and passing position, and encourage themto observe proper traffic behavior. The research area was a regional city in Japan, a primary school district in thesuburban residential area of Shunan City. The primary school was Katsuma Primary School and the number of students
was. Most of these students subsequently attend one junior high school, Kumage Junior High School (Figure 3).

Figure 1. Location of Yamaguchi Prefecture

Figure 2. Location of Sunan City in Yamaguchi Pref.

345

The purpose of this section was to provide a road safety education for both Katsuma Primary School andKumage Junior High School sharing the same route to and from school, gasp the changes in students’ awareness andbehavior, and obtain the knowledge necessary to encourage them to observe proper traffic behavior. (Figure 3).

Map ofCommuting Route

KATSUMA ELEMENTARY SCHOOL

North SideSouth SideKUMAGE JUNIOR HIGH SCHOOL

Figure 3. Location of Katsuma Primary School and Kumage Junior High School .

2 PURPOSE OF LECTURE FOR ROAD SAFETY AND MEASURING METHOD OF EFFECTS OF LECTURE

The purpose of this research was to encourage primary school and junior high school students to comply withtraffic regulations and good manners while commuting to and from school through road safety education, and improvetheir traffic behavior.
By grasping the changes of awareness and behaviors concerning road safety through questionnaire surveys,
and by observing changes in children’s passing position through observation survey, the effects of the road safety
education were discussed.
As for the method of research, road safety education was provided to both a primary school and junior highschool in the Katsuma area of Shunan City. The road safety education focused on the improvement of traffic spaces
shared by both the primary school and junior high school. The structure of the survey is shown in Figure 4.

Sellect district
andSchools
BeforeAfter

Questionnaire
Survey↓Lecturefor Road Safety
Education↓
Questionnaire
SurveyBehavioral intention
andPassing position⇔

Obsevation
Survey⇔Obsevation
SurveyFigure 4. Structure of the Survey .

346

3 ABBREVIATIONS AND UNITS
3.1 OBSERVATION SURVEY
The number of pedestrians and bicycles passing through an observation site installed during the commuting
hours for students of primary school and junior high school were counted by a counter for each direction.
At the same time, in order to confirm the passing positions of pedestrians and bicycles, a video shoot of the
walkway was conducted. The changes in passing positions before and after the lecture were examined, and the impactof the road safety education on student behavior was discussed.
iOutline of observation at Katsuma Primary School district (implementation date: May 22)
An observation was conducted at two points from 07:00 to 08:00: spot A（Photograph 1） on a walkway of
National Route 2 and spot B (Photograph 2) on a side strip of a city road (Figure 5).
iiOutline of observation at Kumage Junior High School district (implementation date: June 24)
An observation was conducted at spot C (Photograph 3) from 07:00 to 08:00, as shown Figure 5.

Spot B

Spot C
200m
Figure 5. Location of Observation Survey Spots

Photograph 1. Snap Photo of Spot A

347

Photograph 2. Snap Photo of Spot B

Photograph 3. Snap Photo of Spot C
3.2 QUESTIONNAIRE SURVEY
The pre-questionnaire was conducted two weeks before the lecture was given and the results were aggregated,organized and reflected on the contents of the lecture.
There is the correspondence relationship in the question items between pre- and post-questionnaire.
As the question items were the same as the last two years, the changes in students’ awareness in accordancewith school year progress were confirmed.
3.3 DATE OF LECTURE ON ROAD SAFETYi

June 2, 2015, Shunan City, Katsuma Primary School, 281 students of the third, fourth, fifth and sixth gradesii

June 26, 2014, Shunan City, Kumage Junior High School, all 382 students

4 CHANGES OF AWARENESS AND BEHAVIOR OBSERVED IN THE STUDENTS OF KATSUMA PRIMARYSCHOOL
4.1 CHANGES OF AWARENESS AND BEHAVIOR（from 2013 to 2015)
That reduces the recognize who the safety is, that is, it means that the person who was aware of the danger has
increased. The percentage of the fifth grade students in 2013 who “didn’t think” the route to and from school was safe(or were aware of danger) rose to 33% after the lecture.

348

The percentage of the sixth grade students who were aware of danger in 2014 had remained high at 36% before
the lecture and it rose to 46% after the lecture. However, that of the students of Kumage Junior High School in 2015
from Katsuma Primary School lowered to 17% before the lecture (please see Table 2).
It is considered to be due in part to the students’ awareness being reset when their commuting means changed
from foot to bicycle.
4.2 CHANGE IN ACCORDANCE TO SCHOOL YEAR PROGRESS （from 2013 to 2015)
The fifth grade students in 2013 were good at maintaining risk awareness for three years. However, the sixth
grade students’ risk awareness lowered after the lecture compared to before the lecture. The first grade junior highschool students retained low risk awareness at 13% before the lecture and 20% after the lecture (please see Table 3).
However, the second grade junior high school students kept 19% before the lecture and it can be confirmedthat their risk awareness would be maintained and promoted by repeating the lecture.
Table 2. Question: Do you think about the route to and from school was safe.

answerthink
N/A
did`nt think

5th grade
KATSUMA P.S.
(2013)
before
after
65%
46%
18%
21%
17%
33%

6th grade
KATSUMA P.S.
(2014)
before
after
43%
38%
21%
16%
36%
46%

1st grade
KUMAGE J.H.S(2015)
before
after
48%
36%
35%
27%
17%
35%

answerthink
N/A
did`nt think

6th grade
KATSUMA P.S.
(2013)
before
after
64%
60%
19%
28%
16%
12%

1st grade
KUMAGE J.H.S(2014)
before
after
60%
46%
27%
33%
13%
20%

2nd grade
KUMAGE J.H.S(2015)
before
after
47%
37%
34%
40%
19%
23%

4.3 COMPLIANCE OF SEVEN ROAD SAFETY RULES
The three items of “Keep to the left when walking a narrow road,” “Do not cross a broad road where there isno pedestrian crossing” and “Walk on the opposite side of the walkway from the road” were only observed at a rate ofaround 50-60%. However, after the lecture, it increased up to just below 80% (please see Figure 6).
Some primary school students were not conscious of passing position and it was found that their awareness of
it improved after the lecture.

Figure 6. Compliance of Seven Road Safety Rules, Katsuma Primary School (Katsuma P.S.)

349

4.4 BEHAVIORAL CHANGE AT SPOT A
A behavioral change regarding “Walk on the opposite side of the walkway from the road” of the seven rules
was recognized. In accordance with the observations before and after the lecture, those who walked on the opposite sideof the walkway from the road rather than its center increased. However, this has not been quantified yet.
4.5 BEHAVIORAL CHANGE AT SPOT B
The behavioral change regarding “walk on the inner side of the side strip relative to the roadway in roads
without walkways” was recognized. The percentage of primary school students who walked on the side strip’s outerside decreased from 20% before the lecture to 14% after the lecture.
Because the students commute to and from Katsuma Primary School in groups, the scenes where upper gradestudents guide the lower grades not to stray outside side strips are often observed.

5 CHANGE IN AWARENESS SEEN IN KUMAGE JUNIOR HIGH SCHOOL STUDENTS
5.1 RISK AWARENESS WHEN COMMUTING TO SCHOOL
No remarkable change was observed in risk awareness of the first grade junior high school students in 2014,
shown as 15% before the lecture and 19% after the lecture. When they proceeded to the second grade, it increased alittle from 18% before the lecture to 21% after the lecture; however, the change was not remarkable (Table 3).

5.2 CHANGE IN ACCORDANCE TO SCHOOL YEAR PROGRESS (from 2014 to 2015)
A great change was observed in risk awareness of the 2nd trade students in 2014 from 19% before the lecture to
33% after the lecture.
After they proceeded to the 3rd grade, the percentage before the lecture decreased to 26% and its percentage
after the lecture was remained at 32%, the level of the previous year. The percentage of risk awareness was highest in
the third grade students among all three grades (Table 3).
Table 3. Question: Do you think about the route to and from school was safe.

answerthink
N/A
did`nt think

1st grade
KUMAGE J.H.S(2014)
before
after
60%
52%
25%
28%
15%
19%

2nd grade
KUMAGE J.H.S(2015)
before
after
48%
38%
34%
40%
18%
21%

answerthink
N/A
did`nt think

2nd grade
KUMAGE J.H.S(2014)
before
after
49%
45%
31%
22%
19%
33%

3rd grade
KUMAGE J.H.S(2015)
before
after
41%
39%
33%
29%
26%
32%

350

5.3 STATUS OF COMPLIANCE WITH SEVEN ROAD-SAFETY RULES
Before the lecture, the three items of “Keep to the left when walking a narrow road,” “Do not cross a broadroad where there is no pedestrian crossing” and “Walk on the opposite side of the walkway from the road” wereobserved only 50% of the time, compared with other items; however, after the lecture it increased to 70%. From theabove, it was clarified that students’ awareness was also promoted by the lecture in Kumage Junior High School.
(Figure 7).

Figure 7. Compliance of Seven Road Safety Rules, Kumage Junior High School (Kumage J.H.S)

5.4 COMPLIANCE INTENTION OF FIVE RULES FOR SAFE USE OF BICYCLE
Before the lecture, the awareness of “Can use walkway only when it is specially approved” and “Go slowly on
the left side of roadway” were low in particular. It is considered that the awareness of the students commuting to schoolby bicycle became low because their commuting means changed(Figure 8).

Figure 7. Compliance Intention of Five Rules for Safe Use of Bicycle, Kumage Junior High School (Kumage J.H.S)351

6. CONCLUSIONS
From the results of research, following were clarified:
The higher grade students had higher risk awareness of the route to and from school. However, it is often
observed that when they proceeded to junior high school, their risk awareness fell.
The lecture on the seven road safety rules and the five rules for safe bicycle use provided to students ofprimary school and junior high school could make their traffic behavior safer.
Their risk awareness maintained the same level into the next grade year.
To conclude, it was confirmed that in order to encourage compliance with the rules of the road, theimplementation of road safety education to both primary school and junior high school is beneficial.
The author would like to deploy the same method to other areas of Shunan City, Yamaguchi Prefecture andcontinuously conduct research.

7 ACKNOWLEDGEMENTS

Acknowledgement: In order to proceed with this research, we received great cooperation from the people
concerned at Katsuma Primary School, Kumage Junior High School and road administrators (Public Transportation
Division, River and National Highway Office, Land, Infrastructure and Transportation Ministry, Yamaguchi Prefecture;
Road Construction Division, Yamaguchi Prefecture; and Road Division, Shunan City) and the Board of Education(School Security and Physical Division, Education Bureau, Yamaguchi Prefecture).
This is part of the achievement obtained through the instruction by our laboratory activities to graduate
research students of National Institute of Technology, Tokuyama College (Kozo Harada, Keita Fukuda and Mao
Harada) in the previous year.
It is also part of the achievement of the research made possible by the Sasagawa Scientific Research Grant
from The Japan Science Society. I would like to thank all those who have been involved in this research.

8 CITATIONS AND REFERENCES
CITATIONS1)National Police Agency(2015): Traffic Safety Guidelines for Pedestrian and Cyclists,
https://www.npa.go.jp/koutsuu/kikaku/trafficsafety/traffic_safety_english.pdf

REFERENCES
1) Meyama, Naoki(2015).Change of Risk Recognition for Schoolboys and Girls both Elementary School andJunior High School Through the Road Safety Education, 31rd Japan Road Conference, Tokyo（inJapanese）

352

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Sustainable Pavement Design - Delivering
Sustainable Options Considering Existing
Materials and Pavement Lifecycle.

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATION

Project Manager - Engineer

Pavement Management Services

POSITIONORGANIZATIONCOUNTRY
Australia

Trent McDONALD
CO-AUTHOR(S)(Capitalize Family Name
Ernesto URBAEZ
Scott MCINTYRE
E-MAIL(for correspondence)

Senior Engineer
Principal Engineer

Pavement Management Services
Moreton Bay Regional Council

COUNTRY
Australia
Australia

eurbaez@pavement.com.au

KEYWORDS:
Sustainability, Pavement, Asphalt, EME2, Perpetual

ABSTRACT:With a drive toward sustainability and pavement longevity, there is an ever growing evolution in pavement materials
and design concepts. In this paper, Pavement Management Services has proposed four mechanistic-empirical design
options for a failing road in Moreton Bay Regional Council (MBRC) in Queensland, Australia in 2016. Of the fourpavement designs, two consisted of conventional asphalt and granular pavements, whilst the others consisted of foamed
bitumen and a perpetual pavement design.
An extensive pavement investigation was carried out including Falling Weight Deflectometer, boreholes, andgeotechnical testing; which was used in assessing the in-situ conditions of the pavement and material properties. The
investigation allowed formulating of the foamed bitumen and a perpetual pavement design alternatives. The foamed
bitumen option considered the utilisation of existing materials to incorporate into the rehabilitation, whilst the perpetualpavement considered a three layered asphalt pavement for an extended lifecycle. The three layered asphalt coarse(applied to the perpetual pavement), utilised the characteristics of three different mixes to limit strain at critical locations
within the pavement, to control the mode of failure. By doing so, the pavement was set to last in excess of 100 years
without structural improvement and minimising pavement life cycle cost.
Furthermore, a financial analysis has been conducted incorporating a preliminary cost comparison between convention
asphalt design (deep lift asphalt) and perpetual pavement design. A 100 year analysis period was considered for a better
comparison with the perpetual long life pavement.
This paper outlines the investigation and pavement design options and methodologies used in the design process. The
pavement designs have been proposed and accepted by council, and are awaiting a final decision in the design option for
tendering process.

353

Sustainable Pavement Design - Delivering Sustainable
Options Considering Existing Materials and Pavement
Lifecycle.
Trent McDONALD1, Ernesto URBAEZ2, Scott McINTYRE3
1,2

Pavement Management Services, Sunshine Coast, QLD, Australia
3
Moreton Bay Regional Council, Moreton Bay, QLD, Australia
Email for correspondence, eurbaez@pavement.com.au

1 INTRODUCTION
Large road networks, aging infrastructure and material availability are just a few terms to describe atypical councils continuing battle to maintain their road assets to an acceptable level of service and customer
satisfaction. Also adding population growth, asset acquisition, budget constraints and time constraints, makes
a good argument to strategise towards sustainable and innovative techniques and materials, utilising existing
infrastructure and extending asset design lives.
With no exception the above mentioned stressors and constraints, Moreton Bay Regional Council(MBRC) engaged Pavement Management Services (PMS) in 2015 for a pavement design on an 820m
deteriorated road in their network - Victoria Avenue, Margate, QLD. The arterial road is one of the majorroutes in a grid network seeing some 7.1x103 vehicles per day - the majority of which are light vehicles
serving the surrounding residential properties and schools with 4.0% heavy vehicles.
The pavement investigation encompassed a visual inspection to understand the mode of failure andpossible design constraints; boreholes for pavement profile and material characterisation; laboratory testingfor material properties and Falling Weight Deflectometer (FWD) testing for the in-situ structural condition.
Utilising this information, the remaining life of the pavement was determined following the linear elastic
layered system and mechanistic-empirical methodology. The four proposed design options - also following
the mechanistic-empirical design method, consisted of a mill and re-sheet, deep lift asphalt, foamed bitumen
stabilised and a long life perpetual pavement using a three layered asphalt coarse - incorporating the highmodulus asphalt Enrobés à Module Elevé Class 2 (EME2).
The aim of this paper is a case study into the methodology of the pavement investigation. The paper
will focus on how the results were utilised, the specifications and guidelines used and the design options
considered – focusing on the foamed bitumen treatment and long life perpetual pavement design using
EME2.
A preliminary cost analysis comparison between deep lift asphalt and perpetual pavement designs
has also been included in this paper.
2 VISUAL INSPECTION
The start of any investigation is to ascertain what the current state of the pavement is. This may be in
the form of destructive, invasive and non-destructive testing, however, a simple ‘on foot’ survey with a
trained eye can reveal the mode failure, construction constraints, traffic movements and directions to takewhen considering testing and design.
For Victoria Avenue, the on foot inspection revealed a large asphalt paved surface consisting of a
two lane - bidirectional road, with road side parking varying from 13m to 18m total width. The condition waspoor, with regular occurrences of fatigue cracking, longitudinal and transversal cracking and remedial works
in the form of crack sealing, pothole repairs and heavy patching. There was also evidence of pumping withlight colored material appearing where cracks were present. Rutting and deformation of the pavement was
not a prevailing pavement distress, indicating a reasonable base and subgrade condition. The table below
shows photos of the pavements general condition.

354

Table 1. General Pavement Condition

2 PAVEMENT INVESTIGATION METHODOLOGY & RESULTS
2.1 BOREHOLES AND LABORATORY TESTING
A total of ten (10) boreholes were drilled at regular intervals along the Victoria Avenue. The
thicknesses of the pavement layers were recorded, with material characterisation, which were interpreted foran adopted pavement profile. Dynamic Cone Penetration (DCP) tests were also carried out on the subgrade ateach borehole as an indication of insitu subgrade strength. The results of the borehole logs revealed
variations in the pavement profile, not only in the asphalt coarse, but in the unbound granular base coarse.
The asphalt thickness was typically 60mm thick with two boreholes seeing 100mm. The base material varied
between 170mm to 445mm with the thinner pavement trending toward the end of the road.
The subgrade material was quite consistent as a Sandy Clay and a Clayey Sand to a lesser extent.
The DCP results of the subgrade were sporadic, ranging from a correlated CBR of 9% to 24%, however, lab
testing and back calculation will provide more insight to the subgrade strength and insitu stiffness.
The base and subgrade samples taken from the boreholes were sent to the laboratory for further
testing. Laboratory testing consisted of moisture content, particle size distribution (PSD), Atterberg limits
and California Bearing Capacity (CBR). The PSD was used to classify the granular material in terms ofparticle size distribution and subsequent material grading in accordance with Main Roads specification
MRTS05 (DTMR 2015b). The results found that most samples fell in the lower grade material envelope ‘E’with one exception as a grading envelope ‘C’. The ratio of the 0.075 and 0.425 sieve also characterised thismaterial as a high quality Type 2.1, where the grading envelope ‘E’ materials have no material typecharacterization.
For a foamed bitumen treatment, it is recommended a grading envelope ‘C’ should be used,however, Ramanujam J. et al. indicates a broader grading envelope reproduced in the table below, in which
seven out of the nine samples adhere to (Ramanujam. J et al. 2009). The percent passing the 0.075mm sieve
was also well above 5% which is a critical property recommended by Austroads to get a good mortar likebitumen mastic between larger aggregate particles (Autsroads 2011). On this basis, foamed bitumen wasconsidered a viable design option.
Table 2. Grading Limits for Foamed Bitumen Treatment
Percentage Passing By Mass
Minimum
Maximum
26.5
80
100
2.36
25
85
0.075
5
20
Plasticity Index*
Maximum 10%*Plasticity Index for the base material was not tested

Sieve Size (mm)In addition to PSD of the granular base material, Atterberg limits were taken for all subgrade
samples, along with eight CBR’s from selected boreholes. The Subgrade proved to be variable acrossVictoria Avenue, however, showed sound CBR values ranging between 6% and 12%. The moisture content

355was close to -and generally below- its Optimum Moisture Content (OMC) and the swell was very low, withexception of the subgrade material in borehole 4. Following the Austroads Guide Part 2, the lab results
indicate a prominent subgrade material of a low to moderate expansive nature, however, indicate weak areasof very high expansive nature.
2.2 FALLING WEIGHT DEFLECTOMETER (FWD) TESTING & CUSUM ANALYSISThe FWD testing was conducted on both the trafficable and parking lanes of Victoria Avenue usinga Dynatest Heavy Weight Deflectometer (HWD). Due to the standard principles of the testing, the HWD will
be referred to as FWD for this paper. For the trafficable lanes, the testing was performed at 20m intervals,
staggered between the two lanes (10m stagger) and at 40m intervals on the outer wheel path for the parking
lanes. The loading of the FWD was conducted at 40kN. At each test point the peak applied load and peak
deflections were recorded from 9 geophones, with spacing's ranging from under the center of the load to a
distance of 1.5m from the load. The deflections were used to define changes in the pavement structure using
statistical methods and for the back calculation of pavement layer moduli. For the purposes of this paper, theresults will focus on the trafficable lanes of Victoria Avenue as this is where the deep rehabilitation was
proposed.
Defining the existing pavement profile is a key element to successful pavement modeling anddesign. As noted in the borehole investigation, there were variations in the existing pavement profile,
however, boreholes do not define where the changes are. In this case, FWD deflections were used to identify
areas of similar response and hence similar construction and changes. To identify these changes in the
pavement profile, a Statistical Cumulative Sum (CUSUM) analysis was carried out.
The CUSUM is a sequential analysis typically used for monitoring change detections. It is a
powerful tool in defining zones of similar response within a project dataset. Pavement areas with consistent
response appear as fairly straight lines on the CUSUM plot, while points where the slope changes
dramatically correspond to section boundaries.
The table below shows the CUSUM for curvature and deflection which identified homogeneous
sections for both trafficable lanes.
Table 3. Characteristic Deflection Plot and CUSUM
Curvature CUSUM

Maximum Deflection CUSUM

The CUSUM plot revealed four homogenous sections of similar response. Utilising this method andinteroperating information from the boreholes, four pavement profiles were adopted and used in thesubsequent pavement modeling and design.

356

2.4 BACK CALCULATION FOR PAVEMENT LAYER MODULI
Based on the deflection results of the FWD testing and profiles determined from boreholes and
CUSUM analysis, the existing pavement layer elastic moduli values were back-calculated using the
ELMOD6 computer program and the deflection basin fit method. The following table is a summary of themodulus results and adopted pavement profiles.
Table 5. Pavement Layer Moduli
Chainage (m)0 - 100
100 - 300
300 - 570
570 - 835

Asphalt (MPa)Thickness (mm) Modulus (MPa)
110
2294
63
3732
83
1326
59
2095

Base (MPa)*
Thickness (mm) Modulus (MPa)
790
154
576
396
373
170
210
400

Subgrade (MPa)Thickness (mm) Modulus (MPa)Infinite
92
Infinite
102
Infinite
61
Infinite
61

The subgrade modulus correlated well with the lab CBR results raging between 59MPa to 120MPa
whilst the granular base ranged between a low 127MPa to 480MPa. The asphalt modulus also ranged
between a low 1,241MPa to 2,376MPa. These characteristic moduli values were used in the design and werebased on the lowest tenth percentile level of confidence.
2.6 MECHANISTIC EMPIRICAL PAVEMENT DESIGN
The pavement designs were completed in accordance with the General Mechanistic-Empirical
Procedure published in the Austroads Guide to Pavement Technology Part 2, as well as the Department ofTransport and Main Roads (DTMR) Pavement Rehabilitation Manual and design supplement to Austroads
Part 2 (Austroads 2012) (DTMR 2012)(DTMR 2013).
The Mechanistic-Empirical procedure, like the name suggests, encompasses a mechanistic modelingapproach to pavement design, utilising the theory of elasticity and properties of the pavement materials to
predict stresses and strains at critical locations within the pavement. The empirical side, or sometimes
referred to by researchers as a calibration model, is used to define the limiting criteria at which the pavement
will be considered to fail and hence, derived for empirical observation. The amalgamation of these twoconcepts yields an allowable number of axle repetitions that the pavement can withstand before exceeding
the limiting criterion.
These failure mechanisms are evaluated based on traffic loading from a standard axle configurationconsisting of a dual-wheeled single axle loaded with 80kN. The critical locations within the pavement –forthese particular designs- consist of tensile strain at the bottom of the asphalt, and the compressive strain at the
top of the subgrade.
2.6.1 FATIGUE OF ASPHALT MATERIALSThe pavement design to prevent fatigue of the asphalt is designed to limited tensile strain at thebottom of the asphalt layer to a tolerable level throughout the life of the pavement. The asphalt fatigue
relationship used in the Austroads Guide is the laboratory fatigue relationship published by Shell (1978)
adjusted to predict fatigue life in the pavement using a reliability factor according to the desired project
reliability (Austroads 2012).
For conventional bituminous binders used in asphalt placed on moderate-to-heavily traffickedpavements, the general relationship between the maximum tensile strain in asphalt produced by a specificload and the allowable number of repetitions of that load is: 6918
 RL  0 .856  Vb  1 . 08  
S mix 0 . 36  




5

(1)

357

Where:
N:
:
Vb:
Smix:
RL:

Allowable number of Standard Axle Repetitions (SAR).
Tensile strain produced by the load (microstrains).
Percentage by volume of bitumen in the asphalt (%).
Mix stiffness or modulus (MPa).
Reliability factor for asphalt fatigue (Table 6).
Table 6. Project Reliability
Desired Project Reliability
80%

85%

90%

95%

97.5%

2.5

2.0

1.5

1.0

0.67

For the foamed bitumen design this equation was used to evaluate the tensile strain at the bottom of
the foamed bitumen layer, and also used for the bottom of the deep lift asphalt design. For the perpetualpavement design, this equation was not used as the limiting factor for this design was the stain itself, notasphalt fatigue.
2.6.2 SUBGRADE PERMANENT DEFORMATION
Subgrade permanent deformation is considered in the mechanistic-empirical design by limiting thevertical compressive strain at the top of the subgrade to a tolerable level throughout the life of the pavement.
The strain induced is not fully recoverable, and after repeated loading, the permanent deformation
accumulates at the subgrade level, and overlaying pavement layers. These permanent deformations are
typically manifested as rutting in the wheel paths.
The number of cycles to failure until an unacceptable level of permanent deformation of thesubgrade is computed by the following equation, noting that Reliability Factors have not been incorporated as
the relationship is expected to provide suitable reliability for SARs up to 1x10 8.

 9,300 
N  
  

7(2)

Where:N::

Allowable number of Standard Axle Repetitions before failure criterion is met.
Vertical strain at the top of the subgrade (microstrains).

As the unbound granular materials are considered stress dependent, it is important to consider thatthe modulus of unbound materials is strongly influenced by the level of stress, which at the same time will
limit the allowable number of repetitions. In other words, considering the stress dependency of the unboundmaterials, like a natural subgrade, it will carry a higher number of Standard Axle Repetitions if it has a highresilient modulus, which means high stiffness in the presence of a traffic load.
2.7 PAVEMENT DESIGN OPTIONSIn accordance with the design proceedings the following assumptions and limitations were used in
the design process.
 Each design considers six seasons throughout the year incorporating the minimum and maximum airtemperature and mean monthly rainfall at the project site, determined from Bureau of Meteorology
 Pavement surface temperature throughout the year is based on BOM data and the US Asphalt Instituterelationship published in the Superpave Series No. 1 (SP-1), considering the latitude location of the
project site.
 Predicted asphalt pavement temperature at different depths was based on the BELLS equations.
 Modulus of new asphalt materials are based on asphalt bitumen and mix volumetric properties using the
SHELL nomographs, temperatures and loading frequency for each of the six seasons throughout the year.

358 Sub-layering of granular materials was in accordance with the Austroads method.
 Fatigue Endurance Limit (FEL) was targeted at 100 micro strains and 200 micro strains for the subgrade.
 Foamed Bitumen and EME2 specification and design parameters followed DTMR and Austroads Spec.
 All treatments were structurally equivalent and have been designed to meet a structural design life of 20
years with exception to the Perpetual Pavement Design (100+ years).
In consultation with MBRC representatives four (4) pavement designs were proposed including amill and re-sheet for the parking lanes and a deep lift asphalt, foamed bitumen stabilised and a EME2 longlife perpetual pavement for the trafficable lanes. The following section details the three pavement designs
considered for the trafficable lanes – a simple mill ad re-sheet option was proposed for the parking lanes as acost effective option.
2.7.1 FOAMED BITUMEN DESIGNThis treatment considered pre-milling the existing asphalt material into the base material to a depth
less than the final foamed bitumen depth. The material is then to be graded to height in which material will
be removed to allow for a new asphalt wearing coarse and to keep the existing levels. The material will thenbe treated with hydrated lime, then foamed bitumen using a in situ stabilisation machine, compacted, andcapped with a wearing coarse.
The foamed bitumen layer was modeled as an asphalt layer and the modulus determined from themix properties. The foamed bitumen mix consisted of 3.5% Class 170 bituminous binder and 2% lime as asecondary stabilising agent following Austroads (2015), although may be altered depending on material
susceptibility from sampling and testing (Ramanujam. J & Jones. J, 2000). The following is a summary of the
foamed bitumen design.
Table 7. Foamed Bitumen Design Summary
Direction

Chainage (m)New Dense Grade
14mm (mm)FoamedBitumen (mm)

New Granular Base
Type 2.1 (mm)Existing Granular
Base (mm)Prescribed/Counter
Prescribed/Counter
Prescribed/Counter
PrescribedCounter

0 - 100
100 - 300
300 - 570
570 - 835
570 - 835

50
50
50
50
50

160
100
195
100
150

230

690
486
210
119
-

The design was carried out utilising the existing pavement structure to be mixed in with the foamed
bitumen, and also as a granular base. With a 50mm asphalt wearing coarse, the foamed bitumen layer wasincreased in thickness to satisfy the failure criterion. The existing granular material was also modeled in thedesign with moduli derived from the FWD testing and back calculation. In all but one case, the existing
granular material remained as a granular base, however, was too thin to be considered a structural layer at theend of Victoria Avenue in the counter direction – in which the subgrade needed to be excavated and newmaterial laid.
2.7.2 DEEP LIFT ASPHALT DESIGNThis treatment considered milling the existing asphalt surface and all/part of the base material, andreplacing with new asphalt materials consisting of an asphalt base and wearing coarse. The following is asummary of the deep lift asphalt design.
Table 8. Deep Lift Asphalt Design Summary
Direction

Chainage (m)Prescribed/Counter
Prescribed/Counter
Prescribed/Counter
Prescribed*
Counter*

0 - 100
100 - 300
300 - 570
570 - 835
570 - 835

New Dense Grade
14mm (mm)
50
50
50
50
50

New Dense Grade
20mm (mm)
120
80
150
70
125

Existing Granular
Base (mm)
730
507
255
149
94

359

Like the foamed bitumen design, the deep lift design consisted of a 50mm wearing coarse, and theasphalt base thickness was increased to a thickness that satisfied the failure criterion.
2.7.3 PERPETUAL PAVEMENT DESIGN USING EME2This design considers a relatively new concept in pavement design where the life of the pavement is
set to exceed 40-50 years without undergoing any structural rehabilitation as opposed to a 20 year design (D.
Timm, R. Willis,). The notion involves designing a pavement to limit the flexural strain at the base of theasphalt layer (Fatigue Endurance Limit -FEL), and the vertical compressive strain at the top of the subgrade.
Conceptually, if one was to think of a rubber band that is subject to a cyclic loading (traffic) and is
stretched to a limit (strain defined by the pavement thickness and modulus) - it would fail at a set number ofcycles (20 year design) - this would represent a traditional pavement design. However, if a rubber band was
subject to the cyclic loading only by a small amount (little strain) then the rubber band would recover and lastindefinitely (conceptually). This strain limiting criterion is the principal behind this paradigm shift inpavement design and works towards a perpetual pavement lifecycle and getting the most out of your asset
with minimal lifecycle maintenance and cost. The FEL is not a new concept in pavement design and has been
hypothesised by Monismith from as early as 1972, indicating a FEL of 70 micro strains, however, Witczak
indicates that a range between 70 and 250 micro strains may exist depending on the asphalt mix (Monismith
C.L & McLean D.M 1972)(Witczak 2014). For the perpetual design of Victoria Avenue, the FEL wastargeted at 100 micro strains as 70 is considered as too conservative (Sullivan B et al.). The strain at the topof the subgrade was limited to 200 micro strains (Newcomb D. et al, 2001)(Liedy J. 2014).
The design consists of a multi layered asphalt pavement comprised of an asphalt wearing coarse on
top of a high modulus, rut resistant asphalt base, and a fatigue resistant asphalt material at the bottom. The
top and bottom asphalt layers for this design consisted of conventional dense grade asphalt mixes withnominal 14mm and 20mm aggregate size respectively. The mid layer consisted of the high modulus EME2
mix. The EME2 mix is a hot mix -performance based asphalt- that was designed in the mid-seventies inFrance. The mix consists of a high viscosity bituminous binder with its stiffness attributed to the bitumen
properties and hard penetration grade (Austroads 2014). The product is now being implemented into
Australia by road authorities and other road agencies. This design followed the pilot specification publishedby the DTMR for the EME2 mix properties and modulus determined using the same methodology as
previously discussed (using shell nomographs and temperature adjusted to six seasons) (DTMR 2015). The
table below shows a summary of the perpetual pavement design.
Table 9. Perpetual Pavement Design Summary
Direction

SectionLocation

New DG14
(mm)

EME2
(mm)

New DG20(mm)

Existing Granular
Base (mm)

New Granular Base
Type 2.1 (mm)Prescribed/Counter1

Ch 0.000 to Ch 0.100

50

120

110

630

-

Prescribed/Counter2

Ch 0.100 to Ch 0.300

50

100

90

397

-

Prescribed/Counter3

Ch 0.300 to Ch 0.570

50

140

140

125

-

Prescribed/Counter4

Ch 0.570 to Ch 0.835

50

130

140

-

200

As can be seen, to limit the strain at the critical locations, a thick asphalt layer is to be placed,consisting of a 50mm DG14 wearing coarse, a 100 to 140mm rut resistant EME2 mix and a 90 to 140mm
fatigue resistant DG20 mix. Although the overall asphalt thickness will incur high initial costs, considerationmust be given to the designs structural longevity and minimal maintenance requirement throughout its life
cycle.
2.8 LIFE CYCLE COST ANALYSIS
A preliminary cost analysis has been conducted using the AASSHTO 1993 Pavement Design Guide
for modelling the pavement performance for a period of analysis of 100 years. The cost comparison was
performed using the deep lift asphalt and perpetual pavement design options. On this basis several

360

rehabilitation options were considered along the period of analysis (100 years) using deep lift asphalt
rehabilitation strategy.
for cost comparison purposes, the modeling was conducted on section No. 3 (counter direction) of
Victoria Avenue between Ch 0.300 to Ch 0.570. The following table summarises the AASHTO-93 modellingvariables.
Table 10. Structural Analysis. AASHTO-93 Variables
Material

Type

Stability/Moduleai
AASHTO-93
MethodReference

0.40

Stability:
Brisbane City. Urban Management Division
Reference Specifications for Civil Engineering Work. S310
Supply of Dense Graded Asphalt. December 2001

DG14 / DG20
Nominal Sizeaggregate = 18 mm.

7.5 KPa. (1,686 lb.)

Asphalt Mix%asphalt cement =4-6 (by Mass)

Flow=2-4 mm.

Total Voids = 3-7%

Asphalt Mix

EME2

25°C~68°F/80 KPH:
4,200 MPa
(609,159 psi.)

0.55

Module:Department of Transport and Main Roads. Queensland
Government. Australia. Technical Note 142. High Modulus
Asphalt (EME2). Pavement Design. March 2015
Structural Coeficient (ai):NCAT (U.S.A) Research.
Granular Subbase

Subgrade

1 KN = 224.8 pound

127 MPa(18,420 psi)

TYPE 2

BH5: Sandy Clay,
Med/High Plasticity.
59 MPa (8,557 psi)________
BH6:
Equivalent Design
Clayey Sand, HighCBR Value = 6%
Plasticity Clay Fines
1 MPa. = 145.05 psi. 1 Inch = 25.4 mm.

0.09

Drainage Coefficient (m) = 1.0

N/A

Using the AASHTO-93 modelling, traffic information, and the variables shown above, the followingStandard Axle Repetition to failure (SAR’s) and pavement design life (n) were obtained.
Table 11. Traffic Information
Growth Traffic Rate (%)
Design Period (Years)
Growing Factor (F)

1,8
20
24,03

Table 12. Deep Lift Asphalt
SN

Reliability R (%)
ei (mm.)
50

96
ai
0,40

4,05

361

150
255

0,40
0,09

Po
Pf
WT18
Design Standard Axle Repetition for Fatigue ofAsphalt
Equivalent Axles (Initial year), EEon (years)

4,2
1,5
4,4447 x 106
4,38 x 106
182.249,00
20

Table 13. Perpetual (long Life) Pavement
Reliability R (%)
ei (mm.)
ai
50
0,40
SN
140
0,55
140
0,40
125
0.09
Po
Pf
WT18
Design Standard Axle Repetition for Perpetual
Pavement
Equivalent Axles (Initial year), EEon (years)

73

6.46

4,2
1,5
556,571,328
550.000.000
182.249,00
227,47

As can be seen on the table above, following AASHTO-93 pavement design methodology the
SAR’s to failure and pavement design life expectancy (n) are very consistent compare to the Austroads M-E
pavement design guide. On this basis a pavement performance behavior and structural analysis was
conducted for a further cost life analysis. The following table shows a summary of the pavement performanceand structural analysis using an increment of ∆PSI of 0.2 of both rehabilitation strategies.
Table 14. Pavement Performance-Structural Analysis
Pavement Performance-Deep Lift Asphalt

Pavement Performance-Perpetual Pavement

Using a final PSI (Pt) equal 2.0 as an intervention level, the expected SAR’s(f) were 3.24E6 and3.47E for the deep lift asphalt and perpetual pavement designs, respectively. These SAR’s(f) at Pt equal 2.0
are reached at 15 years for the deep lift asphalt and 199 years for the perpetual pavement designs. It isequivalent to a damage (d) based on the relationship of the design SAR’s (ini) and expected SAR’s(f)(d=SAR’s(f) / SAR’s(ini)) of 0.73 and 0.54 for the deep lift asphalt and perpetual pavement designs,
respectively. Using the condition factor (CF), damage value (d) and remaining life (RL) concept included in
the AASHTO-93 guide, the effective structural number (SNeff) of both rehabilitation strategies wascalculated. The SNeff of the deep lift asphalt is expected to be equal to 3.27 and it resulted in a structural
rehabilitation number (SNreh) of 0.78 (SN(ini) – SNeff). The SNreh of 0.78 is transformed into AC overlay
using AC structural coefficient (aCA) of 0.4 (similar to the DG14 and DG20 used for design). On this basis
the AC overlay at 15 years (Pt=2.0) is 50mm. Regarding the perpetual pavement strategy, conceptually, therehabilitation treatment is considered to be milling and replace the 50mm AC (DG14) on top of the surface.
8362This should allow the pavement structure to be perpetual considering that cracking is occurring from thesurface to the bottom and the high modulus mix (EME2) should avoid the cracking progression to the lower
layers. It is expected (based on AASHTO-93 modelling) that the perpetual pavement rehabilitation treatment
to be conducted at the 199 year (Pt=2.0) of the initial design period.
For life cost analysis purposes life cycle period of 100 years of was evaluated. On this basis, after
the initial construction cost of the deep lift asphalt strategy, six major rehabilitation treatments have been
considered along the analysis period (100 years). The rehabilitation treatments are scheduled every 15 years.
Along that period, 12 years of routine maintenance consisting of crack sealing, superficial and heavy
patching are also scheduled. The major rehabilitation treatments consist of milling 120mm and replace
140mm of AC for the first two initial periods (15 year and 30 year). It will allow maximum overlay of 40mm
in 30 years and having SNreh of 0.78 as expected. The remaining major rehabilitation periods (45, 60, 75 and90 years) are expected to be milling 200mm and replace 200mm in order to keep the surface level and same
SNreh of 0.78.
Regarding the perpetual pavement, after the initial construction cost, three surface treatments
consisting on milling off 50mm and replace by 50mm were scheduled at 30, 60 and 90 years of the analysis
period (100 years). It should be noted that based on the modelling, no surface treatment should be conductedon the perpetual pavement strategy up to 199 years of the design period. In addition, 10 years of routine
maintenance (crack sealing) has been scheduled.
The following table shows the major rehabilitation treatments cost and routine maintenance costscheduled to the two rehabilitation strategies.
Table 15. Deep Lift Asphalt Treatment Cost
Year
0
15 and 30
45, 60 75 and 90
12 years during design period

Treatment
Construction
Major: Mill 120mm and Replace 140mm
Major: Mill 200mm and Replace 200mm
Routine: Crack Sealing (initial 3 years)
Routine: Surface Patching (next 4 years)
Routine: Heavy Patching (final 5 years)

Cost ($/sqm)
569.60398.70569.60
10.00
30.00
50.00

Table 16. Perpetual Pavement Treatment CostYear
030, 60 and 90
10 years during design period

Treatment
Construction
Surface Treatment: Mill 50mm and Replace 50mm
Routine: Crack Sealing

Cost ($/sqm)
1075.50138.30
10.00

Using the initial construction costs and routine maintenance shown in tables above the following Net
Present Values (NPV) were calculated to the Deep Lift Asphalt and Perpetual Pavement rehabilitation
strategies using a rate of 5%.
Table 17. Net Present Value
NPV ($/sqm)
Deep Lift Asphalt
Perpetual Pavement-1,255.61-1.156.39

The negative values of the NPV show the cost of the investment. Benefits that are in general positive
were not included on this analysis.
2.9 CONCLUSION
After a detailed pavement investigation and testing, four pavement designs were proposed torehabilitate Victoria Avenue in Moreton Bay Regional Council. Three of which were for the main carriage
way and a cheaper option for the road parking lanes. The design process followed the mechanistic empiricaldesign methodology and utilised properties of the mix designs to determine the asphalt material modulus andwas adjusted for a six seasonal design. All designs incorporated the existing pavement structure where363possible, particularly the foamed bitumen treatment and utilised high performance materials for a perpetualpavement design.
The life cycle cost analysis showed that the NPV of the perpetual pavement strategy including
routine maintenance cost is lower compared to the deep lift asphalt option. It makes the perpetual pavement
strategy more attractive and cost convenience. A full benefit/cost (B/C) of the alternatives was not conducted,
but it is anticipated that the perpetual pavement should has lower user costs (so higher benefits) compare to
the deep lift asphalt, mainly because the condition of the pavement is higher for a longer period of time on
the perpetual pavement option. It will make a better B/C ratio on thins alternative. Other financial variables
like inflation or variable rates were not considered in the cost analysis that was conducted.
REFERENCES
Austroads 2008, Guide to Pavement Technology Part 5: Pavement Evaluation and Treatment Design”,
Austroads, 2008.
Austroads 2011, Technical Report AP-T178/11 – Review of Foamed Bitumen Stabilisation Mix Design
Methods, Sydney.
Austroads 2012, Guide to pavement technology. Part 2, Pavement structural design, Updated Feb. 2012. edn,
Austroads, Sydney.
Austroads 2014, Technical Publication AP-T283-14 – High Modulus High Fatigue Resistance Asphalt(EME2) Technology Transfer, Sydney.
Austroads 2015, Technical Report – AP-T303-15 – Design and Performance of Foamed Bitumen Stabilised
Pavements, Sydney.
American Association of State Highway and Transport Officials (AASHTO) 1993,AASHTO Guide for
Design of Pavement Structures, American Association of State Highway and Transport Officials,
Washington DC.
Department of Transport and Main Roads (DTMR) 2012, Pavement Rehabilitation Manual, Chapter 5 –Design of Pavement Rehabilitation Treatments: Mechanistic and Deflection Reduction Methods, Departmentof Main Roads and Transport, Queensland.
Department of Transport and Main Roads (DTMR) 2013, Supplement to 'Part 2: Pavement Structural Design'of the Austroads Guide to Pavement Technology, Department of Main Roads and Transport, Queensland.
Department of Transport and Main Roads (DTMR) 2015, Technical Specification PSTS107 – High Modulus
Asphlat (EME2), Department of Main Roads and Transport, Queensland.
Department of Transport and Main Roads (DTMR) 2015b, MRTS05 Unbound Pavements, Department ofMain Roads and Transport, Queensland.
Leidy J 2014, Pavement Structural Design, Texas Department of Transport, Texas.
Monismith C.L, McLean D.B 1972, Technology of Thick Lift Construction: Structural Design
Considerations, Association of Asphalt Paving Technologists, Vol 41, pp. 258-304, University of Michigan.
Newcomb D.E., Buncher M., and I.J. Huddleston 2001, Concepts of Perpetual Pavements, Transportation
Research Circular, Number 503, pp 4-11.
Ramanujam J, Jones J 2000, Characterisation of Foamed Bitumen Stabilisation, Road System Engineering
Technology Forum.
Ramanujam J, Jones J, Jasosevic M 2009, Design, Construction and Performance of Insitu Foamed Bitumen
Stabilised Pavements, Queensland Roads, ed No.7.
Sullivan B, Rickards I, Broadfoot D and Youdale G, Development of a Validated Design Procedure forAustralian Long Life Pavements, Australian Asphalt Pavement Association.
Timm D, Willis R 2009, Field-Based Strain Threshold for Flexible Perpetual Pavement Design, National
Center for Asphalt Technology, Auburn University, Auburn.
Witczak M.W 2014, Its Time to Re-Define the Meaning of a Perpetual Pavement, International Conference
on Perpetual Pavements, Columbus, Ohio.

364

PAPER TITLEINTEGRATED ASSET MANAGEMENT SYSTEM FOR THE SECOND PENANG
BRIDGE (JAMBATAN SULTAN ABDUL HALIM MU’ADZAM SHAH)

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Major (R) Ir. Mohd Ashari
ALIASManaging Director

Jambatan Kedua Sdn. Bhd.

Malaysia

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

E-MAIL(for correspondence)

major.ashari@jambatankedua.com.my

KEYWORDS:

Jambatan Kedua Sdn. Bhd. (JKSB) has embarked into an ambitious project of developing an Integrated AssetManagement System (IAMS) for JSAHMS in January 2015.
The project was tendered out and awarded to Gammerlite Sdn. Bhd. for a seven years contract which includes a one
year on the system development stage and the remaining six years for the operation and implementation stage.
Based on the construction cost for JSAHMS of RM4.5 billion and the numerous quantities of assets involved, thesystem is regarded as the first and the biggest integrated asset management system in Malaysia.
The system has been successfully developed and currently into the early stage of operation and implementation
period.

ABSTRACT:Jambatan Kedua Sdn. Bhd. (JKSB) is the concessionaire responsible for the construction, operation and maintenance of
the RM4.5 billion Jambatan Sultan Abdul Halim Mu’adzam Shah (JSAHMS). JKSB Asset Management System has
been designed to comply with the internationally recognized ISO 55001:2014. JKSB is implementing the Integrated
Asset Management System (IAMS) at a cost of RM134 million that includes a Structural Health & Monitoring System
to provide a more realistic maintenance and repair program for critical assets with more than 500 numbers of sensors to
be installed. The development of the Integrated Asset Management System (IAMS) for JSAHMS as a whole compriseof the following modules:i.
Bridge Management System;ii.
Highway Management System;iii.
Building Management System;iv.
Mechanical, Electrical & Electronic Management System;v.
Landscape Management System; andvi.
Accident Information Management System.

365

JKSB aims to acquire the maximum benefit and value-of–money and obtain innovative solutions in maintaining its
JSAHMS assets by introducing the Performance Based Contracts maintenance contractors in the near future.
Implementation of IAMS with incorporation of ISO 55000:2014 system at JSAHMS shall deliver the highest quality ofasset management towards meeting its organizational objectives of balancing financial, environmental and social costs,
risk, quality of service and performance which are all related to the condition of the assets.

366

Integrated Asset Management System for The Second Penang Bridge(Jambatan Sultan Abdul Halim Mu’adzam Shah)
Major (R) Ir. Mohd Ashari Alias
Jambatan Kedua Sdn. Bhd. Kuala Lumpur, Malaysia.
major.ashari@jambatankedua.com.my

1. INTRODUCTION

Penang has witnessed a rapid growth over theperiod of 15 years, being a major transportation
hub. Despite the existing 1st Penang bridgeconnecting Perai on the mainland and Gelugor on
the island, the traffic flow to the island has reached
65,000 vehicles per day and number is expected torise further. The construction of Sultan Abdul
Halim Mu’adzam Shah Bridge (JSAHMS) also
known as the Second Penang bridge was aimed atalleviating the traffic woes at the existing bridge.
The second bridge is also expected to transform
Penang into the key logistics and transportation
hub for the northern region of Malaysia under the Northern Corridor Economic Region (NCER) programme and
Growth Triangle comprising of Indonesia, Malaysia and Thailand (IMTGT). The construction of the iconic bridge
was completed on 1st March 2014 and is the longest in South-East Asia with a total length of 24km, with 16.9km
spanning across the straits of Malacca.
Jambatan Kedua Sdn.Bhd. (JKSB) is a company formed by the Malaysian Ministry of Finance and was appointed as
the concessionaire to construct, manage, operate and maintain the bridge. Upon completion of the bridge
construction, JKSB had tendered out a project to develop and implement an overarching systems solution to manage
all its infrastructural assets; a system which is also envisioned to be instrumental for establishing an asset
maintenance strategy and annual works programme for all assets. The project was called Integrated AssetManagement System (IAMS) for Jambatan Sultan Abdul Halim Muad’zam Shah.

2. OBJECTIVE OF IAMS
There are two widely accepted definitions of asset management:“the combination of management, financial, economic, engineering and other practices applied to physical assets
with the objective of providing the required level of service in the most cost effective manner” (International
Infrastructure Management Manual).
“a comprehensive and structured approach to the long-term management of assets as tools for the efficient andeffective delivery of community benefits” (American Public Works Association).

367

The IAMS project is a holistic approach to infrastructural asset management as it endeavors to embed industry-wide
accepted best practices in asset management in the IT systems; combined with the regular evaluation of asset
condition during pre-determined site inspections to determine intervention or preventive measures to maintain theuseful life of the assets and lower the Total Cost of Ownership.
There are two principles to the implementation of IAMS for JSAHMS; the capture and maintenance of the asset
inventory with regular inspections and maintenance/rehabilitation of the assets throughout its useful life; real-timemonitoring of the asset components by means of instrumentation which captures eigen-frequencies of the bridge andfor the purpose of remotely managing streetlights to reduce energy consumption optimize the lifespan of thestreetlights.
The asset condition data methodically gathered over a pre-determined frequency of periods form the basis foranalyzing the performance and determining the deterioration model of the key asset components. Maintenance planand intervention points shall be determined based on the system computed analytics and the expert opinion of theasset experts.
The high-level objective of IAMS project can be summarized as follows:
1.
2.
3.
4.
5.
6.

Processing and analysis of collected data and information to monitor performance against prescribed
maintenance standards
Basis for understanding possible consequences of alternative decisions related to preservation of highway
assets
Structured programme minimizing life cycle cost of asset ownership
Maintaining the required service level of JKSB as the concessionaire
Sustaining infrastructure“Cradle to Grave” for maximum performance and usage of built asset

3. WHAT IS IAMS FOR JSAHMS
The Integrated Asset Management System (IAMS) comprise of specialized IT management systems for the assetsthat are managed under the IAMS implementation.
Assets are inventoried and organized by hierarchies to the lowest manageable level to facilitate realistic inspection
programs and sustainable maintenance strategies.
The assets that fall under the bounds of IAMS are:

The Highway Management System – where it can be further characterized as assets classed as pavement,road furniture and drainage



The Bridge Management System – where the bridge components are structurally segmented by theapproach spans, cable stayed section, the interchanges, culverts and the expansion joints



The Building Asset Management System – which comprise of asset systems such as the infrastructure,
rooms, internal fixtures and fittings, roof, internal and external fabric

The Mechanical and Electrical Management System – which is further divided to M&E components in
Building, Highway Lighting System, Traffic Control and Surveillance System and Toll Collection System

368



The Landscape Management System – which are divided by the various zones and the landscapecomponents which are trees, palms, shrubs and turf.

Figure 1: As Built Drawings Converted to 3D Drawings
Baseline data is obtained from the operational activities, historical asset data information from the construction-stage
documents, in-depth understanding of the structures and its behavior to local climate and environment, and otherengineering expert input combined, derive the deterioration model of the structures, trigger values for maintenanceor rehabilitation works. IAMS is envisioned to assist the stakeholders in making decisions with regards to design ofthe structures and its performance.
As built drawings of the structures are digitalised and presented in 3D models and relevant documentation(construction drawings, design and test reports, etc.) are linked to each asset nameplate. The asset-linked document
forms the knowledgebase from which operational and/or management decisions can be made. IAMS system iscustomised and configured to manage the various assets, their attributes, condition data, related documents,
historical maintenance and rehabilitation information (work orders and Non Conformance Records (NCRs) andSupervision Observation Reports (SORs) issued etc.). The implementation of IAMS project for JSAHMS isgenerally split into the development phase (Year 1) and the implementation phase (Year 2 – 7).

369

Figure 2: Project Phase Framework
The first year of the project involves asset inventorization (registration), asset condition data gathering which
provides the baseline of asset condition, the establishment of the systems infrastructure framework and asset
management systems. System requirements are acquired, analyzed and customized to meet the operational andmanagement requirements.
Construction stage documents are digitalized by scanning the hard copies of the documents and storing them in theserver. The documents are linked to the assets and organized by the asset records.

Figure 3: Survey Equipment for Asset Data Collection

The subsequent years of the project duration (implementation phase) involves the transition of operational activities
using the system. System will evolve during the implementation phase to align with the operational processes andmature in terms of data and system features.

370

4. IAMS DELIVERABLES

Figure 4: Development & Establishment of IAMS
The Asset Management infrastructure for Bridge, Highway (Pavement, Embankment, Drainage and Road
Furniture), Building, M&E and Landscape will be managed by a single solution (AMX) software, implemented
separately. AMX is capable of handling various sectors of infrastructure in a single interface. AMX will be clusteredover separate servers for the individual asset sectors and the necessary configurations are performed to reflect thesector specific operations and functions.
The advanced analytical requirements of these individual core components will be supplemented by specialized
systems respectively (e.g. Rubicon and HDM-4 for HMS). Existing systems are interfaced with IAMS to obtainsupporting data to facilitate asset performance analysis.
HDM-4 or equivalent deterioration modelling/analyzing/ projection systems will be applied in AMX for pavement
to project pavement condition and the cost associated with its maintenance and rehabilitation over a fixed timeframe.
This will aid in planning, prioritizing and programming the maintenance works.

371

Figure 5: Asset Registration of M&E Components

Figure 6: Structural Health Monitoring System
The building management system (BAMS) component of IAMS implementation will depend on the supplemented
data provided by the existing Building Automation System (Tridium) that is already in place at JKSB’s premises for
information (from the various building environment controls) and inventory of all assets within the managed
building(s). Readings from the various building control components will be imported into the BAMS to computeanalysis data and present trending information on the Dashboard for management to make informed decisions andrevise management or investment strategies.
The Structural Health Monitoring System (SHSM) will comprise of the sensory component (sensors placed on
bridge and embankment), data acquisition units (PC-based data acquisition systems, which are a combination of
permanent and portable), data processing (Ambient Vibration Monitoring), data storing (an SQL based database that
stores the raw acceleration data) and data delivery system (built-in Modal frequency extractor) that provides
graphical visualization (charts and graphs) of bridge responses in the wide screens of the SHMS monitoring centres.
The built-in Operational Modal Analysis (OMA) feature in SHMS will be used for automatic processing between
the acceleration data reading component and the Modal Data Reader and viewer component within SHMS.

372

Flashnet’s Intelilight street lighting control and management solution will be used with the M&E Asset Managament
System to manage and maintain the streetlights. Intelilight is an intelligent remote lighting management system thatuses LONWorks (open protocol) to facilitate communication between each light pole in the street lighting grid andthe system. The M&E management system and Intelilight streetlight management system combined, will be utilized
to provide asset inventorization and tracking, service life prediction analysis, maintenance management andreporting functionality.
The Accident Information Management System (AIMS) within IAMS provides accident plotting feature among
other traffic collision information management capabilities which will be used by the Traffic and Accident Specialist
and the Road Safety Auditor to plan to study and report on traffic accidents on a monthly basis. AIMS will be used
as a Decision Support Tool to evaluate the safety and operational effects of geometric design decisions of theexpressway.
The Landscape Management System (LMS) is configured to manage all components of the landscape as assets. The
built-in analytics configured in LMS will assist in tree growth forecast, planning, budgeting, benefits calculation andmore. The system also caters for root cause analysis for recurring tree defect observations.

5. STRUCTURAL HEALTH MONITORING SYSTEM (SHMS)
The SHMS is the dedicated real-time monitoring system which comprise of static and dynamic sensors connected
via high speed Fiber Optic Backbone network, the high-end computer servers and network infrastructure and thesoftware solution with analytic capabilities. A modular concept has been approached in the design of the SHMS
with the intention to monitor structural condition and evaluate structural degradation as it occurs rather than detect
structural failure. These fundamental modules are describe in the ensuing sections.
Sensory System
This module comprises of a variety of sensors and their respective interfacing units used to measure the physicalparameters of the bridge structure and its surrounding environment. The measurements can be classified into fourtypes which are environment, operation load, structural feature and structural response.
Data Acquisition Unit
This module will be implemented in with two categories of equipment which are the Data Acquisition Units (DAU)(controlled with proprietary software) and the network systems (tethered) which facilitate the acquisition of data,processing them, temporarily storing them and transmitting it to the monitoring centres.
Data Processing and Controls
The Data Processing component of SHMS encompasses automatic conversion of the raw data into useable
information. It consists of data collection, transmission, pre-processing, analysis, post-processing, and storage andarchival of the data in a format that is easy to access and present. The main goals of data interpretation in connection
to the monitored structure are; structural identification during construction and operation, FE model updating,condition assessment, alarm configurations, service life prediction and maintenance planning. Data analysis may
allow for damage location and quantification as well as for condition assessment.
Structural Health Monitoring Component
The SHMC is a routine and automated process of signal transmissions picked up by the relevant DAUs duringcontinuous monitoring. In the event of detecting anomalous signals, a fault report will be generated to the system
maintenance team to investigate the data further. Corrective procedures shall be initiated and the fault report will be
kept in open status till normal operations are resumed.

373

When no anomalies are detected, the data processing and analysis module of SHMS will compare the measured data
against the defined performance criteria for loads, environments, bridge characteristic and bridge responses.
Performance criteria with definite threshold values will be defined and the signals transmitted will be comparedagainst these threshold values for anomalies. If no anomalies are detected, SHMC will continue to monitor andupdate the database for the purpose of reviewing and refining the monitoring criteria and also to produce thenecessary reports. These are carried out on routine. However, when any of these criteria is violated, the Structural
Health Evaluation component will be triggered.

Seismic Activities Monitoring using SHMS
A seismometer is installed at the yard of JKSB site office close to the bridge. It gathers up to one hundred (100)uninterrupted samples per second of the three axes and the server has the capacity to store up to three (3) years ofthese data. The seismometer is configured to issue an alert seismic activities peaks beyond 10 gal.
During, the earthquake that took place at Southwest of Sumatera, Indonesia (approximately 1500km away from
Penang) on 2nd March 2016, weak Peak Ground Acceleration readings were captured for all three axes. Though noapparent impact or damage was detected of the bridge, a weak signal of the earthquake is captured by theseismometer.
Similarly on 1st June 2016, an earthquake struck Kepulauan Mentawai Region, Indonesia which is approximately
820km away from Penang. Peak Ground Acceleration readings were captured for the three axes. While no apparent
impact or damage was detected for JSAHMS, the highly sensitive seismometer detects the weak signals of thequake.

Figure 7: Earthquake at Kepulauan Mentawai Region, Indonesia

374

Figure 8: Peak Ground Acceleration Readings captured for the Earthquake at Kepulauan Mentawai Region,
Indonesia.

375

6. BENEFITS OF IAMS DELIVERABLES FOR JSAHMS
The System Development stage for IAMS has been successfully completed and JKSB has embarked into theimplementation stage for the next six years. We are confident that IAMS shall provide us with the following
benefits:











Good Business Practice. IAMS results in better decisions. Aligning management of infrastructure withstrategic policies and direction will support the long-term success of the organization’s mission, goals andobjectives.
More Meaningful Financial Reporting. The reporting of the cost of asset ownership can be derived when acost element is included in the financial module of IAMS.
Improved Regulatory Compliance. Standards and best practices embedded within IAMS framework will
improve regulatory compliance for asset management. Part of asset management involves the implementation of
better O&M practices, which can significantly improve compliance.
Improved Reliability. More structured day-to-day attention to system assets and their condition means that
unexpected failures are less likely, thus minimizing emergency repairs and customer relations problems.
Assessing the risk implications of asset failure helps focus resources on critical priorities and reduces overallrisk to the organization.
Long Term System Integrity. The concept of “sustainable infrastructure” is gaining increased visibility,
probably due to the problems in many sectors where sufficient reinvestment in infrastructure has not been made.
By relating costs to asset condition and conducting long term planning for each asset, policy makers get thefacts they need to help sustain the infrastructure.
Cost Savings. There is evidence that asset management systems that maintain infrastructure in a sound andreliable condition and are based on minimizing life cycle costs, can significantly reduce operating andmaintenance cost, as well as long-term capital expenses. A life cycle approach means that the utility always getsthe most assets for its money.
Eligibility for Funding. The apparent need for increased infrastructure spending coupled with concerns overthe quality of infrastructure management prevalent in the industry have led to a range of provisions in proposed
funding legislation that include requirements for “asset management plans.” Although it is speculative at thistime, it is likely that qualifying for funding assistance in the future will require a demonstration of some level ofproper asset management.

376

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLEDEVELOPMENT OF SUSTAINABLE AND CUSTOMIZED ROAD ASSETMANAGEMENT SYSTEM INCORPORATING THE LESSONS LEARNEDFROM THE PAST INITIATIVES IN VIETNAM

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Bhoj Raj PANTHAManager

Katahira & Engineers
International

Japan

ORGANIZATIONCOUNTRY

CO-AUTHOR(S)(Capitalize Family Name

E-MAIL(for correspondence)

POSITION

pantha@katahira.com

KEYWORDS:
Road Asset Management, Customization, Sustainability, Database, Pavement Management System (PMS), Bridge
Management System (BMS)ABSTRACT:In recent years, Road Asset Management System (RAMS) is expanding in developing countries also with assistancefrom donor agencies. However, due to insufficient capacity of road administrator (human and financial) and lack ofcustomization of the system into local context, RAMS is operable only in few countries. This paper attempts to analyze
the reason of failure of past attempts of introduction of RAMS in Vietnam and introduce a new integrated RAMS which
is being developed in Vietnam for national roads (currently 21,000km) with assistance from the World Bank and JICA.
The new RAMS consists of sound road asset database with strict data quality control function, maintenance planningsystem for major road assets such as pavement, bridge and drainage. As for pavement, Pavement Management System
is developed and it consists of manly three modules, namely pavement deterioration evaluation, strategic budget
simulation (for long term plan) and repair work planning module (for short to medium term plan). Pavement
deterioration evaluation and strategic budget simulation modules are customized by importation from Kyoto Model
which was developed by Kyoto University, Japan. Pavement deterioration evaluation module evaluates the deterioration
speed considering the most influential factors using Markov Transitional Probability theory which is incorporated in
Kyoto Model. The strategic budget simulation with Monte-Carlo simulation is performed for three different scenarios(worst to best scenarios). Repair work planning module formulates annual and 5-year repair work plans with due
consideration of pavement deterioration speed. Similarly, Vietnam Bridge Management System formulates maintenanceplan based on bridge condition index which will be computed based on bridge inspection data. In addition to VPMS and
VBMS, other management systems such as drainage management system are also developed. For RAMS’s
sustainability, other activities such as development of maintenance and management manuals, pilot repair works andtrainings for central to field level staff are also carried-out.

377

DEVELOPMENT OF SUSTAINABLE AND CUSTOMIZEDROAD ASSET MANAGEMENT SYSTEM INCORPORATING
THE LESSONS LEARNED FROM THE PAST INITIATIVESIN VIETNAM
Dr Bhoj Raj Pantha1,2,3
1Katahira & Engineers International, Tokyo, Japan
Deputy Project Manager, Vietnam Road Asset Management Project, Component A-1
3
PMS System Technology Expert, JICA Project for Capacity Enhancement in Road Maintenance inVietnam
Email for correspondence: pantha@katahira.com
2

1. INTRODUCTION
Road transportation infrastructures are backbone of development for every country. Many countries
have been making significant investments in road transport infrastructures. These infrastructures are used andexposed to natural forces, therefore their condition deteriorates over the time due to infrastructure aging,traffic loading and degradation due to natural exposure. It is challenging to all level of road agencies varying
from central to local level to preserve the functionality of the existing transportation system while at the sametime funding expansions of the transportation network to cope with the increasing demands. In developed
countries, there is a gradual shifting of investment policy from new construction to maintenancemanagement. However, in developing countries including countries with high economic growth rate,
investment in new construction (i.e. expansion of road network) and maintenance of existing roadtransportation network are equally important. To cope with such kind of balancing investment approach, asystematic approach is needed to optimize the resources. In this regard, Road Asset Management System(RAMS) can play a crucial role by assisting decision maker to take appropriate decision. Road asset
management is a systematic process of effectively maintaining, upgrading and operating road assets,
combining engineering principles with sound business practice and economic rationale, and providing thetools to facilitate a more organized and flexible approach to making decisions necessary to achieve thepublic's expectations.
Road asset management offers a discipline for integrating asset data in a way that facilitates its use
for decision-making. It provides a framework for managing road networks using a long-term perspective,
rather than the relatively short-term view currently adopted by many road operators. These all contribute toimproving the ability to deliver services in the long term, which is one of the catalysts for the implementationof modern asset management systems. According to the Organization for Economic Cooperation andDevelopment (OECD), a sustainable road asset management system should include:• Data collection methods that are affordable, appropriate and provide relevant information;• Road information management system (or database management system) that is flexible andcapable of producing both standard and ad hoc reports;• A decision support system that can be used to investigate the consequences of various
management decisions and strategies; and• Adequate management information that are practical and pertinent to the needs of roadorganizations.
Figure 1 shows the key components of road asset management system. Asset management is a datadriven process that provides road operators with a very important analysis capability. Therefore, reliable andgood quality data are indispensable and those data can make available only by collecting with standard
method and stored in proper database management system.

378

Source: Asset Management for the Road Sector, OECD
Figure 1. Components of Road Asset Management System
2. PAST AND ONGOING INITIATIVES OF INTRODUCTION OF RAMS IN VIETNAM
Since 1998, several attempts have been made to implement RAMS in Vietnam under technicalassistance from the World Bank (WB), Asian Development Bank (ADB), Japan International Cooperation
Agency (JICA) and other donors. A number of decrees, decisions and circulars are promulgated and available
in relation to road asset management in Vietnam. These regulatory provisions have been revised timely tocope with actual demands. Nevertheless, the actual implementations are not satisfactory due to various
circumstances including mainly institutional issues, lack of trained human resources, and software issues.
Table 1 shows the status of RAMS introduced in the past and their operational status at present in Vietnam.
Table 1. Existing RAMS software in Vietnam
Computer
SoftwareOperability

Pavement Management System (PMS)
VPMS
Operational (Upgrading)
HDM-4
Non-Operational
RoSyBASE
Non-Operational
RoSyPLAN
Non-Operational
RoSyMAP
Non-Operational
VPRoMMS
Operational (some provinces only)
RoadNAM
Non-Operational (license issues)
Bridge Management System (BMS)VBMS
Operational (Upgrading)
Bridge CV
Operational(Hard-Copy)
Asset Valuation System
National Asset
Operational
Database

National Roads
DRVN
RMBs PDOTs
√
√
√
√
√

√

√*

√

√

√

√
√

√

√

√

√

√

√

√

√

√

Provincial Roads
PDOTs
PPCs

√
√

√

√**

√**

√

√

Note: * Technically operational if same quality of data are collected and used for PMS** Currently under upgrading to make applicable in provincial roads
DRVN: Directorate for Roads of Vietnam
RMB: Road Management Bureau,
PDOT: Provincial Department of Transport
PPC: Provincial People’s Committee379

In the recent year, priority has given in development of bridge and pavement management system
including database, however in the very short time, there are other several assets which also needs to be
managed and maintained. The Decree No.10/2013/NĐ-CP promulgated on January 11, 2013 (Themanagement and use of road transport infrastructure assets) recognizes a total of twenty-eight (28) roadfacilities as road asset which have to be properly maintained and asset values have to be estimated andreported to Ministry of Finance (MOF) annually. Recently, Government of Vietnam has established theRoad Maintenance Fund (RMF) in order to secure sustainable maintenance fund to provide needed
maintenance budget to the road operators. Decree No. 18/2012/NĐ-CP promulgated on March 13, 2012
(Road Maintenance Fund) guides the utilization of RMF. According to Decree No. 18, a systematic
maintenance plan shall be prepared and submitted to RMF council for approval.
In this section, attempt is made to review RAMS established in the past in Vietnam. DRVN RAMS
introduced in the past are briefly reviewed as below.
(1)

Database System

So far DRVN has no comprehensive road database system which become fully operational. In thepast, it was decided to use RosyBASE as official road database system in DRVN. However, it could notreach to operational level due to various circumstances including system related issues and data quality. Road
data collected and inputted in the system in 2007 resulted to the waste of resources due to incapability of thesystem to control the quality of data while inputting.
(2)

Highway Development and Management-4 (HDM-4)

HDM-4 is a software package exclusively developed for pavement management system. HDM-4
serves as the primary tool for the analysis, planning, management and appraisal of road maintenance,
improvements and investment decisions. HDM-4 has four main areas of application; strategic planning,
roadwork programming, project analysis and research and policy studies. In Vietnam, HDM-4 wasintroduced in 1998 in the first time to the national road network, since then, six trials had made from 2001 up
to 2006 with assistance from the World Bank and Asian Development Bank. Some international consultants
had conducted the analysis to prepare three-year work programs under technical assistance projects. HDM-4
is still in use fat project level specially for economic analysis of the projects funded by the World Bank.
Since HDM-4 has no dedicated database system to feed data into the system, it has to be rely on
external database/dataset. In the past, DRVN had practiced to prepare HDM-4 dataset in MS-Excel format aswell as converting from database management system such as RosyBASE. Pavement condition data werecollected in different times were populated in MS-Excel format and imported in the system for running
HDM-4. In 2007, DRVN (then Vietnam Road Authority; VRA) had decided to use HDM-4 as official
planning system and RosyBASE as official database system for managing national road network in Vietnam.
In order to integrate HDM-4 and RosyBASE as planning system and database respectively, an interface had
developed to convert data from RosyBASE to formulate HDM-4 dataset. In 2007, when RosyBASE wasdecided as an official database system, VRA has collected necessary data by its own fund first time to input
data in RosyBASE. However, due to poor quality of data inputted in RosyBASE, the data conversion
interface could not work properly thereby arising system error. As a result, integration of HDM-4 andRosyBASE could not be successful which eventually forced to DRVN to abandon both systems and opt foralternative. Thus, HDM-4 could not be a management system for DRVN to manage entire road network till
now.
(3)

Rosy System

The Rosy system consists of four (4) components; RosyBASE, RosyPLAN, RosyMAP and
RosyADMIN. A full set of Rosy was introduced to DRVN headquarter and four (4) Regional Management
Bureau (RMB) in 2005. In 2007, RosyBASE was endorsed as official database system of DRVN. Under
Special Assistance for Project Implementation Phase II (SAPI II) in 2008, Rosy’s trial runs were conducted
and revealed that unidentified errors caused the failure of trial runs. Due to termination of contract with Rosy
supplier, system trouble could not fix at that time. Analytical function of the RosyPLAN customized for
DRVN was presumed as same as the program analysis module of HDM-4. None of the Rosy system except

380

RosyBASE had used as official system for management of road network in Vietnam. Therefore, RosyPLAN,
RosyMAP and RosyADMIN had not reached to operational level in DRVN in the past.
(4)

Vietnam Pavement Management System (VPMS)

Since 2011 Vietnam Pavement Management System has been developed under JICA TechnicalCooperation Project; The Project for Capacity Enhancement in Road Maintenance in Vietnam. In JICA Phase
I Project implemented in the period from 2011.09 to 2014.04, VPMS had been developed for national roadunder jurisdiction of RMB I region as pilot region. JICA Phase II Project which is being implemented fromFebruary 2015 to upgrade the outputs of the JICA Phase I Project to make them applicable to the nationwide
national road network in Vietnam. In JICA Technical Cooperation, DRVN is also involving actively in its
development and technology transfer activities which have been conducting through seminar, workshop, onthe-job training and working group meeting.
VPMS has been developed taking consideration of lessons learned from past attempts ofintroduction of RAMS and their operational status in DRVN. VPMS framework was designed taking
consideration of importance of dedicated PMS database, data quality assurance, management need of DRVN,
technology transfer, user friendly operation, etc. VPMS has its own database which will provide necessary
data to run it. As pavement condition data are key for pavement maintenance planning, pavement condition
data collection vehicle has also been provided to DRVN to ensure the quality and consistency of pavement
condition data. Therefore, in the framework of VPMS, it does not only consider the computer software formaintenance planning but also the data collection, dataset preparation, database management, displaying
pavement condition data on the GIS map (for monitoring), and pavement data analysis system in the same
all-in-one software package.
VPMS consists of three main modules, namely pavement deterioration evaluation module, strategic
budget planning module and repair work planning (medium-term and annual plan) module. Based on the
result of pavement deterioration evaluation module (i.e. pavement deterioration prediction), VPMS canformulate strategic budget plan, medium-term (5 year) repair work plan, and annual repair work plan.
(5)

Vietnam Bridge Management System (VBMS)VBMS has been developed under JICA Transport Sector Loan Project as a standalone system.
Development of VBMS and bridge data collection and inputting was conducted under transport sector loan
project. The bridge database operates in the web-based system and data are coded in GIS format as well.
Currently Second Transport Sector Loan Project (Component B) is improving and applying VBMS for
formulating bridge maintenance plans.
VBMS consists of four (4) modules, namely inventory module, bridge inspection module, planning
module and system administration module. Inventory module manages inventory information, providing
inventory information for the annual report. Bridge inspection module manages periodic inspection
information, conditions and evaluation results of technical state. Similarly, planning module enables toevaluate investment scenarios by applying bridge condition index of bridge.
(6)

Asset Valuation System

Ministry of Finance (MoF) has developed asset management system in accordance with Decree No.
52/2013/NĐ-CP promulgated on June 03, 2009 (Management and Use of State Properties). DRVN is alsousing the same system for road assets. Department of Finance (DoF) of DRVN is in charge of managing asset
database on national roads under management of RMBs and Provincial Department of Transport (PDoTs).
The unit asset value is defined by asset type, class of asset, classified type of asset and terrain. The asset
value is stored in the Asset Valuation System, however, those data are manually calculated and does not haveany function to calculate asset value by connecting to asset database. The value of the asset constructed
before 1st March 2013 was calculated by unit price per kilometer which depends on road class, terrain type,
etc.
(7)

Other Management System

381

There are no other management systems exist in DRVN to manage road assets other than pavement
and bridge neither in the past nor at present.
3. LESSON LEARNED FROM THE PAST INITIATIVESIn the past, road network data were collected by different departments without integration and rigid
quality control due to absence of systematic road network data collection and evaluation procedure. Past
attempts to introduce RAMS in DRVN were not successful mainly due to institutional issues and thecomplexity of the proposed systems. Also it has been pointed out that past technical assistances from thedonors have been focused on providing technology and equipment, rather than human capacity development
and its process. Through the analysis of failure of the past attempts in data collection and introduction of roadasset management system in DRVN the following failure reasons are identified:• Absence of database in asset management system; database is a base for asset management system• Lack of clear responsibilities assignment among DRVN departments• Lack of trained human resources• Lack of adequate budget for data collection and database management• Lack of ownership (none of department took the ownership
These all problems analysis and efforts for improvement were made under JICA SAPI Study (Phase
I and Phase II). As a recommendation of SAPI Study, JICA and DRVN agreed to develop new VBMS and
VPMS including database. As a result, with assistance from JICA, development of VBMS and bridge datacollection and inputting have been carried out under transport sector loan project. Similarly, development of
database framework, pavement management system and pavement condition data collection of RMB I havebeen carried out by JICA Phase I and Phase II Projects in collaboration with DRVN.
Taking the past lessons and ongoing development initiatives by DRVN into account, a new RAMS
by integrating existing VBMS and VPMS is now under development under Vietnam Road AssetManagement Project (VRAMP) with assistance from the World Bank. A new RAMS is being developed bypaying attention varying from fundamentals of asset management system to its long lasting sustainability, as
well as to capacity building / technology transfer in the overall cycle of road asset management.
4. FRAMEWORK FOR DEVELOPMENT OF A NEW CUSTOMIZED RAMS IN VIETNAM
As of December 2014, the total length of road network in Vietnam has reached to 309,832 km, of
which national road is 21,109 km, provincial road is 26,218 km, district road is 53,299 km, commune road is
178,294 km, urban road is 20,076 km and exclusive road is 10,836 km. Currently, roads are managed by
Directorate for Roads of Vietnam (delegated to RMBs), Provincial Department of Transport, Build Operate
and Transfer (BOT) operators. With the increase in road length, the challenges in their maintenance andmanagement have also increases due to budget constraint in road maintenance. Therefore, the systematic andscientific decision making tools is needed for road operators to allocate the maintenance budget efficiently inorder to ensure safe and smooth traffic operation.
Thus, framework for development of a new customized RAMS is developed by reviewing of allconcerned regulatory provisions, assessing needs of each concerned institution, capacity development of
human resources and taking account of lesson learned from the past initiatives. The following framework areconsidered to develop customized RAMS in DRVN.
(1)Asset Database

Road asset database is a major components of DRVN RAMS. Therefore, database framework is
prepared by thoroughly reviewing regulatory provisions (including data required as per Decree 10/2013/NĐCP and Decree 18/2012/NĐ-CP), data necessity of all concerned organizations and data requirements for
management systems such as VPMS, VBMS, drainage management system and other asset management
system. A total of 39 road assets are considered as road assets to include in the road asset databaseframework. In addition to these road asset specific data, maintenance history and condition data of majorroad assets, traffic volume data, road administration data, traffic accident data, etc. are also included. Sincemany organizations from central to field levels are the prospective user of road asset database, the number of382

data items is comparatively high. Therefore, in order to optimize the resources effectively and efficiently,
data collection priority has been defined.
Table 2. List of Assets included in Road Asset Database

Asset / Data Group

Asset Group

No.

Asset Name

Data Input Priority

Stipulated in Decree 10

Urgency for formulating
maintenance plan

Directly Related to Road
Traffic Operation(Facilty in road surface)

Road Side Facilities
which affect on roadtraffic operation andsurrounding environment

Criteria for Data Collection Priority

GeneralInformation

-

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48

Road Administration Data
Road M ain Details
Road Overlap Section
International (Asian/Asean) Highways
Road (Pavement)
BridgeRoad Tunnel
Ferry Terminals
Underpass (Box culvert)
Retaining Wall
Road Slope (Protection Work)
Box Culvert
Pipe Culvert
Roadside Drain
M anhole
Drainage on the Road Slope
Spillway / Causeway
Road Intersection
Railway Crossing
Pedestrian Crossing Bridge
Intellegent Transport System (ITS)
Weigh Stations
Toll Booths
Traffic Lights
Road Lighting
Road Signs
Road Surface M arking
Guardrails / Guide Posts
Barrier
Road Separators (M edian Strip)
M ilestones (kilo post)
Noise Barrier
Shade Fence
Parking Lots / Rest Stops / Service Area
Bus Stops
Bus Terminals
Road Disaster Response Facility
Road Administration Office
Utilities within ROWLand belongs to Road Asset
Highway Inspection Vehicles
Rescue Vehicle/Equipment
Ferries
Traffic volume
Pavement, Bridge, Drainage, etc.
Pavement, Bridge, Drainage, etc.
Traffic Accident Record Data
Black Spots

I
I
I
I
I
I
II
II
II
II
III
I
I
I
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I
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-

Road Transport Infrastructure Assets(Fixed Assets)I

M ain Structures

II

Slope Works

III

Drainage Work

IV

Crossings

V

ITS & Fee
Collection

VI

Road Side Workfor Traffic Safety

VII

Building andService Area

VIII Land and Utilities
O&M Vehicle and Equipment
Traffic Volume
Asset Inspection (Condition) Data
Asset M aintenance/Repair History Data
Traffic Safety & M anagement

IX

M ovable
Equipment-

Road asset database is designed for web-based and cloud computing technology. The proper
attentions have been paid for web-security, load balancing, data backup system, etc. The database will be
relational among related databases, connected with GIS maps and linked with state asset database. Figure 2
shows the conceptual image of road asset database structure.

383

State AssetDATABASE

INTERNETi-CLOUDDRVN GIS Map Server

Pavement

5

4

3

2

BridgeDATABASE........

DRVN........

Drainage1Tunnel

6

5

4

3

Road
Slope

2

1

Traffic
Light

Road
Intersection

11. Road Asset Inventory Database
22. Maintenance History Database
33. Pavement Condition Database

4 Traffic Volume Database
55. Bridge Database
65. Other Databases of DRVN

Figure 2. Conceptual Image of Road Asset Database Structure(2)Road Asset Management System (RAMS)Taking consideration of requirements of DRVN and lessons learned from the past attempts ofintroduction of RAMS and their current operational status in DRVN, the following key criteria are applied inselecting RAMS for DRVN.
Table 3. Key Criteria for Selection of RAMS for DRVN
1. Availability of In-built Database
2. Availability of Management Functions
Required for DRVN
3. Possibility of Integrating Different
Management System
4. Possibility of Customization into
Vietnamese Context
5. Possibility of Editing and Updating the
System

6. Optimization of Currently Available Resources in DRVN
7. Compatibility to Cloud Computing and Web-based
Technology
8. Availability of External Technical Support for System
Maintenance and Management
9. User Friendly Operation

RAMS that had been attempted to introduce in the past and Commercial-Off-The-Shelf (COTS)
were evaluated with the above key criteria and decision was made to develop a new customized RAMS byintegrating VPMS and VBMS which are under development. RAMS is developed in a flexible platform using
local IT consultant so that it can be updated whenever necessary. The components of DRVN RAMS are
shown in Figure 3.

384

State Asset
Database

INTERNETi-CLOUDRoad Asset
PMS: Pavement Management System
BMS: Bridge Management System

Database

GIS Server

MS: Management System

Figure 3. Components of Vietnam Road Asset Management System(i)

Bridge Management System

Vietnam Bridge Management System (VBMS) which has developed under Transport Sector Loan
(TSL) Project and being upgraded is to be integrated into the DRVN RAMS. VBMS has mainly four
modules, namely administration, inventory, inspection, and planning modules. VBMS is already in operation
under DRVN and PDOTs. VBMS has also been integrated with GIS map. Bridge Condition Index (averageand critical; BCIavg and BCIcrt) is used as a key index for bridge maintenance planning. The maintenanceplanning flowchart is shown in Figure 4.

Figure 4. Maintenance Planning Flowchart and Sample Output (approx. 4,300 bridges)(ii)

Pavement Management System

385

Vietnam Pavement Management System (VPMS) which is being upgraded under JICA Phase II
Project in collaboration with DRVN is to be integrated. VPMS is being developed with its own PMS
database and the pavement condition data are to be collected by data collection vehicle provided by JICA for
assuring data consistency and accuracy. VPMS can formulate a strategic budget plan (long term) and a
medium to short term budget plan (annual and 5-year) based on pavement deterioration speed. Pavement
deterioration evaluation and strategic budget simulation modules are developed by importation from Kyoto
model; developed by Kyoto University, Japan. Pavement deterioration evaluation module is developed using
markov transitional probability theory (hazard model). PMS has three main modules, namely pavement
deterioration evaluation module, strategic budget simulation module and repair work planning module.
Budget simulation can be performed by three scenarios; maintain current budget level (worst scenario),
maintain current pavement condition level and maintain target management level (best scenario). Similarly,
repair work planning module assist in formulating annual and medium term repair work planning by due
consideration of deterioration speed. Some outputs of VPMS are shown in Figure 5.
Case-1: Current Budget Level
Cracking condition
100%
80%

60%
40%
20%

0%
1
50<=C

3

5

40<=C<50

7

930<=C<40

11 13 15 17 19 21 23 25 27 29
Year
20<=C<30

10<=C<20

0.1<=C<10

0<=C<0.1

Rutting condition

Pavement Deterioration Evaluation by Route

100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
0%
1

3

40<=R

5

7

9

30<=R<40

11 13 15 17 19 21 23 25 27 29
Year
20<=R<30

10<=R<20

0<=R<10

IRI condition
100%

80%
60%
40%

20%
0%

1
12<=IRI

Simulation Outputs of Three Scenarios

3

5

10<=IRI<127

9

11 13 15 17 19 21 23 25 27 29
Year

8<=IRI<10

6<=IRI<8

4<=IRI<6

2<=IRI<40<=IRI<2

Deterioration Transition for Case I and Case II

Note: The output of repair work planning module consists of repair section information of each 100m section(kilometer post information), repair work type, repair work priority (based on Maintenance Control Index),
repair work quantity, repair work unit cost and repair work cost.
Figure 5. Output of VPMS run for National Road Network (approx. 4,700km) under RMB I Jurisdiction(iii)

Drainage Management System (DMS)

Road drainage system is one of the important factors in deteriorating pavement condition andsurrounding environment. Though it does not directly relate to traffic operation, the improper management ofdrainage system may adversely effect on pavement layers including sub-grade, shoulder erosion, inundation386

on road surface, etc. Unlike pavement deterioration forecasting, deterioration of the drainage system cannot
be predicted. Therefore, drainage inventory and inspection data should be utilized for maintenance planningof drainage system. The following three main modules are considered for development of the drainage
management system.
a.

Inventory Module

The inventory module manages the inventory data related to the drainage system. The inventory data
includes data of cross-sectional drainage system (box culvert, pipe culvert), longitudinal drainage system(road side drain), slope drainage system (catch drain), and tunnel drainage system.
b.

Inspection Module

As inspection data will be the main data for maintenance planning of drainage system, the inspection
module will manage the inspection data and the result of diagnosis (evaluation). Inspection items andevaluation method will be followed as provisioned in the Road Facility Inspection Guidelines which is being
drafted under JICA Phase II Project in collaboration with DRVN.
c.

Planning Module

The planning module will assist in preparing a maintenance plan for the drainage system by utilizing
the inspection evaluation results. The planning module will produce a maintenance plan by consideration ofseverity of damage (damage grade B, C, D), frequency of flood incidents, importance of road sections, etc.
Prioritization method should be considered in the RAMS development.
(iv)

Other Asset Management System

The management system for other assets, whose deterioration prediction cannot be estimated,
similar management system as recommended for drainage system will be applied. Therefore, inventory dataand inspection data will be the major data requirements. The other asset management system can be
developed in DRVN RAMS as necessary with the same approach as described for drainage management
system.
(v)
Asset Valuation System
Asset valuation system developed by MoF is to be integrated into RAMS.
(3) Data Collection Plan
Since DRVN is developing this scale of RAMS first time and past data are neither sufficient nor
fully consistent with the new RAMS database framework, data collection plan for feeding data in the system
are also planned. For the short term, a multi-year data collection plan is prepared to collect inventory andcondition data. Once inventory data are collected and stored in the system, annual update is necessary
whenever there will be a big scale repair work and new construction. Since condition of pavement andbridges will be deteriorated due to several reasons including traffic loading, a periodic condition datacollection is necessary. Therefore, such periodic data collection plans are also prepared. Based on the multiyear data collection plan, data collection work is ongoing and planned to complete within next 3 years.
(4) Capacity Building / Trainings
RAMS is a complex system and users are different level varying from asset maintenance planner tofield level engineer for traffic operation and management. The sustainability of the system greatly depends onthe effective technology transfer during the system development phase. Therefore, attention has been paid in
effective technology transfer to all level of users. Training plan is prepared for “during the project” and “after
the project”. During project, seminar, workshop and On-the-Job-Training (OJT) both by using computer aswell field visit are planned. The courses are designed for professionals as well as for Trainer of the Training(TOT). Training materials for all training courses are to be prepared and provided to all concernedorganizations and officials.

387

6. CONCLUSIONS
Investment in road transport infrastructures is huge and for several decades. There is direct
relationship between road transport infrastructures and socio-economic activities in the regional scale.
Therefore, if road transportation system does not perform properly, there are multiple effects in various
fields. Therefore, preservation of road transport infrastructures is very much important not only forpreservation of road facilities but also maintain the chain of socio-economic activities. Since road network in
Vietnam is expanding rapidly, many of the aged structures needs to be maintained properly and past attempts
of introduction of RAMS were not successful due to various circumstances, development of a customized
RAMS to make it more sustainable is necessary. Under Vietnam Road Asset Management Project funded by
the World Bank (Component A-1), an integrated RAMS is designed to develop locally by customizing theforeign practices into Vietnam. RAMS under development consists of many components of RAMS including
a comprehensive web-based road asset database, VBMS, VPMS, DMS, multi-year data collection plan anddata collection provision and effective training programs. It is anticipated that upon completion ofdevelopment of RAMS, it will be a milestone for management of road transport infrastructures effectively
and efficiently in Vietnam. Also, it is expected that this approach of RAMS development will be a model fordevelopment of RAMS in Southeast Asia.
7. ACKNOWLEDGEMENTS
Author would like to express my sincere appreciation to all persons and institutions who are directly
and indirectly involve in two projects, namely “Vietnam Road Asset Management Project, Road Database
Framework and Development of the Road Asset Management System and Road Asset Management Plans(Component A-1) and “JICA Project for Capacity Enhancement in Road Maintenance Phase II” for providing
necessary information related to respective project. Author would also like to acknowledge to all project teammembers of two project for their cooperation in preparing this paper.
REFERENCES
Japan International Cooperation Agency, Katahira & Engineers International, NEXCO-Central, Oriental
Consultants Co. Ltd. (2014). Final Report on JICA Project for Capacity Enhancement in Road
Maintenance in Vietnam Phase I. Project Report, Directorate for Roads of Vietnam and Japan
International Cooperation Agency.
JICA Project Team (2016). Progress Report on JICA Project for Capacity Enhancement in Road
Maintenance in Vietnam Phase II. Project Report, Directorate for Roads of Vietnam and Japan
International Cooperation Agency.
JICA Project Team (2026). Guidelines for Road Facility Inspection. JICA Project for Capacity
Enhancement in Road Maintenance in Vietnam. Directorate for Roads of Vietnam and Japan International
Cooperation Agency.
JICA Project Team (2015). Work Plan for JICA Project for Capacity Enhancement in Road Maintenancein Vietnam Phase II. Project Report, Directorate for Roads of Vietnam and Japan International
Cooperation Agency.
Katahira and Engineers International (2016). Inception Report on Road Database Framework andDevelopment of Road Management System and Maintenance Plans. Project Report, Directorate for Roads
of Vietnam.
Katahira and Engineers International (2016). Database Framework Design and RAMS Requirement
Specification. Project Report, Directorate for Roads of Vietnam.
Katahira and Engineers International and Oriental Consultants Co. Ltd. (2009). Final Report on Special
Assistance for Project Implementation Phase II (SAPI II) for Transport Sector Loan for National Network
Improvement. Project Report, Japan International Cooperation Agency.
OECD (2001). Asset Management for the Road Sector, OECD Publication Service, Paris.
World Road Association (PIARC) (2005). Highway Development and Management – 4 (HDM-4),
France.

388

2nd IRF Asia Regional Congress & Exhibition Kuala Lumpur, 16-20th October, 2016
The Influence of Trips Generated From New Projects Development
to the Efficiency of the Road Network
Badrul Bin Rahim(Planner, Highway Planning Division)
Ministry of Works
Dr Jamilah Mohd Marjan(Under Secretary, Highway Planning Division)
Ministry of Works

Abstract
Urbanization has a significant impact on the future performance of surrounding road network. The
Municipalities or Local Authorities who plan, manage and approve future land use, play a crucialrole to address the impact of urban growth, which causing severe congestion onto the current road
network. Policies and tools used for new development traffic impact evaluation are critical todetermine the performance of road network for a more balanced and sustainable environment inurban area to be achieved. Thus, the present approach of approving new development project byLocal Authority in relation to traffic needs is to be revisited. Trip generation of every proposed land
use activities need to be evaluated on its impact to current road network capacity. The traffic
evaluation should not merely focus on the proposed development site, rather it should be explored to
improve surrounding impacted road network for more comprehensive solution surrounding vicinity.
This paper trigger the need for new approach or better policies to ensure urban growth and road
network capacity can be equally prioritised.
Keywords: Land use planning, trips generation and attraction, congestion, capacity and efficiency ofroad network.

Introduction
Currently, rapid development occurring along the main road network is an undeniable trend in urban
area. In fact, high accessibility to main road network became the most significant reason for new
development to keep encroaching to available nearby land. In the developer’s perspective, every new
development will be exploiting the advantage of current road network capacity towards making themost profit by having more complex development including mix used of high rise building.
However, through continuous urbanization process, the generated traffic from complex land use
activities has resulted road network capacity reached to its maximum. The more traffic induced willdefinitely deteriorate road network performance. Thus resulting in human tension, wastage of time onroad, high cost of transport and the worst, it contradicts our mission to achieve a low carbon city.

389

Thus, this paper focus on investigating how trips generated from new developments can influence theroad capacity and road performance. In order to do this a pilot study was carried out to compare andobserve the before and after situation in the Subang Jaya and Puchong Area.

Methodology

The methodology used in an effort to match the development of an area to the road capacity is asshown in four stages below:
Stage 1: A study area with a very high rate of development was chosen
Stage 2: Analyse satellite images of 2 different years 2006 and 2016 to look at the urbanization
process and how it effect to road network.
Stage 3: Study of the road network and its capacity
Stage 4: General Trip generation evaluation
Nevertheless the fourth stage of computing the trips generated from the development was not carriedout at this stage.
The municipality area chosen for a pilot study were Sunway, Subang Jaya and Puchong. The twoareas are adjacent to one other and are flanked by a network of non-tolled and tolled urban
expressways. Figure 1 shows the study area.

Figure 1: Map of Subang Jaya and Puchong Area
(Source Google Maps)390

Both Subang Jaya and Puchong has a total area of approximately 70sq.km and 51.7sq.km
respectively. Both these areas are quite similar in terms of development. The land use makes up ofresidential, industrial, commercial, schools and higher education, with amenities like hospitals,
shopping malls, hypermarkets and many others. The ready catchment of 500,000 population within
Bandar Sunway and Subang Jaya including 50,000 students coupled with the 40 million visitations
per annum attests to the existing high rate of the development in the area.

Photo1: Picture of the highly developed Sunway, Subang Jaya Area

The two areas are serviced by the earlier mentioned highways which are the KESAS Highway (E5),the New Pantai Expressway (E10), the Damansara–Puchong Highway, LDP (E11) and the untolled
Federal Route 2 from Klang to Kuala Lumpur. Even today, the area is still being developed, years
after all the above road network has been in operation.

Analysis of Satellite Images
Satellite images of the said area were obtained from the Remote Sensing Department to see thedifference in development that has occurred over the last 10 years, between 2006 and 2016. Figure 3
shows the difference in both the land use pattern and the road network. At this stage the type of land
use and the computation of the trips generated was not done. However it is obvious that developmentin the area has increased, thus resulting in increased traffic. It can be seen that the expansion at theinterchanges are also carried out. These are examples of road infrastructure improvement carried out
either by the Government or by the developer themselves. However if it was done by the Government,
then it is only appropriate for the developer to share the expenses on the construction of the road
expansion. There is an existing policy in place where, the developers are required to pay for any
intersection improvement but not on the road links. Figure 4 shows similar change that can be seen
between land use and the road network.

391

Figure 3: Change in Land use pattern between 2006 and 2016

Figure 4: Change in Land Use Pattern and Road Network

392

However, there are many cases where the new developments are approved without any improvement
to the road infrastructure. Cases where the Level of Service (LOS) has almost reached capacity, yet
the Municipalities or Authorities concerned are approving projects without the traffic analysis of theroad network in the vicinity. For large developments, analysing using traffic models should be
imposed onto the developers for introducing new traffic onto existing highways. There are also
instances where upgrading of the existing roads are simply too costly, therefore there must be a limit
to the scale of project development that can be approved.

Road Network Analysis
In gathering evidence to show that there is an increase in traffic volume, the traffic along the New
Pantai Expressway (E10) and LDP (E11) was used. The traffic over the 8 years more than doubled
that in 2006. Similarly there is also an increase on the LDP, more than double in 6 years.

Table 1: Average Daily Traffic on NPE at Pantai Dalam (E10)(Source: Road Traffic Volume Malaysia, HPU, KKR)
2006
2014
Class1
37,564
95,311
Class 2371
950
Class 3
166
651
Class 42233
4,319
Class 5
135
284
Total
40,460101,516Class1
Class 2
Class 3
Class 4
Class 5
Total

Table 2: Average Daily Traffic on LDP at Pencala (E11)(Source: Road Traffic Volume Malaysia, HPU, KKR)
2006
2014
45,291
127,802
1,263
1,905
890
1,313
3,517
54
302
47,922
134,416

Thus there is a relationship between development and traffic increase. In depth study on the trips
generated is a pre requisite before any approval is given. For big developments a traffic modellingshould be insisted, not simply a Traffic Impact Assessment study will suffice.

393

Figure 5 shows if not all, some of the amenities in the Puchong area. Even today there are still new
development in the Puchong area despite the fact that the LDP (E11) is congested. Photo 2 shows thecongestion near the toll booth on LDP.

Figure 5: Amenities in the Puchong Area

Photo 2: Congestion on the Damansara-Puchong Highway (LDP)394

Land Use Control Mechanism
Municipality produces land use zoning map as part of the mechanism to control new development asshown in Figure 6. Land use zoning map indicates in details future land use activities of every land
plot as well as plot ratio and plinth area for free standing building, number of floor, and size.
However, this mechanism is to be insufficient because induced traffic to mainline is not wellmanaged. Current TIA evaluation only focus on intersection and internal road network of new
development, induced traffic of overall development continuously contribute more traffic on mainline
network without any threshold to manage its capacity.

Figure 6: Land Use Zoning in Subang Jaya

Trip Generation
Trip generation is the first step in forecasting travel demands followed by trip distribution, mode
choice and route assignment. It predicts the number of trips originating in or destined for a particulartraffic analysis zone. For a big development which generate and attract trips greater than somethreshold level, some consideration of charging the developer for the use of the road network should
be considered. This is to ensure that the existing road capacity is sustainable or otherwise thedeveloper should share the cost of building additional extension to the existing road network to caterfor the induced traffic due to the new development.
A good example is Puchong and Sunway, Subang Jaya. Over the years the rate of development in thearea has caused an increase in traffic multiple times over. The six lane dual carriageway, DamansaraPuchong Highway (LDP) has long reached capacity especially during peak hours as can be seen in
Figure 3. There are alternative routes but the urban dwellers in its rat race chose to pay their way inorder to save time. The daily congestion has caused public outcry, insisting the Government to solve395the traffic woes. There seem to be no control on the development in Puchong especially the residential
land use. Condominium after condominiums have been approved, without the Municipality nor theFederal Government charging on the use of existing roads not towards the expenditure to expand or
maintain the roads.
Typically, trip generation analysis focuses on residences and residential trip generation is thought ofas a function of the social and economic attributes of households. At the level of the traffic analysis
zone, residential land uses "produce" or generate trips. Traffic analysis zones are also destinations of
trips, trip attractors. The analysis of attractors focuses on nonresidential land uses.

There must also be a clear definition of land use categories for trip generation purposes. In Malaysia,
the Highway Planning Division in the Ministry of Works has published The Trip Generation Manual
to assist the planners and engineers to predict traffic from new developments to see if theinfrastructure is adequate. The approving Authority must also have a clear understanding of what kindof land use development should they approve if the surrounding infrastructure has already reached its
network performance without any chance of expansion. Land use change – acreage of land use forhousing, industry and commercial may have to be re-studied.

Conclusion & recommendation
The municipalities or the road authorities must not be the only parties responsible in providing asmooth, comfortable and safe road facility as means of land transportation. The need to maintain roadcapacity by applying traffic threshold to ensure better road network performance is required. This
responsibility must be shared by the developers using the road network in the vicinity as access. The
possibility of traffic charges induced be chargeable to the developers, not only at intersections oraccess but through the use of the link itself, should be made possible with careful study and guidelines
should be developed.
Traffic evaluation process for new development project need to be revisited by stressing on road
network capacity and the implementation of traffic charge based on trip generation as continuous road
network improvement need to be implemented.

Acknowledgement
The writers would like to express their gratitude to Malaysia Remote Sensing Agency for support withsatellite images as well as Ministry of Works for supporting this effort.

References
1. Trip Generation Manual 2010 Malaysia, Highway Planning Unit, Ministry of Work.
2. Road Traffic Volume Malaysia, Highway Planning Unit, Ministry of Work.
3. Subang Jaya Municipal Council Local Plan 2020, Town and Country Planning Department
Peninsular Malaysia.

396

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Operators’ and Users’ Perspective on Service Quality Dimensions of Toll Road
PPP

TRACK
AUTHOR(Capitalize Family Name)POSITION
Head

Indonesia
Toll
Road
Authority,
Ministryof
Public Works and Housing

Herry Trisaputra ZUNA

CO-AUTHOR(S)(Capitalize Family NameNaya Cinantya
DRESTALITA

E-MAIL(for correspondence)

ORGANIZATIONPOSITION
Staff

ORGANIZATION
Indonesia
Toll
Road
Authority,
Ministryof
Public Works and Housing

COUNTRY
Indonesia

COUNTRY
Indonesia

hatezet@gmail.com

KEYWORDS:
PPP, service quality, toll road

ABSTRACT:
Toll road is one of the most important infrastructures in supporting population and economic growth in urban areas.
Under a toll road PPP, consentient perspectives of operators and users on service quality become important to provide
excellent services with reasonable price. This paper aims to identify dimensions and attributes of toll road service
quality based on both perspectives. 17 attributes were analyzed and divided into seven dimensions based on TRSQ
model, to better represent every aspect of toll road service quality. The survey was conducted on 2015 in 33 Indonesiantoll roads. Using Importance Performance Analysis, both operators and users agree that information, accessibility,
reliability, and safety & security dimensions should be prioritized. Toll road users, however, contended that mobility ,which contains an attribute of travel time, is also important for toll road performance. Furthermore, these dimensions
can be used to measure toll road service pricing.

397

Operators’ and Users’ Perspective on Service Quality
Dimensions of Toll Road PPP
Herry Trisaputra Zuna1, Naya Cinantya Drestalita1
1

Indonesia Toll Road Authority, Ministry of Public Works and Housing, Indonesia
hatezet@gmail.com

1 INTRODUCTION
Public Private Partnership (PPP) is a new approach in providing public infrastructures, as the government tends
to have limited source of funds and private sectors are able to provide them. International Road Federation or IRF(2016) defined PPP as “Alternative Financing and Procurement to maximize risk transfer and achieve value for moneyin the delivery of large, complex projects”. Projects under PPP’s ownership remain with the public sector, but thefunding could be combination of public and/or private.
Toll road projects in Indonesia run under PPP, where the government makes toll roads plan, and private sectors
are responsible to build, operate, and maintain the toll roads during concession. As the operator, private sectors havetheir own point of view of their toll road performance. These are often different from what users think of toll roadservices they perceived. On the other hand, the government as a regulator must set toll road service quality standards fortoll road operators to meet.
Toll roads are built as alternatives for road users which provide better services, mainly shorter travel time.
Zuna (2015) mentioned two main indicators for toll road performance, namely physical condition and travel time. For
those services users must pay for toll fare, therefore they naturally have expectations of toll road service quality. In
experiencing journey on toll roads, users have their own point of view of how toll road service quality should be
whereas toll road operators also have their perspectives. It is the government’s job to set toll road service quality
standards that meet both operator’s and user’s perspectives.
This paper aims to determine toll road service quality dimensions and attributes by comparing toll road
operator’s and user’s perspectives. These dimensions can be used by the government as consideration to set standards
for toll road and service pricing.

2 LITERATURE REVIEW
2.1 HISTORY OF PPP IN INDONESIA
The first toll road in Indonesia was built in 1978, funded by both government’s budget and foreign loan which
granted to PT. Jasa Marga (Persero) Tbk, a government-owned company, as a paid-up capital. The toll road is 59 km
long, connects Jakarta, Bogor, and Ciawi, and it is called Jagorawi Toll Road. Private sectors have been participating intoll road provision since 1987 as toll road operators. In 1997, 553 km toll road had been built, 418 km of them wereoperated by PT. Jasa Marga, and the remaining 135 km by private sectors. Furthermore, only 13,3 km of toll roads werebuilt during 1997-2001 due to monetary crisis, despite 19 toll road segments had been carried out through tender. In
2005, Indonesia Toll Road Authority was established as the toll road regulator in Indonesia, and the construction of 19
toll roads was recommenced (Indonesia Toll Road Authority, 2014).
Hereinafter, Indonesian government is funding toll road constructions through three schemes, namely private
full-financing scheme, Public-Private Partnership (PPP), and government-funded-construction with private-fundedoperation and maintenance scheme.
2.2 INVESTMENT SCHEMES
Indonesia Toll Road Authority (2014) formed three investment schemes, they include government andbusiness entity as stakeholders. The first scheme shows that the government conducts land acquisition and constructionof toll road, and business entities are responsible for toll road operation and maintenance. The second scheme showsthat land acquisition and construction of toll road are conducted by both government and business entities, while tollroad operation and maintenance are conducted only by business entities. The last scheme shows that business entities
398

are responsible for the whole project, from land acquisition, construction, operation, and maintenance of toll road.
Feasibility

Economic
Financial+-

Economic
Financial

marginal

Economic
Financial+++

Land Acquisition and Construction

Operation and Maintenance

Government

Business Entity

Government

Business Entity

Business Entity

Business Entity

Business Entity

Figure 1. Investment Scheme (Indonesia Toll Road Authority, 2014)
2.3 SERVICE DOMINANT LOGIC
Vargo and Lusch (2004) introduced a new perspective of marketing, called Service Dominant Logic (SDL). In
SDL, the aims of economic and marketing activities are services, while goods, money, and organization areintermediaries of service exchange. SDL was developed from Good Dominant Logic (GDL), where marketing is
product oriented. Lusch (in Dakael, 2009) mentioned two types of resources, namely operand resource and operant
resource. Operand resource includes machines, products, office buildings, and other objects, while operant resource
includes human resources.
As mentioned, marketing used to be product oriented and focused on operand resources (Good Dominant
Logic). The products distributed must deliver benefits, profits, efficient, and standardized. On the other hand, SDL seescustomers as active participants in transaction process and as co-producer. Goods are intermediary used by customers tocreate value. Based on this perception, interactions between producers and customers are considered important, andmarketing is focused more on service and the process instead of the goods distributed.
Since SDL, service quality and customer’s perception are considered important in marketing. In economic
activities, producers must focus on things more than just goods.
2.4 SERVICE QUALITY ON TOLL ROAD AND TRANSPORTATION SECTOR
In road sector, specifically toll road, service is one important aspect that must be considered by toll road
operator. The government sets the standard for toll road service quality that the operator must meet, in order to reachusers satisfaction. That is why in setting toll road service quality standards, user’s point of view must be considered.
SERVQUAL model by Parasuraman et al (1988) mentioned five dimensions to measure service quality, namely
Reliability, Assurance, Tangibles, Empathy, and Responsiveness. This concept has been adapted in several research
about service quality, including transportation sector. Randheer (2011) used SERVQUAL as the basic concept inmeasuring user’s satisfaction on public transportation. Randheer used SERVQUAL dimensions and one additional
dimension namely culture in his research. Castillo and Benitez (2012) mentioned eight dimensions to measure service
quality of public transportation, for evaluating user satisfaction. Those dimensions are (1) Connectivity, (2)Accessibility, (3) Information, (4) Time Satisfaction, (5) User Attendance, (6) Comfort, (7) Safety/Security, (8)Environmental Impact. Maruvada and Bellamkonda (2012) tried to analyze main factors influencing service quality ofrailways in India, and they developed RAILQUAL model with six service quality dimensions. Those are (1) reservationand ticketing, (2) railway platform amenities, (3) in-train-service, (4) employee service, (5) punctuality, (6) safety andsecurity in the journey.
Furthermore, Zuna et al (2016) conducted a research in toll road service quality model using user’s
perspective. SERVQUAL was used as the basic theory, it was compared to Minimum Service Standards for Toll Roads
in Indonesia. The research delivered a service quality model for toll road, called Toll Road Service Quality (TRSQ)
Model. It contains seven dimensions, namely information, accessibility, reliability, mobility, safety & security, rest
area, and responsiveness.
This paper uses TRSQ model for toll road service quality attributes grouping.

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3 DATA COLLECTING AND RESEARCH METHODS
The data used in this research is toll road users’ satisfaction survey conducted by Indonesia Toll Road
Authority, Ministry of Public Works and Housing, in 2015. There are 3.400 respondents from toll road operators andtoll road users of 33 toll roads in Indonesia. Those respondents are divided into two groups, user and operator. There are
17 toll road attributes on the questionnaire, and the respondents were asked to evaluate every attribute in terms ofimportance and performance using 1-5 likert scale. This research aims to identify toll road service quality dimensions
based on both perspective, including their differences and similarities. The 17 attributes are shown on table 1 below.
Table 1. Research Attributes
Attributes(1) Toll road information(2) Access road(3) Entrance information board(4) Entrace transaction(5) Toll road condition(6) Information board on toll road(7) Travel time(8) Accident handling(9) Parking lot(10) Toilet(11) Gas station(12) Restaurants(13) Exit transaction(14) Signage(15) Tariff(16) City access(17) Response to complains

This paper uses Importance-Performance Analysis (IPA) with slight modification. The aim of this paper is todetermine toll road service quality attributes that matter to both operator and user, therefore only importance of each
attribute is analyzed. The mean importance level of each attribute is calculated. Attributes with importance value above
the mean importance are prioritized and considered as important toll road service quality attribute. The result of thisanalysis is mapped in importance diagram using SPSS to show importance level of each attribute according to both
point of view.
Mann-Whitney test was performed before doing the importance analysis. Based on the test, ten out of 17
attributes have significance value of below 0.05. This figure means there are significant differences between operator’sand user’s point of view of the attributes’ importance.

4 RESULT AND DISCUSSION
Toll road operator’s perspective represents toll road performance based on service providers’ point of view,
while user’s perspective represents customer’s point of view of services they received. Importance-Performance
Analysis is used in this research, however only two quadrants are used, which are top and bottom quadrants(importance). Furthermore, 17 research attributes are grouped into seven TRSQ dimensions, namely information,accessibility, reliability, mobility, safety and security, rest area, and responsiveness.

400

Table 2. Importance of Each Attribute Based on Operators’ and Users’ Perspective
Dimension
Information

Accessibility

Reliability
Mobility
Safety and security
Rest Area

Responsiveness

Attribute
Toll road information
Entrance information board
Information board on toll road
SignageAccess road
Entrance transaction
Exit transaction
City accessRoad condition
TariffTravel time
Accident handling
Parking lot
ToiletGas Station
Restaurants
Response to complaints

Importance
User
Operator
4.074
3.983
4.166
4.071
4.226
4.156
4.157
4.149
4.154
3.989
4.182
4.088
4.153
4.103
4.113
4.119
4.211
4.119
4.132
4.170
4.200
4.033
4.188
4.170
4.070
3.906
4.092
3.993
4.126
3.912
4.068
3.923
3.993
4.034

Table 2 shows the importance level of each attribute according to toll road operator’s and user’s perspective.
As explained before, this research only uses importance level of the attributes. Then, all 17 attributes are grouped into
two quadrants to determine important and not important attributes. Attributes with high importance level (above
average) are grouped in quadrant I, and attributes with low importance level (below average) are grouped in quadrant II.
User

Operator

Figure 2. Attributes Grouping Based on Toll Road Operators’ and Users’ Perspectives
Figure 2 depicts attribute grouping based on both perspectives, using SPSS. From those pictures, it is seen thatimportance level based on toll road user’s point of view has higher mean. Some attributes are important according tousers, but considered less important to operators. This condition shows that consensus has not been reached between
both parties, in terms of important toll road service quality attributes.
Based on toll road operators’ point of view, there are nine important attributes, namely entrance information
board, information board on toll road, signage, entrance transaction, exit transaction, city access, road condition, tariff,
and accident handling. According to the dimension grouping, information, accessibility, reliability, and safety &security are important dimensions for toll road operators.
Furthermore, based on users’ perspective, there are also nine important attributes in toll road service quality,
namely toll entrance information board, signage, entrance transaction, access road, exit transaction, road condition,
travel time, and accident handling.

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Table 3. Importance Level of Toll Road Service Quality Attributes
Quadrant I
Important Attributes (User)
Attributes
Dimensions(2) Access road
Accessibility

Quadrant I
Important Attributes (Operator)
Attributes
Dimensions(3) Entrance information board
Accessibility(3) Entrance information board(4) Entrance transaction(5) Road condition(6) Information board on toll road

Accessibility
Accessibility
Reliability
Information(4) Entrance transaction(5) Road condition(6) Information board on toll road(8) Accident handlingAccessibility
Reliability
Information
Safety & Security(7) Travel time(8) Accident handling(13) Exit transaction(14) Signage

Mobility
Safety & Security
Accessibility
Information(13) Exit transaction(14) Signage(15) Tariff(16) City access

Accessibility
Information
Reliability
Accessibility

Quadrant II
Less-Important Attributes (User)
Attributes
Dimensions(1) Toll road information
Information(9) Parking lot
Rest Area(10) Toilet
Rest Area(11) Gas station
Rest Area(12) Restaurants
Rest Area(15) Tariff
Reliability(16) City access
Accessibility(17) Response to complaints
ResponsivenessQuadrant II
Less-Important Attributes (Operator)
Attributes
Dimensions(1) Toll road information
Information(2) Access road
Accessibility(7) Travel time
Mobility(9) Parking lot
Rest Area(10) Toilet
Rest Area(11) Gas station
Rest Area(12) Restaurants
Rest Area(17) Response to complaints
Responsiveness

Table 3 depicts the important and less-important attributes based on toll road operators’ and users’
perspectives. If those attributes are grouped based on TRSQ dimensions, five dimensions are important according to tollroad users. Those dimensions are information, accessibility, reliability, mobility, and safety & security. Toll road
operators, however, contended that mobility is less important. There are only four important dimensions namely
information, accessibility, reliability, and safety & security.

5 CONCLUSIONS
Toll road is one of the most important infrastructures in urban areas, as it supports mobility of the citizens. PPP
has been one of the effective solutions for toll road provision, as it involves both the government as regulator andprivate sectors as operator. Toll road provision under PPP could maximize risk transfer, drive innovation in scope,schedule, and budget, and also exploit the discipline of private sector capital.
As the regulator, the government must be able to set toll road service quality standards that represent toll road
operator’s and user’s perspective. This aims to get higher toll road performance and users satisfaction. Based on theanalysis results, generally toll road users and operators have the same perspective on toll road service quality. Bothagree that information, accessibility, reliability, and safety & security are important dimensions. Therefore thegovernment should focus on those dimensions in setting toll road service quality standards. However, mobility should
also be considered as it is important for users. It was also mentioned earlier that travel time is one of the main indicators
for toll road performance.
Based on the finding of this paper, government should involve not only toll road operators, but also toll road
users, in setting toll road performance standards. Toll road user’s satisfaction should also be one of toll roadperformance indicators. Moreover, further research can be held, if necessary, involving the government, toll road users,
and toll road operators, to achieve consensus in toll road performance indicators and standards.
6 ACKNOWLEDGEMENTS
Authors would like to thank Indonesia Toll Road Authority, Ministry of Public Works and Housing, forproviding data of toll road users’ satisfaction survey, 2015.
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7 ACKNOWLEDGEMENTS
At the end of the main text you can include a statement of acknowledgement of assistance. Grant or award
numbers can be quoted as can departmental publication numbers. Acknowledgements must be brief and confined topersons and organisations who have made significant contributions. Do not include the title or rank of people.

8 REFERENCES
Castillo, J. M. D. & Benitez, F. G. (2012). a Methodology for Modeling and Identifying Users Satisfaction Issues in
Public Transport Systems Based on Users Surveys. Procedia – Social and Behavioral Sciences 54, 1104-1114.
Dakael, J. (2011). Service Dominant Logic dan E-Commerce Dalam Pemasaran. Jurnal Cita Ekonomika 5(1), 60-71.
International Road Federation. (2016). Public-Private Partnership (PPP) in the Road Sector: Overview, Key
Stakeholders and Roles in PPP Process. ‘Public-Private Partnership in the Road Sector’ Executive Seminar. Bali, 22-28
May 2016.
Maruvada D. P. & Bellamkonda, R. S. 2012. The Effects of Demographic Variables on Railway Passenger Service
Quality: Finding from Indian Railway Passenger Service through Rail Qual. International Journal of Advances inManagement and Economics Vol 2.
Parasuraman, A. (1988). SERVQUAL: A Multiple-Item Scale for Measuring Consumer Perceptions of Service Quality.
Journal of Retailing, 64(1).
Randheer K., AL-Motawa A. A., Vijay. P. J. 2012. Measuring Commuters’ Perception on Service Quality Using
SERVQUAL in Public Transportation. International Journal of Marketing Studies, 3(1).
Vargo, S. L., & Lusch, R. F. 2004. Evolving to a New Dominant Logic for Marketing. Journal of Marketing 68, 1-17.
Zuna, H. T., Retapradana, A. 2015. Analyzing User Perspective For Toll Road Service Quality Improvement (CaseStudy Of Surabaya Metropolitan Toll Road). Jurnal Sosial Ekonomi Pekerjaan Umum , vol. 7 no.3.
Zuna, H. T. 2016. Pengembangan Model Kualitas Pelayanan Jalan Tol. Dissertation. Universitas Indonesia.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

The Italian ITS Logistics Platform for the management of
dangerous goods transport and parking area for heavy trucks

TRACK
AUTHORPOSITIONORGANIZATIONCOUNTRY

Leonardo Domanico

Project Manager

TTS Italia

Italy

CO-AUTHOR(S)POSITIONORGANIZATIONCOUNTRY

Olga Landolfi

Secretary General

TTS Italia

Italy

CO-AUTHOR(S)POSITIONORGANIZATIONCOUNTRY

Rodolfo De Dominicis

President

UIRNetItaly

CO-AUTHOR(S)POSITIONORGANIZATIONCOUNTRY

Nicola Bassi

Project Manager

UIRNetItaly

E-MAIL(for correspondence)

Leonardo.domanico@ttsitalia.it

KEYWORDS:
Dangerous goods transport, intelligent transport systems, logistics platform, parking area, safety & security

ABSTRACT:
Italy is one of the European countries with the highest traffic density. Road is the main transport mode used both for
freight and passengers transport with congestion, safety& security and environmental pollution issues, despite thegeographical features of Italy should favour other transport modes.
To make more efficient, secure and safer the national logistics system, in 2005 the Italian Ministry of Infrastructures andTransport established the UIRNet company with the aim to create, control and manage the ITS National Logistics
Platform.
In the frame of this Platform, UIRNet has to contribute also at the improvement of road safety. The paper deals with the
projects implemented by UIRNet to control and manage both road transport of dangerous goods and information
services for safe and secure parking area for trucks, and the benefits obtained in terms of enhanced safety and efficiency
that make UIRNet a best practice for any similar application worldwide.

404

1
TRANSPORT IN ITALY
Italy is one of the European countries with the highest density of internal traffic that is uneven distributed
across its transportation network that includes 278 ports, a rail network of 16.752 km, a road network of
255,980 km, a highway network of 6,751 km (5,724.4 km toll road) and 44 airports.
In 2014 the total cargo traffic of national carriers with origin and destination within Italy, and travelling
distances over 50 km was more than 176 billion tons-km/year, with 56.51% of the demand focused on theroad, while the rest was distributed between rail / pipeline (15.63%) and inland waterways (27.28%). The
percentage of freight transport by air is instead irrelevant (0.59%). Furthermore, rail and pipeline traffic, theshare of international traffic carried out on national territory, are comprised in the data above (see Figure 1).

Figure 1 – Modal Shift in 2014 (% of Millions of ton-km)
Considering that for passengers transport there is the same modal shift, this data clearly outlines the absolute
preference for road transport over other modalities in Italy. Unfortunately, this preference is not matched by
the infrastructure currently in place, which is not yet adequate, compared to the heavy demand. This shortfall
results in extensive negative externalities, in terms of congestion, environmental pollution and safety.
Furthermore, the demand for road transport is not spread evenly on the territory: traffic flows areconcentrated in a few critical road segments and nodes around major metropolitan and industrial areas. In
fact the problem of traffic in urban areas has become very serious as we find 50% of the population, over
70% of production activities, and 60% of circulating vehicles all converging in one area. Moreover, in thepast two decades we have seen a strong tendency for people to reside outside large cities, which hasconsequently increased the number of commuters, which in turn has increased traffic on the already stressedurban road network.

2
FREIGHT TRANSPORT IN ITALY
Logistics is a vital and crucial sector for the national economy of the country.
The ability of a country to maximise profits on its production and to be competitive on the global arena arestrictly connected to its capacity of optimize the distribution process, and thus to its logistics sector.
The most recent statistics released by the Italian Ministry of Infrastructure and Transport (2013-2014)highlight that the total transported goods in 2014 are around 176 billion ton-km, with a decrease of 25,7%
compared to 2005. The available data for the 2014 (as reported in Table 1) confirm the prevalence of roadtransport respect the other modes with the following value of ton-km and percentage:






99.649 Millions of ton-km (56,51%) via road;
48.100 Millions of ton-km (27,28%) via waterways;
27.556 Millions of ton-km (15,63%) via railways and oil pipelines;
1.040 Millions of ton-km (0,59%) via airways, a very limited percentage.

405

Transport modes
Waterways

Year 2005
46.928Year 201053.291

Year 2014
48.100Railways / Oil Pipeline

33.66828.22227.556

Road

155.872134.261

99.649Airways

982

1.013

1.040

237.450216.787

176.345

Total

Table 1 – Modal shift overview (Millions of ton-km)
Therefore, freight transport by road is the mode more used respect to the others. The main reasons can besummarised as follows:
the average distance for freight transport in Italy is less than 300 km and therefore the road mode is
the most efficient (main reason);
the inefficiency of intermodal transport process: often it is occurred that wagons/trailers were missed
during the modal change phase and also usually the modal exchange takes a lot of time;the trade associations of haulage freight transport are very strong and obtain subsidies/contributions
for toll and fuel costs.
The challenge in Italy is to improve the efficiency of the logistics sector, favouring a more balanced modal
shift in favour of other modes respect to roads.

3
THE ROLE OF ITS FOR ENHANCING LOGISTICS
In order to address the challenges of the increasing demand for transport of goods, and to be in line withother European countries, the Italian Ministry of Infrastructure and Transport has stated the need for Italy torethink the whole transport network.
The aim is to deal with transport as an “integrated system”, where information, management and control
operate in synergy, optimizing the use of vehicles and infrastructure and of the existing logistics platforms ina multimodal manner. This is possible only through the extensive use of Intelligent Transport Systems (ITS).
In particular as regards logistics, the Ministry of Infrastructure and Transport in 2005 established UIRNet
company with the aim to create, control and manage the ITS National Logistics Platform.
Such need is reported in the National Action Plan on Intelligent Transport Systems adopted by the Ministryof Infrastructure and Transport as requested by the ITS Directive 2010/40/EU. In such Plan, Priority Area 2
Continuity of ITS services for the management of traffic and goods transport specifies that “the objectivethat it is necessary to achieve is the possibility of organizing integrated multimodal mobility services forpeople and for freight that enable the planning and management of movements in an informed andpersonalized way without solutions of continuity from the point of origin to the destination, using all
available ways efficiently and securely through open and operable integrated platforms”.
The ITS National Logistics Platform is the implementation of what outlines the National ITS Action Plan.

4
THE ITALIAN LEGISLATIVE FRAMEWORK ON ITSth
On 6 August 2010, the European Commission published the ITS Directive 2010/40/UE adopted on the 7
July 2010. This Directive establishes a framework in support of the coordinated and coherent deployment anduse of Intelligent Transport Systems (ITS) within the Union, in particular across the borders between theMember States, and sets out the general conditions necessary for that purpose. According to the ITS
Directive 2010/40/UE, all Member States are requested to adopt this Directive and to implement an ITS
National Action Plan.
Italy adopted the ITS Directive in 2012 and the ITS National Action Plan the last 12 February 2014. The
Italian Plan includes four priority areas, reflecting those indicated by the ITS Directive 2010/40/UE:
1.
Optimal use of road, traffic and travel data;

406

2.
3.
4.

Continuity of traffic and freight management ITS services;
ITS road safety and security applications;
Link the vehicle with the transport infrastructure.

The second priority area addresses the issues related to the achievement of safety conditions, efficiency,
interoperability and continuity of ITS services for the management of traffic and transport, as well as thoseneeded to stimulate inter-modality and co-modality in the European transport corridors and conurbations.
The goal is to achieve integrated multimodal mobility, both for people and goods, to plan and manage themovement in an informed, personalized and seamless way from the point of origin to that of destination,using all the available modes efficiently and safely.
The development of integrated mobility services for both people and goods is based on: availability, accessand set up of data and information that constitutes the key to enabler such services; the management andorganization of this data must be integrated platforms open and interoperable; same for payment systems
integrated with the transport services. It is necessary that the different operators collecting and processing
information on mobility, dialogue with those platforms.
The second priority area identifies the five priority actions needed to reach the objectives listed. Priority
actions 1, 2 and 4 are particularly relevant to freight transport.
Priority action 1 aims at encouraging the creation of telematics platforms in the logistics nodes of the
distribution network that are consistent with the ITS National Logistics Platform. This will allow theexchange of data, information and documentation between operators, which will improve, simplify and speed
up all processes and administrative issues within the complex cycle of intermodal transport (road, rail andsea).
This will necessitate the promotion of an extensive information and training campaign aimed at the real usersof telematics platforms, in order to facilitate their use and encourage the development of open ITS systems,
which have to be interoperable with each other and with the ITS National Platform for the Logistics.
Priority action 2 aims at encouraging the use of ITS for the management of multimodal transport systems andlogistics through open and interoperable platforms. Within the second priority action, the challenge is toimplement ITS systems dedicated to logistics and freight transport, by stimulating and intensifying the intermodality and co-modality of transport both at national and international level, through 21 corridors
recognized at European level.
ITS systems will have to be interoperable, standardized and will use the ITS National Platform for the
Logistics as reference point for road transport.
Furthermore, the continuity and the interoperability of the ITS services that facilitate the switch between roadtransportation to other modes in every node (ports, freight villages, stations and airports) will have to beguaranteed in terms of:







release of information;
simplification of administrative proceedings;
fluidity of circulation in intermodal areas;
reduction of waiting times;
harmonization of interactions among the different actors involved through the National Logistics
Platform, to manage:

freight transport information and the related e-documents;



tracking and tracing of vehicles transporting dangerous goods through RFID (Radio Frequency
Identification), GPS (Global Positioning System) and EGNOS (European Geostationary
Navigation Overlay System)/Galileo;

use to technologies to check status of both vehicles and goods, adopt standard protocols andopen and interoperable ITS architectures for data exchange.
According to the specific characteristics of the Italian framework, special attention will be given to city
logistics to control vehicle type and time of pick up and delivery of goods within the urban area.

407

Priority action 4 aims at guaranteeing the continuity of services on the national network and along borders.
Within this priority action, the "interfacing" of national control systems of passenger and freight traffic, will
be favoured at the European level to ensure the continuity of management services and information on theentire national network and along the borders, trans-borders collaborations with the other Member States willbe established.
The logistic sector is crucial for Italy: this is underlined both by the ITS Action National Plan, as describedabove, and also by the National Plan for Logistics 2011-2020: Italy could save up to 4 billion Euro by
reducing the inefficiencies of the logistics sector.
The creation of an ITS National Platform for the Logistics is a primary step to improve the efficiency of thesector and support Italian economy.

5
UIRNET: THE ITALIAN ITS LOGISTICS PLATFORM
UIRNet S.p.A. is the only entity entitled by the Italian Ministry of Infrastructure and Transport for thecreation and control of the platform for the management of the national logistics network.
The ITS National Logistics Platform has been defined in 2005 and instituted to improve the efficiency andsafety of the Italian logistics network favouring the interconnection of modal interchange nodes (ports,
freight villages, goods centres and logistic plates).
The main mission of UIRNet is to create a network integrating the complex world of transport and logistics
in a simple way, without introducing any market change and without privileging one or the other category ofoperators.
Such an integration can be achieved through the Platform that can interconnect the main actors of the Italianlogistics system, allowing the coordination of the information flows and of the related processes. Therefore,
the physical flow of goods along the roads in and out towards the logistics nodes can be better modulated.
The Italian ITS Logistics Platform has been conceived to offer services to all the logistics operators, acting as
the interconnection platform for data and related processes. Nowadays, the National Logistics Platform isfocused on the road freight transport and aims at regulating the interaction between transport companies andnodes operators (customers, warehouses, terminal operators, shippers, MTO).
UIRNet has developed a Platform able to offer several services to many actors of the logistics system such astransport companies, infrastructures managers, production companies and public authorities.
At the moment, the Platform is composed by integrable and scalable modules and UIRNet has primarily
created the core modules, essential for the minimum services offered by the Platform:
SMARTRUCK: The module addresses the freight transport companies and whoever is interested inorganizing and managing a journey or mission.

DANGEROUS GOODS: UIRNet, through the module Dangerous Goods (an extension of SmarTruck)adds a powerful tool of control of documents related to dangerous goods.

CONTROL TOWER: the Control Tower module allows the logistics actors such as nodes, shippers,
MTO, maritime actors, to receive accurate and almost in real time information on vehicles travelling
towards them.
BOOKING: the Booking module allows on one hand to those who offers services related to transport
to make such services available for all UIRNet users; on the other hand it allows transport companies
and goods settlors to use the same services by booking them.

FREIGHT TAXI: the Freight Taxi module allows a transport supplier (with a cargo space at disposal)
or a costumer (with goods to be delivered) to gain further business opportunities.

GNOSCERE: it is the Data Warehouse, a specific module based on SAP - Business Object, allowing
to elaborate and analyse all the data acquired during the system operation and to show them in a
simple and effective manner (both through tables and graphics).

SOLUTION: concerning the needs of the main logistics nodes, UIRNet has realised a module that,through ad hoc services and processes, allows the management of the resources and of the available
services at nodes, the management of the inbound queue and/or emergencies and the management of
the registry of the road transport common to all nodes.

408












CUSTOMS CONTROLLED CORRIDOR: to support the requests from the Agenzia Dogane eMonopoli, UIRNet has realised a module to transport and manage goods subject to customs
constraints (not national or subject to customs constraints) along road stretches pre-defined by the
Agency.
PORT COMMUNITY SYSTEM INTEGRATION (PCS): it is an applicative framework able toevolve and integrate the information already in operation in the port area of reference (PCS) into afurther connected system where the ITS National Logistics Platform operates.
DANGEROUS GOODS (DG BASE): this is the module integrating the ITS National Logistics
Platform allowing the development of ad hoc services for the dangerous goods transport, by
calculating the dynamic risk factor, optimizing the route, to increase the land safety and, at the sametime, to comply with the rules for the transport security.
PARKING AREA AND BUFFERING: this is the module to manage the parking areas and also
allowing both the planning of the ordinary stops and the management of the buffering areas in case ofnegative events that can prevent the node operations.
THE REGIONAL LOGISTICS PLATFORM (PLR): an autonomous system integrated with the ITS
National Logistics Platform services and managing its own users at regional level.
MASTER DELIVERY SERVICE (MDS): the module has been developed to manage the inboundflows to the exhibition area of Expo 2015 of the logistics vehicles through a planning algorithm
specifically designed, but replicable in other situations.

6
UIRNET SOLUTIONS FOR DANGEROUS GOODS MANAGEMENT
In November 2015, UIRNet ended two different projects aimed at the control and management of thedangerous goods road transport. All these projects, Picoge-MP and Module DG Base, aimed to increasing
both safety and security level and achieved the expected results.
Picoge-MP projectPicoge-MP is an integrated platform for the transport and logistics governance of dangerous goods as well asa tool for emergencies management. It acts as a strategic architecture to define the guidelines to be adopted
by the Italian Ministry of Infrastructures and Transports to monitor and manage dangerous goods and able toguarantee the fusion, interoperability and communication through a common language of ITS applications.
The main objectives the project have been:
To design and realize a strategic architecture able to define specific guidelines for the control andmanagement of dangerous goods. The aim is to make the different ITS applications integrated,interoperable and able to communicate through a common language;
To harmonize all the existing projects on the dangerous goods management;
To create of the National Map for Risk, based on static elements and whose geo-referenced elements
are available through machine-to-machine services or for consultation;
To create a website for the dissemination of all the issues related to dangerous goods in order tocommunicate with users and foster their participation (www.picoge.it).
According to the above listed objectives, as a first step, UIRNet has defined and shared with the Italian
Ministry of Infrastructures and Transports both guidelines and specifications to design the telematics
architecture to act as a referring point for the dangerous goods transport. UIRNet has analysed in deep thestate of the art of telematics platform and ITS project in the dangerous goods sector in order to collect all theexisting experiences and share with the users and actors a new approach.
Finally, a website and a tool to support ITS systems design have been created. Therefore, all the gathered
information are available online through the dedicated website www.picoge.it
Picoge-MP benefits
The PICOGE-MP project gathered some important results:
The definition of a standard for ITS systems design to harmonise project proposals at least as concerns
the presentation language. On the Picoge_MP website (www.picoge.it) a design tool is available based409

on the standard and meant to ease and speed the project redaction. In addition, a tool for pre-validationof architectures has been inserted to be used as a support in the projects evaluation to be funded. For
example, the tool would be useful to support the Italian Ministry of Infrastructure and Transport intechnical tenders evaluation for ITS systems design as well as in receiving homogeneous proposals foran easier and faster evaluation.



The availability of a geo-referenced database for vulnerable elements. A single national referring point
for land maps including the evaluation of eventual incidents. The map can be consulted through theuser interface or through services. The main advantage of such a referring point is the possibility to
manage data in a harmonised way and to make them available for Police, Fireman, ITS systems
dealing with incidents management.

DG Base project
The DG (Dangerous Goods) Base designed, realized, implemented, activated and managed an integrated
telematics system to monitor and control both at operative and administrative level the dangerous goods
transport in Calabria and Sicily Regions, involving the main ports and freight village.
The objectives of the project have been:
To design and realize a real time control system for the dangerous goods transport on the main
infrastructures at regional level, guaranteeing a higher level of safety and limiting the risk linked tovehicle transit without decreasing efficiency;To reduce the risk of accidents related to dangerous goods transport by monitoring both the state of
the vehicle and of the goods;To improve the emergencies management to reduce the effects of eventual accidents;To improve the PA action through the identification of all the required elements for a map of risks on
the territory;
To improve the logistics standard to support drivers with effective information on the dangerous
goods transport modes;
To collaborate with other regions to ensure the interoperability of the tools used for the inter-regional
control.
To reach the above listed objectives, a traffic control room has been established in Messina (South Italy).
Also, video surveillance cameras have been implemented to detect both vehicles and KEMLER-ONU plates.
The services offered by the DG Base project to manage the dangerous goods transport are the following:
Localisation of the vehicle transporting dangerous goods;
Vehicles monitoring;
Monitoring of the dangerous good;Improvement of emergencies management through a warning system;
Real time messages to logistics chain actors;Use of dynamic elements on the risk maps;
Route planning;Data archive and management;Application of intelligence business tools.
To facilitate the remote control, an App has been developed which is able to query the Logistics Platform andto collect all the information.
DB Base project benefits
The Module DG Base has gathered the following benefits:It enables the match between the qualified and certified consultants for dangerous goods and thecompanies that, according to Italian law, must use them. Therefore the module allows an automatedcontrol with relevant benefits for security both of working places and dangerous goods transport.
Actually, at the moment such controls are rare and based on paper documents. It allows themonitoring of dangerous goods transport both through vehicles tracking and cameras for optical
identification. The system defines both the current and expected situation for transport by calculating410

the risk index related to transport. For example, if a petrol transport passes close to a liquid oxygen
transport, then the system will alert the control room and operators can manage any eventual risk.

Through an electronic brain able to record rules and experiences, the system is able to detect abnormal
situations, ie. situations involving risk of deviation from the transport rules. For example, a tanker
carrying substances that are not treated in the area where it moves or vehicles that take too long or
perform non-linear paths between the source and destination (typical case of those who empties thestreet tanks.
UIRNet is discussing with the Italian Ministry of Infrastructure and transport in order to receive otherinformation on dangerous goods transport from other petrol companies. Obviously the presented system isimmediately extended to the entire country.

7
UIRNET SOLUTIONS FOR THE MANAGEMENT OF PARKING AREA FOR HEAVYTRUCKS
The project “Remote management of the areas of buffering and parking for trucks withexperimentation in the area of Catania Bicocca” aimed at interconnecting all the parking areas, freightvillages and road / highway crossings with the systems of the National Logistic Platform. The project was
open only to road transport to increase the level of security in the parking areas and to ease the access to theservice, supporting the respect of driving and resting time foreseen by the law for truck drivers. The truck
drivers can access the service and obtaining all the needed information on parking areas availability through a
dedicated App.
The project answers to a specific Delegated Regulation of the European Commission: Delegated Regulation(EU) N° 885/2013 of 15 May 2013 integrating the Directive 2010/40/UE with regard to the provision of
information services for safe and secure parking places for trucks and commercial vehicles.
The main objectives of the project have been:
To supply online services for the National Logistics Platform users;
To ease the access to services to allow the driver the guide/rest time compliance as well as a higher
comfort;
To increase the security level in the parking areas;To improve the perception both for economic operators and drivers of the increased safety level and of
the possibility to work in the law respect;To ensure a greater collaboration between the National Logistics Platform and the other actors of thesystem.
The achievement of the objectives of the project was possible thanks to the integration capabilities provided
by UIRNet National Logistics Platform, which allows to refer to a single standard of information exchange,
ensuring systems interoperability, and to use the basic services already in place.
The system is at the moment available in the parking area of Catania but can be replicated in any parking andbuffering area thanks to a configuration tool able to personalise its functionalities. The module is able to plan
ordinary stops and to manage the buffering areas in case of negative events that can prevent the nodeoperation. The system converges in a unique solution the management of physical and logic safety of the stop
infrastructure. Therefore execution and actions time are integrated and optimized.
Benefits gathered
The Module for parking areas control has allowed the following benefits:Online booking and management of parking lots within parking areas. Therefore truckers can safely
plan their stops;Control of parking areas access by cameras with optical identification. Therefore safety is increased
and gates management is improved by automation;
Combining safety and organization, the module services allow parking areas to organize services forthe passage of the drive between tractors (shifts in security) and to exchange trailer (trailers,411

semitrailers, trucks ...) between tractors even at different times. This will give possibilities to small
customers forms of organization at the time exclusively available only to large operators of shipments.

CONCLUSIONSThe paper presented an overview of the Italian freight transport, the ITS National Logistics Platform andsome initiatives promoted by UIRNet for the management of dangerous goods transport and parking area forheavy trucks.
The adoption of the National ITS Logistics Platform can maximise the efficiency and the quality of the
Italian logistics sector. The ITS Platform offers to the whole logistics chain a new strategic opportunity to
improve the efficiency and security of the entire supply chain. This has a significantly positive impact on thenational economy in terms of increased competitiveness, security, environmental benefits, as well as
opportunities for internationalisation.
The Platform will greatly improve the efficiency and safety of the Italian freight transport: the system istailored to address the territory characteristics and each stakeholder needs, optimizing each process,maximising assets and minimizing negative externalities.
Moreover, the ITS National logistics Platform, when it will be full operative in 2018, is expected to havehuge impacts in terms of:
Increasing national economic impacts, through the reduction of the logistics enterprises costs thanks toa better logistics efficiency: increase of intermodal transport, development of freight villages,
integration with other logistics systems at national and international level, etc; this benefit is estimatedin 2,5 billions of Euro/year;Positive impacts on employment in Italy, thanks to the reduction of the logistics performance gap
respect to other European countries; this benefit is estimated between 52.000-95.000 new jobs;
Positive environmental impacts, thanks to the optimization of the logistics flows and monitoring of
dangerous goods transports; this benefit is estimated between 1,6 and 2,5 Billions of Euro/year;Positive impacts on GDP, thanks to the increase in competitiveness of the logistics sector; this benefit
is estimated between 2,6 and 4,7Billions of Euro of GDP;

Increasing safety through the monitoring, managing and controlling of the goods transport (anddangerous goods transport in particular), and the parking area for heavy trucks;
Internationalisation through the integration with European and Asian ports, as well as integration withany other logistics project worldwide;
Therefore UIRNet is expected to become a pillar in the field of logistics and transport.

REFERENCES(1)
Directive 2010/40/EU of the European Parliament and of the Council of 7 July 2010 on the framework
for the deployment of Intelligent Transport Systems in the field of road transport and for interfaces
with other modes of transport(2)
Italian ITS Decree of the 1st February 2013 on the diffusion of ITS in Italy(3)
Italian ITS Action Plan adopted and published by the Ministry of Transport the 12th February 2014
(4)
Ministry of Infrastructure and Transport (2013-2014) transport statistics(5)
Commission Delegated Regulation (EU) No 885/2013 of 15 May 2013 with regard to the provision of
information services for safe and secure parking places for trucks and commercial vehicles

412

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
Zaffan Farhana Zainal

Cars – Motorcycles Collisions Prediction Model Based on
Road Design Consistency
ID: 59POSITION
Postgraduate Student

CO-AUTHOR(S)(Capitalize Family NamePOSITION

Dr.-Ing. Joewono Prasetijo,
Wan Zahidah Musa

Assistant Professor,
Postgraduate Student

E-MAIL(for correspondence)

joewono@uthm.edu.my

ORGANIZATION
Universiti Tun Hussein Onn
Malaysia
ORGANIZATION
Universiti Tun Hussein Onn
Malaysia

COUNTRY
Malaysia
COUNTRY
Malaysia

KEYWORDS:
Road accident, design consistency, operating speed profile, global positioning system

ABSTRACT:
Almost 1.25 million people in a year around the world involve with road accident and suffering serious injury, slightly injury anddisability based on road accident. In developing country, Malaysia is among that has the highest road accident risk and more than
50% of the road accident fatalities involves motorcyclist. Analysis shows that, the three main types of accidents in Malaysia iscollision with passenger cars, collisions with other motorcycles and single-motorcycle accidents. The reasons of accident happened
because lacks of road design consistency and most drivers make errors due to the geometric features on the road. Design consistency
in a road section usually is results from geometric features that vary significantly and may cause drivers to make speed errors or
unsafe driving leading to higher collision risk. By evaluate design consistency are through based on operating speed evaluation of 85th
percentile speed of vehicles, and obtained by using continuous speed profiles (normalized area bounded of speed) for consistency
value for the selected segment. These studies are to determine the integrated road design consistency (IC) of motorcycles and cars atselected segment F0050. GPS DG-200 system is used to get speed data for motorcycle and cars for develop design consistency
profile. Only operating under free flow conditions were considered in this study. Geometric factors such as number of access point,
tangent length, and curve length are influence for operating speed profile for developed of tangents and curves of motorcycle andcars. Use ACAD software for develop consistency model profile. The developed of consistency model are based on parameter: thebounded area between the profile and the average speed, standard deviation of speed along a segment. The motorcycle design
consistency for distance of 5 km is 2.90 meanwhile; distance of 25 km is 2.30. Both distances show a good design consistency eventhe threshold are different. The cars design consistency for distance of 5 km is 2.41 while distance of 25 km is 1.26. Both distancesshows a different threshold of design consistency: 2.41 (good consistency) meanwhile 1.26 (acceptable consistency). The integratedconsistency model is to incorporate the impact of the speed profile on design consistency in traffic and safety evaluations. As a result,Integrated consistency motorcycle and cars for distance of 5 km are 2.81 (good consistency) whereas for distance of 25 km are 2.29
(good consistency). From the consistency prediction models, integrated design consistency route F0050 of motorcycles and cars aregood consistency.

413

Cars – Motorcycles Collisions Prediction Model Based on
Road Design Consistency*)

Zaffan Farhana Zainal, Joewono Prasetijo , Wan Zahidah Musa
Faculty of Civil and Environmental Engineering
Universiti Tun Hussein Onn Malaysia, 86400 Batu Pahat, Johor, Malaysia
joewono@uthm.edu.my

1 INTRODUCTION
Every year almost 1.25 million people around the world involve with road accident. Among 20 and 50
million people are suffering serious injury, slightly injury and disability based on road accident occurring(WHO, 2015). Besides that, WHO stated road traffic accident can causes one million people are died, three
millions are severely are disabled for life, and thirty millions are injured. By 2020, road accidents will be thethird leading cause of death worldwide. In developing country, every year shows that road accidents are killmore people than war and virus. Furthermore, in Asia continent only, almost 400,000 people are died on theroads and more than four million injured every year (Kareem, 2003). The causes of road accident are basedon imperfect vehicles, irregular roads, careless driving, speeding, drunk driving, not enough sleep, under the
influence of alcohol and other drug effect and many more. In Malaysia, road accidents are one of the most
relevant issues in today’s civilization and the main cause’s road accidents are death and injuries. In the
middle of the ASEAN, Malaysia has the highest road accident risk and more than 50% of the road accident
fatalities involves motorcyclist, and the numbers of accident kept rising. The West Coast Area of Malaysia
been stated as the highest motorcycle fatalities due to the highest number of registered motorcycles andpopulation. Previous study said the entire of motorcycle billion kilometers travelled in Malaysia are increased
from 1990 to 2008, therefore, motorcycle fatalities also increased as well (Abdul Manan et al., 2012 andTorregrosa et al., 2011). The increase in motorization led to consequent increase in the number of roadaccidents (Radin, 2005). Motorcycles represent more than half the total vehicle population and contribute
more than 47% of the casualties based on deaths, serious and slightly injuries in road accidents which
recorded 48%, 47.4% and 47.7% for the year 2006, 2007 and 2008, correspondingly (Yuen et al., 2014). In
year 2009, total number of motorcycles in Malaysia was 8,940,230 with fatalities contributed as 60% (Abdul
Manan et al., 2012). Investigation shows that, the three main types of accidents in Malaysia is collision withpassenger cars, collisions with other motorcycles and single-motorcycle accidents. Generally, riding
motorcycle is 17 times more dangerous than driving a passenger car and also the motorcyclist will be in frontof higher risk of injury or fatality because the level of exposure to injury is higher if compared to othervehicle such a passenger car in accident (Radin Umar et al., 1995). Meanwhile, according to the study byRoad Safety Research Center of University Putra Malaysia, motorcyclist represent about 55 – 57% of thetotal number of accidents and 60 percent of traffic fatalities in Malaysia. Their risk of injury is estimated tobe 12 times higher than car passengers.
Accident occurs due to lack of road design consistency, which most drivers make, mistakes in thearea of geometric features (Prasetijo J. et al., 2016). The worse the consistency, the more likely that drivers
will be unexpected and an accident will happen (Lamm et al., 1999 and Juan de Oña et al., 2012). Design
consistency in a road section usually results from geometric features and may cause drivers to make speed
errors or unsafe driving maneuvers leading to higher collision risk. Hence, geometric design consistency isemerging as an important component in highway design relate to the safety performance. Most consistency
concepts today deal with the variation of vehicles speed but less variation types (heteregenous) on roadsection and this speed variation is affected mainly by horizontal alignment and vertical alignment of roads(Lamm et al., 1999; Juan de Ona et al., 2012; Torregrosa et al., 2011). The most criteria used to evaluate
design consistency are based on operating speed evaluation of 85 th percentile speed of vehicles, and obtainedby using operating speed prediction models (Gibreel et al., 1999). Some researches (Hassan, 2004; Polus etal., 2004; Mattar-Habib et al., 2008) have extended the concept by using continuous speed profiles(normalized area bounded of speed) to determine the speed variation along a road segment and determining asingle consistency value for the whole road segment. In transportation engineering, GPS has been frequently
used in study of travel time, route choice, car following and behaviors’ of driver’s speed. GPS allows

414researchers to track vehicles at second-by-second resolution at any time of the day and under any weather
conditions. The use of GPS technologies has used up to carry out traffic data collection for transportation
studies. Field study by using GPS device with differential potential switched on and the data were examined
to verify the result of theoretical analysis.
2 DATA DESCRIPTION
The models are developed based on the new method of speed profiles analysis. Some models have beendeveloped to predict operating speed (85 th percentile), by estimating the 85th speed variation along the road.
By using a Global Positioning System (GPS), continuous speed profile data are using new method analysis,
to develop road design consistency profile of motorcycle and cars (Prasetijo, J. et al., 2016). Only operating
under free flow conditions were considered in this study. Geometric factors such as number of access point,
length of tangent and length of curve are influence for operating speed profile, 85 th percentile for developedof tangents and curves of motorcycle and cars. Using the Excel Software, analysis was carried out. Multiple
Linear Regression method been used to develop the model for prediction of 85 th percentile speed for tangent
and curve. Using ACAD software to developed road design consistency model.
2.1 ROAD LOCATIONThe road location selection is F0050 (Batu Pahat – Ayer Itam), based on the highest accident by using
ranking accident point system based on weightage adopted by Highway Planning Unit (HPU) and based onroad accident along Johor Federal road through accident data from IPK Johor Bharu, Malaysia. The data wascollected during weekdays and off-peak hours. By using Global Positioning System (GPS) that placed inside
moving vehicle, the speed data were collected for two type of vehicle (cars and motorcycle). Data speed fromsignalized intersection been remove about 300 m to avoid the effect of traffic control devices on vehicle
speeds and free flow speed (Schurr et al; 2002). The data for this research consisted of two parameter; GPS(speed) and geometric parameter (length of tangent, length of curve and access point).

Figure 1. Road Location Batu Pahat to Ayer Hitam (31km)

2.2 DATA COLLECTION
The data was collected through test driver method using the same vehicle for cars and motorcycles. In thisstudy, continuous speed profile (GPS DG-200) was used rather than collecting using spot speeds. GPS DG200 was placed in the moving vehicle to record the data along a test segment. GPS are used to collect speed
data of motorcycle and cars in traffic stream under free flow condition as mention early. Each data point
recorded by GPS includes the vehicle position, speed, time and the distance. The results based an average
speed vehicle profile that captures the whole moving process of the traffic flow travel along the roadsegments.

415

Figure 2. Global Positioning System DG-200

3 DATA ANALYSIS
Many research works defined the operating speed is the parameter of real driving performance and the speed
where drivers travel in free flow conditions during daylight and calculated using a specific percentile ofspeed distribution, that normally used the 85th percentile (Russo et al., 2012). The profiles were obtained byconsidering continuous speed profile by using GPS devices from individual drivers which allowed accurate
determination of the starting and ending points of all speed transitions and also the actual maximum andminimum speeds for the different road geometric elements (Torregorasa et al., 2011). According to the
Mattar-habib (2004), continuous speed profiles are used to determine the speed variation along a roadsegment and determining a single consistency value for the whole road segment. The design consistency
index is a continuous function instead of being based on ranges. Two main parameters for this model; first isequation 1; the bounded area between the profile and the average speed and the equation 2; the standard
deviation of speeds along a two-lane highway segment. Based on the two independent measures, aconsistency model was developed. Table 1 shows design-consistency quality (Matta-Habib et al., 2008).
Threshold values state for good, acceptable, and poor design consistency was to know a consistency model.

𝑅𝑎 =(∑ 𝑎𝑖 )

(1)

𝐿

Where, 𝑅𝑎 is relative area (m/sec) measure consistency, ∑ 𝑎𝑖 is sum of i areas bounded between the speed
profile and the average operating speed (𝑚2 /𝑠𝑒𝑐) and L is entire segment length (m).

𝜎= {(𝑉𝑗 − 𝑉𝑎𝑣𝑔 )
𝑛

0.5

}

(2)

Where σ is standard deviation of operating speed (km/h), 𝑉𝑗 is operating speed along the 𝑗𝑡ℎ geometricelement (tangent or curve) (km/h), 𝑉𝑎𝑣𝑔 is average weighted (by length) operating speed along a highway
segment (km/h) and n is number of geometric elements along a segment (km/h).

416

Table 1. Design-consistency quality (Matta-Habib et al., 2008)
Design-consistency quality
𝐶 = 2.808. 𝑒𝑥𝑝 (−0.278∗𝑅𝑎∗𝜎)Good
C > 2 (m/s)

Acceptable1< C ≤ 2 (m/s)

PoorC ≤ 1 (m/s)

Integrated-consistency model is needed as a function of speed profile of cars and motorcycle. The model is
included with the impact of speed profile of motorcycle on design consistency. The model takes into the
combine effect of speed profiles of cars and motorcycles. The formula (Mattar-Habib et al., 2008) fromequation 3, can be used to conduct between motorcycle and cars to found integrated-consistency model.

𝐼𝐶 = [2.808 ∗ 𝑒𝑥𝑝 (−0.278∗𝑅𝑎∗𝜎) ] ∗ 𝑒𝑥𝑝 (−0.01∗ 𝐴𝐶𝑇 )(3)

Where IC is integrated consistency of road sections, 𝑅𝑎 is normalized bounded area by speed profile of cars
/motorcycle (m/sec), σ is standard deviation of car speeds/ motorcycle and 𝐴𝐶𝑇 is normalized bounded area
between the speed profile of cars and motorcycle (m/sec).
3.1 OPERATING SPEED MODEL
The speed profiles based on the models for curves were developed by (Krammes et al., 1995), while themodels for tangents were developed by (Polus et al., 2008). Dependent variable selected based on speed atselected segment and independent variables are length of target and curve and access density. Excel Software
been used to analysis multiple regressions. Operating speed model related based on 85th percentile speed,access density, length of tangent and curve. The selected operating speed model, statistical results are shows;
Motorcycle;
𝑉85𝑡= 84.13 + 0.10 𝐿𝑡 + 0.209 AP
𝑉85𝑐= 82.41 + 0.13 𝐿𝑐 ̶ 0.798 AP

𝑅2 = 0.13
𝑅2 = 0.10

Cars;
𝑉85𝑡
𝑉85𝑐

𝑅2 = 0.75
𝑅2 = 0.75= 75.03 + 2.50 𝐿𝑡 ̶ 1.64 AP= 75.03 + 2.50 𝐿𝑐 ̶ 1.64 AP

Where;
𝑉85𝑡 = Operating speed of tangent, 𝑉85𝑐 = operating speed of curve, 𝐿𝑡 = length of tangent, 𝐿𝑐 = length ofcurve, AP = access point
3.2 DESIGN CONSISTENCY
The design consistencies are calculated based on continuous operating speed profile models. The continuous
operating speed profile models are plotted based on operating speed model developed. The developed of
consistency model are based on parameter: the bounded area between the profile and the average speed,
standard deviation of speed along a segment. The Area Bounded, 𝑅𝑎 are calculated based on speed profile
along the road. Analysis of road design consistency is a good way to reduce road accident along the segment.

417

Figure 3. Design Consistency Profile of Motorcycle (KM5 – KM10)

Figure 4. Design Consistency Profile of Motorcycle (KM5 – KM31)
Figure 3 shows Design Consistency Profile of Motorcycle (KM5 – KM10). The motorcycle design
consistency for distance of 5 km is 2.90. Figure 4 shows Design Consistency Profile of Motorcycle (KM5 –KM31) for distance of 25 km at F0050. The motorcycle design consistency for distance of 25 km is 2.30.
Both distances show a good design consistency even the threshold are different.

Figure 5. Design Consistency Profile of cars (KM5 – KM10)

418

Figure 6. Design Consistency Profile of cars (KM5 – KM31)
Figure 5 shows Design Consistency Profile of cars (KM5 – KM10) for distance 5 km. The cars design
consistency for distance of 5 km is 2.41. Figure 6 shows Design Consistency Profile of cars (KM5 – KM31)
for distance of 25 km at F0050. The cars design consistency for distance of 25 km is 1.26. Both distancesshows a different threshold of design consistency: 2.41 (good consistency) meanwhile 1.26 (acceptableconsistency). Table 2 shows the summary design-consistency quality based on type of vehicle.
Table 2. Design-consistency quality based on type of vehicle
Type of vehicle
Cars
Motorcycles

Segment (KM)
5 – 105 – 25
5 – 105 – 25

Design Consistency
Threshold
2.90
Good Consistency
2.30
Good Consistency
2.41
Good Consistency
1.26
Acceptable Consistency

3.3 INTEGRATED DESIGN CONSISTENCY (IC)The integrated-consistency model is to incorporate the impact of the speed profile on design consistency intraffic and safety evaluations. Figure 7 shows Design Consistency Profile of Motorcycle and Cars (KM5 –KM10) for distance of 5 km. Figure 8 shows Design Consistency Profile of Motorcycle and Cars (KM5 –KM31) for distance of 25 km. Integrated consistency motorcycle and cars for distance of 5 km (KM5 –KM10) are 2.81 (good consistency) whereas Integrated consistency motorcycle and cars for distance of 25
km (KM5 – KM32) are 2.29 (good consistency). Speed between cars and motorcycles shows a good design
consistency in this segment. Table 3 shows the summary Integrated Design Consistency of Motorcycle andCars

Figure 7. Design Consistency Profile of Motorcycle and Cars (KM5 – KM10)419

Figure 8. Design Consistency Profile of Motorcycle and Cars (KM5 – KM31)

Table 3. Integrated Design Consistency of Motorcycle and Cars
Type of vehicle
Motorcycle & Cars

Segment (KM)
5 – 105 – 31

Integrated Design Consistency
2.81
2.29

ThresholdGood Consistency
Good Consistency

4 CONCLUSIONSThe consistency of the geometrical can be defined the synchronization between drivers’ expectancy on theroad and geometry. Continuous speed profile data that collected using Global Positioning System (GPS DG200) equipment through under free flow condition are to develop design consistency profile of motorcycles
and cars. Therefore, develop operating speed profile, 85th percentile of motorcycles and cars for tangents andcurves been using speed parameter and geometric parameter. The design consistency prediction models are
based on two independent, which is normalized area bounded and standard deviation of operating speeds.
There are several km along the segment that has a high ranking based on police accident. From theconsistency prediction models, can calculate integrated design consistency route FT0050 (KM5 – KM31) of
motorcycles and cars are good consistency. This stated although the accident collision occurred between carsand motorcycles, road design consistency is still in good consistency. Factors that may occur are due to theaccess point along road on the route F0050, and others such as the speed of vehicles itself. Combining theresults the road consistency with accidents frequency along the sections, it’s expecting to produce therelationships between accidents frequency and road design consistency. For the future research, it’srecommended to select more study site selection for further analysis and modeling based on road design
consistency.
5 ACKNWOLEDGMENT
The authors would like to thank to the Ministry of Education of Malaysia for supporting the research throughthe Fundamental Research Grant Scheme (FRGS) Vot. 1452. Appreciation is also given to all individuals andorganization that have made this study possible. Thank you is also extended to the Faculty of Civil
Engineering and Environment, Universiti Tun Hussein Onn Malaysia.

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Schurr, K., McCoy, P. T., Pesti, G., Jessen, D., & Huff, R. (2000).Relationship between Design, Operating
and Posted Speeds under High-Posted Speed Conditions (No. SPR-PL-1 (36) P519,).
Torregrosa, F. J. C., Zuriaga, A. M. P., & García, A. G. (2011). New Geometric Design Consistency Model
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WHO, Global Status Report on Road Safety: Time for Action, World Health Organization, Geneva,
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Yuen, C. W., Karim, M. R., & Saifizul, A. (2014). Analysis of motorcyclist riding behaviour on speed
table. The Scientific World Journal, 2014.

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1

Determining the real impact of speed limit enforcement cameras in the UK

2
3

John McKerrall Lamberta, B. Eng, Idris Francis, B.Sc. in Electrical Engineering

4

Abstract

56
7
8

The first UK fixed speed camera was installed in 1992; by 2005 there were 4000 and a peak of
6000. Most fixed cameras are painted yellow, and have markings on the road which provide asecondary speed check. Most sites were selected based on 4 or more KSI crashes over a recent
three-year period.

9
10
11
12
13
14

Research papers since the late 1990's have estimated the effect of speed cameras on crash rates,with KSI reductions ranging from 65% in early reports to 22% in Allsop (2013) report. Other
researchers in the UK and elsewhere considered these claims to be excessive given that police
analyses of contributory factors from 2005 consistently show that only ~8% of KSI crashes identify
exceeding the speed limit as a “likely” or “possible” contributory factor – and even then notnecessarily as the primary cause.

15
16
17
18

Idris Francis decided to undertake a thorough investigation. He obtained details of some 5 million
injury crashes from 1987 to 2011 from the UK Data Archive and obtained from police or UK Safety
Camera Partnerships the precise location and installation month for cameras in London, Wales,
Scotland and 19 other police areas in England, covering more than 50% of all such UK collisions.

19
20
21
22
23

The crash histories of camera sites were then compared to areas that did not receive cameras. With
the benefit of very large volumes of (monthly, not annual) data that minimise random effects it
became clear that the benefits long claimed simply do not exist and were instead the result ofseriously flawed analysis of insufficient and imprecise data, coupled with astonishing willingness tobelieve impossibilities.

24
25
26
27
28

It should also be noted that if cameras reduced crashes, those effects would be bound to start at thetime of installation and reach a maximum within a matter of months as the proportion of drivers
aware of the cameras reaches a maximum – and not continue to provide increasing benefit year afteryear. That characteristic dip at just the right time does indeed exist, but not remotely to the extent
long claimed, nor do those effects persist.

2930

Note: The term crash has been used throughout except where it is a title – for example Stats
19 Accident database.

31

Introduction – safe driving and the role of speed, speed limits and speed cameras

32
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36
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38

Safe driving/ riding requires an alert driver/ rider, not impaired by alcohol, illicit drugs, prescribeddrugs, a medical condition or fatigue, using occupant protection equipment, and choosing anappropriate speed and appropriate clearance distance to allow them to stop or swerve in time to
avoid a collision. Studies show distraction is a factor in around 65% of near crashes and 78% of
crashes (Klauer et al 2006). For Australian fatal crashes, alcohol or drugs are factors in around 30%,
failure to wear seat belts or helmets in around 20%, fatigue in around 18%, driving below the speed
limit but at an inappropriate speed in around 17%, and exceeding the speed limit in around 13%.

39
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41

Speed has been recognised as a factor in crashes from long before the “Speed kills” campaigns in
the 1970’s, and speed limits and tolerances have in some jurisdictions increasingly been used tolimit vehicle speeds. Since the early 1970’s there has been a progressive increase in speedaDirector John Lambert & Associates,

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43

detection/speed enforcement equipment - handheld radar and laser speed detectors, mobile speed
cameras, fixed red light and speed cameras, and recently average speed cameras.

44
45
46
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48

The first UK fixed speed camera was installed in 1992; by 2005 there were 4,000, and at the peakthere were around 6,000. Most UK fixed cameras are painted yellow, and have markings on theroad which provide a secondary speed check based on two images 0.5 seconds apart. Most sites
were selected for 4 or more KSI crashes over recent three-year periods, though long delays betweensite selection and installation can cause analysts problems in research.

49

Contributory factor “exceeding the speed limit” in KSI crashes

50
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52
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55
56

UK police have a menu of 77 contributory factors to be applied to reported crashes – on average
there are 1.95 contributory factors for fatal crashes, and 1.75 contributory factors for other casualty
crashes. The contributory factors include Exceeding the speed limit and Travelling too fast for theconditions. These contributory factors are aggregated against fatal, serious and slight crashes andpublished in the Department for Transport statistics Table RAS50001. Data from those tables forthe years 2010 to 2013 have been included in the table below, with the sum of the fatal and serious
crash contributory factors being added together to give a figure for KSI crashes.

57
58

Table 1. Table RAS50001: Contributory factors: Reported crashes by severity:
www.dft.gov.uk/statistics
Year

59
60

2010
2011
2012
2013
ExceedToo
ExceedToo
ExceedToo
Exceed
Too
limit
fast
limit
fast
limit
fast
limit
fast
221
215
213
207
173
167
216
191
Fatal
1620
1663
1497
1486
Total
13.6%
13.3%
12.8%
12.5%
11.6%
11.2%
14.5%
13.9%
%
1179
1565
1095
1470
1041
1498
1093
1326
Serious
18043
18391
18196
16974
Total
6.5%
8.7%
6.0%
8.0%
5.7%
8.2%
6.4%
7.8%
%
1400
1780
1308
1677
1214
1661
1309
1517
KSI
19663
20054
19693
18460
Total
7.1%
9.1%
6.5%
8.4%
6.2%
8.4%
7.1%
7.8%
%
Note that despite the high emphasis on reducing speeding, the exceeding the speed limit rates have
hardly changed.

61
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As shown, exceeding the speed limit is a contributory factor in 6.2% to 7.1% of KSI crashes. It
would be wrong to assume however that cameras could ever bring about similar reductions becauseeven if speeding were fully eliminated – which it is not – many of those crashes may still happen
due to other causal factors.

65
66

Note that exceeding the speed limit was stated as a contributory factor in 3.7% to 4.4% of slight
injury crashes over the period.

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The USA FARS crash database also has a speeding related data entry variable. It covers “Racing”“Exceeded Speed Limit” and “Too Fast for Conditions.” Council (2010) contains data for North
Carolina and Ohio crashes shown below. Note severity categories do not allow a direct
determination of the % of KSI crashes where exceeding the speed limit was a factor.

71

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Table 2: Frequency and number/percentage of Speed Related crashes regarding crash severity inNorth Carolina 2002-2004
Severity

74
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Over limit
Too fast
Total speed
Not speed
Total
No
%
No
%
No
%
No
%
No
Fatal injury
733 24.0%
404 13.2%
1137 37.3%
1913 62.7%
3050
Disabling
835 13.8% 1076 17.7%
1911 31.5%
4156 68.5%
6067
Evident injury
2916
7.7% 6427 17.0%9343 24.7% 28536 75.3% 37879
Totals4484
9.5% 7907
12391
34605
46996
As shown in Table 2, 9.5% of all casualty crashes involved “Exceeding the speed limit.”
Table 3: Frequency and number/percentage of Speed Related crashes regarding crash severity in
Ohio 2003-2005
SeverityOver limit
Too fast
Total speed
Not speed
No
%
No
%
No
%
No
%
398 20.8% 156 8.2%
554 29.0% 1355 71.0%
1720 15.0% 753 6.6%2473 21.6% 8994 78.4%
5255 11.0% 3668 7.7%8923 18.6% 38995 81.4%

Total
No
1909
11467
47918

77
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79

Fatal injury
Incapacitating injury
Non-incapacitating
injuryTotals
7373 12.0% 4577
11950
49344
61294
As shown in Table 3, 12.0% of all casualty crashes involved “Exceeding the speed limit”
These percentages are higher than the UK percentages but still much lower than many of theclaimed impacts of speed cameras on casualty crashes.

80

Evaluations of the impact of speed cameras on road trauma – Australia references

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83

An evaluation of Victoria, Australia’s covert mobile speed camera program – Cameron (1992) found a reduction in casualty crashes across Victoria of ~ 20%; in Melbourne of ~22%; in rural
Victoria of ~ 18%; and on Melbourne’s arterial roads a reduction of ~ 33%.

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90
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And in a more general review of speed camera programs – Cameron (2006) - referenced reductionsin Table 2 as detailed below:

Fixed and/or known/signed installations –:o
In Great Britain –– Local reductions of 65% in serious casualty crashes for fixedcameras and 28% for mobile cameras;o
In New Zealand – Local reduction of 28% in serious casualty crashes for mobile
cameras, and a general reduction of 13%; ando
In Queensland Australia - Local reduction of 35% in casualty crashes, and a general
reduction of 26%;

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95



96

Evaluation of the impact of speed cameras on road trauma – formal UK research

97
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100
101
102

In their executive summary PA Consulting (2005) claimed that after allowing for long-term trend
there was a 22% reduction in personal injury collisions (PIC)at camera sites, a 42% reduction inpersons killed or seriously injured, and a 32% reduction in persons killed. Appendix H of the report
noted that after using the empirical Bayes analysis to try to deal with regression to the mean
(RTTM) the reduction in personal injury collisions at camera sites was 16% and the reduction in
KSI collisions was 10%.

Unsigned sites or zones – in Victoria Australia:oGeneral reductions of 21% for Victoria & 32% for Melbourne with mobile cameras; andoa 21% reduction in serious casualties per crash for mobile cameras in Melbourne.

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In Allsop (2010) a number of approaches were taken to estimating the effect of speed cameras on
PIC and KSI crashes. These included adjustments for trend, the use of reductions in average speeds
at camera sites plus Nilsson / Elvik power relationships to predict reductions, and the use of
empirical Bayes analysis. All of these can now be shown to be seriously flawed.

107

And in Table 7 of that report it was estimated that overall the reductions were as shown below.

108

Table 4: Allsop (2010) estimated % reductions in PIC and KSI crashes

109
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Type of site
Percentage reduction - PIC
Percentage reduction - KSI
Fixed urban
between 20% and 25%
between 35% and 40%
Fixed rural
between 20% and 30%
between 30% and 50%
Mobile urban
between 15% and 20%
between 15% and 30%
Mobile rural
between 10% and 15%
between 15% and 30%
In Allsop (2013a) the executive summary references a 25% reduction in PIC after establishment ofcameras, and a 38% reduction in KSI crashes.

111
112

In Allsop (2013b), the executive summary references a 22% reduction in PIC after establishment ofcameras, and a 32% reduction in KSI crashes.

113
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All these claims much exceeded the contribution of speeding to crash causation in the first place as
noted previously, even though speeding had far from been eliminated. This was primarily becauseof analysts’ abject failure to understand and deal properly with trend and RTTM.

116

Concerns about the formal UK speed camera research

117
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123

The principal concerns are the large differences between the exceeding the speed limit contributory
factor reported by police – 11.6% to 14.5% for fatal crashes; 6.2% to 7.1% for serious crashes and3.7% to 4.4% for slight injury crashes – and the reported reductions in deaths and casualty crashes
at camera sites. Note that the figures include both possible and very likely contributory factors. This
led to a number of individuals undertaking their own research into the effectiveness of speed
cameras. (Note – the above para arguably makes some of my earlier changes unnecessary.
Idris)

124

An alternate approach to researching speed camera effectiveness

125
126
127
128
129
130
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132

This research is based on the hypothesis that:
Cameras cannot have an impact until they are installed;
Any impact commences immediately after installation and rapidly reaches a maximum;
As a result the month of installation, and monthly crash data is required for camera sites andother similar sites where cameras were not installed; and
By comparing trends in numbers of crashes at camera sites, and trends at other similar sites
from a period well before installation to well afterwards any step reduction in crashes atcamera sites would be easily identified.

133

Research by David Finney, an electronics engineer

134
135
136
137

Dave Finney’s research relates to Thames Valley speed cameras and is available at
http://www.speedcamerareport.co.uk. The data used by David was provided and verified by theThames Valley Safer Roads Partnership (TVSRP), the organisation responsible for the cameras. In
the process of developing a robust speed camera assessment method David recognised a number of

138
139

issues and developed ways to work around them. For example, to deal with any trend effects (theinfluence of other factors on crash numbers, his analysis used the proportion of crashes at speed
425

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141
142

camera sites compared to the total number of crashes in the Thames Valley area. And to obtainmeaningful results, crash histories for mobile camera sites, and for fixed camera sites wereseparately aggregated.

143
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145
146
147
148
149
150
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152
153
154
155
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He also determined that there are four periods (others had used as few as two) relating to site data:the period prior to the site selection period (pre-SSP);
the site selection period (SSP) –most sites have been chosen based on at least four KSI
crashes over a recent three-year period. Due to chance variation in site KSI numbers, thetotals are abnormally high and these are bound to return to normal the moment selection ends
(RTTM);
the period after the SSP but before the cameras were commissioned (ASBiC) when numbers
have already returned to normal; and
finally, the period during which the speed cameras were operating.
Often, only limited official data is to hand to allow identification of these four periods andaccordingly it is necessary to analyse site data to identify the SSP period. This is a particular
problem with fixed speed cameras because the time between site selection and commissioning
varies greatly due to planning and logistical problems. Mobile speed camera sites become
operational as soon as the mobile speed camera vehicles are deployed, but that does not mean there
are no delays.
2.5%

2.0%

Adapted from Finney Figure 8.2 Proportion of KSI collisions at all 75 active mobile speed camera sites in Thames Valley

preSSP
SSP
ASBiC
After installation

Average during
SSP

Averageduring ASBiC
Average after
mobile speed
cameras were
deployed

Mobile speed
camerasstartedoperating here

Average before
start of SSP

1.5%

1.0%

0.5%
www.SpeedCameraReport.co.uk
Data source: TVSRP

0.0%-16 -15 -14 -13 -12 -11 -10

-9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

6-month periods for the 8.5 years prior to speed cameras and the first 3 years of mobile speed camera operations (in red)

158
159
160

Figure 1. Adapted from Finney figure 8.2 - proportion of all KSI collisions at all 75 active mobile
speed camera sites in the Thames Valley

161
162
163
164
165
166

As shown in Figure 1 in the pre-SSP period on average 1.07% of all Thames Valley KSI collisions
occurred at these mobile speed camera sites. This percentage rose to 1.94% in the SSP period,
dropped back to 0.96% in the ASBiC period, and rose to 1.20% over the 3 years after the mobile
speed cameras started operating. Finney recognised that abnormal selection period data should
never have been used as a baseline reference and accordingly sought other ways of determining
normal levels..

426

2.0%

Adapted from Finney Figure 8.3 Proportion of KSI collisions at all 43 active mobile speed camera sites operating for 5 or more years in Thames Valley

Average during
SSP

1.5%

preSSP
SSP
ASBiC
After installation

Averageduring ASBiC

Average before
start of SSP

Mobile speed
camerasstartedoperatinghere

Average after
mobile speed
cameras were
deployed

1.0%

0.5%

www.SpeedCameraReport.co.uk
Data source: TVSRP

0.0%-16 -15 -14 -13 -12 -11 -10 -9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

8

9

10

6-month periods for the 8.5 years prior to speed cameras and the first 5 years of mobile speed camera operations (in red)

167
168
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Figure 2. Adapted from Finney figure 8.3 - proportion of all KSI collisions at all 43 active mobile
speed camera sites operating for five or more years in the Thames Valley

170
171
172
173

As shown in Figure 2 will in the pre-SSP period on average 0.79% of all Thames Valley KSI
collisions occurred at these mobile speed camera sites. This percentage rose to 1.58% in the SSP
period, dropped back to 0.78% in the ASBiC period, and rose to 0.88% over the 5 years after themobile speed cameras started operating.

174
175

In both cases the pre-SSP period figures and the ASBiC figures are similar as expected. And as
expected the crash rate in the SSP period is significantly higher.

176
177
178

However in contrast to earlier claims, post commissioning crash rates are in fact higher than theprior level. Prima facie this confirms that cameras had a negative impact on reducing crashes androad trauma.

179
180
181
182

There were a total of 212 fixed speed camera sites in the Thames Valley. For many sites Finney was
unable to source crash data from well before the commissioning of the cameras. As a result he wasunable to identify a pre-SSP period. In order to get reliable pre-SSP data, data for the 74 mostrecently installed fixed speed cameras was separately analysed as shown in figure 3.

427

Adapted from Finney Figure 9.1 Proportion of KSI collisions at the 74 most recent fixed (Gatso-type) speed camera sites in Thames Valley

3%
Average KSI collision
rate in SSP period

preSSP
SSP
ASBiC
After installation

Estimate of average
KSI collision rateprior to speed
camerasAverage KSI collision
rate after installation

2%
Fixed speed cameras
installed here

1%

www.SpeedCameraReport.co.uk
Data source: TVSRP

0%-13 -12 -11 -10 -9

-8

-7

-6

-5

-4

-3

-2

-1

0

1

2

3

4

5

6

7

8

9

10 11 126-month periods for the 7 years prior to speed cameras and the first 6 years after fixed speed cameras were installed (in red)

183
184
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Figure 3. Adapted from Finney figure 9.1 - proportion of KSI collisions at all 74 most recent
fixed (Gatso – type) speed camera sites in the Thames Valley

186
187
188

In the pre-SSP period and the ASBiC period 0.89% of all Thames Valley KSI collisions occurred atthese fixed speed camera sites. This percentage rose to 1.62% in the SSP period, and was 1.09%
over the 6 years after the fixed speed cameras were installed.
Adapted from Finney Figure 9.3 Proportion of KSI collisions at all 212 (Gatso-type) speed camera sites in Thames Valley

3%

Average KSI
collision rate in SSP
periodRough estimate ofaverage KSI
collision rate prior
to speed cameras

Average KSI collision
rate after installation

preSSP
SSP
ASBiC
After installation

Fixed speed cameras
installed here

2%

1%

www.SpeedCameraReport.co.uk
Data source: TVSRP

0%-12-11-10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
3-month periods for the 3.25 years prior to speed cameras and the first 6 years after fixed speed cameras were installed (in red)

189
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191

Figure 4. Adapted from Finney figure 9.3 - proportion of KSI collisions at all 212 fixed (Gatso –type) speed camera sites in the Thames Valley

192
193
194
195
196

As shown in Figure 4 there is no identified pre-SSP period. However the ASBiC period, being freeof selection bias, is arguably a better indication of “normal” than levels some years before that havebeen affected by trend effects. On average 1.59 % of all Thames Valley KSI collisions occurred atthese fixed speed camera sites during the ASBiC period. In the SSP period the rate was 2.13%, andin the after installation period the rate was 1.75%.

197

Again the post-commissioning crash rates were higher than the ASBiC rate.

198
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Research by Idris Francis

200
201
202
203
204

In the early 2000’s statisticians claimed that speed cameras in the UK were achieving tremendous
road safety gains with reductions in crashes of the order of 40% to 60%. And even before the DfT
causal factor analysis was first published in 2006, many independent observers, mostly engineers
more used to working with data than probability theory, refused to believe that such large
reductions could ever be achieved with such modest reductions in speeds.

205
206
207
208
209

In order to determine the real effectiveness of speed cameras Francis decided to obtain a great deal
more than others had used, including precise locations and dates. He also obtained the precise
locations and installation dates of as many cameras as possible. Currently that includes details for
22 out of 43 police areas including the three largest areas. His aim was to compare the crashhistories of camera sites with those where there were no cameras, on a very large scale.

210

Issues – form and quality of data

211
212
213
214

While some official site data has been published it is difficult or tedious to collate especially whenprovided as separate pdf or Excel sheets for each camera site. Stats19 Police data on the other handis published annually in a consistent format so that re-formatting into convenient databases is
simple.

215

Methodology

216
217
218
219

Idris obtained some 5 million Stats19 Accident and related casualty records from 1987 to 2011 fromthe UK Data Archive, including the 6 digit Easting and Northing grid references and the date andspeed limit of every crash. It was then entered into a Silicon Office relational database software
which he had used for 30years.

220
221
222
223
224

The official data contained many errors and omissions, including absurd location codes showing
crashes miles out to sea! In order to address this issue the northing, easting, southing, and westing
coordinates of the extremities of each police area were identified and where discrepancies appeared
each record was reviewed. More recently, the Department of Transport issued corrected location
data from 2000 onwards.

225

Stats19 Data

226
227
228
229
230

The police records of every reported injury road crash routinely published by the DfT do notinclude all of the details needed for speed camera analysis, but the csv files available to researchers
from the UK Data Archive include all recorded Stats19 information (other than causationassessment, considered too sensitive for inclusion). However there are restrictions prohibiting
copying the data to others unless in summary or redacted form.

231

Annual Crash, Casualty and Other Data used in this analysis

232
233
234

Stats19 uses one crash file and one casualty file for each year, each casualty record being linked to
the relevant crash by unique codes. For the most part this analysis uses crashes not casualties.
However the comparative results are much the same for both.

235
236
237
238
239
240

Separate Excel files for Slight Injury and Fatal/ Serious injuries show as a minimum:
Police Code 9 digits (2 being Force code, the remaining 7 are normally of no significanceother than for identifying particular crashes;
Limit Relevant Speed Limit;

EW
Ordnance Survey Easting Grid Reference, 6 digits identifying the East/West location
within 1 metre;
429

241
242
243
244
245
246
247



248

Camera Site Data (where available)

249
250
251
252
253
254
255

These files, one per Partnership area, generally provide the following data
Police Code 2 digits
EC
Ordnance Survey Grid Reference, 6 digits identifying the East/West camera
location.
NC
Ordnance Survey Grid Reference, 6 digits identifying the North/South camera
location within 1 metre
WHEN Numerical code for installation month of camera, e.g. Year *12 + month;

256
257
258
259
260

To date, speed camera data for 22 police areas has been obtained and analysed. In some cases it was
obtained despite the apparent reluctance of Partnerships to provide it, while others claimed not tohold it. Given that the Stats19 data is available to them, and they must know where and when theirsites were installed, the reality is that the data is available. They have not bothered to collate it to
date.

261

Distances between Crashes and Casualties in Relation to Camera Sites.

262
263
264
265

From this point on, the raw crash/casualty data was split up into separate files for each police area.
Then, given the co-ordinates of crashes and camera sites, within one area, Pythogoras Theorem canfind the nearest camera to each crash and enter that distance into the DIST field of each crashrecord.

266
267

It was found that indexing camera locations by the first 3 digits of the Easting codes greatly speeds
up the processing.

268

Months between Crashes and Casualties in Relation to Camera Site Installations.

269
270

Similarly, comparing the WHEN codes of the accident and camera installation, the DIFF field of
the accident record can be entered and stored.

271

Processing

272
273
274
275
276
277
278
279

The resulting data may be processed to provide the following:A single Excel sheet showing 1987-2011 Stats19 fatal and serious crash (FSC) data
aggregated by police area, year, distance from camera site if within 1km, speed limit, anddelay in months between crash and camera installation. This allows large numbers ofgraphs to be drawn very quickly.

A similar sheet covers Slight Injury Collisions.

1987-2011 Stats19 FSC data for all police areas by area and month
As above for each camera in 22 police areas for any desired site radius.

280

Analysis

NS
Ordnance Survey Northing Grid Reference, 6 digits identifying the North/Southlocation within 1 metre;
WHEN Numerical code for date of crash, e.g. Year *12 + month;
DIST Initially blank field to hold distance from nearest camera; and
DIFF Initially blank field to hold the difference in months
As might be expected, crash and casualty trends are very similar so the analysis only uses crashdata. This cuts down the data handling requirement as only the collision files are needed.

430

281
282

Analysis only requires the application of simple arithmetic to FSC crashes near any one of 3,400
camera positions in the 22 police areas for which data is currently available.

283
284
285

Critically, with this method there is no need for estimates, probability theories, mathematicalmodels, or any other manipulation of the data in order to make comparisons between sites where
cameras have been installed, and similar sites where cameras have not been installed.

286
287

And if a camera or group of cameras have any beneficial effect, it will appear as a quite sudden
reduction in accidents their reach camera from the month of installation onwards.

288
289
290
291
292
293
294

In the first two of the following graphs, to make comparison easy, the numbers of non-camera site
KSI have been scaled down to equal the number of KSI at camera sites in 1991. The first method(Fig.5) compares FSC rates near cameras with rates elsewhere in the same police area(s) Siteselection based on high numbers of crashes causes previously common trends to diverge and after
selection this effect ends, leading to convergence. Once past that transient effect, camera benefit, if
it existed, would be confirmed by crash numbers falling further than non-site data. It is clear thatthey do not.

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Figure 5. Method 1 – London camera site KSI in blue (475 Sites -last one installed in 2008)
versus non-camera site KSI crashes in red

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After the separation in the two graphs caused by camera sites being selected for high crash rates, thetwo graphs converge from 2007 onwards – there is no difference in the trends in the number ofcrashes, the scaled trendlines overlapping in 1991, and then again overlapping from 2007 through to
2011.

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Figure 6. Method 1 – KSI in England and Wales within 500m of camera locations on 30mph
roads - camera site KSI crashes in blue versus non-camera site KSI crashes in red

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There is no discernible difference in the scaled trendlines in numbers of crashes in the two graphs
either side of the period in which most cameras were installed - around 1995 to 2004. This graph ofsites on 30 mph roads represents about 60% of all camera sites identified in the 32 police areas.

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The above two graphs and some others use Transport for London data published in July 2014.
Unfortunately London is one of only 10 or 11 areas to have published sensibly usable data, and theonly where the volume of data is in any case large enough to allow accurate analysis. For thatreason the second method used in this analysis is based in circular sites centred on cameras, forthese reasons:

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

It bypasses the failure of so many partnerships to publish usable data and so thereby allows amuch larger scale analysis which is inherently more accurate.

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

It allows monitoring of the distances over which camera effects extend, which partnerships
are unable to do with their fixed and necessarily subjective site boundaries.

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Doubtless some who would prefer not to believe the results provided, will claim that they areinvalid because they do not conform to a view of where site boundaries should be drawn. Research
known to the authors tends to show that the effect of speed cameras on speed behaviour typicallyextends around 700 m either side of the camera. For that reason boundaries have been chosen up to
1000 m from the camera location.

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Also, if crash numbers appear to fall within narrowly defined boundaries, they should also fallwithin wider circular boundaries. If they do not, that can only be because the cameras are merely
shifting crashes from one place to another (by for example by causing drivers to divert) rather than
reducing them

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It brings consistency to the results, as opposed to the variations arising from the different ways inwhich site boundaries are determined by different partnerships.

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This second method uses monthly data for cameras installed between 1994 and 2008, adjusted
relative to camera installation month (in this case set as month 85) to identify and quantify any
reductions in KSI following installation..

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Figure 7. Method 2 –FSC within 500 m of cameras for 22 Police Areas–with installation
adjusted to month 85. Average Trend in red > 1km from cameras, * 0.996/ per month
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334

There is no identifiable drop in KSI within 1km of the cameras after installation in month 85.

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Hundreds of graphs can be drawn from the each single Excel sheet of crash data, for different
combinations of police area, speed limit, radius from camera and camera type. Every graph drawn
to date shows the same results – minimal and short-lived reductions close to cameras and significant
increases further away. The same applies to Slight Injury Collisions as to FSC.

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Conclusion

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Previous research suggests that speed cameras reduce crashes by 22% - 65%. However UK and US
contributory factor data shows that exceeding the speed limit is only a factor in around 11% to 24%
of fatal crashes; 6% to 10% of KSI crashes and 4% to 5% of slight injury crashes. And logic
suggests that significantly lower figures than these should be the limit to the effectiveness of speed
cameras.

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In an effort to get around this apparent contradiction both Finney and Francis used unadjusted data(no statistical tools such as the empirical Bayes method were used) to directly determine the impactof speed cameras on crashes. Both their analyses showed that speed cameras have no significant
impact on road trauma.

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References

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Allsop, R. E. (November 2010). The effectiveness of speed cameras – a review of evidence, RAC
Foundation UK

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Allsop, R. E. (2013a) Guidance on use of speed camera transparency data, RAC Foundation UK

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354

Allsop, R. E. (2013b) Guidance on use of speed camera transparency data –updated November
2013, RAC Foundation UK

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Cameron, M., Cavallo, A., Gilbert, A., (1992) Crash-based evaluation of speed camera program in
Victoria 1990-1991 - Phase 1: General effects - Phase 2: Effects of program mechanisms (Report
No. 42) MUARC Australia

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Cameron, M., Delaney, A., (2006) development of strategies for best practice in speed enforcementin Western Australia – final report (Report number 270) MUARC Australia

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Council, F. M., Reurings, M., Srinivasan, R.,, Masten, S.,, and Carter, D.(2010) Development of a
Speeding-Related Crash Typology (Report No. FHWA-HRT-10-024) US Department ofTransportation:

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Klauer, S.G., Dingus, T. A., Neale, V. L., Sudweeks, J.D., and Ramsey, D.J (April 2006) The
Impact of Driver Inattention On Near-Crash/Crash Risk: An Analysis Using the 100-Car
Naturalistic Driving Study Data (Report DOT HS 810 594) US National Highway Traffic Safety
Administration

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368

PA Consulting Group & UCL (2005) the national safety camera program: four-year evaluation
report. London: PA consulting group or

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1

Lambert (2)Do crash rates really increase with increases in average speed?

2
3John McKerrall Lamberta, B. Eng,

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Abstract

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For more than two decades speed limit enforcement has been supported by research that "shows"that crash rates increase with increasing average speed.

789Safe driving is primarily determined by being alert, being unimpaired, and driving at an appropriate
speed and with an appropriate clearance distance for the environment at the time. And note speed
limits are not set based on maximum safe speeds.

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This paper reviews the papers by Nilsson, TRL, Kloeden et al and others that show benefits fromreducing average speeds, and shows they contain errors or are inconclusive. It supports that
MUARC report 307 correctly determines enforcement cameras have virtually no effect on roadtrauma even though studies show average speeds are reduced at camera sites. And it reviews
Allsop's 2013 report which claims speed cameras reduced KSI crashes, shows no correlation
between the change in average speeds and the change in crash rates at camera sites.

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It reviews research on crash rates by road type and speed limits, and finds no correlation between
crash rates and average speeds.

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This paper shows that it cannot be asserted that crash rates increase with average speed. This has
serious implications for the reports that show speed limit enforcement reduces speeds and then use
Nilsson, TRL, Kloeden or other results to claim there would be a reduction in casualty crashes.

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Introduction – safe driving and the role of speed and speed limits

22

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Safe driving/ riding requires:
an alert driver/ rider, not impaired by alcohol, illicit drugs, prescribed drugs, a medical
condition or fatigue,
the use of occupant protection equipment, andchoice of an appropriate speed and appropriate clearance distance to allow them to stop or
swerve in time to avoid a collision.
Speed has been recognised as a factor in crashes from before the “Speed kills” campaigns in the
1970s. And speed limits and speed limit tolerances have in some jurisdictions been increasingly
used to control vehicle speeds. Since the early 1970’s there has been a progressive increase in speed
detection/speed enforcement equipment. And in evaluating the effectiveness of these technologies it
has been a fairly common practice to measure the effect of the devices on average speeds and thenuse relationships between average speeds and crash rates to predict changes in crashes.

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Speed and crashes – a conceptual model

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For a particular vehicle, driver and situation the chance of a crash is highly variable. Take twovehicles, travelling at 90 km/h, with deceleration rates of 8.5 m/s^2, and reaction times of 0.75, 1.25
and 2.25 seconds, with the front vehicle suddenly braking. The impact speed vs separation distancecan be modelled.

aDirector John Lambert & Associates,

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Lambert (2)36Figure 1. Impact speed versus initial separation distance
Impact speed versus initial separation distance - start speed
90 kph, deceleration 8.5 m/sec^2
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Impact speed (kph)

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0
0

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Initial separation distance (m)370.75 Reaction time

1.25 Reaction time

2.25 Reaction time

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The results are shown in Figure 1. The reaction time determines the maximum impact speed. Eachgraph comprises 4 zones: A period where the following car has not yet applied its brakes; a period
where both cars braking; a period where lead car has stopped; and a period where both cars havestopped without colliding..

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For a particular on road situation the overall crash risk factor will depend on the crash risk factors
for the range of vehicles and conditions that occur at that location. For example consider a 275
meter curve with 4.5% superelevation. This curve would be likely to have a 70 km/h advisory speed
limit.

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Figure 2. Likely distribution of crash risk on a 275 m curve
Percent unable to negotiate curve

Conceptual speed versus crashes on a 275 m radius curve - all conditions& limits for particular situations/ vehicles
100%

Modern passenger
car – dry road

Semitrailer with high heavy load(due to stability)

80%
Advisory sign speed limit on
100/110 kph roadPhysical speed limit
for best driverin best passenger car
in best conditions

60%

40%
Icy road surface
Modern passenger
car – wet road

20%
Rigid truck with low load(due to stability)

0%
0

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Speed (km/h)

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In icy conditions vehicles would slide and crash off the road or into each other at around 60 km/h. A
semitrailer with a high heavy load would rollover at around 90 km/h and so on. The crash risk forthe population of vehicles over a range of weather situations approximates an S-curve. And in a
100/110 km/h speed zone the relevant crash risk curve would be the section from 0 to ~120 km/h.
To this crash risk would need to be added risks associated with distracted, impaired of fatigued
drivers crashing off the curve at any speed.

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Driver populations and crash rates

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Lambert (2)55
56Based on all the data I have seen over my 50 years of involvement in road safety and using
Australian data I have been able to determine the following approximate crash causation rates.

57

Table 2: Crash causation rates per years of driving – Australian data

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Crash type
Most responsible 30% Next 50% Less responsible 12% Irresponsible 8%
Fatal
140,000 yrs
42,000 yrs
10,500 yrs
1800 yrs
Serious8,700 yrs
2,500 yrs
950 yrs
155 yrs
Other injury
500 yrs
150 yrs
90 yrs
15 yrsAs shown the responsible 80% of drivers have very low crash rates. The chance of them causing acrash where someone is injured is around once in 2 to 3 driving lifetimes. And necessarily thesedrivers must be skilled at choosing appropriate speeds and clearance distances to avoid crashes,
must not drive when they are unimpaired, and must use occupant protection devices.

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And being the majority of drivers they have a huge impact in controlling driving behaviour onroads. Except where traffic is light this group basically controls vehicle speeds.

64

Driver behaviour – speed versus speed limits

65

Figure 3. Average speeds versus speed limits on a length of UK B class road

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The Figure 3 is from UK DfT Traffic Advisory Leaflet 2/06. These average speeds are basicallycontrolled by the 80% of responsible drivers. It is interesting to note the degree to which thesedrivers follow the actual speed limits. In the initial 40 mph zone the drivers chose generally to travel
above the speed limit; in the following 50 and 40 mph zones the drivers chose to follow the speed
limits with one significant variation; and in the 60 mph zone the drivers chose to travel below the
speed limit. Note that the enforcement tolerance in the UK is 10% of the speed limit +2 mph so thatexcept in the initial 40 mph zone the average driver would not be at risk of being infringed.

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Average speeds reflect driver’s responses to perceived varying levels of risk. And in the 60
mph zone, average speeds along this 7 km length varied from 40 mph to 60 mph. In a study of
average speed versus crashes average speed measurements could be highly variable.

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Figure 4. Average speeds versus traffic flow on a section of the Monash Freeway in Victoria
Australia (speed limit 100 kph)436

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Lambert (2)7980

Figure 4 is VicRoads Managed Freeways Handbook (2013) Figure 24

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In Australia drivers drive on the left side of the road, so the left lane is the slowest lane and the rightlane is the fastest lane in a three lane freeway situation. In the uncongested situation speeds in lefthand lane average 90-95 km/h; 95-100 km/h; in the middle lane and 100-105 km/h in the right lane.
Once a lane reaches saturation the speeds rapidly drop. And lower speeds equal lower capacity.

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As shown in this figure at 400 vehicles per hour in the uncongested situation vehicles are travellingat about 100 km/h, or 100,000 m/h. Assuming the average vehicle length was about 4.5 m then the
400 vehicles would occupy 1800 m of the 100,000 m. Hence the average distance between themequals (100,000 – 1,800)/ 400 or of the order of 250 m. And at 800 vehicles per hour in theuncongested situation vehicles are travelling at around 96 km/h, or 96,000 m/h. The same
calculation gives a separation distance of the order of 120 m. It would therefore be expected thatcrashes would be rare in mid blocks situation. However low traffic flow would allow lessresponsible drivers to travel faster than the general traffic stream, and create a risk of serious
crashes. In comparison in the saturation zone and congested zone, the average separation distances
will be 25 metres to 55 m (1.2 to 2.5 seconds) with significant risk of nose to tail crashes especiallyat intersections. However because vehicle travel speeds before braking will be similar and lower,
crash severity is likely to be low.
In summary figure 4 reflects a large range of speeds and clearance distances and varying
crash type risks. For the purpose of average speeds and crash rates, a single value for average
speed for this segment of road or any other high volume road would be a nonsense.

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Crash rates versus speed limits by road class

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If crash rates increased with average speed in an absolute sense, it would be expected that the roadclasses with the highest average speed would have the highest crash rates.

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Figure 5. Trauma rates versus road category USA & UK

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Lambert (2)

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As shown in the diagrams above (USDOT(2003) Figure 4 & Bayliss (2009) Figure 6) to a large
extent the reverse is true – the roads with the highest speeds – the motorways and freeways – havethe lowest crash rates. And the roads with the lower speeds have the highest crash rates.

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Research by Nilsson (2004)

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Nilsson’s research used Swedish National Road Administration 1997 mean speed data for two laneroads with a road width of 13 m - 43 road sections had a speed limit of 90 km/h and 62 Road
sections had a speed limit of 110 km/h. Crash data was for the period 1991 to 1997.

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The data was grouped by average speed to give reasonable number of crashes per group. In the 90
km/h zones the groupings were 87-91 km/h (94 crashes), 92 km/h (154), 93-94 (200), 95-96 (144),
97 (190), 98 (190), 99 (116) and 100-112 (165). In 110 km/h zones the groupings were 97-100km/h (53), 101-102 km/h (63), 103 (163), 104 (136), 105 (104), 106-108 (118), 109 (94) and 110112 (96).

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Figure 6. Nilsson (2004) Figure 28

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Figure 6 above shows the 16 fatal accident rates together with Nilsson’s power model curve in pink,plus a linear model and a power model from be accident rate data. What is not highlighted is thefact that these data points relate to road sections with different speed limits. And the fact that theroad managers had specified different speed limits is prima facie evidence that they perceived therisks with the two road types to be significantly different.
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Lambert (2)124

Figure 7. Based on Nilsson (2004) Figure 28
KSI crash rate per million kilometres
0.070
0.060
0.050

0.040
0.030
0.020
0.010

0.000
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90 kph92

110 kph

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Average speed (km/h)

Nilsson 3rd power

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Figure 57 shows the two groups of data highlighted separately, plus one outlier value circled in red.

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Figure 8. Trend lines based on Nilsson (2004) Figure 28
KSI crash rate per million kilometres
0.070
0.060
0.050
0.040
0.030
0.020
0.010

0.000
88

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90 kph9092
110 kph94

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Nilsson 3rd power

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Trend 90 kph

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Trend 110 kph

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Trend 110 kph (2)

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Three linear trendlines have been added in figure 8 above - for the 90 km/h data; for the 110 km/h
data; and for the 110 km/h data less the one outlying value. Note that the linear trendlines are
significantly different in slope to the Nilsson third power model except for the adjusted trend for the
110 km/h data. Similar results are found for other crash types. This brings into question the validityof Nilsson’s power model.

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Research by Allsop (2013)

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In Appendix 4 - Joint Analysis of Collision and Speed data, data was examined for eight UK Speed
Camera Partnership (Partnership) areas. Where it was clear that one or more observations weremade before establishment of a camera and one or more afterwards, the observations of mean speed
before and after establishment were each averaged, and the difference between the two averages
was taken as an estimate of the change in mean speed in the vicinity of the camera following its
establishment.

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Changes in mean speed were estimated in this way for 132 cameras in these eight Partnerships, andranged from a reduction of 13.7 miles/h to an increase of 1.7 miles/h. All but three were reductions.

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The change in collision occurrence at the camera concerned was measured by number of personal
injury crashes (PIC) per year in the vicinity of the camera in years throughout which the camera
may have been in operation.

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Figure 9. Change in PIC crashes versus change in average speed – 132 UK speed camera sites

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Peer review stream

Lambert (2)Change in PIC crashes versus change in average speed
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-15.0

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-12.5

-10.0

-7.5

-5.0

-2.5

Allsop graph

TRL

NilssonAllsop trend

0.0

2.5

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Allsop’s data is shown above with the trend line shown in green. Note he found a slight increase in
PIC crash crashes with reductions in average speed. I have compared Allsop’s data and trend withthe predicted trends by TRL and Nilsson based around the average of all Allsop’s data. As shown
Allsop’s data does not support the TRL or Nilsson trendlines at all.

152

Research by Kloeden and McLean (1997) – Urban roads

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This study was a case/ control study

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Case vehicles

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The following criteria were used for the selection of case vehicles: Crash was in the Adelaide
metropolitan area, with a 60 km/h speed limit, not on a section of road with an advisory speed signof less than 60 km/h, case vehicle was a car or car derivative, at least one person was transported
from the crash scene by ambulance, case vehicle had a free travelling speed prior to the crash, wasnot executing an illegal manoeuvre prior to the start of the crash sequence, the case vehicle driver
did not suffer from a medical condition that caused the crash, and had a zero blood alcohol
concentration (BAC), there was sufficient information was available to carry out a computer-aided
crash reconstruction, the case vehicle did not roll over, and crash did not occur while it was raining

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Cases were restricted in the interest of uniformity. Higher speed zones would have had
fundamentally different speed distributions which would have made the case-control analysis more
complicated to perform and the results harder to interpret.

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The end result was that 28% of the notified crashes were selected for analysis. Those crashes weredisproportionally intersection crashes between cross traffic or turning traffic (60% of cases versus
expected frequency of around 17%-20%).

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Control vehicles

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The selection of 4 control vehicles were based on same location, weather conditions, day of week,
and time of day as the crash; same direction of travel as the case vehicle; car or car derivative, freetravelling speed, and most were checked for zero BAC.

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Figure 10. Distribution of average speeds of groups of control vehicles

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Lambert (2)

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As shown average speeds of the control vehicles varied dramatically from 43 km/h up to 74 km/h.
As these average speeds are the result of decisions made the responsible group of drivers, it must be
the case that the risks vary dramatically between sites. Reference to the actual Kloeden and Mclean
data shows that the high speeds were recorded on roads where the pavement width in one direction
was 12 m wide or more, whilst in the low speed situation the pavement width had been restricted to
6 ½ m wide in one direction using traffic calming methods.

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Kloeden and McLean professionally used available information to determine the speed of the casevehicles prior to the crash. However inexplicably when they analysed the data to determine a crashrisk, they used 60 km/h as the reference speed instead of the average speed of the control vehicles.

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Figure 11. Crash risk versus speed differential
CRASH RISK VERSUS SPEED DIFFERENTIAL
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RELATIVE RISK

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Lambert analysis

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Kloeden report

0

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SPEED (km/h)

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And in figure 11 above the dashed line shows the results of their analysis. Note that there is hardly
any increase in crash risk for vehicles travelling much slower than 60 km/h. This is in conflict withthe general experience in road safety that shows that vehicles travelling much slower than the traffic
stream represent a significant crash risk – hence all the warnings required with slow moving
vehicles.

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In my paper Lambert (2000) I reanalysed the data using the control vehicle speeds as the reference
speed. The results of my analysis are shown in figure 11 in the full black line (I have overlaid theKloeden and McLean graph placing the zero value at the 60 km/h value of the original graph).

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The implications of my analysis is that it’s not the average speed differential from 60 km/h that
controls crash risk, it is the variation from the average speed that the 80% of responsible drivers
choose that is the critical factor. And note that as expected vehicles travelling much slower than the
average travel speed also generate a significant increase in crash risk.

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In summary the crash rate does NOT double for every 5 km above 60 kph.

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Lambert (2)199

Research by Kloeden and McLean (2001) Rural roads

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This research project was of a similar design to the previous research project but for rural roads.
The differences were that rather than limiting cases to a single speed limit zone, it covered 80 kmh,
100 km/h and 110 km/h speed zones. In addition the analysis followed the approach in Lambert(2000).

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Figure 12. Control vehicle average speeds versus speed limit or advisory speed

Control average speed (km/h)

Control vehicle average speeds versus speed limit or advisory speed
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As is shown above at most sites the average speed for control vehicles are significantly less than the
speed limit or advisory speed. In only 14 (8.4%) of the 167 cases is the average control group speed
at or above the speed limit or within 5 km/h of the speed limit. Prima facie this reflects that
responsible drivers perceive these sections of road as being of higher risk and therefore reduce their
speed to control that risk. And the implications of this are that the data in this research project isonly appropriate in relation to speed limits at problem locations in the rural road network.

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The results showed that the crash risk increases significantly where vehicles travel faster than the
speed responsible drivers would choose – it does not show that crash risk varies with average speed.

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Research by Taylor et al (2002) TRL Report TRL511

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This Research Report aimed at determining the relationship between speed and crash rate on UK
Rural roads with 60 mph speed limits.

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Four Groups of roads were identified that can be broadly described as follows:

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Group 1: Roads which are very hilly, with a high bend density and low traffic speed - low quality
roads.
Group 2: Roads with a high access density, above average bend density and below average traffic
speed - lower than average quality roads.
Group 3: Roads with a high junction density, but below average bend density and hilliness, andabove average traffic speed - higher than average quality roads.
Group 4: Roads with a low density of bends, junctions and accesses and a high traffic speed - highquality roads.

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Unfortunately nowhere in the paper is the base data displayed so that readers are faced with a blackbox analysis. Two model forms were developed – Level 1 which was of the form accident count =Function(years of accident data; AADT flow; link length; mean speed); and Level 2 which was of
the form accident count = Function(years of accident data; AADT flow; link length; mean speed;road geometry). Model results were presented in Figure 3 of the report.

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Lambert (2)The Report is puzzling to the writer for a number of reasons. Firstly it contains none of the basedata. Figure 2 represents the model for a very specific situation, and figures is A1 and A2 are asynthesised construction to demonstrate a masking situation.

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Further the trends shown in Figure 3 of the report did not make sense to the writer in relation to any
hypothesis as to what factors would drive reductions in crash frequency or KSI crash frequencies
versus mean travel speeds. This is especially so given that responsible drivers are very good at
adjusting speeds and mean speeds to maintain a high level of safety. I decided to analyse the trendlines in Figure 3 of the report. That analysis showed the crash frequency trend line ≈ 2.405 x (1/V);
and the KSI crash frequency trend line ≈ 2.765 x (1/V). The correlation between the TRL511 report
data and my model is shown in figure 13 below.

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Figure 13. Comparison between TRL511 trend lines and my model% reduction in crashes per 1 mph reduction in mean
speed

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12.0%

TRL511 model versus Lambert model - % reductions in crashfrequency per 1 mph reduction in mean speed

10.0%

8.0%

6.0%

4.0%

2.0%

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Mean speed (mph)

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TRL511 AF

Lambert AF

Lambert KSI

TRL511 KSI

The authors offer no hypothesis as to why % reductions are proportional to the inverse of the mean
speed on rural single carriageway roads.

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As shown in the segment of Figure 1 of the TRL report, low quality group 1 roads are associatedwith low mean speeds and high crash rates, whilst high-quality group for roads are associated withhigh speeds and low crash rates. Hence the relationship shown in figure 13 above may be the resultof road standard rather than mean speed.

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Conclusion

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Almost universally studies into mean speeds versus crashes have failed to recognize that a) speed
alone never defines safe driving – it is speed and clearance distance that underlies safe driving; b)that on heavily trafficked roads traffic flow has a complex and dramatic impact on speed and on443

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Lambert (2)

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types of crashes; c) that on lightly trafficked rural roads crashes are mostly concentrated at “blackspots” connected by safe sections of roads where – yet the safe sections are where speeds arechecked; and d) that responsible drivers continually adjust speeds even within a speed zone so thatany mean speed reading is highly likely to not represent the mean over that section.

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There is little consistency in the various models. The slope of the Allsop trend line is opposite to theslopes of other models, and the Kloeden serious crash trend is very different to the other trends.

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261
262
263
264
265
266

In summary based on my analysis of the reports above, and the concerns stated, there is no robustmodel that can be used to predict reductions in crash frequency with reductions in mean speed.
Further data from various jurisdictions show that the highest speed roads have the lowest
fatality/crash rates per 100 million km, so there is no underlying relationship between speed andcrashes that would indicate a reduction in crashes with a reduction in mean speed. And finally giventhat speed alone never describes safe driving, it is not unexpected that any research aimed atrelating speed alone to crashes is likely to be inconclusive.

267

References

268

Allsop, R. E. (2013a) Guidance on use of speed camera transparency data, RAC Foundation UK

269
270

Allsop, R. E. (2013b) Guidance on use of speed camera transparency data –updated November
2013, RAC Foundation UK

271
272

Bayliss, D., (March 2009) Motoring Towards 2050 – Roads and Reality - Background Paper No.9
RAC Foundation

273
274

Kloeden CN, McLean AJ, Moore VM, Ponte G (1997) Travelling Speed and the Risk of Crash
Involvement NHMRC Road Accident Research Unit, The University of Adelaide

275
276

Kloeden CN, McLean AJ, Moore VM, Ponte G (2001) Rural Speed and Crash Risk Road Accident
Research Unit, Adelaide University 5005

277
278

Lambert, J., (2000) Does the crash rate really double for each 5 km/h above 60 km/h Available
at http://acrs.org.au/files/arsrpe/RS000039.pdf

279
280
281

Nilsson, G., (2004) Bulletin 221 Traffic Safety Dimensions and the Power Model to Describe theEffect of Speed on Safety, Lund Institute of Technology, Department of Technology and Society,
Traffic Engineering

282
283
284

Taylor, M. C., Baruya, A., KennedyJ. V., (2002) TRL Report TRL511 The relationship between
speed and accidents on rural single-carriageway roads Prepared for Road Safety Division,
Department for Transport,Local Government and the Regions

285
286

US Department of Transportation (September 2005) Speed Management Strategic Initiative (Report
DOT HS 809 924)

287
288
289

VicRoads Managed Freeways Handbook – Chapter 2 (2013), Available athttps://www.vicroads.vic.gov.au/business-and-industry/technical-documents/freeway-ramp-signalshandbook

290
291

UK DfT traffic advisory leaflet 2/06, (2006) Available athttps://www.gov.uk/government/publications/traffic-advisory-leaflets-1989-to-2009444

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

New Low-Activity Nuclear Gauge for Soil Wet Density Measurement with Low
Regulatory Burden

TRACK
AUTHOR(Capitalize Family Name)
Linus DEP
CO-AUTHOR(S)(Capitalize Family NamePOSITION

Senior Nuclear PhysicistResearch & Development
POSITIONORGANIZATION

Troxler Electronic
Laboratories
ORGANIZATIONCOUNTRY

U.S.A.
COUNTRY

Robert TROXLER

DirectorResearch & Development

Troxler Electronic
Laboratories

U.S.A.

William TROXLER, Jr.

President- CEO

Troxler Electronic
Laboratories

U.S.A.

E-MAIL(for correspondence)

LDep@Troxlerlabs.com

KEYWORDS:
Include up to 5 keywords
soil, density, moisture, nuclear, gamma-ray

ABSTRACT:
For decades, measuring soil density and moisture content using nuclear gauges has been a well-accepted testing method
for road and embankment construction. The ownership and use of nuclear gauges come with some regulatory burdens
such as the need for licensing, special storage, transportation requirements, gauge operator training, and personal
dosimetry. As a result, the industry has been searching for alternatives to nuclear gauges. So far, no such non-nuclear
solution has been found.
Recently, in the United States, the Nuclear Regulatory Commission declared a nuclear gauge exempt from licensing due
to its safe design and use of an extremely low-activity radioactive source. The availability of such an instrument allows
many countries to accept a proven testing method where often little or no testing was completed. The outcome will be alonger lasting road foundations and safer embankments. We will present the technical aspects of this nuclear gauge andits performance.

445

New Low-Activity Nuclear Gauge for Soil Wet Density
Measurement with Low Regulatory Burden
Linus Dep, Robert Troxler, and William Troxler, Jr.1
Troxler Electronic Laboratories, 3008 Cornwallis Road, Research Triangle Park, NC 27709, USA
Email for correspondence, ldep@troxlerlabs.com

1 INTRODUCTION
Soil compaction is essential to increase the load bearing capacity during construction of roads, airfields,
building sites, embankments, and parking lots. Soil compaction is verified by measuring the soil density which isdefined as mass per unit volume. The resulting density measurement is a measure of the degree of compaction. During
the entire process of constructing the road foundation, dry density and moisture content of the compacted soil andaggregate base are monitored by the direct measurement of wet density and moisture content of soil.
Soil wet density can be measured by the direct determination of mass and volume of a sample. When using
this measurement methods, soil mass is removed in the measurement area creating a small hole. Although the mass ofthe soil can be measured accurately, the volume measurement is challenging due to the irregular geometry of the
excavated hole. Several methods based on this concept are used in the industry. They are the sand cone method(ASTM D1556), the rubber balloon method (ASTM D2167), and the drive cylinder method (ASTM D2937). Althoughthese methods can be accurate, from early on, the construction industry understood the drawbacks of using thesemethods such as long measurement time and operator errors.
Nuclear techniques for soil density and moisture content measurements were introduced in the 1950s (Krueger
1950; Pieper 1949; Belcher and Cuykendal, 1950). Historically, this soil density measurement method is based on
gamma-ray scattering and this moisture content measurement method is based on neutron scattering. Gauges based on
nuclear techniques, which are called nuclear density gauges (NDG), have been in use worldwide as a soil compaction
measuring device for over five decades. These gauges are widely used in the industry because of the ease of use,
accuracy of density and moisture measurements, large measurement volume, and short measurement time. The
accuracy of measuring density and moisture by NDGs has been well-established and in many places the nuclear
techniques are used as the standard method for quality control or quality assurance (ASTM D6938-10).
The NDGs use radioisotope sources of gamma-rays and neutrons. The source activity or strength are less than
370 MBq (10 mCi) for density gauges and less than 1850 MBq (50 mCi) for combined density and moisture gauges.
Although such levels of source activity is not high and gauge design provides adequate shielding from radiation for thegauge operator, regulatory agencies worldwide consider them as controlled devices. These regulations impose certain
burdens for ownership and operation of nuclear gauges such as the need for licensing, special storage, transportation
requirements, gauge operator training, and personal dosimetry. On account of these burdens, many non-nuclear
technologies, based on soil electrical properties, stiffness, and modulus, have been evaluated as alternatives to the
nuclear techniques but with limited success (Berney and Kyzar 2012; Mejias-Santiago et al. 2013; Rose 2013; Wen etal. 2015).
In order to lessen the regulatory burden for gauge users without sacrificing the accuracy and precision of themeasurement, a new nuclear density gauge has been developed to be used in the United States and its territories withthe expectation of the acceptance of its use by other countries in the near future. The new gauge uses a low-activity
gamma-ray source of strength less than 3.7 MBq (0.1 mCi) and measures the soil wet density by the gamma-ray
scattering method. The new low-activity nuclear density gauge (Low-activity NDG) is exempt from nuclear regulationsin the United States and its territories. Furthermore, with the use of a reliable non-nuclear soil moisture measurement
method, the Low-activity NDG can obtain the dry density of soil and perform measurements comparable to a traditional
NDG.
This paper describes design features and the measurement properties of this new Low-activity NDG andpresents the results of several field studies conducted in North Carolina, USA.

446

2 LOW-ACTIVITY NUCLEAR DENSITY GAUGE FOR SOIL WET DENSITY MEASUREMENT
2.1 General Description
The Low-activity NDG for soil wet density measurement (Figure 1 and 2) is based on the physics of gammaray interactions with matter. The primary interaction mechanism of gamma-rays with energies in the range from 0.1 to
2 MeV with atomic electrons of chemical elements in typical soils is Compton scattering. The Compton scattering rates
depend on the density of electrons in the material and therefore depend directly on the bulk density of the material.

Figure 1. The Low-activity NDG for soil wet density measurement: Troxler Model 4590.
The gauge contains a radioisotope source of gamma-rays from a Cesium-137 source of primary energy of 0.662
MeV and an energy selective high efficiency gamma-ray detector. The gamma-rays traversing through the test sample
that reach the detector having energies in the Compton range can be counted exclusively by the energy selective highefficiency detector. The scattered gamma-rays also scan a large volume of the sample enabling the estimation ofdensities of a heterogeneous material like soil. The instrumentation of this Low-activity NDG is similar to that of alaboratory nuclear density gauge for measuring bulk density of cylindrical compacted asphalt specimens, which is also
exempt from regulations in the United States and its territories (Dep and Troxler 2000; Malpass and Khosla, 2001).
Table 1 provides specifications and features of this Low-activity NDG and a conventional NDG for comparison.
The operation of the Low-activity NDG is similar to that of a conventional NDG except for one aspect, a shortbackground count is required occasionally (Troxler and Dep 2009). The background count includes gamma-rays
originated from the soil due to the natural radioactivity. For conventional NDGs, this background radiation is
negligible when compared to the radiation from the gamma-ray source in the gauge. Since the Low-activity NDG uses
nearly 1% of the source activity as that of a conventional NDG, the background radiation is measured and accounted forin the density determination. To measure the background radiation, a gamma-ray count is taken by placing the gammaray source in a special position where the source is still inside the gauge but is shielded by radiation shielding material
in the tip of the source rod, bio-shield, and the extra shield between the bio-shield and the detector (Figure 1).

2.2 Measurement Process
The measurement process for the Low-activity NDG starts with the preparation of the test location by leveling thesoil using the scraper plate, drilling a 16.5 mm (0.65 inch) diameter access hole about 50 mm (2 inches) deeper than theplanned measurement depth, and then positioning the gauge directly on the soil. If this test is the first test for the day,the daily standard count (Cstd) is taken first by taking two gamma-ray counts: one with the source at the safe position
and the other with the source at the background position (Figure 1).
447

Figure 2. The Low-activity N for soil wet density measurement: Troxler Model 4590 (left) and thenon-nuclear
moisture probe: Troxler Model 6760 (right). The moisture probe communicates wirelessly with the gauge.
After accepting the standard count, the measurement is made by lowering the source rod to the desired depth iand taking the measurement count (Cmi) followed by moving the source rod up to the background position and taking
the background count (Cb). The gamma-ray count-density relationship is given by(𝐶𝑚𝑖 − 𝐶𝑏 )𝐶𝑠𝑡𝑑

= 𝐴𝑖 𝑒𝑥𝑝 𝐵𝑖 𝜌 + 𝐶𝑖

(1)

where Ai, Bi, and Ci are the calibration constants which are determined during the factory calibration of the gauge. The
gauge computes the wet density  using the measured counts and the pre-determined constants.
2.3 Safety and Security Features
The Low-activity NDG comes with innovative safety features incorporating a very low activity or strength Cesium137 gamma-ray source. The radiation shielding for the source during storage and transport reduces the annual radiation
exposure to the gauge operator to be less than that of the natural terrestrial radiation- 0.12 mSievert (12 mrem) vs. 0.28
mSievert (28 mrem). The self- shielding source rod design eliminates the need for a spring loaded shutter mechanism
as is used in the conventional NDGs. This also eliminates the need for cleaning of the shutter area due to accumulationof soil. The source rod removal requires a special proprietary tool. The source rod tower and bio-shield are ruggedized
against accidental damage to the gauge in the field (Troxler Electronic Laboratories, 2016).
3 GAUGE MEASUREMENT PROPERTIES
3.1 Density Calibration
The wet density calibration procedure for the Low-activity NDG is similar to that of a conventional NDG.
Since the gamma-ray source decays with time, the gauge response or the gamma-ray count decreases with time.
Therefore, to eliminate the time dependence, the gauge count is standardized by dividing with a count that only depends
on time (Cstd). Since the Low-activity NDG uses a low strength gamma-ray source, gamma-rays detected other thanthat from the source traversing through the test sample, C b, are also excluded.
The Low-activity NDG is calibrated using the same three density calibration standards in specially designed
bays that are used to calibrate the conventional NDGs. These standards are made out of solely magnesium,

448

combinations of magnesium and aluminum, and solely aluminum. They have different densities covering a density
range from 1780 to 2690 kg/m3 (111 to 168 lb/ft3).
Table 1. Gauge properties for Low-activity NDG and a conventional nuclear density gauge
Property

Details

Soil Property
Measurement Method
Technology
Gamma-ray Source
Source Strength
Detector
Depth modes
Analysis
Accuracy & Precision of
Wet Density Measurement
Security
Radiation Dose
SafetyRegulatory Burden

1

Radiation safety Training
requirement in US
BurdenLicensing in the US
Shipping in the US:
Type A packaging

Low-Activity Nuclear
Density Gauge(Troxler Model 4950)
Wet Density
Gamma-ray Compton
Scattering
Cesium-137
3.33 MBq (0.09 mCi)
High Efficiency(solid phase)
Up to 200 mm (8 inch)
Spectrometric
Meets Industry standard

Conventional Nuclear
Density Gauge(Troxler Model 3440)1
Wet Density and Moisture
Gamma-ray Compton
Scattering
Cesium-137
286 MBq (8 mCi)
Low detection efficiency(gas phase)
Up to 300 mm (12 inch)
Counting
Meets Industry standard

Lower Activity SourceLess risk
Lower doses
0.1 μSv/hr (0.01 mrem/hr)
at 1 mHigher Activity Source
Greater risk
Higher doses
3 μSv/hr (0.3 mrem/hr)
at 1 m

Not Required

Required

Very low
Not Required
Not RequiredHigh
Required
RequiredTroxler Electronic Laboratories (2015).

Calibrating the Low-activity NDG requires gamma-ray counts taken by placing the gauge on the threecalibration standards for each measurement depth. For each calibration standard i of density ρi and the gamma-ray
source at depth j, let the gamma-ray count be Cmij. Let Cbi be the gamma-ray count for the background. The calibration
constants for the depth j,, Aj, Bj, and Cj are determined using the measured counts and the densities of standards. Note
that, when calibrating the new gauge, the count time is selected to minimize the natural error from randomness ofradioactive decay of the source.
The calibration curves for the measurement depths 50 mm (2 in), 100 mm (4 in), 150 mm (6 in), and 200 mm(8 in) for a Troxler Model 4590 Low-activity NDG are shown in Figure 3. The figure also contains, for the same
depths, the calibration curves for a Troxler Model 3440 conventional. For comparison purposes, curves for Model 3440
gauge was scaled so that both types of gauges have the same count ratio at the lowest density. The instrument
sensitivity to soil density, the change in gauge count to the change in density as given by the slope of the curve, isslightly better for the Low-activity NDG especially at higher densities. The sensitivity at 2480 kg/m3 (155 lb/ft3) for the
150 mm (6 in) for Low-activity NDG is -0.00136 per kg/m3 and for the conventional NDG is -0.00102 per kg/m3.
3.2 Density Measurement Precision
The measurement precision is a measure of repeatability of a density measurement. The precision varies withmeasurement depth and density, and depends on the uncertainty of the measurement count and uncertainty of the
background count. We have estimated the density measurement precision for the four depth modes 50 mm (2 in), 100
mm (4 in), 150 mm (6 in), and 200 mm (8 in) at the three calibration standard densities for the Low-activity NDG. The
precision estimates were made using a Monte Carlo method allowing random variations for measurement count andbackground count using actual data collected from a gauge calibration. For these estimates, we have considered thevariability of a 2 minute measurement count and a 1 minute background count for each depth mode. Figure 4 provides
the results. The measurement precision at 2000 kg/m3 (125 lb/ft3) for the Low-activity NDG is 3 kg/m3 (0.18 lb/ft3)
and for a conventional NDG, for 1 minute count, is 3.4 kg/m3 (0.21 lb/ft3) .

449

3.3 Density Measurement Precision: Repeatability and Reproducibility
For our preliminary study of determining the repeatability and reproducibility, we used four Troxler Model
4590 Low-activity NDGs. Three gauge operators conducted the test each operating a separate gauge. The fourth gauge
was operated at different times by one of the same operators. We selected four test locations covering a 192 kg/m3 (12lb/ft3) density range in a road construction project in Roxboro, NC. We selected the 150 mm (6 inch) depth mode ofoperation. For all measurements, a measurements count time of 2 minute and a background count time of 1 minutewere used. On each test location, three measurements were obtained with each gauge. The repeatability of themeasurement using the new nuclear gauge in the density range of 1955 to 2160 kg/m3 (122 to 135 lb/ft3) was (0.3 to 0.4
lb/ft3) and the reproducibility was (0.5 to 0.6 lb/ft3) (Table 2). For comparison purposes, Table 2 also shows the resultsof a more extensive test conducted for the conventional NDGs (ASTM D6938-10) where the measurement time of 1
minute, which is sufficient for the application, was used. The repeatability and reproducibility for the Low-activity
NDG is similar to that for the conventional NDG.

Figure 3. The wet density calibration curves for the Low-activity NDG (solid line) and aconventional nuclear density gauge Troxler Model 3440 (dashed line).

Figure 4. The Low-activity NDG density measurement precision for various measurement depths.
Here, the precision is estimated for a measurement count time of 2 minutes and backgroundcount time of 1 minute.

450

For Low-activity NDG, the precision values estimated considering only the uncertainty of the gamma-ray
counts from Poisson nature of radioactive decay as shown in Figure 4 was about 3 kg/m3 (0.2 lb/ft3) at 2162 kg/m3 (135lb/ft3). This low value is expected since for this estimate gauge operator errors present in an actual measurement was
not considered.
Table 2. The repeatability and reproducibility of wet density measurements¹ for Low-activity NDG and conventional
nuclear density gauge

Low-activity NDG(Troxler Model 4950)
Test Location

1

2

3

Average Density

1967 kg/m3(122.8 lb/ft3)
6.4 kg/m3(0.40 lb/ft3)
8.7 kg/m3(0.54 lb/ft3)
17.6 kg/m3(1.1 lb/ft3)

2036 kg/m3(127.1 lb/ft3)
7.0 kg/m3(0.44 lb/ft3)
9.0 kg/m3(0.56 lb/ft3)
19.2 kg/m3(1.2 lb/ft3)

2156 kg/m3(134.6 lb/ft3)
4.6 kg/m3(0.29 lb/ft3)
9.3 kg/m3(0.58 lb/ft3)
12.8 kg/m3(0.8 lb/ft3)

Conventional Nuclear Density
Gauge(Troxler Model 3440)
Three locations(three soil types)
1837-2084 kg/m3(114.7-130.1 lb/ft3)
4.2-7.4 kg/m3(0.26-0.46 lb/ft3)
10.6-12.3 kg/m3(0.66-0.77 lb/ft3)
11.2-20.8 kg/m3(0.7-1.3 lb/ft3)

24.0 kg/m3(1.5 lb/ft3)

25.6 kg/m3(1.6 lb/ft3)

25.6 kg/m3(1.6 lb/ft3)

30.4-33.6 kg/m3(1.9-2.1 lb/ft3)

Repeatability at 1-σ
Reproducibility at 1-σ
Difference Between Two Test
Results at 95% Limit for
Repeatability
Difference Between Two Test
Results at 95% Limit for
Reproducibility¹The depth mode for both types of gauges is 150 mm (6 inch). The measurement time for Low-activity NDG is 3
minutes and for the conventional nuclear density gauge is 1 minute.
3.4 Source aging effect on density measurement precision
The gamma-ray source in the new gauge, Cesium-137, has a 30 year half-life. Since the gauge uses a low activity or
strength source, the change in source activity with time due to natural radioactive decay can degrade the density
measurement precision. The degradation of density precision was estimated by using a Monte Carlo method allowing
the decrease in the source activity with time and the random variations for measurement count and background countusing data collected for gauge calibration. The degradation of density measurement precision for the first ten years isshown in Figure 5 (left). The Low-activity NDG can hold the required density measurement precision for about 8 to 10
years after that it requires a gamma-ray source replacement. In addition, the source aging effect can add a significant
bias to the density reading Figure 5 (right). To avoid addition of a bias to the density measurement, the gauge requires acalibration every 1 to 2 years.
3.5 Bias on density measurement due to variability in the backgroundIn a given project, if the natural variability of the composition of the soil, for example the sand to clay ratio, isminimal, the magnitude of the background count remains a constant. However, due to the randomness in theradioactive decay process, the background count follows a Poisson distribution and a one-time determined backgroundcount can have a magnitude two standard deviation from the average count. Therefore, when using the backgroundcount measured at the first test site for all subsequent counts, a bias can be introduced to the density measurement.
When count time for the background is long enough to reduce the standard deviation, the uncertainty in the
background count can be lowered thus reducing the possibility of a bias to the density value. We have estimated thedensity bias by using a Monte Carlo method allowing for the random variations for measurement count and backgroundcount using actual data collected from a gauge calibration. For this study, we have estimated the bias for measuring the3density of a sample having a density of 2155 kg/m (134.5 lb/ft3) with a 2 minute measurement and 1 minutebackground count. The density bias estimate for 150 mm (6 inch) and 200 mm (8 inch) measurement depths was found3
to be than 8 kg/m (0.5 lb/ft3). Therefore, if the background count is measured at one test location and used for all
subsequent measurements in that project, the bias in the density reading were small.

451

Figure 5. The gamma-ray source aging effect for the Low-activity NDG. Here, the source aging effect on precisionand density are estimated for the 200 mm (8 inch) measurement depth and for a measurement count time of 2
minutes and background count time of 1 minute.
3.6 Field density measurement in comparison to a conventional gauge
Three Low-activity NDGs and one conventional NDG were used in a road construction project in Wayne
County, North Carolina. Measurements were taken at four locations with each location wet density was determined fortwo depth modes 150 mm (6 in) and 200 mm (8 in). The results are shown in Figure 6. As expected, the three Lowactivity NDGs showed good repeatability and reproducibility for wet density measurement with a range of 6 to 24
kg/m3 (0.4 to 1.5 lb/ft3) for the 150 mm (6 inch) measurement depth and 18 to 27 kg/m3 (1.1 to 1.4 lb/ft3) for the 200
mm (8 inch) measurement depth. The difference in the wet density values for the two types of nuclear gauges is less3
than 18 kg/m (1.1 lb/ft3) for both measurement depths.

Figure 6. Low-activity NDG vs conventional nuclear density gauge density measurements for four test locations in a
project. For the Low-activity NDG,, the count time for measurement is 2 minutes and for the background is
1 minute.
The gauge was tested at eight different road construction projects in North Carolina covering a wide range of soil
types including aggregate base courses. One to two new nuclear gauges and one conventional gauge were used in452

density measurements done by multiple operators. Measurements were made at 6inch and 8inch depths. The newgauge measurement time was 2 minute with a one minute background count whereas the conventional gaugemeasurement time was 4 minutes. The results are shown in Figure 7 for 150 mm (6 inch) and Figure 8 for 200 mm (8inch) measurements. For both depth modes, the new nuclear gauge showed a high correlation to conventional gauge3measurements with a 95% reproducibility limit on the difference between two readings of about 38 kg/m (2.4 b/ft3).
This proves to be close to the difference between two readings from two conventional gauges as stated for
reproducibility in ASTM D6938-10.

Figure 7. The Low-activity NDG and conventional nuclear density gauge density measurements for multiple locations
in several projects. Here, the measurement depth is 150 mm (6 inches). For the Low-activity NDG, themeasurement count time is 2 minutes and background count time is 1 minute.

Figure 8. The Low-activity NDG and conventional nuclear density gauge density measurements for multiple locations
in several projects. Here, the measurement depth is 200 mm (6 inches). For the Low-activity NDG, themeasurement count time is 2 minutes and background count time is 1 minute.

453

4 SOIL DRY DENSITY MEASUREMENT
The Low-activity NDG only measures the soil wet density (WD). In order to determine the soil dry density (DD),it uses the moisture density (M) measured by a Troxler Model 6760 Moisture Probe. This probe uses electromagnetic
technique for moisture measurement. The probe is inserted to the same access hole prepared for the Low-activity NDG
when measuring the soil wet density. The dry density of soil is given by
𝐷𝐷 = 𝑊𝐷 − 𝑀(2)Table 3 provides the results for the road construction project in Wayne County, North Carolina. Also shown in
the table are the results from a conventional NDG. The results show a good agreement of the dry density determined by
the two types of nuclear gauges with a maximum difference of 10.4 kg/m3 (0.65 lb/ft3).
Table 3. Soil dry density measurement by Low-activity NDG and a non-nuclear moisture probe. For comparison, also
included are the measurements using a conventional nuclear density gauge. Here, WD, M, and DD are soil wet
density, moisture density, and dry density respectively.
Conventional NDG
Sample

1
2
3
4

WD
kg/m3
(lb/ft3)2177(135.9)2134(133.2)2061(128.7)2220(138.6)M
kg/m3(lb/ft3)
170(10.6)
186(11.6)
155
(9.7)
191
(11.9)

Low-activity NDG and Moisture ProbeDD
kg/m3(lb/ft3)
2007(125.3)1948(121.6)
1906(119.0)2029(126.7)WD
kg/m3(lb/ft3)2177(135.9)2147(134.0)2055(128.3)2225(138.9)M
kg/m3(lb/ft3)180(11.2)
189(11.8)
149
(9.3)
184
(11.5)

DD
kg/m3(lb/ft3)
1997(124.6)
1958(122.2)
1907(119.0)2041(127.4)

If the gauge operator wishes to use another method for measuring the moisture content of soil, this moisturevalue can be entered into the gauge using the gauge key pad. Then, the gauge can compute the soil dry density using
the wet density determined by the gauge and the moisture content.
5 INTERNATIONAL REGULATIONS FOR NUCLEAR GAUGES
The conventional NDGs are used in most countries around the world with the requirement of a permit orlicense and other restrictions such as training, monitoring badges, shipping paperwork, etc. However, there are a few
countries which will not allow these nuclear gauges inside their borders at all due to the activity of the sources. It is
likely that the new Low-activity NDG will be allowed in these areas due to the extremely reduced activity or strength of
the Cesium-137 gamma-ray source, elimination of the Americium-241-Beryllium neutron source from the gauge, andthe innovative safety features incorporated to the gauge.
Troxler and our international partners are targeting some countries, which currently have similar regulations to
the United States, as potentially open to the same exempt designation for the new Low-activity NDG as the UnitedStates. This would allow gauge use in those areas with no permit or license requirements. This will take some time andassistance from our partners located in those areas as well as from our friends in the construction industry. As
advocates for proper quality control / quality assurance in the road building industry, we can see this opportunity tomake it easier to perform the required density measurements. When little or no density and moisture testing is
performed on a prepared roadbed, the life of the road is diminished. Great improvements in the quality of roads
constructed around the world would result.
6 CONCLUSIONS
1) The measurement sensitivity of the Low-activity NDG is slightly better than a conventional NDG especially in thehigh density region and is acceptable for the soil compaction application.
2) The measurement precision for the Low-activity NDG when taking measurement counts for 2 minutes and abackground count for 1 minute meets the industry requirement. However, the total measurement time for this gauge islonger than that for a conventional NDG: 3 minutes compared to 1 minute.

454

3) The repeatability and reproducibility of density measurement for the Low-activity NDG when taking measurementswith measurement counts for 2 minutes and a background count for 1 minute is comparable to that of a conventional
NDG using a count time of 1 minute.
4) The Low-activity NDG can hold the required density measurement precision for about 8 to 10 years after that it
requires a gamma-ray source replacement. To avoid addition of a significant bias to the density measurement, thegauge requires a calibration every 1 to 2 years.
5) For a given project, when the soil type is not significantly changing, the measurement time can be shortened bytaking the background count only at the first measurement location. The bias for density is small and can be ignored inthis case. Whenever the accuracy of the density measurement is most essential, a separate background should be taken
for each measurement.
6) The density measurements taken with the Low-activity NDG for 17 different sites at 150 mm (6 inch) and 200 mm (8inch) depth agreed well with that of a conventional NDG. This high degree of correlation between the density values
determined by the two types of gauges (R-squared is 0.98) is due to the fact that both type of nuclear gauges are basedon the same measurement method- gamma-ray scattering. The small bias between the density values is due to the factthat both gauge types were calibrated on the same set of calibration standards.
7) The wet density measured using the Low-activity NDG together with the moisture content measured by other reliable
methods should show sufficient accuracy for determining dry density for QC/QA purposes.
8) In the USA and its territories where the new Low-activity NDG is exempt from regulation, the gauge user has no
additional regulatory burden in purchasing, storing, transporting to the test site, shipping the gauge to the manufacturer
for calibration, and using the gauge in multiple states.
9) The new Low-activity NDG will allow reliable quality control of road foundations to be possible in parts of theworld where it is currently not. Fewer, less restrictive regulations will make it easier to obtain and use the nuclear
density measurement methods around the world extending the life and improving the safety of roads everywhere.

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Method. ASTM International, West Conshohocken, Pennsylvania.
ASTM D2167-15 (2015). Standard Test Method for Density and Unit Weight of Soil in-Place by the Rubber Balloon
Method. ASTM International, West Conshohocken, Pennsylvania.
ASTM D2937-10 (2010). Standard Test Method for Density of Soil in-Place by the Drive-Cylinder Method. ASTM
International, West Conshohocken, Pennsylvania.
ASTM D6938-10 (2010). Standard Test Method for in-Place Density and Water Content of Soil and Soil- Aggregate by
Nuclear Methods (Shallow Depth). ASTM International, West Conshohocken, Pennsylvania.
Belcher, D.J. and T.R. Cuykendall. (1950). The Measurements of Soil Moisture and Density by Neutron and Gammaray Scattering. Civil Aero. Adm. Tech. Dev. Rept. 127, Washington D.C. pp 279.
Berney, E. and Kyzar, J.D. (2012). Evaluation of non-nuclear soil density and moisture devices for field quality control.
Transportation Research Record, Journal of the Transportation Research Board 2310:18-26.
Dep, W. L. and Troxler, R. E. (2002). Apparatus and Method for Gamma-ray Determination of Bulk Density ofSamples. Troxler Electronic Laboratories, assignee. Patent US 6492641 B1. 10 Dec. 2002.
Krueger, P. G. (1950). Soil Density by Gamma-Ray Scattering. MS Dissertation: Cornell University, New York.
Malpass, G. and Khosla, N.P. (2001). Evaluation of Gamma-ray Technology for the Measurement of Bulk Specific
Gravity of Compacted Asphalt Concrete Specimens, Journal of the Association of Asphalt Paving Technologists, Vol.
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Troxler Electronic Laboratories (2016). Manual of Operation and Instruction: Model 4590 Soil Density Gauge,
Research Triangle Park, North Carolina, USA.
Troxler Electronic Laboratories (2015). Manual of Operation and Instruction: Model 3440 Surface Moisture-Density
Gauge, Research Triangle Park, North Carolina, USA.
Mejias-Santiago, M., Berney, E. S., and Bradley, C. T. (2013). Evaluation of a Non-Nuclear Soil Density Gauge on
Fine-Grained Soils. Report Number ERDC/GSL TR-13-20, US Army Corp of Engineers, Vicksburg, MS.
Pieper, Jr. G. F. (1949). The Measurement of Moisture Content of Soil by the Slowing of Neutrons. MS Dissertation:
Cornell University, New York.
Rose, M. W. (2013). Evaluation of Non-Nuclear Density Gauges for Determining in-Place Density of UnboundMaterials. MS Dissertation: Washington State University, Pullman.
Troxler, R. E. and Dep, W. H. L. (2009). Methods, Systems, and Computer Program Products for Measuring theDensity of Material. Troxler Electronic Laboratories, assignee. Patent US 7569810 B1. 4 Aug. 2009.
Wen, H., Rose, M., Timm, A., and Sharma, S. (2015). Review of Non-Nuclear Density Gauges as Possible
Replacements for ITDs’ Nuclear Density Gauges. Report Number FHWA-ID-15-210/RP 210, Idaho Transportation
Department, Bois, ID.

456

Probability of Crash Involvements based on Drivers’ Characteristics andTraffic Rule Violation Records

Mohamed Shawky, Ph.D.,*,1,2
Iyad Sahnoon, M.Sc. 2
Yousef Al-Badi, M.Sc. 1

1

Traffic and Patrols Directorate
Abu Dhabi Police, Abu Dhabi,
United Arab Emirates

2

Department of Civil Engineering,
Faculty of Engineering,Ain Shams University,
Cairo, Egypt* Corresponding Author:
Mohamed Shawky, Ph.D.,
Tel: +971 561236607
Email address: m_shawky132@hotmail.com

Accepted for presentation at the 2nd IRF Asia Regional Congress
October, 2016457

Abstract
This paper aims to investigate the factors associated with driving risk potential to be involved intraffic crashes. The relationships between the driver’s historic records of traffic crashes, traffic
rules violation and demographic characteristics have been explored. The individual driver’s data
were collected from four different databases during five years (2010-2014). A total of 713,783
individual driver’s records were employed in the analysis process.
The Logistic regression modeling approach was applied to determine the most appropriate
variables that can be used as predictors for crash involvement risk. Several variables are
examined in the model including the number property damage only (PDO) crashes records, total
number of traffic violations, speeding-related violations, unsafe driving behavior, number ofviolation with penalty points, number of penalty points and the demographic characteristics ofthe drivers (age, gender, years of experience and nationality). The results showed that violation
records related to drivers’ behavior during driving, driver demographic characteristics (age,gender, nationality), and property damage only related crashes records can be used as goodpredictors for identifying the risky drivers.

Key words: Driver behavior, crash rates, road safety in Abu Dhabi, traffic rule violations,driver demographic characteristics

458

INTRODUCTION
Factors that affect the occurrence of the traffic crash are fundamentally classified into threegroups: human, vehicle and environmental. However, the human factors are considered as themain cause of the traffic crashes in the majority of the reported crashes (97%-98%) (Karscasu
and Er 2011). Accordingly, examining the contributing factors regarding the drivers’ behavior
has received a significant attention in prior studies. Early on, Peck et al. (1971) stated that it isdifficult to accurately predict drivers who will and will not be involved in crashes. However, one
year after, Stewart and Campdell (1972) investigated the probability of future crashes in terms ofhistorical crash and/or violation records. The study observed a four-year history of crash andtraffic violation records of North Carolina drivers to predict the future crashes. After that in1990s’ and more recent, several studies had been published to suggest that the involvement in a
traffic crash is not a random event and it can be predicted. This suggestion gives hope thatinterventions can be found to prevent traffic crashes occurrence and reduce the severity andnumber of casualties. These interventions might range from simple driver improvement letter, tochanges in the existing strategies and polices of traffic safety to implementation of new strategies
and polices. Accordingly, the term of “traffic accidents” in the field of road safety researches has
been gradually changed to “traffic crashes”.
In general, there is no much information in regard of driver behavior in the Gulf Corporation
Council (GCC) countries. Hence, the interaction between drivers’ behavior in terms of theirtraffic rule violation records and their involvements in traffic crashes has not been investigated
yet or published in any prior studies. In Abu Dhabi (AD) Emirate, the capital of UAE, a tangible
effort has recently been done to improve the road safety through the three main strategic
approaches: Engineering, Education and Enforcement. Accordingly, road crash fatalities have
reduced from 376 in year 2010 to 245 in year 2015 (about 35% reduction). Despite theincreasing number of registered vehicle increased by 46% and licensed drivers by 45% during
the same period.
Understanding the driver’s behavior is the key factor to maintain a proper reduction rate offatalities and improving the road safety strategies. Especially in the case of UAE where morethan two hundred different nationalities are residing in the country along with different educationlevels, culture, language, and driving skills background which creates a considerable challenge
for different agencies that are responsible for road safety especially the department of traffic
police.
Therefore, the primary objective of this study is to investigate the contributing factors
affecting driver risk potential to be involved in a traffic crash. Relationships between the at-fault
drivers involved in traffic crashes and their historical records of traffic rules violations were
investigated in terms of demographic characteristics of drivers.

459

LITRATURE REVIEW
Among the huge number of prior studies that examined the contributing factors that affect theoccurrence of the traffic crashes, relatively few studies were tackled the interrelationshipbetween the drive’ behavior in terms of his/her historical records of traffic rule violations andhis/her involvement in traffic crashes. In this topic, two different data were employed in priorstudies: historical recorded data and self-report survey data of a sample of drivers.
Based on driver’s data of Californian, Gebers (1999) developed 17 logistic regression
models to test the most significant factors affecting drivers’ involvement in crashes. After several
tries the final model could correctly classify crash-involved drivers up to 27.6%. Gebers andPeck (2003) found that the driver’s violation recorded is better than crash history record to
predicate crash-prone drivers by using equation constructed modeling approach. Chandraratna etal. (2006) studied Kentucky drivers to develop a crash prediction model that can be used toestimate the likelihood of a driver being at fault for a near future crash occurrence by using
logistic regression modelling technique. The significant association between the subsequent
frequency of crash involvements of Canadian drivers and their crash and violation records in theprevious period was also confirmed in three studies (Boyer et al., 1990; Hauer et al., 1991; Chenet al., 1995) by using multiple regression models. Blascoa et al. (2003) conducted a follow-up
study for a sample of drivers over 8 years to investigate the probability to be involved in a trafficcrash after a crash occurrence. The study founded two different style of driving related to theaccumulation versus the non-accumulation of crashes in short intervals.
Through examining drivers' age impact, previous violation records and crash data,
Daigneault et al. (2002) concluded that prior crashes would be a better predictor for crash risk
than prior violations. It was also found that this relationship increase with elder drivers (drivers
have more than or equal 65 years old). Gerber and Peck (1992) showed a significant effect ofage and prior violations on subsequent of crashes, especially for elder groups of drivers (aged 6069 and above 70).
More recent studies focused on analyzing at-fault driver’s data. Zhang et al. (2013)
analyzed crash severity and violation data of Chinese drivers. The results established the role oftraffic violations as one of the major risks threatening road safety. In addition, specific risk
factors associated with traffic violations and accident severity were determined. The authors
suggested that to reduce traffic crashes and fatality rates, measures such as traffic regulations
targeting different vehicle types/driver groups with respect to the various human, vehicle andenvironment risk factors are needed. Some studies proved the significant effect of specificdrivers’ behavior such as speeding and drunk and drug usage on the prediction of the crash-prone
driver (Watson et al. 2015; Das et al., 2015; Kim 2015). Nishida (2015) analyzed crash andviolation data of 81 million licensed drivers in Japan (approximately 1 million crash record and
10 million violation records per year). It was found that drivers who experience accidents drive
more carefully immediately after an accident, revealed high accident rates among drivers who
have experienced certain violations, and produced other findings that could constitute a460

foundation for developing individual driver-targeted measures. In addition, the drivers with ahistory of numerous accidents or apprehensions/violations are more likely to cause accidents.
Self-report survey technique was also intensively used by a number of researchers to
identify the interaction between drivers’ history of violations/behavior and his/her crash
involvements (for example, Winter and Dodou 2010 (in USA); Constantinou et al., 2011 (inGreek); Illiescu and Sarbescu 2013 (in Romania); Peasrson et al. 2013 (in USA); Sumer, 2003
(in Turkey); Stanojevi´c 2013 (in Serbia and Kosovo), Xu et al., 2014 (in China), Ona et al.,2014 (in Itali and Spain)). These studies proved the same tendency of drives who frequently taketraffic rule violation tickets is more likely to be involved in traffic crashes. In addition, Berdoulat
et al., (2013), investigated the aggressiveness and impulsiveness in the prediction of risky
drivers. It was found that aggressiveness and impeded progress were the best predictors ofviolations and aggressive violations. The results supported that transgressive driving behaviors
are relevant indicators of aggressive driving. The same finding was found by Bachoo et al.
(2013) from a sample of post graduate students in Durban, South Africa. A new definition of theimpulsivity in driving context was suggested by Bıcaksız and Ozkan (2015) during analyzing
288 student self-reported questionnaires in driving behavior, violations and accident
involvements. Machado-Leon et al. (2016) investigated crash risk perceptions in an inter-city,
two-way road context of 492 drivers by using a Stated Preference ranking survey. The study that
all risky driving behaviors showed a significant potential effect on crash risk perceptions, andmodel’s results allowed to differentiate more important from less important unsafe driving
behaviors based on their weight on perceived crash risk. Furthermore, the study analyzed thepotential differences in risk perception of these traffic violations between drivers of different
characteristics, such as driving experience, household size, income and gender.

DATA COLLECTION AND PREPARATIONThe employed data in this paper were extracted from four different databases of Abu-Dhabi(AD) traffic police during five years (from 2010 to 2014). These databases are; 1) traffic
violation system, 2) property damage only (PDO) crashes system, 3) severe crashes system and4) driving license information system. Then an integration process among the different systems
was carried out to define the historical date of individual drivers in a new integrated dataset
system to be used in this study. As shown in Figure 1, the integration process was carried out by
utilizing a unique traffic code that is given to each licensed driver when he/she issues a driving
license in AD. This code is called Unified Traffic Code (UTC) in the traffic police databasesystems.
Around 1.1 million registered driving licenses exist in the driving licenses database by the endof 2014. Data filtration was conducted to exclude the drivers have missing information anddrivers issued driving licenses during the period of the study period. As a result, about 713,583
drivers’ records were settled in the integrated database system. The integrated database for five
years (from 2010 to 2014) includes a total number of traffic rules violation of 2,762,275 and total

461

PDO crashes of 682,136 and total severe crashes (i.e., any crash with at least one injury or
fatality) of 8,604. All of these records were employed in the analysis and modeling process inthis study.

Figure 1. Integrated driver’s database system in AD (crashes, violations, and demographic
information)

Table 1: Examined variables with respect to traffic crashed records of the driver
Variableclass

Variable name
Number of Violation Records ofthe Driver
Number of Face to Face Traffic
Rule Violations
Number of Absent Violations
Number of Violations That
Have Traffic Points
Number of Traffic Points of the
DriverI

Number of Hazard Violations
Number of Class (A) Violations

Number of Class (B) Violations

Number of Class (C) Violations

II

Driver’s Demographic
Characteristics

Variable description
the total number of violation tickets over five years of the driverthe violations that he driver are taken on street by the police officers
the violations that were recorded by automated enforcement devices
such as: speed camera, radars and red light violation camera
about 73 violation have a traffic points range between 2 to 24 points
based on AD traffic violation law
the sum of the traffic point of the driver over the five years of thestudy
about 25 type of violations defined by AD traffic police including
speeding when the speed exceeds 60 km/hr over the speed limit, redlight violation, tailgating, mobile use, alcohol use, etc.
The speed-related violations
about 32 type of violations that related to drivers’ behavior during
driving and that may affect road safety such as: tailgating, red lightviolation, traffic rule and signs violations, overtaking violations,mobile use, alcohol or drug use, set bet violation, reckless driving,sudden lane changing, illegal U-turn priorities violations, etc.
the other types of violations out of class (A) and (B) listed in the
traffic violation law such as: illegal parking, drive with expired
license, made changes in the vehicles, illegal horn use, vehicle plat
number missing or unclear, increasing in vehicle exhaust, overloaded, etc.
Variables of driver’s characteristics such as: age, gender, nationality
and years of experience in driving.

462

Variables Description
Based on the developed integration database system, more detailed information regarding
drivers’ records were extracted and used as independent variables to investigate the chance ofdriver involvement in future traffic crashes. All variables are driver-based information during
five years from 2010 till the end of year 2014. The examined variables can be classified into twogroups as shown in Table 1. Class I variables include the violation variables categories and class
II variables include the demographic characteristics of drivers. Table 1 shows the name anddescription of each examined variable in this study.

DATA ANALYSIS
Crash Rates of Different Driver’s Groups

Crash Rate per driver

All drivers were classified into groups based on the examined variables shown in Table 1. For
example; class (A) violation group includes all drivers who got at least one violation in thatgroup. Then, a crash rate of the drivers has been calculated (crash rate = total number of crashes /total number of the driver) at each aforementioned group. Figure 2 shows the crash rate ofdrivers who belong to Class I variables. It shows that the drivers who experienced any type ofviolations have the highest crash rate during the five years of the study data period followed bydrivers who got face to face (present) violation types. This figure reveals that drivers who getpresents violation ticket are more dangerous than who got absent violations. In addition, drivers
who got violations of type (B) are more dangerous than who got violations of type (A). From thisresult, the hazard violations list should be revised to take violations from type (B) in order tocover all violations that have high risk relationship. So more violation types should be added tothis list and more enforcement in such violation types should be taken by face to face tickets(present violations).
4.50
4.00
3.50
3.00
2.50
2.00
1.50
1.00
0.50
0.00

3.87

2.59
1.92
1.37

1.23

1.21
0.63

Total
violations

0.48

Face toTraffic
Hazard Violation Violation Violation Absent
face
Poin's violations of type (B) of type (C) of type (A) violations
violations violations

Figure 2: Crash rate of the driver’s group belonging to class (I) variables

463

2.50
1.96

2.00

Crash rate per driver

Crash rate per driver

2.50
1.84

1.50
1.00
0.50

2.19

2.00

Male

46-60

1.00
0.50
18-30

Female

2.22
1.94

1.81

1.69

1.61

1.50
1.00
0.50
0.00
Emirati Arabian

Asian

> 60

Age Group

GCC

Other

Crash rate per driver

Crash rate per driver

31-45

1.83

1.50

Gender

2.00

1.70

0.00

0.00

2.50

1.77

3.00

2.61

2.50 2.10 1.96
2.10
1.81 1.85 1.83 1.79 1.83
2.00

2.29

1.50
1.00
0.50
0.00
< 5 6 ~ 10 ~ 12 ~ 16 ~ 21 ~ 26 ~ 31 ~ 36 ~ 41 ~10 11 15 20 25 30 35 40 50

Nationality

years of experiance

Figure 3: Crash rate of the driver’s group belonging to class (II) variables

Figure 3 shows the crash rate of the drivers who belong to Class II variables (driver’s
demographic characteristics). This figure shows that the male drivers have slightly higher crashrate than females and UAE local drivers (Emirati) have higher crash rates than othernationalities. In addition, younger drivers have the highest crash rate and the crash rate slightly
increases for elder drivers compared to mid-age drivers. Furthermore, the crash rate decreases
with increasing the experience years of driving up to 30 years. After 30 years of experience thecrash rate increases that can be explained due to the elder age of the drivers.
Driver’s Percentage Involved in Crashes
Percentage of driver’s involvement in crashes was calculated for each driver’s group. The driverpercentage values can be calculated as follows:% 𝑜𝑓 𝐷𝑟𝑖𝑣𝑒𝑟𝑠 𝑖𝑛𝑣𝑜𝑙𝑣𝑒𝑑 𝑖𝑛 𝑐𝑟𝑎𝑠ℎ𝑒𝑠 =𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑑𝑟𝑖𝑣𝑒𝑟𝑠 𝑖𝑛𝑣𝑜𝑙𝑣𝑒𝑑 𝑖𝑛 𝑐𝑟𝑎𝑠ℎ𝑒𝑠
𝑡𝑜𝑡𝑎𝑙 𝑛𝑢𝑚𝑏𝑒𝑟 𝑜𝑓 𝑑𝑟𝑖𝑣𝑒𝑟𝑠. . . . . . . . . . . . . (1)Figure 4 shows the percentage of drivers involved in crashes with respect to the number ofviolations the driver received during the five years of the study. This figure shows a strong
correlation between the percentage of drivers and their violation records. This result reveals thatthe likelihood to be involved in a crash increases with increasing the number of traffic roleviolations of the driver. Also, it is clear that the percentage of drivers to be involved in a futurecrash is higher for the drivers who were involved in at least one historical violation. On the other
hand, Figure 5 shows the percentage of driver involved in severe crash only (i.e., crash with atleast one injury) with respect to drivers’ violation records. This figure shows that the percentage
of drivers involved in severe crashes increases with increasing violation record of the drivers,464

however; the percentage value is very low compared to involved in any crash that shown in
Figure 4.
100%
y = 0.4707x0.1974
R² = 0.9465

Driver percentage80%
y = 0.1892x0.4169
R² = 0.9697

60%
40%

drivers involved in at least one crash
y = 0.0695x0.6464
R² = 0.987

20%drivers involved in at least two crashes
drivers involved in at least threecrashes

0%
0

10
20
30
40
Number of violations over 5 years of the driver

50

Figure 4: Percentage of drivers involved in crashes (PDO or severe)

Percentage of drivers
involved in severe crash

16%
14%
12%
10%
8%

y = 0.004x0.8257
R² = 0.9066

6%
4%
2%
0%
0

10
20
30
40
Number of violations over 5 years of the driver

50

Figure 5: Percentage of drivers involved in a severe crashes only

Driver’s Involved in Crashes Model Development
In this section, the authors have attempted to study the previous variables that affect the crash
involvement and form them in a defined model to predict the likelihood of drivers to be in
evolved in at-fault-crash. The response/ dependent variable is a binary nature (1= involved in atleast one PDO/ severe crash, 0= not involved in a crash). Binary logistic regression has goodpotential to examine the independent variables (predictors) of the dataset that were shown in
Table 1. The logistic regression model was utilized to predict the occurrence of an at-fault crashfor the ith case that is can be calculated from the following equations:
𝑃𝑖 =

𝑒 𝑢𝑖
1+𝑒 𝑢𝑖. . . . . . . . . . . . . . . . . . . . . . . . . . . (2)465𝑈𝑖 = 𝑎𝑜 + 𝑏1 𝑌1𝑖 + 𝑏2 𝑌2𝑖 + ⋯ + 𝑏𝑛 𝑌𝑛𝑖. . . . . . . . . . . . . . . . . . . . . . . . . . . (3)Where: Pi is the probability of involved in at-fault crashes by crash-prone drivers
Ui is the linear combination of predictor variables
bi is the coefficient estimated using the maximum likelihood method
Yi is the explanatory variables as listed in Table 1.
For the logistic model, Eq. (2) can be rewritten as follows:
𝐿𝑛 (

𝑃𝑖
1−𝑃𝑖

) = 𝑎𝑜 + 𝑏1 𝑌1𝑖 + 𝑏2 𝑌2𝑖 + ⋯ + 𝑏𝑛 𝑌𝑛𝑖. . . . . . . . . . . . . . . . . . . . . (4)The linear regression is simply the natural logarithm of the probability of having one crashdivided by the probability of having no crash. The followed procedure for estimating the model
coefficients is maximum likelihood where the best combination of the dependent variables is tobe found that maximizes the likelihood of obtaining the observed outcomes.
The first step is to find the significant variables that maximize the likelihood of the estimation
model outputs. In this regards, several trails were conducted to estimate the model parameters by
utilizing all variables that are listed in Table 1. The results showed that most of the variables thatrefer to the violation records of the drivers are significantly affect the crash involvement.
However, the statistical modelling process excluded many variables due to its internal strong
correlations.
Table 2 shows Pearson correlation matrix between the violation-related variables. This tableindicates that all the variables refer to violation records are significantly correlated to crash
involvement of the drivers and corrections among each other’s. The highest five variables
correlated to the crash involvement of drivers are Violations Type B, Total violations, Traffic
point violations, Present violations, Total points. On the other hand, there are strong correlations
among these five variables which affected the goodness of estimated model in the initial trails.
By looking at the correction value “R2” in Table 1, it can be clearly concluded that the violation
type B is the best representative variable among the violation’s variable group due to its strong
correlation to the dependent variable “crash involvement” and other violation related
independent variables. Thus, this variable has been selected to represent the other types of theexamined violation records of the driver in the developing process of the regression model.
Table 3 shows the estimate parameters of the developed regression model. It is shows that,among the tested explanatory variables, five variables are significantly affect the likelihood ofdrivers to be involved in crashes at 95% significant level. These variables can be taken as thebest predictors to identify the risky drivers or drivers that have high potential to be involved intraffic crashes in the future. Three variables related to drivers demographic characteristics (i.e.
gender, age group, and nationality) are shown as significant variables in the estimated model. In
addition, the results show that the drivers that have historical records in PDO crashes have ahigher probability to be involved in future crashes by 5.6 times than other drivers.

466

Present
Violations
AbsentViolations

AbsentViolations

Violation
Type(C)

Present
Violations

Violation
Type(B)

Violation
Type(C)

Violation
Type(A)

Violation
Type(B)

HazardViolations

Violation
Type(A)

Total Points

HazardViolations

Traffic Point
Violations

Total Points

Total
Violations

PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value
PearsonCorrelation
P-value

Traffic
Point
Violations

Crash
Involvement

Total
Violations

Violation-related
Variables

Crash
Involvement

Table 2: Pearson correlation matrix of dependent variables related to violation records

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.903

**

.814

**

.703

**

.706

**

.382

**

.728

**

.845

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

**

.465

**

.445

**

.558

**

.310

**

.742

**

.241

**

.224

**

.227

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

0.00

.408
.372
.326
.211
.542
.305
.386
.208

**

1

.903
**

1

.761
**

1

.254
**

1

.183
**

1

.372
**

1

.845
**

0.00
**

1

** Correlation is significant at the 0.01 level (2-tailed).

Table 3. Results of logistic regression model
Dependent variable

Regression
CoefficientStandard
error

Wald χ

2

P-value

Odds
ratio

Intercept
GenderAge Group
Nationality
Violation Type B
PDO Crash binary

0.023
3.776
-1.8651.939
1.090
10.935

1.465
0.593
0.354
0.976
0.436
1.022

.000
40.56527.7993.947
6.236
114.411

0.098
0.000
0.000
0.047
0.013
0.000

1.02
1.80
0.15
6.95
2.97
5.60

Odds ratio 95%
confidence limits
Lower
Upper

13.7
0.1
1.0
1.3
0.8

139.5
0.3
47.1
7.0
41.6

The estimated coefficients of the regression model variables are seen to be logic indicating since
all variables have positive impact of crash involvement probability except the driver’s age. That467

means the local residents and mal drivers have potential be involved in crashes more than other.
It shows that the male drivers are 1.8 times more to be involved in future crashes than females.
This particular result can be explained since about 85% of licensed drivers in AD are males.
Regarding the age, the negative since of the coefficient mean your drivers are more likelihood to
be involved in crashes and the probability decreases with increase the driver’s age; however the
analysis shown in Figure 3 showed that the this deceasing trend starts to be increases for elder
drivers (age > 50 years old).

CONCLUSION
The prime goal of this study is to explore the factor associated to drivers who have high potential
to be involved in traffic crashes (i.e., property damage only PDO and severe crash types).
Several variables related to the historical records of drivers’ violation types and the demographic
characteristics of the drivers are examined. Five years (2010-2015) of historical data of
individual drivers are employed. The data analysis showed that driver’s crash rates and thepercentage of drivers involved in crashes increases are different among the examined violation
types. Young drivers (aged between 18 and 30 years), male and low experiences have higher rateof crashes compared to others. In addition, older drivers (greater than 60 years old) have higher
crash rate than younger drivers.
Logistic regression model was developed to estimate the associated variables of the drivers’
crash involvements. After several trials the results shows that five variables have significantly
affect the crash involvement of drivers: Violations Type B (about 32 types of violations refer to
un safe driving behavior), PDO crashes history, driver’s age, nationality and gender. Thesevariables could be taken as the best predictors to identify the risky drivers in the future.
An immediate implication is: if the traffic rule violation records could be reduced orcontrolled successfully, then the rate of crashes and resulted in injuries and fatalities would be
reduced accordingly. Further research aiming to investigate specific violation types in terms ofcrash rates is currently conducted by the author for deeply understanding the interaction between
drivers’ behavior in terms of their violation records and road safety indicators.

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470

Road Tunnel Inspection with High-Performance Devices
Fernando Sánchez-Domínguez1, José Antonio Ramos García2

1

2

Innovation Director, Euroconsult Group, Av. Montes de Oca 9-11, 28703, San Sebastián delos Reyes, Madrid, Spain; fsanchezd@euroconsult-group.com

Advanced Technologies Director, Euroconsult Group, Av. Montes de Oca 9-11, 28703, San Sebastián delos Reyes, Madrid, Spain; jramosg@euroconsult-group.com

1 ABSTRACT
The management and maintenance of the tunnels currently in service require the application of techniques forthe inspection of linings and facilities, using high performance systems. Besides, many of the contracts ofmaintenance of the infrastructures, including those of tunnels, are managed through contracts of service
quality indicators. In order to assess the different indicators of the state of the tunnels, it is necessary to have
objective inspection tools (not only visual inspection performed by surveyors) to measure the evolution ofdeterioration.
The paper presents different automated techniques, some of them already fully implemented in theinfrastructure maintenance market, such as the Lidar, and some of them which are brand new and make itpossible to complete the information for the inspection of deterioration in all kinds of lining. We will present
how the results obtained in different tunnels through to visual inspections performed by specialist surveyors
can be completed with the information obtained of them through a combination of techniques mainly basedon imaging and laser.
The automated inspection offers a better knowledge of the state of the tunnel and avoids subjectivity
problems associated to traditional inspection. The paper will show also how these techniques may function asa basis for accepting new tunnels.
2 NEED TO INSPECT ROAD TUNNELS
It is currently necessary to inspect road tunnels in order to maintain an inventory focused on preventive
maintenance, so the real condition of the infrastructure is known and it is possible to take the necessary
actions in case critical issues are detected. In addition to this, the tunnel inventory must be precise enough so
as to assess which investments are necessary to ensure the operation safety and to prevent structural,
geotechnical or infrastructure/operation issues or failure.
Scheduled routine inspections are key to detect safety issues and to prevent failure. Thus, it is necessary to
devote time and resources to acquire the best possible information that allows us to plan the necessary repairs
to prevent structure failure and, what is worse, loss of life.
It should be considered that the external signs of deterioration that appear on the lining surface –such as
humidity, corrosion, concrete cracking (face loss or spalling)– are indicative of possible structure problems.
Hence the importance of conducting such inspections.
3 VISUAL INSPECTION OF THE STRUCTURE BY MEANS OF INSPECTORS
More detailed inspections conducted with non-destructive methods present the drawback of being slow,
entailing complex tests and demanding many material resources, so they are usually replaced by visualinspections conducted by staff checking the tunnel. However, this method does not ensure having the mostcomprehensive and swift information.

471

In order to solve both issues, new systems have been under development for these last years so as to conduct
quick and, most importantly, accurate inspections regarding the tunnel condition that facilitate using nondestructive techniques in more specific areas.
The data analysis provided by these systems can be automatically processed at a later stage, wherevisualization, analysis and management tools can be included.
We will now see which techniques are achieving greater progress.
4 HIGH-PERFORMANCE AUTOMATED INSPECTION TECHNIQUESThe most commonly used techniques for continuous automatic visual inspection up to now are using linear
CCD cameras with an adequate lightning, and using the LIDAR. 3D cameras that were used for otherpurposes are also being used in tunnels. These 3D cameras use a linear laser spotlight and make it possible toincrease the inspection speed while offering maximum resolution. The deformation of the projected light ofthe spotlight is monitored with a camera to check for defects on the surface.
As it will be shown in the paper these 3D cameras –used in combination with LIDAR technology subsystems
and visible infrared light subsystems– are the basis to conduct an accurate tunnel inspection. This informationthat can be later used and focused or directed in analysis tools -later inspections with indirect non-destructive
methods such as Radar, Thermography, Impact Echo Test, etc.
The combination of techniques offers the best possible results in terms of visual inspection; it is possible toapply data analysis to show where to use slower, more expensive techniques requiring more resources, suchas geophysical methods. This combination of techniques will depend on the needs and the type of the tunnels
to inspect, and the available inspection time, among other constraints. This paper presents a solution mainly
based on the use of 3D cameras to detect deterioration on the supports, together with other sensors such as
LIDAR or inertial units to know the tunnel geometry (slope, profile, radius, sections, clearance…), and thevisible infrared light subsystem and the panoramic cameras to obtain global images of the tunnel course.
The 3D cameras will be used, as mentioned, to inspect the support deterioration but also to survey the
pavement to check for its texture and the eventual existence of cracks, potholes or other deformation.
5 SYSTEM DESCRIPTIONThe Tunnelings system, used to conduct high-performance, automatic visual inspections, is based on 3D
cameras that allow for the high-resolution, high performance inspection and analysis of the defects in tunnel
supports. These are 3D cameras, each of them consisting of an area-scan camera and laser line spotlight,
which are monitored by a control unit.
The Tunnelings system also includes the following subsystems:








A LIDAR system able to obtain a point cloud that represents in 3D the surroundings of the area
surveyed;
An inertial motion unit attached to each 3D camera, which provides 3D orientation and position of
the vehicle and makes it possible to obtain a 3D virtual model of the infrastructure;
An inertial motion unit to control the position of the vehicle and to correct it if needed;
A GPS that provides the global coordinate references at the beginning and the end of the tunnel;
A visible 360º camera that takes panoramic images every few meters in order to visually locate thearea surveyed;
A set of illuminators and visible infrared cameras able to acquire high-resolution images in dark
environments;
An odometer that provides the system with sufficient accuracy to trigger the 3D camera every 1mm,
i.e. to obtain profiles with a spacing of 1mm.

All the sensors are precisely integrated and synchronized. The odometry system (DMI) is used to synchronize
the information of the data perception sensors (3D cameras, LIDAR and panoramic cameras) with the sensors472

used for positioning and localization purposes (GPS and the inertial motion units). Thus, all the data of thecomponents of the system can be unequivocally referenced between them.
The 3D laser cameras used in Tunnelings apply the triangulation principle to extract 3D information fromthe sensors, as shown in Figure 1. A pattern of known light, a line in this case, is projected from the laser
onto the object to be inspected. The line is recorded by an area-scan camera positioned away at a fixed
distance, at an oblique angle relative to the projected light. The relative position (rotation + translation)
between camera and laser is obtained by means of a precise calibration process.

Figure 1 - Triangulation measurement principle for high-speed acquisition of 3D information
The 3D sensor cameras used in Tunnelings (Figure 2) are the LCMS camera-laser units originally developed
for road surface inspection tasks by INO (National Optics Institute, Canada), and marketed by Pavemetrics.
These sensors have been adapted and integrated for tunnel inspection within the Tunnelings system.

Figure 2 - 3D cameras: a) Camera-laser units and control unit; b) Surveying scheme
The 3D laser cameras are triggered by a Distance Measurement Instrument (DMI) to acquire profiles ofpoints, and then images are created by means of profiles aggregation. Their most relevant features are thefollowing:•••

Speed: 5600 profiles per second
Number of points per profile: 2352
Maximum resolution:- Longitudinal: 1 profile every 1 mm
- Transversal: 1 point every 1 mm
- Radial (depth): 0.5 mm

Each camera of the Tunnelings system captures an array of 2352 points per profile in a width of approx. 2 mwith three-dimensional information. The profiles are acquired every time the system receives a signal fromthe Distance Measurement Instrument (DMI) of the vehicle. The DMI measures the displacement in the473

driving direction of the survey with millimetre resolution and, for example, every 1000 consecutive profiles
are merged, so that images with a 2352 x 1000 mm resolution are obtained and saved in a common file foreach camera.
The image shown in Figure 3.a corresponds to the intensity image of the lining surface, whereas theregistered depth map of the lining surface (also referred to as range data) is shown in Figure 3.b. The brighter
pixels in the depth image indicate more depth, i.e. these points are farther from the sensor. Finally, the 3D
reconstruction can be seen in Figure 3.c, where the lining surface and its defects can be examined on-site inclose detail.

Figure 3 – 3D sensors data: a) Intensity mage b) Depth Image c) Point Cloud

Tunnelings subsystems
The Tunnelings system has two LIDAR installed, which are electro-optical laser measurement sensors thatwork under the principle of pulse propagation time measurement: the LIDAR scans its perimeter in a plane
using laser beams, and measures its surroundings in two-dimensional polar coordinates. The laser beams arereflected using a mirror, and they scan the surroundings in a circular manner. The measurements are triggeredusing an angular encoder. When a laser beam strikes an object, its position is determined. The distance to theobject is calculated from the propagation time that the light requires from the emission to the reception of thereflection at the sensor, and the direction is obtained from the angular encoder information. Figure 4 displays
all the subsystems that are installed on a truck in order to conduct the inspection.

Figure 4 – Subsystems (Lidar-Infrared Visible cameras) assembled together with 3D cameras on a truck474

Figure 5 shows the results these subsystems are able to offer. An example of the data retrieved by this
LIDAR sensor type: a profile every 10 cm when the platform is driving at a speed of 18km/h (5m/s), and thepanoramic images in well-lit tunnels.

Figure 5 – Road tunnel reconstruction from LIDAR data and panoramic cameras
In order to obtain a panoramic image of the tunnel, different sensors are used –depending on the lightning
conditions. If the tunnel is well lit, 360º cameras are used to obtain a full picture that can be rotated. In casethe tunnel is not sufficiently lit, the visible infrared cameras are used. The visible infrared system includes aset of illuminators and infrared cameras (Figure 6) able to acquire high-resolution images in completely dark
environments.

Figure 6 – Visible infrared cameras and illuminators
The cameras have a CMOS sensor of e2v which features a high quality and sensitivity at the near-infrared.
Besides, these cameras also include a global shutter that allows for accurate moving snapshots andreproduction of sharp contrasts.
6 INSTALLATION FOR ROAD TUNNELS
Using the most common setting (trade-off between transverse accuracy and transverse field of view), eachcamera-laser unit described in the previous section is able to inspect a 2 m wide section with an accuracy of
1 mm. Therefore, in road tunnels that usually have large sections it is necessary to assemble several sensors
to inspect the full section of the tunnel. In large tunnels that include a number of traffic lanes, this generally
involves several runs. Most road tunnels require surveying first one half of the tunnel and later the second
half. A scheme of six sensor assembly for 4 lane road tunnel inspection is depicted in Figure 6.

475

Figure 6 - Scheme of six sensor assembly for a road tunnel inspection and installation.
The laser cameras should be installed at certain distances from the tunnel surface and their laser beams must
be projected perpendicularly towards the tunnel surface. In addition to this, the camera uses a laser beam
which can opened up to 50 degrees. In order to avoid cross-talk between two consecutive cameras, they must
be installed in a staggered pattern. To design the most efficient assembly for these cameras, it is necessary tokeep these requisites in mind and to have a sound knowledge of the tunnel sections. As each tunnel has its
particularities, the assembly of the cameras must be customized for every particular survey. Thus, a software
has been developed to place the cameras in such way that the inspections can be performed in the shortest
time possible.
The Tunnelings devices can be installed in different kinds of vehicles, as shown below:

Figure 7 – The Tunnelings system installed on truck with six sensors and on a van with four sensors
In roads or road networks that include many tunnels, it is usual to continuously measure several tunnels,
keeping the tracing whenever it is possible. Maneuverability and speed during the inspection prevent
unnecessary disruptions to traffic.
7 ANALYSIS AND PRESENTATION OF RESULTS
Once the data are registered, the results are analysed. International standards regarding road tunnels arefocused on the inspection of facilities. From the structural point of view of analysis, tunnels are considered as
any other type of infrastructure. Thus, the deterioration analysis will depend on the type of support; then, theseverity of the different types of deterioration will be classified based on previous experiences in similar
tunnels and in similar geotechnical conditions.
In order to analyze the results, it is very useful to view the whole tunnel in a single composition, and to use
automatic or assisted tools to detect defects according to the images and to the 3D reconstruction.
To this end, a newly developed software enables the user to arrange the images of the lining in a wider view.
It makes it possible to select the analysed defects and to overlap them. The user can move forward along thetunnel, or reach a given milestone or kilometre point. Thanks to a listing, it is possible to locate and display
the defects and the area where they are located, as shown in Figure 8. The software offers tools to measurecracks and 3D profiles of the lining; besides, other incidents can also be noted.

476

Figure 8 – General Tunnel´s image view and detail view

In order to improve the user experience, the 3Dinteractive display is available (Figure 10): thesoftware can combine the images and reconstruct thetunnel in a 3D point cloud, which allows the users tomove along the tunnels to perform an on-site
inspection of the full lining from their own computer.

Figure 10 - Tunnel point cloud reconstruction

It is also possible to generate cartography of the full tunnel, obtaining a quick view of the lining of the wholetunnel and other areas with defects (see Figure 11).

Figure 11 - Cartography: a) Intensity images b) Defects mapping
8 INFORMATION ANALYSIS OF THE LINING SURFACE USING 3D CAMERAS
Even when no regulations are in place, the following defects are considered the most important either in roador railway tunnels: (a) leaks, spalling, lining face loss and cracking on the tunnel surface, and (b) concretedelamination, steel and reinforcement corrosion, voids and debonding in the interior lining –eventuallydetected during visual inspections.
Although it is not possible to conduct inspections using NDT tests to detect delamination, corrosion ordebonding in the lining, performing an automated detailed inspection of the surface allows for the detectionof areas where later radar-type tests or impact-echo tests would be most appropriate in order to detect
possible debonding or to measure the speed of corrosion of the reinforcement.
The information of the sensors provided by Tunnelings makes it possible to develop image analysis
algorithms that automatically detect defects on the surface of the lining. The detection algorithms must firstconsider all the elements located in the tunnel (electrical installations, fire-fighting systems, ventilation…) inorder to distinguish them from the supports and to process them separately at inspection level. Once extracted
the information of the supports, the software must process the tunnels according to their type.
Considering the type of lining used in the tunnel support, the shape of the tunnel section –due to theirconstruction method–, and the type of defects they might present, Tunnelings detects and assesses breaks inthe supports (chipping), lining face losses cracking indicative of opening and extension, and damp areas. In
addition, the clearance and any eventual significant deformations are assessed and compared to thetheoretical sections of the project.
Cracking Evaluation

477

The cracks are detected through Computer vision. The area of interest is processed as a 3D point cloud(Figure 12). The 3D point cloud is divided in perpendicular scan-lines along the cracking. Each scan-line isseparately evaluated to obtain the width and depth of the crack at that point, and these values are combined toobtain a value representative of the whole crack. Then the cracks are classified according to their extent andseverity.

Figure 12: 3D Reconstruction of cracks on a shotcrete lining and a in-situ concrete support
Face loss evaluation
The range image provided by the 3D camera is used to assess the face loss in the different materials that we
usually find in the lining of road tunnels:
1.
2.
3.
4.

Tunnels with concrete lining or mass concrete lining with transverse joints,
Tunnels with shotcrete lining,
Tunnels constructed with the cut and cover technique using slabs and diaphragm walls,
Concrete segment slabs and others.

The main step to detect any face loss or deformation that could pose any potential risk for the lining is toseparate all facilities and elements that appear on the image and, using a segmentation method as shown in
Figure 13, selecting all areas that present raveling, falling or deformation, and then assessing their extent andseverity.

Figure 13 - Lining Face Loss example: a) Point cloud; b) Depth image
Joints evaluation
In the case of segment tunnels, precast tunnels or in situ concrete tunnels, the system allows for a very
precise definition that makes it possible to know the location of its elements and to evaluate the opening andstepping of the joints between them (Figure 14). Thus, it would be possible to check in subsequent
inspections that no movements have occurred and to provide an initial reference for the new construction
tunnels.

478

Figure 14 – Condition analysis between module joints in in-situ concrete tunnel
In road tunnels, it is frequent that the structural support of the tunnel is covered by waterproof sheets or
decorative elements that improve the lightning and the cleaning works. In these cases, the visual inspection islimited as it is not possible to directly access the support.
In case the support remains hidden, only eventual deformation or breaks of these decorative/waterproof
covering will allow us to know that there is deterioration. Tunnelings offers very detailed information on thebending and the relative deformations in millimetre sections, so it offers information about the eventual
deformation of coverings (for instance, due to material falling from the keystone) and the condition of thewaterproof sheets.
9 INFORMATION MANAGEMENT (PERFORMANCE INDICATORS) WITHIN A INFRASTRUCTURE
MANAGEMENT SYSTEM
Condition assessment
With an inspection system such as the one described in this document, we have an objective analysis that will
not depend on the judgment of the person in charge of the assessment, as is the case of visual inspections.
This analysis will offer the same results in successive inspections of an infrastructure in the same state.
Besides, having a quantitative analysis of the infrastructure condition will allow us to obtain statistics forevery type of assessed defect and to define status indicators that will facilitate the assessment of the current
state of the asset and its evolution over time.
The statistics are very useful to obtain a quick overview of the general state of the asset, to identify areas inworse condition and to determine which areas require a closer visual inspection by specialist technicians. The
statistical revision of all the data throughout the tunnels enables the user to extract, for example, those areas
where the presence of cracking, chipping, repaired areas and dampness is more relevant.
Some representative graphs of the tunnel lining condition are depicted in Figure 18. Moreover, the software
makes it possible to acquire a greater level of detail with respect to the analysis, and to carry out multiple
combinations and queries about pathologies and surveyed sections. The results are presented by adding thelength or area, depending on the incident threshold in each meter of the tunnel,

479

Figure 18 - Statistics
As for the indicators, these will allow us to get a general overview of the condition of the assets, to compare
the state of the different assets within our network, and to prioritize the maintenance, either according to theexisting risks, or to the profitability of the interventions, as specific interventions will allow for a significant
improvement of the overall rate of the asset.
The implementation of tunnel condition indicators makes it possible to integrate the results of the automatic
inspections with management systems that use detailed visual inspection performed by specialist technicians.
With this method, visual inspection can be focused on areas identified as highly problematic, while the
network manager is able to keep working with the assessment systems used until now.
For each of the assessed assets, a value or “item score” is obtained. This value, obtained by combining theextent of the defect and its mean severity, will indicate the state of the asset respect the element considered.
Extent means the proportion of the assessed area presenting this defect. In order to calculate the severity, it isnecessary to define thresholds respect the measured parameters, resulting in a series of categories for each of
the assessed defects. For example, the mean width can be used for the assessment of the cracking, asrepresentative characteristic of the defect severity. In other cases, such as face loss, the most representative
parameter will be the mean depth and the area affected.
Using the extent and the severity of the different parameters we can obtain an item score for each of theassessed elements. In many cases, knowing or even predicting the evolution of the state of the tunnel is as
important as finding out the current condition of the asset. This can be seen in the statistics obtained indifferent areas, by comparing the cumulative values obtained in different inspections or, more simply, bycomparing the overall rate.
In addition to this, 2D and 3D comparisons may be performed with Tunnelings as seen in Figure 19, that
displays a comparison between the extent of humidities in different periods of the year.

480

Figure 19 - Comparison of two inspections in different periods of the year to see the evolutions of humidity

With all this information obtained thanks to the automated inspection, and after the analysis of defects andindicators (score), this could be the basis to schedule the instrumentation of those deteriorations which haveshown some progress or that could pose a risk for the integrity of the tunnel. In some cases, the said
instrumentation will need to allow for the monitoring of deformations, cracks or other structural parametersin order to keep continuous track or real-time track, as shown in the following image of the instrumentationof a joint monitored by means of a fibre optic sensor in order to check the deformations both staticallyand dynamically.
Integration of the data obtained by all the sensors into BIM
The use of a BIM system (Building Information Modeling system) allows us to have a virtual 3D model ofthe infrastructure (in this case, of the inspected tunnels) with spatial location of the different elements,
including geographical information (e.g. absolute coordinates). It also makes it possible to determine theproperties of the different components. Therefore, these systems offer a unique environment where it ispossible to share all the infrastructure data and to optimize their management, incorporating infrastructure
inspection data and indicators and facilitating the analysis of repair and reconstruction costs.
The BIM systems make the collaboration between tunnel designers and constructors easier. These systems
are currently revolutionizing the management of the life-cycle of the infrastructures and optimizing themaintenance works. Despite the BIM have a strong presence in tunnel conferences and published works, theincorporation of 3D information obtained through dynamic inspection systems is not widely spread for the
management of huge infrastructures.
Tunnelings offers the possibility to integrate the inspection in an existing BIM system, as well as to create a
new virtual model of the infrastructure.
The data provided by the 3D laser cameras, LIDAR and visible or infrared cameras are processed to obtain a
3D reconstruction with integration of inertial data in a fully automated manner, without any user supervision,
so it very convenient for the generation of a virtual reconstruction and its integration into a BIM platform.
Once the data are stored into a BIM platform, the information can be retrieved by means of different softwaretools.

481

Conclusions
The management and maintenance of the tunnels currently in service require the application of techniques ofinspection of linings and facilities, using high performance systems. This requires having available systems
capable of reducing the risk of traffic interruptions that may occur, reducing the disturbances to road users
and the potential incidents in the tunnel structure.
Tunnelings is a system to inspect the condition of the lining of the tunnels (cracks, deteriorations anddampness) that uses high resolution images from the surface while it is illuminated with laser emitters.
The system uses high speed and high resolution digital cameras together with high power lasers aligned in
one transversal plane. This configuration offers a large variety of benefits and, together with otherconventional techniques of image analysis, its operation is much faster than regular and traditional scanners.
This provides the optimal configuration to create a 3D image of the characteristics of the crack anddeterioration of the inspected area. The inspection vehicle can also include Lidar-type sensors so as tofacilitate the 3D reconstruction of the section and the plan for their incorporation to the BIMs.
In some cases, the inspection of the tunnel supports can be performed together with the pavement inspection(evenness, cracking, macrotexture…). Finally, these systems of lining inspection can also be used for thefollow-up and inventory of different elements: firefighting, electricity, anchoring of ventilation systems…
With this method it is possible to obtain results no subjective in relation with the lining surface affected by
defects and the severity of those defects. It is possible also to obtain a combined quality indicator in relation
about the general structural behavior of the tunnel. Finally, with this value (the combined performanceindicator) we can manage the needs to maintain the tunnel in good or propose repairs or permanentmonitoring and instrumentation in order to keep track of the evolution of the detected defects.
The software allows the user to combine additional information, such as geotechnical cuttings, parameters oftunnel's progressing during its construction, etc. and also allows the use to overlap the image with theanalysis of observed impacts (joint openings, splits and deformations, etc.).
References
1.

2.
3.

4.
5.

TRB (2014) “Renewal Project R06G.: Mapping Voids, Debonding, Delaminations, Moisture, andOther Defects Behind or Within Tunnel Linings”. Strategic Highway research program. Strategic
Highway Research Program (SHRP) 2
Carsten Rother, Vladimir Kolmogorov and Andrew Blake (1993), “GrabCut: interactive foregroundextraction using iterated graph cuts”. SIGGRAPH '04 ACM, Pages 309-314.
Gavilán, M.; Sánchez, F.; Ramos, J.A: “Mobile Inspection Systems for Hihg-Resolution Assessment
of Tunnels”. The 6th International Conference on Structural Health Monitoring of Intelligent
Infrastructure Hong Kong, December 2013.
Sánchez, F.; Ramos, J.A.: “Automated Structural Evaluation of Tunnels in Service”. ITA WTC2015 Congress May 22-28, 2015, Dubrovnik, Croatia.
23 CFR Part 650 National Tunnel Inspection Standard. Federal Highway Administration. July 2015.

482

Pedestrian Safety and Road Crossing Behavior: A Case Study of Abu Dhabi

Mohamed Shawky, Ph.D.,*,1,2Badr A. Al-Harthei, Ph.D., 2

1

Traffic and Patrols Directorate
Abu Dhabi Police, Abu Dhabi,
United Arab Emirates

2

Department of Civil Engineering,
Faculty of Engineering,Ain Shams University,
Cairo, Egypt* Corresponding Author:
Mohamed Shawky, Ph.D.,
Tel: +971 561236607
Email address: m_shawky132@hotmail.com

Accepted for presentation at the 2nd IRF Asia Regional Congress
October , 2016483

Abstract
Reducing the fatalities resulted in traffic crashes, especially pedestrian-related crashes is a
strategic target of all road safety authorities around the world. This paper aims to investigate thecontributing factors affecting the severity of pedestrian-vehicle collisions in Emirate of AbuDhabi (AD). About 20% of severe crashes in AD are pedestrian-related crashes that led to about
24.5% of total fatalities and 12% of total crashes’ injuries. A logistic regression model wasdeveloped to examine the variables that may affect the severity of pedestrian crashes. About
3,770 pedestrian from year 2008 to 2015 are employed in the analysis. The majority of thesecrashes were occurred when the pedestrians trying to cross road (about 92.5%).
The results indicated twelve variables associated with the fatality of pedestrian crashes. thesevariables include young pedestrian (less than 18 years old), older pedestrians (more than 60 years
old), pedestrians crossing at non designated crosswalk locations, speeding behavior of thedrivers, speed limit of the road, number of lanes, road type, crash locations, pedestrians location,commercial area, road surface condition and darkness. The estimated odds ratios showed that theprobability to be involved in a fatal pedestrian crashes increases with increasing speed limit of
the road, number of lanes, lack of designated crosswalk, crossing at mid-block section, crossing
rural roads and dark locations. In addition, young pedestrians and older pedestrians are more
likely to be involved in fatal-crashes than injury-crashes. Finally, preventative countermeasures
for increasing road safety of pedestrians are provided.

484

INTRODUCTION
The pedestrians are always considered as the vulnerable road users due to their lack ofprotection. Many prior studies proved that the human error is the major cause of traffic crashes(Ren, 2013). In Abu Dhabi Emirate (AD), the capital of the United Arab Emirates, pedestriancrashes and related casualties represent a significant contribution in total number of severecrashes (i.e., any crash with at least one injury or fatality). Table 1 shows the percentage ofpedestrian crashes and resulted causalities from the total severe crashes occurred from year 2008
to 2015. The table shows that the pedestrian-related crashes represent 20.2% of total severecrashes, about 24.5% of total fatalities and 17.1% of serious injuries. However, the slight injury
represents 7.4% only of all pedestrian causalities. These results reflect the high severity ofpedestrian crashes.
Table 1: Percentage of pedestrian-related crashes (2008-2015)
Item

Numberof crashes

All severe crashes
Pedestrian Crashes only
Percentage

18581
3762
20.2%

Number of casualties
Fatalities
2553
625
24.5%

Serious injury
2962
507
17.1%

Medium injury
13219
2002
15.1%

slight injury
12812
949
7.4%

Table 2 shows the distribution of the pedestrian- related crashes that have been reported by AD
traffic police between 2008 and 2015. The table shows that 15.4% of the pedestrian casualties
are fatalities. The majority of the pedestrian crashes occurred in urban roads and about 80.2%
occurred during the pedestrian crossing at undesignated crosswalk locations. In addition, 42.9%
of pedestrian crashes occurred at roads with speed limit 60 kph that represent the majority ofroad network especially at city center area.
It is worth mentioning that, the Emirate of Abu Dhabi has a unique profile of population
where more than two hundred different nationalities are living there. The Emiratis compriseabout 18% of the total population of about three million. The majority of the population falls
under the working age group (between 18 and 45 years old), which in-turn leads to challenges intraffic mobility and other road safety concerns. As a result, the majority of the pedestrian’s
casualties (about 60%) fall in the age group from 30 to 45 years old.

485

Table 2: Pedestrian crashes distribution
Category

Pedestrian
behavior

Injury-severitylevel

Age group

GenderSpeed limit of
the road

Frequency

Percentage

During crossing roads
crossing at intersection

3,462
266

92.5%
6.5%

crossing at mid-blockcrosswalkcrossing at mid-block not atcrosswalkSlightMediumSerious
fatal
Total
< 18
18-30
31-45
46-60
> 60
Male
female
< 60
60
80
100
120

239

5.8%

3283

80.2%

951
2007
509
629
4,096
763
1215
1252
680
199
3146
622

23.2%
49.0%
12.4%
15.4%
100%
18.6%
29.6%
30.5%
16.5%
4.8%
83.5%
16.5%
26.2%
42.9%
11.1%
14.0%
5.9%

986
1616
419
526
223

Such unique composition of population put challenges to traffic police for improving roadsafety. Several actions including engineering constructions especially for pedestrian, awarenessand education campaigns and automated speed enforcement devices insulations in order toreduce the number of injuries and fatalities resulted in traffic crashes were taken during last five
years. As a result, severe crashes reduced from 2,537 in year 2010 to 1,803 in year 2015 that led
to a reduction in the fatalities from 376 to 245 (34.8% reduction) during the same period. The
statistics shown in Table 3 indicates that a significant improvement in pedestrian crashes andrelated fatalities has been occurred during the last six years. However, the fatality rates ofpedestrian crashes per 100,000 inhabitants and 10,000 registered vehicles remain the same
during the last three years. These findings can be justified due to a pedestrian initiative for
reducing pedestrian crashes that was conducted between 2010 and 2013 including intensive
constructions of crosswalk facilities in AD during this period.

486

Table 3: Statistics of the total and pedestrian-related crashes in AD
Item

2008

2009

2010

2011

2012

2013

2014

2015

Total number of severe crashes

2,954 3,086 2,537 2,283 2,056 2,071

1861

1803

Total number of fatalities

376

409

376

334

271

288

267

245

Number of pedestrian crashes
Number of severe injuries in pedestriancrashesNumber of fatalities in pedestrian crashes

625

644

531

486

401

388

334

324

76

93

76

63

77

58

26

41

110

118

101

81

70

48

54

48

Pedestrian fatality rate /100,000 inhabitants
Pedestrian fatality rate / 10,000 registeredvehicles% of pedestrian crashes

3.9

3.8

3.2

2.6

2.1

1.5

1.5

1.5

2.0

1.7

1.4

1.0

0.8

0.5

0.6

0.5

21%

21%

21%

21%

20%

19%

18%

18%

% of fatalities in pedestrian crashes

29%

29%

27%

24%

26%

17%

20%

20%

To keep the improvements in pedestrian safety, more understanding about the factors that
affect the severity of pedestrian crashes while they are crossing the roads is needed. Two
approaches are usually used to enhance the safety of pedestrians: (1) reducing the number ofvehicle-pedestrian crashes and (2) reducing the severity level of the injury when pedestrians are
exposed to vehicle collisions. Fatality rates especially fatality rate per 100,000 inhabitants, areconsider as main performance indicators to monitor the improvement in road safety and forcomparison reasons over time and between different countries. Accordingly, this paper focuseson investigating the contributing factors that affect the severity of vehicle-pedestrian collisions.

LITERATURE REVIEW
There are many researchers have attempted to investigate the factors affecting the occurrence
and severity of pedestrian crashes. Pour-Rouholamin and Zhou (2016) used ordered-responsemodels to test the contributing factors of pedestrian-vehicle collision occurred in Illinois between
2010 and 2013. It was found that many variables are associated with severe injuries: older
pedestrians (more than 65 years old), pedestrians not wearing contrasting clothing, younger
drivers (16–24), drunk drivers, time of day (20:00 to 05:00), divided highways, multilane
highways, darkness, and heavy vehicles. In addition, crossing the street at crosswalks, older
drivers (more than 65 years old), urban areas, and presence of traffic control devices (signal andsign) are associated with decreased probability of severe injuries.
Jimenez, et al. (2016) applied logistic regression modeling to quantify the association
between pedestrian and driver related factors by using crash data between 1993 and 2011 inSpain. The study suggested preventive measures for subgroups of high-risk road users including
young and male pedestrians, pedestrians with psychophysical conditions or health problems, the487

youngest and the oldest drivers, and drivers with markers of high-risk behaviors (alcohol use,
nonuse of safety devices, and driving without a valid license). Abdul-Aziz et al., (2013) used
log-likelihood ratio test associated variables of pedestrian severity levels in New York City. This
study showed that, among many variables, road characteristics (e.g., number of lanes, grade,light condition, road surface, etc.), traffic attributes (e.g., presence of signal control, type of
vehicle, etc.), and land use (e.g., parking facilities, commercial and industrial land use, etc.) arefound to be statistically significant in the pedestrian severity.
Regarding pedestrians’ behavior, Preusser et al. (2002) and Oxley et al. (2006) stated that morethan half of the pedestrian deaths occur due to illegal human behavior in UAS, such as violating
traffic lights, impairment by alcohol or drugs, misjudgment, fatigue and poor pedestrianvisibility. Spainhour et al. (2006) reviewed about 353 pedestrian fatalities and found that alcohol
use by pedestrian is the primary factor in 45% of all cases. The results also showed that the useof cell phones and other distraction could increase the severity and the risk of the pedestriancrash.
In terms of pedestrian characteristics, two demographic factors (i.e., age and gender) havebeen addressed in prior researches (for example; Rosén and Sander 2009; Kim et al. 2008; 2010).
Holland and Hill (2007) showed age and gender differences in the likelihood of adult pedestriancrashes. It was found that older people do take fewer risks, being less likely to intend to cross inrisky situation. In addition, women are less likely illegally cross roads than what men do.
Tournier et al., (2016) provided a reviews current knowledge of older-adult problems with themain components of pedestrian activities. It showed that visual impairment, physical frailty, andattention deficits have a major negative impact on older pedestrians’ safety and mobility,
whereas the roles of self-evaluation and self-regulation are still poorly understood. Accordingly,
all these elements must be taken into consideration, not only in developing effective safety
interventions targeting older pedestrians, but also in designing roads and cars. However,Fredriksson et al., (2010) showed that all factors are equally influences on pedestrian crashseverity in terms of gender and there is no gender difference in fatality risk.
Other researchers investigated the impact of traffic volume of both vehicles and pedestrians
on the occurrence pedestrian crashes (i.e., Elvik (2009), Megan et al. (2009) and Zegeer et al.
(2005)). The developed models in these studies showed that pedestrian and vehicle traffic
volumes have a significant contribution with positive sign which means the pedestrian-related
crashes increase with increasing the traffic volumes of pedestrian and for both locations ofmarked (designated) and unmarked crosswalks.

DATA DESCRIPTION
The employed data in this study were extracted from the crashes reports of AD traffic police
from year 2008 to 2015. The crashes database includes different sets of information as
summarized in Table 4.

488

Table 4: Data reported by AD traffic police in cases of pedestrian crashes
Data set

Collected information

Pedestrian and casualties
Characteristics

Age, gender, nationality, and injury severity level (Four levels:
Slight, Medium, Severe, and Fatal) *Pedestrian behavior

Crossing location related to the available crossing facility(crossing at zebra crossing area, not at the zebra area, facility
not available)

Road Characteristics

Accident location (intersection/mid-block/out of theroad/median), exist of crossing facility, speed limit, number oflanes, road type and class, surrounding land use, and area
category

Environmental andgeneral Information

Accident location, coordination, weather condition, lighting,road surface condition, vehicle type, accident description, andaccident causes, driving license data, etc.

* The level of injury is determined from the medical reports of the accidents

REGRESSION MODEL DEVELOPMENT
As indicated earlier, the main objective of this study was to identify the factors that might affectthe severity of pedestrian-vehicle collisions in AD. The response variable (crash severity) is abinary variable with two levels: “1” if the crash resulted in a pedestrian’s fatality or more and“0” if the crash resulted in at least one pedestrian’s injury. The binary logistic regression is thebest modeling approach to deal with this nature of outcomes (i.e., whether it was a fatal or nonfatal pedestrian’s crash).
The logistic regression model can be written in the following form:E(Y /X) = π(X) =eBo +B1 x
1+ eBo +B1 x. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (1)Where the transformation of the π (x) logistic function is known as the logit transformation:𝜋(𝑋)𝑔(𝑥) = ln [1−𝜋(𝑋)]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2)The logistic regression model estimated in this study can be expressed as follows:𝑃(𝑓𝑎𝑡𝑎𝑙 𝑐𝑟𝑎𝑠ℎ) = 𝜋(𝑋) =𝑒 𝑔(𝑥)
1+ 𝑒 𝑔(𝑥). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (3)Where, g(x) is the function of the examined explanatory (independent) variables that shown in
The examined variables were classified into three groups: (I) pedestrian characteristics
including, age and gender, (II) pedestrian behavior including, crossing location selection,pedestrian position, crash cause and (III) environmental characteristics including, speed limit,

489

road width in terms of the number of lanes, road type, light condition, road surface condition,
existence of formal crosswalk, weather condition, day-time, week-day and the surrounding land
use type. Several trials were conducted to select the most appropriate variables to estimate themode and integration in some categories were done in these trails. Table 5 shows the descriptionof the selected explanatory variables that have been used in the estimation of the logistic model.
In this study logistic regression was estimated using the SPSS package.
Table 5: description of the explanatory variables used in the logistic regression model
Variable

Code value

Crash severity
Fatal = 1 , Injury = 0(I) pedestrian characteristics
GenderMale = 1, Female = 0
Young pedestrian (<18) = 1 ,Otherwise = 0
AgeOlder pedestrian (> 60) = 1 ,Otherwise = 0(II) pedestrian/driver behavior
Cross at crosswalk = 1, Otherwise =Cross at crosswalk
0
location doesn’t
Not crosswalk exists = 1, Otherwise
have crosswalk=0
Crossing the road = 1, Otherwise =Pedestrian position0
Speeding driving
Speeding = 1, Otherwise = 0
giveaway togive away = 1, Otherwise = 0
pedestrian(III) environmental characteristics
Road type
Urban = 1, Rural = 0
Speed limit
Continues variable
No. of lanes
Continues variable
Mid-block section= 1, Otherwise =Crash location0
Day time and good lighting at nightLight= 1, Otherwise = 0
Weather
Clear weather = 1, Otherwise = 0
Road surface
Dry = 1, Otherwise = 0
condition
Commercial area = 1, Otherwise = 0
Surrounding land
School and government area =1,
use
Otherwise = 0
Weekday
Weekend=1 , Otherwise = 0
Day time
During daytime = 1, , Otherwise = 0

Frequency

Percentage

Mean

612

16.2%

0.162

Std.
dev.
0.369

3146

83.5%

0.835

0.371

732

19.4%

0.194

0.396

185

4.9%

0.05

0.216

420

11.1%

0.111

0.315

2342

62.1%

0.620

0.185

3510

93.1%

0.931

0.253

350

9.3%

0.093

0.290

2023

53.7%

0.537

0.499

1739
3770
3770

46.1%
100%
100%

0.461
65.3
2.56

0.499
24.8
0.91

3220

85.4%

0.854

0.353

3539

93.8%

0.939

0.240

3639

96.5%

0.979

0.145

3488

92.5%

0.925

0.263

1405

37.3%

0.373

0.484

615

16.3%

0.163

0.370

997
2632

26.4%
69.8%

0.264
0.698

0.441
0.459

490

Modelling Results and Discussions
Table 6 shows the output of the estimate logistic regression model. The Odds ratio is directly
related to the probability of having a more fatality crash. The variable with positive Odds ratio
denotes the increasing probability of getting a fatal pedestrian/s in a certain pedestrian-vehicle
collision. As shown in Table 6, among the 20 examined variables, twelve variables significantly
affect the fatality of the pedestrian-related crashes at a significant level of 95%. These variables
varied between pedestrian characteristics, pedestrian and driver behavior, crash location
characteristics and road parameters. Among these twelve variables, five variables refer to thedrivers’ characteristic and behavior; young age, older age, crossing at location that has notdesignated crosswalk, position of the pedestrian and speeding of the driver. The road variables
include number of lanes, speed limit of the road and road type. Finally, the environmental andcrash location variables include intersection-related location, commercial area; light condition
and road surface condition are significantly affect pedestrian severity.
Table 6: Result of the logistic regression model estimation
95% C.I.for EXP(B)(odds ratio)
Lower
Upper

Variables

Estimate

S.E.

Wald

Sig.

Odds
ratio

Constant
GenderYoung age < 18 years oldOlder age > 60 years old
No crosswalk available
Crossing at crosswalk
Pedestrian position
Crash location-6.708
.111
.356
.769
.385
.349
-.723

.580
.156
.145
.217
.138
.210
.216

133.911.509
6.038
12.6027.760
2.768
11.233

.000
.476
.014*
.000*
.005*
.096
.001*

.001
1.118
1.427
2.158
1.470
1.417
.485

.823
1.075
1.411
1.121
.940
.318

1.517
1.895
3.300
1.928
2.136
.741

.337

.160

4.415

.036*

1.400

1.023

1.917

Giveaway to pedestrian
Speeding drive
Commercial area
School and Governmental
zones
Light condition
Number of lanes
Speed limit of the road
Road typeRoad surface condition
Weather condition
DaytimeWeekday

-.198
.906
-.358

.113
.181
.125

3.051
25.000
8.273

.081
.000*
.004*

.820
2.474
.699

.657
1.735
.547

1.024
3.529
.892

-.243

.159

2.318

.128

.785

.574

1.072

-.649
.280
2.307
-.919
-.559
.560
-.161
-.038

.182
.066
.136
.157
.193
.354
.110
.116

12.67917.998289.51734.307
8.414
2.502
2.163
.107

.000*
.000*
.000*
.000*
.004*
.114
.141
.744

.523
1.323
10.045
.399
.572
1.750
.851
.963

.366
1.163
7.701
.293
.392
.875
.687
.767

.747
1.506
13.103
.542
.834
3.502
1.055
1.208

* Significant variables at level of 95%

491

The odds ratio presented measure the amount by which the crash severity increases. Taking an
example of the explanatory variable, no crosswalk available, which has an odds ratio of 1.470, it
can be stated that the probability of fatal pedestrian’s crash is about 1.47 times higher in cases ofthe pedestrians cross at locations that haven’t designated crosswalk, assuming that rest of thefactors remains the same. The likelihood to be involved in fatal pedestrian crashes at notdesignated crosswalk locations, rural roads, darkness and mid-block locations are significantly
high compared to others. In addition, pedestrian more likely to be killed on roads with higher
speed limit ≥ 60 kph) by 10 times more than in case if the crash occurred on roads with speed
limit less than 60 kph. Furthermore, the fatality increases with increasing number of lanes.
Regarding pedestrians’ characteristics, the age showed a significant variable which young(less than 18 years old) and older (greater than 60 years old) are more likely to be involved in a
fatal than injury in the pedestrian-related crates. Among the drivers’ behavior variables, thespeeding is the most effective variable since the speeding behavior increases the probability to
involve in fatal-crash rather than injury-crash. The speeding behavior of vehicle’s drivers
increases the probability to involve in fatal pedestrian crashes rather than injury-crash. The
results also indicate that if the vehicle hits the pedestrian when he/she stopes at roadside, theprobability to be a fatal crash is higher than in case of the vehicle hit the pedestrian during crossthe road. That can be justified as this type of crashes usually occur when the driver lost controlof the vehicle may be due to high speed or Preoccupation with something like a mobile use whiledriving and then run out of the road and hit a pedestrian. In this scenario, driver hit the pedestrianin high speed that usually lead to his/her death.
Countermeasures for Improve Pedestrian Safety
In light of the model findings, preventive strategies could be developed in order to reduce thefatality of the pedestrian-vehicle collisions in AD. Table 7 summarizes some of possible
preventive countermeasures for each of the factors that have been proven as significant variablesin the regression model. It seems the proposals not new or unfamiliar proposals but most of them
have been proposed in prior studies (for example, lee and abdel-Aty, 2005, World HealthOrganization, 2013b). This table indicates that improving the pedestrian behavior by the threemain elements of road safety; engineering, education and enforcement should be conducted inparallel to achieve the target of AD police for deducing the fatality rates resulted in pedestriancrashes. Integrated efforts with other authorities that have responsibility in road safety such as
DOT and municipalities should also be take into consideration during implementation of thepedestrian safety strategies.

492

Table 7: Proposed countermeasures for pedestrian safety risk factors
Risk factor identifies in
the model
Young age < 18 years oldOlder age > 60 years old

No crosswalk available
Pedestrian position &Crash location
Speeding driving

Commercial area
Light condition
Number of lanes
Speed limit of the road
Road typeRoad surface condition

Possible preventive countermeasures- Emphasize awareness campaign for road safety at schools and colleges- Improving road-crossing facilities at school and education intuitionsarea- Develop safe walking paths for children in high-risk locations- design the road crossing facilities as friendly as possible for older andhandicapati peoples.
- Construct designated crosswalks including crossover at high crossing
pedestrian demand locations.
- Construct guardrails at roads median to prevent illegal crossing at
high-risk locations.
- Emphasize road safety education for both drivers and pedestrian
regarding taking care and be aware always.
- Emphasize enforcement for illegal road crossing- Emphasize enforcement for speeding behavior for drivers.
- Emphasize awareness campaign for speeding behavior at driving
training schools and by different ways.
- Improving road-crossing facilities at commercial areas- Installing light poles at high-risk locations.
- Improving visibility at hazard locations.
- Prevent at-grade crossing facilities and construct pedestrian crossovers
at wider roads (4 lanes and more), roads with high speed limit (greaterthan or equal 100 kph and at rural roads.
- Emphasize awareness campaign regrading prohibition to crossroads
during wet conditions and to be aware in rainy weather

REFERENCES
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crash severity in New York City. Accident Analysis and Prevention 50 (2013) 1298– 1309.
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Transport”. Accident Analysis and Prevention, Vol. 41, No. 4, 2009, pp. 849-855.
Fredriksson R., Rosén E. and A. Kullgren (2010). Priorities of pedestrian protection - A real-life study of
14 severe injuries and car sources. Accident Analysis and Prevention, Vol. 42, No. 6, pp. 15 16721681.
Holland, C., and Hill R., (2007). “The effect of age, gender and driver status on pedestrians’ intention tocross the road in risk situation”, Accident Analysis and Prevention, Vol. 39, pp. 227-237.
Jiménez-Mejíasa, S., Martínez-Ruiza, V., Amezcua-Prietoa, C., Olmedo-Requenaa, R., Luna-delCastillob, J.D., Lardelli-Clareta, P., (2016). Pedestrian- and driver-related factors associated with therisk of causing collisions involving pedestrians in Spain. Accident Analysis and Prevention 92 (2016)
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Characteristics of Severe Crashes during the Holy Month of Ramadan

Mohammed Kishta, M.SC.
Road and Traffic Engineer
Traffic and Patrols Directorate
Abu Dhabi Police, Abu Dhabi, UAE
E-mail: eng.m.kishta@gmail.com, Tel: +971 503220883
Mohamed Shawky Ahmed, PhD
Assistant Professor
Department of Public Works
Ain Shams University, Cairo, Egypt
E-mail: m_shawky132@hotmail.com , Tel: + 971 561236607
Hussain Al-Harthei, M.SC.
Director
Traffic and Patrols Directorate
Abu Dhabi Police, Abu Dhabi, UAE
E-mail: alharthei@saaed.ae, Tel: +971 25127222

Paper submitted for presentation at the 2nd IRF Asia Regional Congress & Exhibition,
Kuala Lumpur, Malaysia, October 16-20, 2016.

495

Kishta M., Shawky M., Al-Harthei H.

ABSTRACT
Ramadan is the holy month for Islamic World. In this month more than 1.6 billion
Muslims around the world fast during day time. Accordingly, daily life routines andactivities of people change markedly. This paper aims to explore the changes in the
traffic crash patterns during Ramadan compared to the rest months of the year. Severecrashes data during six years at Abu Dhabi Emirate are employed. The statistics showsthat the percentage of crashes during Ramadan remains between 7 and 8% of the total
yearly crashes. Despite the severe crashes decreased by 29.2% during last six years, thesevere crashes during Ramadan decreased by 38.6%. Logistic regression model wasdeveloped to examine the contributing factors affecting the crashes occurrence during
Ramadan compared to other months. The model results showed that five variables
significantly affect the crash occurrence in Ramadan; day time, week days, crashes
caused by red light crossing and alcohol usage and feeling sleep and fatigue. Amongthese variables, crashes caused due to sleeping and fatigue of drivers has higher
probability to occur during Ramadan 2.4 times more than other months. In addition,crashes due to alcohol usage decreased by 4.23 times. Furthermore, the results indicatedthat young drivers are more committed to traffic rules and drive more safely during
Ramadan. These findings reflected the impacts of fasting and change of daily activities
on the road safety in AD.

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INTRODUCTION
There are more than 50 Muslim majority countries and over 1.6 billion Muslims aroundthe world which represents about 23.4% of the world population. The holy month of
Ramadan is considered as a special month for Muslims world where many religious
activities take place, mainly the fasting. Ramadan is the 9th month of the Hijri (Islamic /Lunar) calendar. Ramadan month doesn’t start at the same time every year because thelunar year is 11 days shorter than the Gregorian (our conventional) calendar. Ramadan
starts and ends at the sighting of the new moon, so sometimes its exact start and end dateare a little unpredictable and it may differ from country to country. Ramadan’soccurrence varies each year and may in some years falls during very hot summer months,
so it is usually a challenging time to remain safe on the road during the summer months.
Emirate of Abu Dhabi, the Capital of UAE, is a Muslim Country. However, there are
more than two hundred different nationalities are living there. In Ramadan, working
hours are changing for all the people in UAE with all respect from non-Muslims to thereligious environment of this month. During the last six years a significant improvement
in road safety has been gain in AD. Table (1) shows the statistical information of roadsafety indicators in AD. It shows that the frequency of severe crashes (i.e., crashes thathave causalities; hereafter said traffic crash). In general, all indicators show a significant
improvement in road safety during this period by different levels. The crashes reduced byabout 29.2% in year 2015 compared to 2010. However, it was reduced by 38.6% forcrashes that have been occurred during Ramadan. That means the improvement moresignificant in the month of Ramadan regarding the pedestrian-related crashes; the numberof pedestrian fatalities decreased by 52.5% but not changes has been occurred during
Ramadan.
TABLE 1: Statistics of Crashes during Ramadan in AD% ofchange-29.2%

Abu Dhabi Emirate

2010

2011

2012

2013

2014

2015

Total number of crashes
Severe crashes in Ramadan% of crashes in Ramadan

2,537
215
8%

2,283
176
8%

2,056
149
7%

2,071
166
8%

1,864
157
8%

1,797
132
7%

Total number fatalities

376

334

271

289

267

245

-34.8%

Number of fatalities in Ramadan

28

22

20

30

25

19

-32.1%% of fatalities in Ramadan

7%

7%

7%

10%

9%

8%

-

Total number of serious injuries

400

390

364

366

240

293

-26.8%

Number serious injuries in

41

32

26

43

17

29

-29.3%% of serious injuries in Ramadan

10%

8%

7%

12%

7%

10%

-

Total number of pedestrians’ fatalities

101

81

70

48

54

48

-52.5%

Number of pedestrians’ fatalities in
Ramadan

6

4

5

7

5

6

0.0%

% of pedestrians’ fatalities in Ramadan

6%

5%

7%

15%

9%

13%

-

-38.6%-

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Kishta M., Shawky M., Al-Harthei H.

In general, the changes of people daily life style are markedly altered during Ramadan.
The commitment to eat and drink only during the night leads to a definite change in therhythm of life; sleep duration becomes shorter, eating schedule, and the alternation of rest
and activity are especially affected. Understanding how such changes affect drivers’
behavior and as a result affect traffic crashes pattern is a key for improving traffic safety
performance during the month of Ramadan. Accordingly, this paper tries to investigate
the factors that may affect the frequency of traffic crashes, crash type and traffic crashes
patterns during Ramadan.
LITRITURE REVIEWMonthly and seasonal variations of traffic accidents at different places have gained asignificant attention from the researches. Many studies tackled the impact of special
events on the traffic accident patterns and road safety aspects, such as during Christmas
and holiday season, in western countries. However, very few studies addressed thechanges in the traffic accident pattern during the month of Ramadan despite the relatively
big number of Muslim countries and Muslim population.
A study conducted by Yildirim et al. (1) used observational data to examine how
Ramadan was associated to observable driving behaviors (i.e., speeding, horn honking,and using seat belts) as compared to non-Ramadan. The observational survey was
conducted during and after Ramadan in different times of the day in the same region of
the city of Ankara. The results demonstrated that mean speed was lower, honked horns
were higher, and seat belt use was lower in Ramadan as compared to non-Ramadan,though each negative driving behavior was prevalent in both periods.
Hossein Ebrahimi et al. (2) found that the significant reduction in the in the incidenceof traffic accidents in August (2011) may be due to the coincidence of August with
Ramadan, which had led to a significant decrease in out of city journeys.
M.N. Tahir et al. (3) investigated trends in road traffic crashes (RTCs) managed by anemergency service, in 2011 in Punjab, Pakistan. Results of the study showed thatambulance service experienced a higher burden of RTC emergencies in the month of
Ramadan 2011 compared with the preceding months of the year. This increase wasmostly concentrated among younger ages, especially those driving motorcycles.
Furthermore, the majority of RTCs were caused by speeding during the peak rush hours
before Iftar (breakfast).
Shawky M. et al. (4) investigated the change in the traffic accident patterns and roadsafety concerns during the holy month of Ramadan in Abu Dhabi, UAE during the period(2008-2012). His comparison study is carried out using statistical t-test to examine thedifference between Ramadan and other months with respect to traffic accident patterns(over months, weekdays, and daytime), accidents’ severity, causalities, types, and causes.
In addition, a comparison of the main traffic safety indicators is presented. The
comparisons have been further extended to the drivers’ behavior in terms of their traffic
violation, attitude of speed limit, crossing during red light, etc. The findings of this study
indicated that there are significant differences between the traffic accident fluctuation
during the month of Ramadan compared to other months across days of the week andhours of the day. No evidences of that the traffic accident number, severity, causes, and498

Kishta M., Shawky M., Al-Harthei H.

types have been significantly changed during the month of Ramadan. However, thatstudy didn’t provide statistical model to investigate the contributing factors affecting theoccurrence of crashes during Ramadan.
Al-Houqani et al. (5) showed that driving during Ramadan was a predictor of sleep
related collisions which was prevalent during this particular period. Monirah Alnasser etal. (6) conducted a retrospective study, which included all pediatric trauma cases related
to Motor Vehicle crashes, from 2001 to 2009, which were registered in King Abdulaziz
Medical City Trauma Registry. Trauma patterns were divided into two groups according
to the date of occurrence: victims in Ramadan versus victims in non-Ramadan. They
compared trauma in the pediatric age group in Ramadan with non-Ramadan months interms of frequency, patterns, and severity. The results showed that there were no
significant differences between trauma cases related to Motor Vehicle crashes in
Ramadan and non-Ramadan months, except for the higher percentage of vascular andneurological injuries in Ramadan.
Another study conducted in Karachi, which analyzed frequency of injuries in
Ramadan in 2009 and 2010, found that traffic behavior changed in the approach to Iftar(the time of breakfast) and speeding was observed, increasing the chances and severity ofcrashes (7).
Another study conducted by Yildirim et al. (8) used observational data to investigate
the risky driving behavior during Ramadan. The observational survey was conducted in
any three days during and after Ramadan in different times of the day (i.e. morning,
afternoon and evening) for driver violations (i.e., speeding, mild aggressive driving, andnot using a seat belt). The results demonstrated that more frequent aggressive driving,less seat belt use and less speeding were observed during Ramadan than before it. These
results were discussed in terms of moral, spiritual and self-regulatory explanations, aswell as religion`s distal influence on traffic behavior.
Another study conducted on 2007 by Tolon et al. (9) examining traffic accidents in
Turkey between 1984 and 2004 found that the number of accidents was not higher in
Ramadan compared to other months. Muhammad et al. (10) observed that the rate of roadtraffic accidents was lower during the month of Ramadan than other months in Jordan.
They believed that delaying the daily time of work and school beside the religious andspiritual atmosphere that embraces people during the holy month of Ramadan is the main
reasons of these results.
Variety of factors including alteration in traffic pattern or observation of traffic rules in
Ramadan may influence the frequency of car accidents. Rezaei N. et al. (11) conductedstudy to compare car accidents in Ramadan with other months during a 4-year period(1997-2000). They extracted frequency of car accidents from related files of Police
Office in Tehran and stratified according to the months. Then frequency of car accidents
was estimated in Ramadan and compare with other months. Their study concluded thatcar accidents in Ramadan did not significantly differ from other months. They also foundthat changes in the traffic pattern and people’s behavior to observe the regulations and therights of others are among the factors which increase or decrease accidents during
Ramadan compared to the other months.
Rachida et al. (12) found that diurnal fasting induces an increase in subjective andobjective daytime sleepiness associated with changes in diurnal rectal temperature. Also,
Kadri et al. (13) noted that significantly increased irritability during the month of499

Kishta M., Shawky M., Al-Harthei H.

Ramadan; this is noticed more among smokers and especially related to the decrease in
the sleeping hours.
DATA COLLECTION AND METHODOLOGY
As mentioned before, the month of Ramadan doesn’t start at the same date every year due
to the differences between the lunar year and solar year. Ramadan starts and ends at thesighting of the new moon, so sometimes its exact start and end date are a little
unpredictable. Also, the start and end dates of the month of Ramadan may differ fromcountry to another at the same year around one-day shift. The start and end dates of themonth of Ramadan during study period in UAE are shown in Table 2.
TABLE 2: Dates of Ramadan months during the last six years in UAE
Year

2010
2011
2012
2013
2014
2015

Start Day of Ramadanth

11 August
1st August
20th July
10th July
29th June
18th June

End Day of Ramadan

9th September
29th August
18th August
7th August
28th July
17th July

The employed data in this study was extracted from the traffic crashes database of Abu
Dhabi Traffic Police for six years from 2010 to 2015. Severe crash (i.e. any crash
involving at least one injury) data are used in this analysis due to the limitation of theavailable property damage only crash data. The database includes different sets of datagroups; basic crash information, at-fault drivers and vehicle’s characteristics, casualties’
information, environmental and surrounds condition, traffic violations, etc. Full data of
about 12,611 crashes has been extracted and utilized in this study. It is worth mentioningthat the driver’s community in AD consists of more than one hundred different
nationalities. Male drivers represent 85% of total number of licensed drivers and 92% has
age less than 45 years.
To achieve the objectives of this study, detailed descriptive statistical analysis will befirstly provided. After that an investigation of the contributing factor that affects
Ramadan related crashes (i.e. crashes occurred during Ramadan) will be conduct byapplying logistic regression modeling approach.
STATISTICAL DESCRIPTIVE ANALYSIS
Comparisons between the month of Ramadan and the rest of months of the year was
conducted in terms of the frequency of traffic crashes, crash severity, weekdays, daytime,crash types, crash causes and traffic violations as follows:
Frequency of Crashes Cross Years
Figure (1-a) presents the number of severe crashes that occurred during Ramadan and theaverage monthly of rest months. In general, a significant decrease (about 29.2%) in thenumber of severe crashes was occurred during the month of Ramadan in the last six
years. In addition, a decrease in the average monthly number of crashes for the same
period, where the number of crashes decreased in the month of Ramadan, during the500

Kishta M., Shawky M., Al-Harthei H.

study period by 38.6%, while the monthly average of crashes declined across the emirateby 30%.
The crashes fatalities in Ramadan decreased during the study period by 22.7%, while
the monthly average of the fatality incidents at the emirate level significantly decreased
by 37% as shown in Figure (1-b) which presents the crashes rates per 10,000 vehicles.
These two figures indicate that serious traffic crashes during Ramadan are around theaverage value of the rest of months. Furthermore, Figure 1 shows a gradually
improvement in number and rate of traffic crashes during the last six years in AD. The ttest analysis proved that no significant difference for serious accident number between
Ramadan and other months of the year at significant level of 5%.

a) Crashes Frequencyb) Crashes rate per 10,000 vehicles

FIGURE 1: Traffic crashes during Ramadan and the rest months

Crashes Frequency Cross Weekdays
The analysis of traffic crashes number across the days of the week showed that one of
the weekend days (Friday and Saturday in UAE), which is Saturday, have the highest
number of accidents and Thursdays (The last day of Weekdays in UAE) also have thehighest number of crashes at each year individually. Also, during Ramadan the highest
number of traffic crashes occurred on same days mentioned above during the last six
years. The lowest number of crashes occurred at the weekdays like the rest months of theyear. Figure 2 shows the percentage distribution of traffic accident across the days of theweek during Ramadan and other the months over the last five years. The aggregated dataof the six years showed that Saturday and Thursday gained the highest crashes number
during the month of Ramadan.
Crashes Frequency Cross Daytime
Figure 3 shows the distribution of traffic crashes during Ramadan and non-Ramadan
across the hours of the day. It shows a significant difference between Ramadan and therest months of the year. The morning peak hour of accidents shifted from 7:00 to 8:00am
and a clear peak hour at noon 12:00 has been occurred. These changes can be explained
due to change of working hours during Ramadan. In addition, other peak hours ofaccidents appeared during Ramadan; at 16:00 pm (before the breakfast time), during theperiod after the Tarawih prayers, which extends from 20:00 pm until 12:00 at midnight,
and at 2:00am (the time before starting fast, Suhoor). This clearly proves how the501

Kishta M., Shawky M., Al-Harthei H.

changes in the routine of the daily life in Ramadan affect the traffic crashes fluctuation
over the hours of the day. The highest number of incidents occurred on Ramadan was
during the time from 12:00 until 13:00 in the afternoon followed by a time of 02:00 in themorning until 03:00 in the morning.

FIGURE 2: Percentage distribution of traffic crashes across the weekdays

FIGURE 3: Percentage distributions of traffic crashes across hours of the day

Severity of Crashes
Figure 4 shows the distribution for number of traffic crashes fatalities during Ramadan
and non-Ramadan across the study period. It shows a non-significant difference between
Ramadan and the rest months of the year except the years 2011 and 2013. In generally,
the number of crash’s fatality in the month of Ramadan during the study period decreased
by 32%, and the average monthly crash’s fatality decreased in the Emirate by the samerate. In addition, Figure 5 shows the distribution for Pedestrian Crash’s Fatalities &Serious Injuries during Ramadan and non-Ramadan across the study period. It shows that
serious injuries and fatalities during the month of Ramadan due to pedestrian crashes areless than the monthly average during the years from 2010 to 2012, while those injuries
and fatalities increased than monthly average during the years 2013 to 2015. Serious
injuries and fatalities increased during the month of Ramadan as a result of pedestriancrashes increased than the monthly average during the year 2015 by 28.6%.

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Kishta M., Shawky M., Al-Harthei H.

FIGURE 5: Pedestrian Crash’s Fatalities &Serious Injuries

FIGURE 4: Number of Fatalities

Crash Types and Causes
Table 3 shows the percentage of the highest five types of traffic crashes in Abu Dhabi
Emirate during the month of Ramadan and the other months of the year. It shows nonsignificant differences in the percentage share values of the crash types over the six years
that occurred during Ramadan and during other months for all crash types except a slightincrement in turn-over accidents during Ramadan.
TABLE 3: Crash Types Distribution
Year

Turn-overPedestrian

Side collision

No.

No.

No.

%

%

Rear end
Collision
No.
%

Perpendicular
Collision
No.
%

N

%

160

155

16%

171

17%

1835 16% 1,728

15%2253 19%%

Ramadan 185 19% 182 18% 141 14%
The rest
1896 16% 2,282 20% 1,622 14%
months16%

OthersTable 4 shows the percentage of the highest five causes of traffic crashes in Abu Dhabi
Emirate during Ramadan and the rest of months of the year. In general, non-significant
differences exist between Ramadan and other months in terms of the causes of trafficcrashes except a slight increment for those due to carelessness and sudden lane changing.
TABLE 4: Crash Causes Distribution
Year

Ramadan
The restmonthsNo.

%

Sudden lanechange
No.
%

120

12%

199

20%

116

12%

98

10%

101

10%

372

37%

1048

9%

2024

17%

1579

14%

1237

11%

1019

9%

4709

41%

Carelessness

Overspeeding
No.
%

No.

%

Red light
Crossing
No.
%

No.

%

TailgatingothersFigure 6 shows the distribution of sleeping & fatigue crashes during Ramadan and nonRamadan across the study period. It shows a significant difference between Ramadan andthe rest months of the year except the years 2011 and 2015.

503

Kishta M., Shawky M., Al-Harthei H.

FIGURE 6: Number of crashes due to Sleeping & Fatigue of drivers

Traffic Rule Violations Records
Number of traffic violations can be used as an indicator of drivers’ behavior changes. The
database includes two types of violation tickets; in presence (by face to face tickets) andin absent (by automated enforcement devices). Table 5 shows that the total number oftraffic violations increased in the month of Ramadan during the years 2010 to 2015 by
about 109%. The total number of in presence traffic violations increased in the month of
Ramadan during the years 2010 to 2013 by about 67%, and then decreased during theyears 2013 to 2015 by about 41%. It was observed that the total number of absent traffic
violations during the month of Ramadan increased than the monthly average during theyear 2015 by 42%.
TABLE 5: Traffic Rule Violations Records In Ramadan
Violation
Type
Presence
AbsentTotal
Changes %2010
33,572
137,436
171,008-24.6%

2011
37,564
251,233
288,797
68.9%

Years
2012
2013
36,58756,060259,342
259,139
295,929
315,199
2.5%
6.5%

2014
24,799170,144
194,943-38.2%

2015
32,921
325,080
358,001
83.6%

Over-Speeding traffic violations represented about 84% of the total number of traffic
violations during the month of Ramadan over study period, while it represented about
82% of the total number of traffic violations during other months.
Figure 7 shows the distribution of Over-Speeding traffic violations during Ramadan andnon-Ramadan across the study period. It shows reduction between Ramadan and the rest
months of the year especially a significant reduction on the last two years.

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Kishta M., Shawky M., Al-Harthei H.

FIGURE 7: Main Traffic Violations, Abu Dhabi (2010-2015)

Figure 8 shows a significant increasing for red light violations during Ramadan. Other
violation types showed a significant reduction in driving recklessly violations, drinking
alcohol violation during Ramadan, despite its limited use in AD. Also, a reduction in seatbelt, tailgating, and using mobile during driving violations was observed during
Ramadan. These results cannot be explained based on an improvement in driver’s
behavior during Ramadan that related to such violations because it also depends on theintensity of Abu Dhabi Police enforcement campaigns during the month of Ramadan.

FIGURE 8: Main Traffic Violations, Abu Dhabi (2010-2015)

LOGISTIC REGRESSION MODEL
In order to define the factors affecting the occurrence of crashes during Ramadan
combined to other months, logistic regression analysis applied. Binary logistic model is agood approach to deal with binary outcomes (1= Ramadan related crashes, 0= Crashes onother days of the year). Also, as one of the aims of the study was to develop models to505

Kishta M., Shawky M., Al-Harthei H.

predict the Ramadan related crashes, logistic regression was identified as the mostsuitable approach to identify the important factors.
In case of binary logistic regression model, the response variable, y takes the form ofeither of the two binary values (0 or 1). For k explanatory variables and i=1, 2, 3, …, n
individuals, the model takes the form as follows. . . . . . . . . . . . . . . . . . . . . . . . . . . . . (1)= Prob. ( =) is the response probability to be modeled, andordered level of y,= Intercept parameter,= Vector of slope parameters,= Vector of explanatory variables.

is the first

The odds ratio for dichotomous explanatory variable, x, which takes value 1 or 0 (with 1
meaning that the event will certainly occur and 0 meaning that the event will definitely
not occur) can be represented as the ratio of the expected number of times that an event
will occur (x = 1) to the expected number of times it will not occur (x = 0). This can beillustrated by the following formula:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2)Where,OR = Odd Ratio= Probability that the event will occur when x=1= Probability that the event will occur when x=0
The model was estimated by using SPSS software package. The total number of trafficcrashes involved in the model estimation is about 12,611 crashes.
Explanatory Variables
Many variables were tested includes vehicle, at-fault driver, roadway, and environment
characteristics. At that stage it considered the fact that the quality of the modeling could
be expected to increase to a certain level once the number of variables increases.
Secondly, selection of the variables was carried out depending on the assumption that a
particular variable would affect the Ramadan’s crashes. The descriptions of 17
explanatory variables that are considered for the modeling are provided along with theirstatistics in Table 5. All the explanatory variables are binary. Binary variables take theform of either 0 or 1; for example, if a crash occurs on WEEKEND, the variable
WEEKEND has been assigned “1” as its value; otherwise “0” is assigned to this variable.
One binary logistic regression model was developed by considering crash been during
Ramadan as the response variable and the description of the model which is binary innature (RAMADAN_RELATED = 1 if the occurred on Ramadan, =0 otherwise).

506

Kishta M., Shawky M., Al-Harthei H.

TABLE 5: Description of explanatory variables considered for severity modeling
Variable
ROAD_SPEED
ROAD_TYPEVEHICLE_TYPE
DAYLIGHTWEEKEND
GENDER_AT_FAULT_DRIVER
DRIVING_EXPERIENCE
LICST
OLD_DRIVER
YOUNG_DRIVER
RED_LIGHT_CROSSINGALCOHOL
SPEEDINGSLEEPING_FATIGUECOLLISIONSRUN_OFF_ROAD
PEDESTRIAN_CRASHES

Description= 1 if crash occurred on road speed ≥100 km/h, =0
otherwise= 1 if crash occurred on Urban road, =0 Rural road
= 1 if the vehicle involved in the crash was light vehicle,= 0 otherwise= 1 if the crash occurred during daylight, =0 after sun set=1If the crashes occur during weekend (Friday &Saturday), = 0 otherwise= 1 if at-fault driver is male, = 0 otherwise= 1 if at-fault driver has experience between (1-5) years ,= 0 otherwise= 1 If at-fault driver got his license on Abu Dhabi,= 0 otherwise= 1 if the driver is over 60 years, = 0 otherwise= 1 if at-fault driver is between 18 and 24 years,= 0 otherwise= 1 if the crash occurred due to Red Light Crossing,= 0 otherwise= 1 if at-fault driver is under influence, = 0 otherwise= 1 if crash occurred due to driving too fast or exceed
posted speed limit, = 0 otherwise= 1 if crash occurred because of at-fault driver sleeping or
fatigue, = 0 otherwise= 1 if crash is any type of two vehicle collisions,= 0 otherwise=1 if crash type is run off road, = 0 otherwise=1 if crash is pedestrian related, = 0 otherwise

MODEL RESULTS AND DISCUSSIONS
Table (6) shows the results of the estimated parameters of the logistic regression model.
The results indicate that five variables are significantly changed during Ramadan
compared to other months of the year at significant of 95%. These variables are day time,
week days, crashes caused by red light crossing and alcohol usage and feeling sleep andfatigue.
The significance of the day time and weekday variable can be justified due to thechange in the daytime routine of people and working time. Among these variables,
crashes due to sleeping and fatigue have higher probability to be occurred during
Ramadan by 2.4 times more than other months. This can be explained due to fasting andlimit hours of sleeping during the month or Ramadan. In addition, crashes due to alcohol
usage decreased by 4.23 times compared to other months. These findings reflect thereligious environments of Ramadan (note: that alcohol usage is total forbidden in Islam)on the people behavior not only the Muslims but also non-Muslims in AD. The
significance of the red light crossing crashes implies that drivers during Ramadan may

507

Kishta M., Shawky M., Al-Harthei H.

not in as high concentration as during other months. The probability to be involved in a
red light crossing crash in Ramadan is higher by about 1.284 times than other months.
The results also show that four variables are significant affect crashes in Ramadan at asignificant level of 90%. These variables are road type, vehicle type, gender of at-fault
drivers and young drivers. It indicates that the probability of crashes on rural road ishigher during Ramadan and also increases with male drivers and private small cars.
However young drivers seem more committed to traffic rules and safe driving Ramadan
compared to other months.
TABLE 6: Results of the estimated model
Variable

B

S.E.

Wald

Sig.

Odds Ratios

ROAD_SPEED

.101

.079

1.656

.198

1.107

ROAD_TYPE

-.149

.084

3.164

.075**.861

VEHICLE_TYPE

.139

.077

3.244

.072**

1.149

DAYLIGHT

-.283

.067

17.561

.000*

.754

WEEKEND

-.187

.082

5.242

.022*

.830

GENDER_AT_FAULT_DRIVER

.188

.111

2.851

.091**

1.207

DRIVING_EXPERIENCE

-.012

.073

.026

.873

.988

LICST

-.028

.073

.145

.703

.973

OLD_DRIVER

-.275

.249

1.224

.269

.759

YOUNG_DRIVER

-.144

.087

2.746

.097**.866

RED_LIGHT_CROSSING

.250

.122

4.208

.040*

1.284

ALCOHOL-1.442.324

19.764

.000*

.236

SPEEDING

-.075

.102

.548

.459

.927

SLEEPING_FATIGUE

.891

.224

15.885

.000*

2.439

COLLISIONS

-.055

.133

.170

.680

.947

RUN_OFF_ROAD

.143

.126

1.283

.257

1.154

PEDESTRIAN_CRASHES

-.042

.159

.071

.790

.958

Constant-2.439.190

165.249

.000

.087

* Significant at α = 0.95 level** Significant at α = 0.90 level

CONCLUSION
The main objective of this paper is to investigate the traffic crash patterns during the holymonth of Ramadan in Abu Dhabi Emirate, and investigate the factors that affect thetraffic crashes type and severity during Ramadan. Traffic crashes and violations datafrom AD Traffic Police database during six years (2010-2015) were employed in thisstudy. The main findings of the data analysis and modelling results can be summarized asfollows:- Severe crashes during Ramadan have been decreased by 395 from 2010 to 2015.
However, the total crashes have been reduced by 29.6%.

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Kishta M., Shawky M., Al-Harthei H.

-

Total number of traffic rules violations were reduced during Ramadan compared toother months.
- There are significant changes in traffic crashes patterns across hours of the day been
proved, and new peak hours of traffic crashes have been raised during Ramadan.
- The crashes caused by sleeping and fatigue of drivers have higher probability to beoccurred during Ramadan by 2.4 times more than other months of the year.
- Crashes caused due to alcohol usage decreased by 4.23 times compared to othermonths- The probability of crashes on rural road is higher during Ramadan and also increases
with male drivers and private small cars.
- Young drivers seem more committed to traffic rules and do more safe driving during
Ramadan compared to other months.
These findings reflected the impacts of fasting, changing in daily activities of the drivers
and the religious environments of the holy month of Ramadan on the road safety in AD.
ACKNOWLEDGEMENTS
The support of the Traffic and Patrols Directorate of Abu Dhabi Police is gratefully
acknowledged. The authors also acknowledge the support from CRISP Consultancy.
REFERENCES(1) Zümrüt Yıldırım-Yenier, Timo Lajunen, Türker Özkan, (2015), “Driving in thefasting month of Ramadan: An observationalstudy on speeding, horn honking, and
using
seat
belts”,
Transportation
ResearchPart
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http://dx.doi.org/10.1016/j.trf.2015.05.001(2) Hossein Ebrahimi, Mahdi Sadeghi, Ali Akbar Azami, Milad Bazghaleh, (2015),“Epidemiological Study of Fatal and Nonfatal Road Traffic Accidents and Their
Outcomes on Children and Adolescents(3) M.N. Tahir, G. Macassa, A.H. Akbar, R. Naseer, A. Zia and S. Khan, (2013), “Roadtraffic crashes in Ramadan: an observational study”, Eastern Mediterranean Health
Journal (EMHJ), Vol. 19 Supplement 3 2013.
(4) Shawky M. , Garib A. , Al-Harthei H., (2013), “Traffic Accident Patterns during theHoly Month of Ramadan: A Case Study from Abu Dhabi, UAE”, 17th IRF World
Meeting Exhibition Technical & Scientific Program (9 – 13 Nov. 2013).
(5) Al-Houqani, M., Eid, H. O., & Abu-Zidan, F. M. (2013). Sleep-related collisions in
United Arab Emirates. Accident Analysis and Prevention, 50, 1052–1055.
(6) Monirah Alnassera, Nahar AlSelaima, Shahla Aldhukairb, Khalid Elbedaha, Hani
Tamim, Saleh Alazzama, Tariq AlTokhaisa, Saleem Alenazia and Mohammed
Zamakhshary, (2012), “Patterns of pediatric trauma in Ramadan: an observational
study”, Annals of Pediatric Surgery 2012, Vol 8 No 1.
(7) Ramadan advisory. Karachi, Jinnah Postgraduate Medical Centre, Road Traffic Injury
Research & Prevention Centre, 2010.
(8) Yildirim, Z. & Lajunen, T., (2009), “Risky Driving during Ramadan: An
Observational Study” 11th European Congress of Psychology.

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(9) Tolon, M., & Chernoff, H. (2007). The effect of fasting during Ramadan on traffic
accidents in Turkey. Chance, 20, 10–18.
(10) Muhammad R. Khammash, MD, FRCSI, Tamer F. Al-Shouha, MD. (2006), “DoRoad Traffic Accidents Increase during the Fasting Month of Ramadan”
Neurosciences 2006; Vol. 11 (1) pp. 21-23.
(11) Rezaei Ghaleh N, Sadeghipur H, Azizi F, (2004), “Comparing Car Accidents in
Tehran During Ramadan With Other Months”, Research in Medicine, Vol. (28), No.
(3) pp. 219-222. Available in http://pejouhesh.sbmu.ac.ir/browse.php?a_code=A-101-114&slc_lang=en&sid=1(12) Rachida Roky, Florian C., Majda T., Benchkoun, Brahim B., and Farid H., (2003)“Daytime Sleeping during Ramadan Intermittent Fasting: Polyomnographic andQuantitative Waking EEG study” J. Sleep Research 20003 , 12 pp.95-101.
(13) Kadri N, Tilan A., El-Batal M., Taltit Y., Tahiri S., Moussaouni D. (2000)“Irritability during the Month of Ramadan” psychosom Med, 62 pp. 280-285.

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YON MARCUERQUIAGA & AHMED AL KUBAISIABSTRACT
•
•
•

•
•
•
•

Title: Development and Deployment of Asset Management Systems for Ashghal(Public Works Authority of Qatar)
Theme: Asset Management
Authors:
Yon Marcuerquiaga Ruiz de Alda; Pavement Management Business Line Manager(Applus+ Velosi), Eng. Ahmed Rashid M.Al Kubaisi: Head of Roads Maintenance
Division. (Ashghal),Adress:Road Operation and Maintenance Asset Management Affairs, Ashghal. P.O. Box:
22188, Doha-Qatar.
Applus+ Velosi Building No 121340, First Floor, New Salata, C Ring Road, P.O.Box
3408, Doha (Qatar).
E-mail: yon.marcuerquiaga@applus.com; akubaisi@ashghal.gov.qa;
Telephone: Yon Marcuerquiaga +97433848821, Ahmed Rashid M. Al Kubaisi +974
44527373,

Development and Deployment of Asset Management Systems for Ashghal
Knowing what you have, where you have it and what shape it is in are some of the fundamental
requirements to effectively managing an established and quickly growing infrastructure.
In addition, Qatar’s 18,000 lane kilometers of assets is undergoing major upgrades and additions
as part of its 2030 Vision. This paper will discuss the scope, strategies and methods currently inplace and already deployed by Applus+ for Ashghal (Public Works Authority) with the aim ofknowing when, where and what maintenance strategies should be undertaken to achieve thedesired performance level within the given budget.
Several key projects already finished will be discussed. The projects relate to the following,• Determining a comprehensive database of what exists. Development and assessment ofhigh advanced asset inventory using lines, polilines and poligons through a 3D cloud
point of the infrastructures.
• Determine the current condition by undertaking a comprehensive pavement condition
survey that includes, surface condition (roughness, rutting, distress, friction) andstructural assessment (FWD, GPR)
• 3D right-of-way video-log including 360º images.
• High accuracy mapping• Deployment and installation of a web based asset viewer.
• Development and installation of a first class COTS PMS that provides different userlevels for decision makers, engineering analysis, technical reporting, maintenancemanagers and more.
The paper will outline the various objectives, methodologies and tools that Applus+ have used
to carry out the task at hand. Details of the latest 3D laser technology for distress analysis andasset inventory as well as the other technology that had been used will be discussed.

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INTRODUCTION
In order to build, conserve and exploit a road network, it is required to know what you have andwhat condition it is in. This is accomplished by doing a complete asset inventory and pavement
condition survey. A powerful asset and pavement management system to handle and analyze thehuge quantities of data and ability to calculate the yearly budget needed to maintain the road
network at the desirable level of quality and service is required.
In simple terms there are two categories of assets, pavement and non-pavement assets.
Pavement assets typically include the pavement structure and bridges. Non-pavement assets
encompass all other street furniture such as signs, hydrants, barriers and many more. The Doha
Survey objective is to identify and collect information on all of Ashghal’s assets.
ASSET INVENTORY: NON-PAVEMENT ASSETS
Data Collection
The first phase of completing the assets inventory is
to run a survey vehicle that is able to capture theright-of-way image data. The image data consists of
360° video images and 3D LIDAR data.
The system used is a Trimble MX-3 with six
cameras and 4 scanning lasers. Each camera has a 2
MP resolution (1600x1200). With the six cameras thesystem obtains the pictures used for the assets
extraction. Pictures are synchronized with a highaccuracy positioning system and the LIDAR point
cloud. The positioning system is an Applanix POS LV 420. It is an inertial aided GPS georeferencing system. When the satellite signal is not available the equipment uses the inertial
component to bridge the positioning gap. Even with one minute of satellite signal loss, forexample in urban canyon areas, the system provides an accuracy of better than 10 cm – X, Y.
The system can operate at high speeds up to 100 km/h.
Asset Extraction
Using the geo-referenced images and point clouds it is possible to accurately locate (3Dposition) Ashghal’s assets to perform the comprehensive asset inventory. The inventory is morethan just locating the asset; it includes recording specific attributes (as its shape throughpolilines and poligons drawings) of the asset and its condition. In most cases the condition will
be determined from a more detailed manual inspection of asset. Where possible, from the image
data, certain high level conditions will be found. The long term goal is collect all necessary
information for the proper maintenance and operation of each asset.
Specific measurement tasks are quickly and economically solved with the help of the
Trident and in house s/w. The Trident s/w performs automated detection and registration onsome assets (signs, lane marking, pole detection, edge detection). Typical production rates arearound 150 features per hour in when working in automated mode. Assets which are notpossible to be collected automatically would be detected manually. It allows extraction thecoordinates of the assets by de user. In manual mode, typical rates are around 30 features per
hour.
Each asset is geo-reference with an accuracy of better than 0.3 m. Approximately 45
different asset types are being collected. Many asset types have attributes that define several
specific assets. For example, the asset type STRUCTURES has an attribute that defines theasset as an underpass, overpass or tunnel. The asset is further defined by additional attributes

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Yon Marcuerquiaga
Ahmed Kubaisithat define the structures use as auto, rail or pedestrian. By setting up this type of relational
structure it simplifies the extraction process and data organization, however, it masks the factthat over 100 different assets are being inventoried.
All data can be easily integrated into an ESRI shape file with comprehensive metadata
for integration into GIS database.
Ashghal Assets
Basically, any asset owned, operated or maintained by Ashghal is included in the list of assets to
be inventoried. Other assets are included in the survey because the information obtained isuseful information for Ashghal with regard to pavement or information management. For
example the location of bus stops and petrol stations is useful information with regard tounderstanding road conditions near these locations.
The amount of detail collected about each asset is determined by the need to know what
information is needed to manage the asset in terms of maintaining its condition. This would
include a list of parts and components contained within the asset in order to know what parts areneeded if someone had to go out and repair it. The inventory data obtained from the Doha
Survey is focused on the identification of the assets, the location and other attributes that can beobtained from the image data. The detailed component survey is carried out via manual handson inspections using portable collection tools.
ASSET INVENTORY: PAVEMENT
Knowing the condition of the road is mandatory in order to determine proper maintenanceactions and strategies. The current condition is determined by undertaking a comprehensive
pavement condition survey using the latest high-tech devices for measuring surface condition(roughness, rutting, distress, friction) and a structural assessment (FWD, GPR).
Surface Condition
Pavement roughness is measured using Greenwood’s LaserProf, a laser based profiler
that can survey at traffic speeds up to 120 km/h. Profile is collected continuously with IRI(International Roughness Index) and PSI (Present Serviceability Index) provided for each 10 m
interval.
Surface friction is measured continuously using the GripTester. A GN (Grip Number) is
reported every 10 m. The GripTester can operate at speeds of 5-130 km/h, however, twodifferent speeds are used for testing in Qatar, 50 km/h for the urban roads and 80 km/h for thehigh speed roads. A correlation equation is used to adjust the GN to an 80 km/h reference forthe network.
Rutting is obtained from the RCMS (Road Crack Measurement System)
instrumentation. Left and right ruts values as well as the average rut are reported on a 10 m
interval. The rutting measurements are accurate to 1 mm.
Surface Distress

Road surface distresses are determined using a Road Crack
Measurement System (RCMS), a 3D laser profiling systemfrom Pavemetrics. Data collection speeds up to 100 km/h arepossible. The system will operate in daylight or darkness during
the night time.
The RCMS captures 3D images of the road surface.
JPEG images of range and intensity data provide 100%

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coverage of the road. Each image represents a 10 m x 4 m wide section of the road with
2000 profiles.
The intensity images are used to detect pavement markings and the ranges images areused to detect the surface distresses (and rutting).
An automated detection application is used to detected longitudinal, transverse andalligator cracks, rutting, raveling, micro-texture, potholes and ruts. A 100% manual review of
the automated detection takes place to visually detect patching, bleeding, depressions and blockcracking. 1 mm cracks can be detected with this system.
In addition to distress type, a severity level for each is determined based on various
factors such as crack width, density and affected area.
Skid Resistance
Friction measurements are used to identify the skid
resistance of the road surface – a measure of theability of the road surface to facilitate safe braking
distances. It can also help identify loss of microtexture due to tire wear and destructive rubber
removal methods such as hydro-blasting. The loss ofmacro-texture can also be evaluated and tracked.
The GripTester is the device of choice for thisproject. It is a continuous fixed-slip device system andoperates within a speed range of 5 – to 130 km/h. The
most usual speed for highway testing is 50 km/h. In
the State of Qatar, friction is measured at two test
speeds; 80 km/h for high speed roads and 50 km/h forthe lower speed roads. Testing at 50 km/h on the highspeed roads is too dangerous and considered an unsafe
practice. A correlation equation to provide a GN (Grip
Number) to an 80 km/h reference speed is used. The
correlation was obtained from empirical data collected
at the start of the project.
Structural Capacity
The Falling Weight Deflectometer (FWD) is used to access the road bearing capacity. The FWD
is used to simulate the dynamic load of a truck. Each test consists of three test drops at different
loads – 40 kN, 60 kN and 80 kN. The collection interval between drops varies by roadclassification. On primary and secondary roads measurements are taken at 100 m intervals in theright-most (slow) lane. On selected local roads the interval is 500 m. The following parameters
can be determined from the collected FWD data; dynamic E moduli, residual life, thecritical layers and reinforcement needs.
Because FWD is stop and go testing significant safety measures are taken when
performing the tests. The use of TMAs (truck and trailer mounted attenuators), mobile variable
message boards and safety cars are used to warn and protest the traveling public and the testingcrews.
FWD Data Analysis
In order to perform a proper analysis it is necessary to have a correct definition of the structure(materials, thicknesses of the different layers of the pavement), traffic information, pavement
and air surface temperature etc. Dynatest’s ELMOD software is used to perform the analysis.

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The back-calculation model considers the pavement as a multilayer system in which thematerial is elastic, linear and isotropic. In case of thin granular layers or similar modules, it ismodeled in two layers together to ensure proper processing of the model. In the back-calculation
we estimate a bowl of initial deflection from the input data for the different layers. This bowl iscompared with the results from the measurements obtained in the trial. The ELMOD program
calculates the values of the critical stress, strains and deflections for each layer and, knowing thefatigue laws, we can calculate the ESAL’s that produce the structural failure of the road.
Comparing the ESAL’s with the traffic data of each road we will be able to know the remaining
service life. In other words, we will now how many years will it take to the road to have astructural collapse in the case where we don’t do anything to maintain the road.
Ground Penetrating Radar (GPR)
The GPR system for the project uses two antennas allowing for the pavement and subgrade to
be measured simultaneously. This multi-channel approacheliminates any necessary compromises of utilizing only one
frequency, giving the highest possible resolution and information
regarding each layer. The shielded antennas are mounted “inline” on the MALÅ RoadCart and attached to the bumper of avehicle via an ordinary tow hitch. The 1.6 GHz and 500 MHz
ground-coupled antennas are positioned 1 cm and 4 cm above thepavement surface respectively. An encoder on the rear left wheel
provides the triggering and distance measurements. Data can becollected at posted speed limits as high as 100 km/h with a dataspacing interval of 20 cm.
The high frequency antenna allows us to estimate the layer thickness of the upper partof the road structure with 1 cm of resolution. The low frequency antenna allows us to know the
thickness of the bottom part of the road structure. With the low frequency antenna we can obtain
3 cm of accuracy.
Layer thickness data from the GPR system is also used as input in the FWD data
analysis. Additionally, because of the 2 m penetration of the radar signal there is potential todetermine the possible presence underground utilities, however, this is more likely to happen
when testing the 700 km of footpaths at slow speeds where the data interval is much less than
20 cm. GPR is also used to determine the presence of moisture and depth of the water table - if
it is within 2 m of the surface.
There is a significant challenge to obtaining the desired results. The ground structurecomposition provides an environment where the material is very conductive for the radar signal
effectively absorbing it and minimizing any echo to be captured. We suspect that this is due tothe high salt residue absorbed into the soil from the high water table. Special processing
techniques are utilized to determine the sub-surface layer thickness.
DATA COLLECTION CHALLENGES
The environment of Qatar provides for some interesting challenges for the project.
• There are many significant road work projects in progress that make it a challenge tonavigate the test equipment through the streets.
• The design and layout of the road network with regard to slip roads and service roads add
significant driving overhead. In is not uncommon to have to drive 350+ km to obtain 20 km
of test data.

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•
•
•
•

Without prior knowledge and information of the road network, planning the data collection
routes for 10 pieces of test equipment is extremely difficult. Using Google maps to findroads and determine if they are roads and if they are roads to be inventoried is a challenge.
Knowing what official permissions are required to collect is another challenge. You obtainwhat you think you need and wait to be stopped in order to find out what else is required.
The extreme heat and testing conditions play havoc with the equipment. Data collection
occurs in the evening in order to have the equipment operational, however, the LIDAR must
work during the day because the system also included video cameras.
New safety standards for work projects were being introduced in Qatar at the start of the
project. These safety standards are a required step forward in the evolution of safe work
programs, however, the equipment required (TMAs and VMS boards) is not readily
available.

ASSET MANAGEMENT SYSTEM
Without the proper tools the data on its own is not of much use. A comprehensive package topresent, manage and analyse the data is needed. The basic premise of infrastructure asset
management is to intervene at strategic points in an asset’s normal life cycle in order to extend
the expected service life while maintain its performance. In order to ensure that premise, an
Asset Management System allows Ashghal to know when, where and what maintenancestrategies should be undertaken to achieve the desired performance level within the given
budget. DTIMS is the package being used on this project.
In addition to data collected within this project additional data such as traffic counts,
accidents and other information can be put in to the system for use by the various modules of
DTIMS. Most any information that the agency deems applicable to pavement and asset
management can be added to the system as a source, it does not have to come from the survey
data collected in this project.
DTIMS is a PMS (Pavement Management System) that includes asset management andmap based data presentation capabilities. The features of the system are presented in thefollowing sections.
Cartography
The cartography is one of the main tools in DTIMS. It allows for cartographical surfing, using
the typical tools of a GIS (Geographical Information System). In each of the modules of the
management tool, users can make queries through the cartography interface.
Data Presentation
Any and all of the data is viewable in graphical or tabular form. ROW and pavement images arealso available for viewing. Navigation through the system can be done through any of the views– the user can click on a particular location on a map or a point on a graph. The system will thennavigate to that particular location for all data that is presented on the screen. Ease of use bydifferent levels of users is paramount to a successful application. DTIMS satisfies that criteria.

Configuration and Setup
In order for the PMS to function certain data specific to Ashghal must be entered into thesystem. Ashghal’s maintenance strategies and associated decision criteria have to been definedwithin the PMS model. Standard costs for repair and maintenance activities are also required.
This information is used to determine the specific maintenance strategy and its associated cost
for any given section of road. Any decisions determined and put forth by DTIMS are only as

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good as the underlying data provided to it. Costing information should be as accurate as
possible.
The large number of descriptive options within DTIMS enables users to view all theroad data in many different formats. One of the best features of the system is the configurationof different levels of users. Users groups can be defined and specific report and data
presentation formats can be preset to these groups. Restricting the capabilities of the specificgroup of users is desirable and achievable. In this manner you configure the system to allow
viewers of the data to access and view only certain data elements. These groups could be
divided into general users, safety engineers, maintenance engineers, administrators andmanagements. It is clear that each of the defined groups would have different needs and accessto different data and analysis functions.
As a web-based system tailoring the different reports and user groups is easily done. All
the data is hosted by a local server and access maintained by the designated administrator. As auser logs in over the internet or intranet their profile is used to provide the proper functionality.
In this manner even the casual user that may use the application infrequently does not have tore-learn or re-familiarize himself with it in order to effectively use it.
Configuration of the system and the custom reports for the various user groups issomething that is done during system installation after consultation with Ashghal. This allows
the system to present a list of available functions and reports to choose from instead of having tobuild it while online.
Pavement Management
The mathematical models that define the evolution of parameters of pavements will be set byanalyzing the information related to,• Analysis of the PMS proposed by the World Bank (HDM-4).
• Experiences of the installation of road management expert systems.
• Other calculation models properly contrasted.
Evolution models predict the growth and decrease of structural and functional parameters ofdifferent network roads. Apart from considering the models that establish this evolution when
maintenance work has not been carried out, they will also predict the evolution of theseparameters when maintenance work has been executed.
One of the most important decisions to be made by the user of the pavement
management system when posing a general problem is to define the desired condition level the
network should have. First it is necessary to specify if the whole network will maintain the samelevel or if it will be ranked by establishing different categories. The PMS enables the road
network administration to establish the categories and name them. Once the Network has been
divided, if applicable, the level of service for each category will have to be defined.
Whether the network is set to one category or multiple categories the first parameter tobe set is the limit value to be maintained by this category. The value represents the desired
trigger value for maintenance – a level at which maintenance activity is desirable.
The second limit value is the compulsory activity limit – the trigger value at which
maintenance activity must take place. In other words, the road is not allowed to fall below thiscondition level.
The analysis of the information to determine the recommended maintenance activities
includes all of the condition data, desired service and intervention levels, maintenance costs andstrategies and the annual budget. The result of the analysis is a recommendation of the work to
be performed within the budget and the cost for each work project. From the report it is possible
to see the cost of each project, total cost, what projects are defined as recommended and what

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projects are defined as mandatory. The PMS will also show predicted future activities andassociated costs based on historical and current condition data.
The PMS also provides the ability to perform a ‘what if’ analysis on the network or part
thereof. The technical manager has the ability to manually select when work will happen, moveprojects in time, change the budget as well as add or delete projects as he sees fit. The end result
would be a new analysis and report reflecting the changes made.
DTIMS provides a module that controls the daily work of the road maintenance team,trouble, revisions, working reports, pending and completed work, surveillance and weather
trouble reports and reminders of periodic operations. The software allows for the schedule ofwork in the form of a list or calendar.
CONCLUSIONS
Ashghal has a complete inventory of it road infrastructure and an objective assessment of its
pavement. In addition to new construction and realignment projects underway Ashghal will
have the required information to make informed decisions about the correct and economical
maintenance strategies to maintain their roads.
As new and refurbished roads are completed it is vitally important to obtain the same
information by performing a condition assessment as they come online. Without continuing the
program on an annual basis it will be impossible to effectively manage the road network withany degree of objectivity and confidence. Decisions made are only as good as the information
behind them.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Mobile Mapping Applications for Data Collection and Evaluation of the Rural
Road Assets

TRACK
AUTHOR(Capitalize Family Name)Dr.

PhisanPOSITIONORGANIZATIONCOUNTRY

Chulalongkorn University

Thailand

COUNTRY

Associate Professor

Santitamnont
CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATION

Dr. Chakree Bumrungwong-

ThailandDr. Preecha Soparat-

Dr. Kawin Saiprasertkit-

Thanachai Lorapibankul-

Nutvara Jantarathaneewat-

Theeraruk Maneenart-

Department of Rural Roads(DRR)
Department of Rural Roads(DRR)
Department of Rural Roads(DRR)
Department of Rural Roads(DRR)
Department of Rural Roads(DRR)
Chulalongkorn University

Sittinun Thongbai-

Chulalongkorn University

Thailand

E-MAIL(for correspondence)

ThailandThailandThailandThailandThailandss.kawin@gmail.com

KEYWORDS:
Department of rural road, Global Navigation Satellite System (GNSS), Inertial Measurement Unit (IMU), Mean Sea
Level, Panorama View Image

ABSTRACT:
Since the Department of Rural Road (DRR) has more than 47,100 km of road network, surveying the whole rural
network would take a lot of resource, equipment and labor work. Therefore, Mobile Mapping System (MMS) has beenused to achieve this goal. MMS has begun in 2014. Due to its initial stage, MMS can only operate on asphalt andconcrete pavements. The MMS has been utilized on over 2,500km of road, from six difference provinces; Sakaew,
Chachoengsao, Samutprakan, Nonthaburi, Nakhonnayok and Prachinburi. MMS records 16 frames per second, and is
attached on a normal four-wheel vehicle which operates less than 60 kilometers per hour.
The visual data, which has been collected by two Ladybug-3cameras installing on a top of a vehicle, was processedto produce 5,400-time-2,700-pixel image. Asset’s position was acquired from the Global Navigation Satellite System(GNSS) and Inertial Motion Unit (IMU) signal, hence enable dimension measurement feature. Furthermore, Mean Sea
Level (MSL) was obtained from existed reference mark, which has been established by National Vertical Reference
Network, or a new reference mark.
At the last step, MMS survey’s data would processed then stored on the Rural Road Management System (RM),
which allows users to access the database via the Web application. Furthermore, RM allows additional modification of
the data in digital form, which shows high-quality detailed visual data, and can be used for more liberate application.
519

Mobile Mapping Applications for Data Collection and
Evaluation of the Rural Road Assets
Dr. Phisan Santitamnont 1
Dr. Chakree Bumrungwong 2
Dr. Preecha Soparat 2
Dr. Kawin Saiprasertkit 2
Thanachai Lorapibankul 2
Nutvara Jantarathaneewat 2
Theeraruk Maneenart 1
Sittinun Thongbai 1
1Chulalongkorn University, THAILAND

2

Department of Rural Road, THAILAND

Email for correspondence, ss.kawin@gmail.com

1 RATIONALE
Conventional surveying method, which requires technician to work on the field, is impractical to apply to thewhole rural network since it would consume huge labor force and time. Therefore, mobile mapping technology is seenas the best way to achieve this goal. Mobile mapping system (MMS) is installed on a vehicle, which operates on
concrete or asphalt pavements. MMS comprised positioning tool and sensors, hence it can collect data rapidly.
In 2014, DRR had collected road asset data for 2,500 kilometer, from difference districts; NakornNayok,
Prachinburi, Sra-kaew, Cha-Seongsao, Nontaburi and Samutprakarn, using MMS.
The MMS system uses 360-omni-video-recording-camera system (Ladybug3) to collect data, which will laterbe processed for later object-position identification by trained spectators. Road-side assets store in RM divided in to 13
categories. A certain quantity and quality could be evaluated or measured on the 360-video. Furthermore, the coordinate
system was tied up to the national vertical reference system (Mean Sea Level: MSL). The mean sea level of roadsurface is useful for road safety management and natural disaster prevention, especially the flood mitigation.
2 SENSORS INSTALLED IN THE MOBILE MAPPING SYSTEM (MMS)
MMS data collection composed of vehicle, Ladybug3, Computer, GNSS and Inclinometer.
Vehicle: The vehicle is a compact passenger car. A rack is installed on the top of the vehicle for fixing a dual
antenna. Dual antenna is designed for azimuth determination which is more accurate than 0.01 degree (RMS).

Figure 1. MMS vehicle installed with sensors

520

LadyBug3: Two panoramic 360 video systems (Ladybug3) are installed on the roof. The first 360 video
camera records picture of all assets surrounding. The second 360 video camera records images of the road surface,which shows the texture of the road for later evaluation. Both 360 video camera have resolution up to 5,400 by 2,700
per frame with maximum frame rate of 16 fps.

Figure 2. The panoramic 360 video camera system
Computer: Computer is used for storing information and synchronizing all sensors. According to the DRR
standard, the storage needs to accommodate more than 2 Terabyte, which is sufficient for a day of MMS survey or 140
kilometer of survey.

Figure 3. Computer and storage inside MMS car
GNSS and Inclinometer: Both GNSS and IMU are used to record location. Global Positioning Navigation
System (GNSS) receives location data from satellites. IMU determines location through the calculation of measured
rotation and measured acceleration rate from six directions. GNSS and IMU are used together to increase the accuracy
and to eliminate bad signal problems in the urban area and dense-forest area.

Figure 4. GNSS/IMU on top roof of MMS car
Inclinometer: Inclinometer is installed with one of the 360 video camera to optimize vertical visual output, andto determine location of assets.
521

Figure 5. Inclinometer

3 SURVEYING METHODOLOGY AND RECORDING OF THE PANORAMIC IMAGERY OF ALL ASSETS ON
THE RURAL ROADSIDE
1) Once all the equipments are installed, MMS will calibrate itself with its surrounding, in order to determine
road assets location. The coordinate of a reference point will be manually measured. Utilizing both reference point
location and recorded pictures, location of roadside assets can be.

Figure 6. Image Processing within MMS2) The calibrated data, from comparison of measurement on panoramic camera fused with the measured
GNSS/IMU trajectory.

Figure 7. Special apparatus Helico for determination of positioning of the GNSS antenna
3) The optimal speed for panoramic video recording is 60 kilometer per hour. Light condition must be takencare since the system is image-based. Too dark or too bright image will prohibited fine detail of the assets and later
coordinate measurement.
4) During MMS survey, positions will be recorded and synchronized with the panoramic video. The postprocessing software will integrated both dataset.
5) GNSS base station must be established before the survey. The distance between MMS car and its basestation has to be kept within 50 kilometer. This system results in30-centimter horizontal accuracy and 1-meter verticalaccuracy.
6) The post-processing includes an image processing and post-processed GNSS Trajectory. The resulted video
could be used to identify road asset objects and to measure their coordinate based on 3-D stereo measurement principle522

Figure 8. Application for measurement of object coordinate
7) Within the period of DRR MMS pilot study, 2,500 kilometers of rural road network have been registered in
the system. The post-process data are prepared and put in to a web-based application named Rural Road Management
System (RM).
RM is a software system which combines road inventory and asset management system. RM is a web-based
application and allows users to easily access by the internet.

Figure 9. Web-based application RM
4 GNSS SURVEYING FOR HORIZONTAL POSITIONING AND VERTICAL POSITIONING (MEAN SEALLEVEL: MSL) OF THE ROAD SURFACE
This project measures horizontal position in form of MSL. The satellite surveying resulted from high-end
GNSS receiver, Novatel ProPak-6 with a geodetic-grade satellite GPS-702-GG antenna. When antenna must be put on asurvey mark, a survey bipod or tripod with 2-meter-fixed height would be used. This 2-meter fixed height antenna will
ensure the quality of MSL of the road surface.

Figure 10. Setup GNSS Base-Station
Referring to the local reference survey mark: MMS refers to a local survey benchmark, which provides
horizontal and vertical reference; Mean Sea Level (MSL). The nation reference survey mark has been established thenmaintained by the Royal Thai Survey Department (RTSD). Furthermore, DRR has developed their own survey
benchmarks for road construction and maintenance purposes.

523

Figure 11. Survey measurement on the DRR survey mark
MMS survey over a new establish survey mark: In case reference survey marks do not exist, new temporary
survey marks must be established. These new benchmark will be measured by Precise Point Positioning (PPP) method.
PPP is a GNSS survey method by receiving data over 24 hour and the data will be computed with precise orbit andclock modelled by an international GNSS service.

Figure 12. measurement over the new survey markFigure 13. Distribution of DRR survey benchmark in 2016

5 GNSS / IMU PROCESSING
PPP Processing The signal from PPP measurement takes around seven days to ten days to calibrate. The delay
is a result from calibration of the Precise Orbit and Clock Correction by International GNSS Service. The processing
model, which is called Post-Processed Precise Point Position (PP-PPP), applies precise orbit and clock corrections.
These precise orbital and clock parameter can be obtained from the International GNSS Service (IGS). The processing
software for GNSS/IMU data is Novatel Inertial Explorer version 8.60
6 CONCLUSIONS
To conclude, by applying mobile mapping system the Department of Rural Road could collect panoramic
images of the DRR assets. All panoramic images and trajectory data are processed and imported to the Rural RoadManagement System (RM). All asset objects can be identified, measured, count and inventoried using the RM.
Extending from pilot project, DRR is now conducting MMS survey for asset management in 47,000 kilometerof its networks. DRR is expecting to complete inventory of DRR assets by 2016.
524

7 ACKNOWLEDGEMENTS
The authors gratefully acknowledge the support and contributions in preparing this report. This report is an outcome ofa collaborative effort between the Department of Rural Road (DRR) and Chulalongkorn University InfrastructureManagement Research Unit.
8 REFERENCES
GPS Measurements Techniques, Retrieved October 10, 2015, from, http://nptel.ac.in/courses/ Webcourse-contents/IITKANPUR/ModernSurveyingTech/lectureB_13/B_13_11summary.html

525

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Road Pavement Design for the Pacific Region –Desk Research on the Use of Locally Available Materials

TRACK

AUTHOR(Capitalize Family Name)

William Gray, TechnicalPrincipal – Pavements at
Opus
International Consultants
Ltd

CO-AUTHOR(S)(Capitalize Family NamePOSITION

E-MAIL(for correspondence)

Working under contract
with the Pacific Region
Infrastructure Facility(PRIF)

Australia

ORGANIZATIONCOUNTRY

Please communicate with Jack Whelan, Secretariat Manager, PRIF,
jwhelan@theprif.org

KEYWORDS:
Road Pavement Design Pacific PRIF

ABSTRACT:The abstract should be written in English, readily understandable to most readers and may contain up to maximum of
500 words. Authors are invited to use Times New Roman Size 10 and the full type width of the page (single column).
Road Pavement Design for the Pacific Region. The study investigates use of locally-available pavement materials toimprove pavement quality, resilience and sustainability and to reduce the overall cost of road construction andmaintenance. The report by the Pacific Region Infrastructure Facility (PRIF) examines which locally available materials
can be used to construct resilient, low volume, roads (both unsealed and sealed). It also sets out factors to ensure
success, including ongoing training and support, coupled with use of appropriately-scaled and resourced pavement
investigation, design, material supply and processing; sound road construction practices; and knowledge of local
materials. However, while the use of more robust, cost-effective and stable materials is important, proper asset
maintenance is also needed to minimize whole-of-life costs and ensure sustainability. Ongoing performance reviews will
enable local engineers to reasonably evaluate material and design options, develop and implement ongoing countrybased training, and support pavement design and maintenance.

526

2nd IRF Asia Regional Congress & Exhibition
Oliver Whalley (World Bank), presenting on behalf ofPacific Region Infrastructure Facility (PRIF)
Email for correspondence: jwhelan@theprif.org

1. INTRODUCTION‘Road Pavement Design for the Pacific Region - Desk Research on the Use of Locally Available Materials’.
This report, published in January 2016 by the Pacific Region Infrastructure Facility (PRIF), represents a collaborationof major development partners in the Pacific region – ADB, World Bank, EIB, EU, Australia, New Zealand and Japan 1.
The study was proposed by the PRIF Transport Sector Working Group (TSWG). It is being managed by the PRIF
Coordination Office (PCO) and consists of two phases: a research phase and a trial phase (underway). The study isdesigned to investigate options to engineer the use of locally available pavement materials to improve pavement quality,
resilience and sustainability and to reduce the overall whole-of-life cost of road construction and maintenance. The
context is the Pacific Island Countries (PICs) in which PRIF operates2.
The published report has been developed during the research phase of the study. It brings together contemporary global
research about a variety of pavement design and material options available to PRIF agencies working in the Pacific,
including the potential use of pavement construction additives that can be reasonably sourced in the region and areappropriate for application in the Pacific context. The use of in-country waste stream materials (e.g. recycled glass or
crumbed tyre rubber) have been considered as an additive to support granular stabilisation. In addition, when comparing
the whole-of-life costs of various pavement rehabilitation opportunities, a number of issues have been taken into
account, including: logistics and likely costs associated with contractor, plant and material establishment future
maintenance needs of the rehabilitated pavement, and what equipment is required to support future rehabilitation andmaintenance works.
While these latter points are mentioned in general terms in this report, they will also be developed further during theremainder of the study. This may involve Net Present Value analysis, using likely unit rate/quantity construction costprofiles, agreed discount factors and supporting information to enable in-country engineers to make informed decisions.
The research report is released as a knowledge product for engineers and project managers to refer to, as needed, in
conducting design and construction work in the Pacific. Further reports will also be prepared during the remainder ofthe study.
1

PRIF Members: Asian Development Bank (ADB), Australian Department of Foreign Affairs and Trade (DFAT),
European Union and European Investment Bank (EU/EIB), Japan International Cooperation Agency (JICA), New
Zealand Ministry of Foreign Affairs and Trade (NZMFAT), and the World Bank Group including the International
Finance Corporation (IFC).
2

At present these are: Cook Islands, Federated States of Micronesia (FSM), Fiji, Kiribati, Nauru, Niue, Palau,
Republic of the Marshall Islands (RMI), Samoa, Solomon Islands, Tonga, Tuvalu, and Vanuatu, with monitoring for
Papua New Guinea (PNG) and Timor-Leste.
2. RESEARCH OBJECTIVES
The objective of this study is to investigate options to engineer the use of locally available pavement materials toimprove pavement quality, resilience and sustainability and to reduce the overall whole-of-life cost of road construction
and maintenance. The report summarises the desk research phase of the study. The report explores the extent to which
locally available pavement materials can be used to construct resilient low volume roads. It also sets out factors toensure success, which include ongoing training and support, coupled with use of appropriately-scaled and resourced
pavement investigation, design, material supply and processing; sound road construction practices; and knowledge of
local materials and their applicability and limitations.
The locally available pavement materials used in road pavements in the Pacific region are largely sourced fromcoralline or igneous rocks. Countries where the central volcanic core remains (e.g. Fiji and Papua New Guinea), haveaccess to inland and coastal igneous rock formations, with associated residual or tropical soil intrusions. Inland coronus
527reserves, coral and coral sand from the adjoining reef also contribute to the pavement aggregate options. In suchcountries, which are typically not low-lying, access to fresh water supply also enables more conventional earthworks
engineering processes to be used.
3. STRUCTURE OF REPORTThe report addresses four topic areas in regard to locally available material for pavements:- geological setting in the PICs
- aggregate materials in use in the Pacific- specifications and standards in use- aggregate stabilisation
Each topic area is discussed in separate sections of the report. The material is broad-ranging in parts, whilst remaining‘on topic’ technically. At the end of each section, a conclusion considers how the findings could be relevant to thecurrent and future use of locally available aggregate materials. A full list of references is included in the report.
4. BACKGROUND
Smaller low-lying island countries e.g. Kiribati and the Republic of the Marshall Islands often retain only the coastal
coral reserves and, given concerns about environmental sustainability, probably only the coralline sand (cascajo)
deposits inside the reef itself. Here access to fresh water is limited, so construction with salt water is more likely.
Experience dating from World War II has shown that pavement construction using coralline materials with salt watercan provide some benefits, assisting with self-cementation of the compacted coral aggregate. Investigations of failing
airfield pavements sections have shown that the failure can be confined to the more recent overlying asphalt boundsurfacing, and not the underlying, more resilient coral-based pavement layers.
A description of how geography and geology affects pavement material supply for each of the countries is summarised
here in Table 1.
Table 1. Expected Local Aggregate Options in Pacific Islands
Country
Coral AggregateCook Islands
FSMFiji Islands
Kiribati

Nauru

Niue

Palau

PNG

RMI

Samoa

Solomon Islands
Timor-Leste

Tonga

TuvaluVanuatu
Source: Brij, V.L., & Fortune, K. (Eds). (2000).

Coronus Aggregate
















Volcanic
Aggregate
















The pavement design and construction principles used around the Pacific study area vary, and appear from anecdotal
evidence to be largely based on recognised, published empirical methods including some local country-based
variations. To be successful, whichever design and construction method is used, the pavement designer needs access torelevant and accurate information about future traffic loading, in-situ foundation conditions and material
characterisations, and environmental constraints.
Questions about pavement project reliability should be raised first with the pavement owner, because reliability, cost
and the importance of the project in the wider context (e.g. small local road versus main highway) sometimes need to be
traded off to achieve the best for project outcomes.

528

5. DESIGN AND CONSTRUCTION PRINCIPLES
Pavement aggregate stabilisation is a proven technique around the Pacific region. The improvements in pavement layer
stability, strength and load bearing capacity can be utilised from the subgrade up, throughout the pavement structure.
On low-lying coral atolls, cement, foamed or emulsified bitumen or cement/polymer stabilization would appear better
suited to the sand grained, unprocessed and compacted coral reef aggregate materials. Self-cementation in constructedcoral aggregate roads is a recognised, beneficial outcome, with proven and tangible pavement performance benefits inlow volume sealed and unsealed roads.
For road aggregates prepared from volcanic source rock, or weathered inland coronus deposits, lime and cement
stabilisation would help to mitigate the adverse effects of high plasticity, water sensitivity, and high natural watercontents.
Generally aggregate stabilisation with cement and/or foamed bitumen can be used with both volcanic and coronus
materials to successfully mitigate the adverse effects of plasticity and enhance layer strength and load bearing capacity,
provided that when a bound or lightly bound layer is prepared that the potential adverse effects of cracking are
considered and proactively managed.
Pavement aggregate materials processed using local coralline or volcanic sources and added to using recycled material
from other waste streams (e.g. recycled crushed glass, tyres or plastic for example), with or without existing or new
polymer or other additives, presents an opportunity. The economics of using waste material need to be carefully
considered, taking into consideration the whole-of-life costs of sourcing aggregate, especially the cost of collection,
storage processing and transport.
Small island states will probably not generate enough waste glass, used tyres and plastics on their own, except perhaps
in one-off project situations. This raises the opportunity perhaps for wider regional collaboration.
6. KEY FINDINGSAll the options described above are technically feasible in the Pacific region. However, investigations in this study
indicate that, whilst larger one-off capital projects may justify the establishment of external plant, resources and evenmaterials, what is needed at a country level is appropriately trained and resourced local contractors, staffed by people
who understand what can be achieved with local materials, with or without modification. With this knowledge, local
contractors may be more credible and competitive when bidding for pavement construction and rehabilitation works
across the region, thereby improving local productivity and, ultimately, supporting poverty reduction.
The study focuses on effective use of local materials and resources for improvement of low volume roads (bothunsealed and sealed). However, it is stressed that while the use of more robust, cost effective and stable materials is
important, proper asset maintenance is also needed to minimize whole-of-life costs and ensure sustainability.
The use of proven modifiers/stabilisers (lime/cement) with existing coral or volcanic source aggregates, and suitable incountry waste stream materials, by means of simple, repeatable production and construction techniques, appears to offer
exciting opportunities, provided that the wider economics associated with collection, processing and utilisation of
locally available aggregate materials incorporating such materials are understood. This would include understanding of
the fixed and/or mobile plant needs to process aggregate materials, and the longer term plant and pavement maintenanceexpectations.
The ideas presented in the published report require corroboration from the secondary phase in-field trials andperformance monitoring to determine the long-term sustainability of the pavements. The resulting information database
containing relevant feedback on processes and costs that can be linked to ongoing project performance reviews will
enable local engineers to reasonably evaluate material and design options, and to develop and implement ongoing
country-based training and support for pavement design and maintenance.
7. APPLICATION OF REPORT FINDINGS
Given the nature of the overall study, it is not expected that all the issues will be applicable to future use of locallyavailable aggregate materials in the Pacific. For example, when discussing pavement design standards (Section 4),
applicable engineering test methods that could be used to define pavement material properties may not all be suitablefor use in the Pacific region under current conditions. Also, the scale of plant and materials needed to undertake largescale pavement aggregate stabilisation projects in an established PIC with access to a range of aggregate and recycling529

sources may not be applicable to a smaller, atoll-based island state, or for use on low volume roads. Where possible,
suitable applications and solutions are identified that are feasible for a range of countries.
7. CONCLUSIONS
The desk-based research undertaken for this study shows that it is possible to use locally available coral and igneousrock-based pavement materials to improve road pavement quality, resilience and sustainability and to reduce the overall
whole-of-life cost of low volume road construction and maintenance in the Pacific region.
The science and technology exists now to source, extract, process and use local pavement materials effectively atwhatever scale is necessary to best suit the local conditions. The properties of the local pavement materials can be
improved by processing and stabilisation using a variety of stabilization agents to suit the needs of unsealed and sealed
pavements in the region.
The challenges to achieving the above are real and immediate:- climate change-induced sea level rise and damage caused by major storm events- poor regulation and control of overweight commercial and industrial traffic- insufficient and poorly informed pavement investigation and design- lack of maintenance of road pavement and drainage infrastructure- lack of investment in any pavement resurfacing.
All of these contribute to the ‘build-neglect-rebuild’ paradigm evident on roads across the Pacific region. As part of thiscurrent study, field trials are underway that will help determine the long-term sustainability and performance of roadpavements built and maintained using locally available materials to meet current and future traffic demands. The
manner in which the trials are developed and implemented will encourage involvement by and training of local
engineers and contractors (as needed), using appropriately-scaled labour-based and equipment supported methods.
8. ACKNOWLEDGEMENTS
The report was researched and drafted by a consultant, William Gray, working under the supervision of a committee ofexperts drawn from the main PRIF agencies and other regional organisations, including Dr. David Aitchison (Universityof the South Pacific), Dr. Theuns Henning (Auckland University), Peter Kelly (Australian Department of Foreign
Affairs and Trade) and Megan Schlotjes (World Bank).
9. REFERENCES
Brij, V.L., & Fortune, K. (Eds). (2000). The Pacific Island: An Encyclopaedia University of Hawai’i Press.
The published report includes a full list of references.

530

Investigating the Characteristics of Drivers with Multiple Crashes
Mohamed Shawky, Ph.D*,1,2
Iyad Sahnoon, M.Sc.1
Abdulla Al-Ghafli, M.Sc. 1

1

Traffic and Patrols Directorate
Abu Dhabi Police, Abu Dhabi,
United Arab Emirates

2

Department of Public works,
Faculty of Engineering,Ain Shams University,
Cairo, Egypt* Corresponding Author:
Mohamed Shawky, Ph.D.,
Tel: +971 561236607
Email address: m_shawky132@hotmail.com

Paper submitted for presentation at the 2nd IRF Asia Regional Congress & Exhibition,
Kuala Lumpur, Malaysia, October 16-20, 2016.

531

ABSTRACT
Identifying the drivers with higher traffic crashes involvement frequency (i.e. high-risk
drivers) is the main concern of all road safety related entities. Driver’s behavior factors are
considered as a leading cause of traffic crashes. Driver’s behavior can be measure based on
the historical records of their violations and crashes. This paper aims to investigate thecharacteristics of drivers who are frequently involved in severe crashes and to define theparameters that can be used to recognize these drivers. About 20 types of unsafe traffic
violations are intensively investigated. The interrelationships between the at-fault drivers’
involved in traffic crashes and their demographic characteristics, historical traffic violations,
historical severe and property damage only (PDO) crashes involvements and historicalviolations of different types were explored.
Negative Binomial Regression modeling approach is applied to define the associatedvariables that can be used to predict the driver’s severe crashes future involvements. The
results show that females, young, local, and less driving experience drivers have higher risk
to be involved in future severe crashes. In addition, the following violations can be used as
predictors to define drivers with multiple crashes: exceeding speed limit by more than 50
kph, car racing involvement, alcohol use, mobile use, tailgating, entering road suddenly, notusing helmet, and overtaking-related violations. The findings can also be used to develop or
improve the preventative strategies against high risky drivers.

Key words: Risky driving behavior, multi-crashes drivers, traffic violations, crash rateestimation. Crash-prone drivers

532

INTROUDUCTION
One of the primary missions of the traffic police in most of the world-wide countries is toenforce the drivers with aggressive attitudes and high crash risks. Each driver has a degree ofrisk to be involved in a crash given some factors related to the environment, human, and road.
Many previous studies proved that the majority of the traffic crashes occurred due to humanfactors (Karscasu and Er, 2011). This conclusion produces a challenge to the transportation
planners and decision makers to develop traffic safety strategies due to the un predictablefactors of crash occurrence.
In Abu Dhabi (AD), the capital of United Arab Emirates (UAE), the driver’s community is a
mix of different nationality groups from all over the world where the total number ofregistered non local (i.e. non-Emirati) driver groups is more than 200. Referring to the local
traffic safety statistics in Abu Dhabi regarding the at-fault drivers who were involved insevere crashes (i.e. a crash with at least one injury) during the period between 2010 and 2015,
about 88.5% of them are male, 40.3% aged between 18 and 30 years old, and about 35% arefrom Asian countries. These facts produce many challenges to Abu Dhabi government tocontrol different backgrounds, cultures, and driving experiences of multi-national driversociety. It is worth mentioning that Abu Dhabi government has a strategic target to reduce theroad fatality rates from the current value of about 7.4 fatalities per 100,000 inhabitants to 3.0
fatalities per 100,000 inhabitants by year 2023. Table 1 shows the main road safety indicators
in Abu Dhabi during the period from 2010 to 2015. The numbers indicate that a significant
improvement in road safety has been achieved during last six years. The number of fatalities
has been reduced by 34.8% and the fatality rate has been reduced by 39.8% at the end of2015 compared to the same period in 2010.
Table 1: Traffic Safety main indicators in Abu Dhabi
Year

Number ofseverecrashesNumber ofcausalities

2010
2011
2012
2013
2014
2015

2,537
2,283
2,056
2,071
1,861
1,803

4,307
3,871
3,498
3,644
3,154
3,025

Number ofserious
injuries
400
390
364
366
240
1478

Number of
fatalities
376
334
271
289
267
245

Fatality rate
per 100,000
inhabitants
12.3
10.7
8.7
8.9
7.6
7.4

Fatality rate per
10,000 registeredvehicles
5.4
4.3
3.3
3.3
2.8
2.4

One of the promising tools to achieve the above mentioned strategic target is to identify thehigh-risk drivers based on traffic safety related criteria as to be demonstrated in this study.
After that, preventative programs and strategies to enforce and aware such driver group canbe developed including some penalties such as license suspension, attending special roadsafety training courses, warning messages, etc. It is worth mentioning that no clear definitionis yet published regarding “high-risk” drivers in Abu Dhabi which leaves a space for thisstudy to set criteria in order to propose such definition.
Table 2 shows statistics of the traffic violations in Abu Dhabi during the period from 2010 to2015. The table shows that the total number of violations has been increased by 130% in year533

2015 compared to year 2010. This increasing trend can be justified due to the increase
number of the installed automated speed enforcement devices in the last few years. The
number of speed cameras has been increased from 414 in 2010 to 704 in 2015 (about 70.0%
increment). In addition, about 198 red light violation cameras have been installed at 77
intersections during the last three years. Also, Table 2 shows that at-site enforcement (i.e.,face to face traffic violation tickets) has been increased by 37% in year 2015 compared toyear 2010.
Table 2: Traffic violations statistics in Abu Dhabi
Year
2010
2011
2012
2013
2014
2015
% of change

Total number
At-siteSpeed-relatedof violations violations
violations% of speedrelated violations

Violation rate perregistered vehicle

504,559
615,826
641,314745,159
719,156
688,845
37%

74.8%
83.6%
83.2%
80.3%
80.2%
86.5%
-

3.5
5.1
4.9
4.4
4.6
6.0
69%

2,477,340
4,011,310
4,085,074
3,832,685
4,338,701
5,692,745
130%

1,851,907
3,352,570
3,399,460
3,197,320
3,477,274
4,921,934
165%

On the light of previous statistical facts, the following question was raised: Was increasing
the number of automated speed enforcement cameras on roads in the past years is the rightapproach to improve road safety levels in Abu Dhabi? In other words, Is there any
relationship between the “high-risk” drivers and traffic rule violations record? This paper
tries to find an answer to the mentioned question by exploring the “high-risk” drivers in termsof their historical traffic safety records (i.e. violations and crashes) in addition to theirdemographic characteristics. Thus, this study focuses on predicting the likelihood that a“high-risk” driver will be involved in at-fault recurrent crashes in the future using driverrecords from the period between 2008 and 2015 (i.e., eight years of data) that have beenreported by Abu Dhabi traffic police.
LITERATURE REVIEW
Many researchers have attempted to determine which variables are the best predictors for
traffic crashes. The examined variables in prior studies can be classified as: demographic
characteristics of drivers, psychosocial (e.g., aggressiveness, impulsiveness), behavioral (e.g.,crash involvements history, traffic rules violations). Early study by Peck at al. (1971)
concluded that the statistical nature of driver crash frequencies makes it impossible toaccurately predict which individuals will or not will be involved in at-fault crashes in the
future. However, many later studies found a statistically significant relationship between thenumber of crashes involvements and the historical number of traffic violations of the driver(Gebers and Peck, 2003; Blascoa, 2003; Chandraratna et al., 2006). The substantial body ofthese studies focused on establishing estimations of the potential of a driver to be involved ina crash based on prior driving records (e.g., crashes and violations).
Lui and Marchbanks (1990) determined a relationship between previous traffic infractions(i.e. violations) and fatal car crashes by studying the fatal accident reporting system from534

1984 to 1986 period. They suggested that the involvement in a fatal crash is not a random
event and showed that the mean time between a previous traffic infraction and a fatal crash
was the shortest for individuals aged 16 to 25 years, who had a mean recurrent time of 14.2
months. In addition, about 97% of the recurrent times occurred within 60 months of a given
traffic infraction, with the highest risk of a fatal crash from three to seven months following
the infraction.
Hauer et al. (1991) examined several methods to identify drivers who are most likely to havea crash in the near future using a four-year record for a large sample of Ontario drivers.
About 16 different prediction models were developed and compared. It was found that themodel that made use of detailed information on age, gender, number of each of 14 types ofviolations, and number of at-fault crashes and not-at-fault crashes, was the most efficientmodel in terms of explaining the variance of estimated crash potential. The authors concluded
that if the prediction model makes use of the driver’s prior crash records, the performance ofthe prediction model is notably improved.
Chen et al. (1995) applied logistic regression approach to identify the drivers who were most
likely to have one or more at-fault crash involvements, based on prior records of at-fault
crash involvements drivers. The results indicated that a model that makes use of prior at-fault
crash information can identify up to 23% more drivers who will have one or more at-fault
crash involvements in the next two years than a model that uses violation records alone. After
studying 17 logistic regression models, Gebers (1999) concluded the final developed model
could correctly classify crash-involved drivers up to 27.6%. In addition, the model indicatedthat age, gender, license class, total citations and total crashes are the greatest prediction
variables of crash-prone drivers.
Alver et al. (2004) explored the interaction between socio-demographic characteristics oftraffic rule violators (four types of traffic violations records were aggregated) and crashhistory for young drivers (18-29 years old) by applying binary logit models. The results
showed that 23.9% of drivers were involved in at least one traffic accident in last three years.
The crash rate increases to 38.3% for drivers who received at least one traffic violation ticketin last three years and peaks to 47.4% for those who were fined for seat belt violations.
Chandraratna et al. (2006) studied Kentucky drivers to develop a crash prediction model thatcan be used to estimate the likelihood of a driver being at fault for a near future crashoccurrence by using multiple logistic regression technique. The authors dedicated that thedeveloped model can be used to correctly classify at-fault drivers up to 74.56% with an
overall efficiency of 63.34%. The total number of previous at-fault crash involvements, andhaving previous driver license suspensions and traffic school referrals are strongly associatedwith a driver being responsible for a subsequent crash. In addition, a driver’s likelihood to be
at fault in a crash is higher for very young or very old, males, drivers with both speeding andnon-speeding citations, and drivers that had a recent crash involvement.
Zhang et al. (2013) analyzed crash severity and violation data of Chinese drivers. The results
established the role of traffic violations as one of the major risks threatening road safety. In
addition, specific risk factors associated with traffic violations and accident severity wasdetermined. The authors suggested that to reduce traffic crashes and fatality rates, measures
such as traffic regulations targeting different vehicle types/driver groups with respect to the535various human, vehicle and environment risk factors are needed. Some studies proved thesignificant effect of specific drivers’ behavior such as speeding and drunk and drug usage on
the prediction of the crash-prone driver (Winter and Dodou, 2010; Watson et al., 2015; Kim,
2015). Dissanayake and Lu (2002) and Baker et al. (1992) proved that the seat belt usage andalcohol usage have major effects on the crash severity. In addition, Tseng (2013) showed thatboth younger and older drivers have relatively higher speeding risk.
Berdoulat et al., (2013), investigated the aggressiveness and impulsiveness in the predictionof risky drivers. It was found that aggressiveness and impeded progress were the best
predictors of violations and aggressive violations. The results supported that transgressive
driving behaviors are relevant indicators of aggressive driving. The same result was
concluded by Bachoo et al. (2013) from a sample of post graduate students in Durban, South
Africa.
A new definition of the impulsivity in driving context was suggested by Bıcaksız and Ozkan(2015) during analyzing 288 student self-reported questionnaires in driving behavior,violations and accident involvements. Machado-Leon et al. (2016) investigated crash risk
perceptions in an inter-city, two-way road context of 492 drivers by using a Stated Preference
ranking survey. The study that all risky driving behaviors showed a significant potential
effect on crash risk perceptions, and model’s results allowed to differentiate more importantfrom less important unsafe driving behaviors based on their weight on perceived crash risk
DATA PREPARATION AND ANALYSIS METHODOLOGY
Database Preparation and Sample Size Selection
The employed data in this study were extracted from four different datasets of Abu-Dhabi
traffic police during the period from 2008 to 2015. These datasets are: 1) traffic violation
system, 2) property damage only (PDO) crashes system, and 3) severe crashes system, and 4)
licensed drivers’ system. Individual drivers’ data were integrated in one comprehensive
database by using the driver’s unique traffic code that is given to each licensed driver at the
day when he/she issued a driving license.
The total number of registered driving licenses in year 2008 was 636,907 and increased to1,234,009 licenses by the end of year 2015. Serial processes of data filtrations were carriedout to select the sample of drivers that will be used in the analysis. First, records of drivers
who have private driving licenses only were used in the analysis (i.e., excluding the driving
licenses of companies, governmental, diplomatic, intuitions, etc.). Second, drivers with zerorecords of both violations and crashes during the eight years were excluded from the analysis
as well as those who do not have fully populated demographic information in the database.
Finally, records of drivers who issued their driving licenses after year 2008 were notconsidered here to assure that all drivers in the data sample have practiced driving during theanalysis period.
Accordingly, the data sample was reduced to be 324,644 drivers. The drivers existed in thedata sample recorded a total number of 4,116,149 traffic violations; 578,619 property damage
only (PDO) crashes (i.e. any crash without any injury or fatality); and 7,676 severe crashes(i.e., any crash with at least one injury or fatality). The database is structured to show the536

detailed historical records of each individual driver as well as groups of selected traffic
violation types that have direct or indirect impact on road safety, at-fault crash involvements
and demographic characteristics. These violations have been clustered into 20 groups ofviolations by aggregating some types in one group, for instance, the (overtaking-related
violations) group which includes four types of violation: overtaking from the right,
overtaking in prohibited locations, overtaking from shoulder, dangerous overtaking behavior.
Data Analysis Methodology
To achieve the objectives of this paper, the analysis process was conducted in two stages:
1) The first stage aims to develop the relationships between the severe crash rates per
drivers in terms of violations types, drivers’ demographic characteristics and thefrequency of the violation types and crashes per drivers. In this stage the violations typeand drivers’ characteristics that have high severe crash rates can be recognized.
2) The second stage provides an estimation model to determine the best predictors/variables
that can be used to identify “high-risk” drivers (i.e., the drivers have a highest likelihood
to be involved in crashes in the future) using negative binomial regression model.
DATA ANALYSISInterrelationship between Crash Rates and Violation Records of Drivers
Unlike traffic crashes, not all traffic violation types are indicative of risky driver’s behavior
or are predictors to future crashes such as: “illegal parking, driving with expired license, etc.”
Therefore, in the primary analysis of this study, the driver’s violations were classified into
two classes. Class (I): speed-related violations which includes six types of violations. Class(II): risky behavioral violations which includes 14 types of unsafe behavior violations suchas: tailgating, mobile use when driving, non-seatbelt use, sudden lane changing, etc.
Accordingly, drivers were classified into different groups based on their historical records ofviolation’s type.
Crash rates and percentage of drivers involved in crashes of each group of drivers as shownin Table 3. It shows that drivers of class II have higher rates of severe crashes than those inclass I. However, class I drivers are more likely to be involved in property damage only
(PDO) crashes than class II drivers. In addition, Table 3 shows that the overall severe crash
rates of the studied sample of drivers is 26.1 crashes per 1,000 drivers during the data period.
Table 3: Crash rates and percentage of divers involved in crashes for drivers group during eight
years (2008-2015)
Drivers’Group

No. ofseverecrashesNo. ofPDO
crashes

Drivers
SeverePDO% ofDrivers% of drivers
No. of involved incrash rate crash
drivers
involved in
involved indrivers
severeper 1000 rate per
involved in
PDO crashsevere crash
crash
driverdriverPDO crashAll16,326 965,341 624,422
drivers
Class I 7,376 253,604 312,496

14,924425,806

26.1

1.5

2.4%

68.2%

6,883

223,603

23.6

0.8

2.2%

71.6%

537

Class II 13,838 341,622 497,571

12,638341,622

27.8

0.7

2.5%

68.7%

Figure 1 shows the calculated severe crash rates of drivers who belong to Class I (speedingrelated violations group). This figure clearly proves the strong relationship between the
speeding behavior of drivers and their crash rates as a representative of their traffic safety.
The severe crash rates of the drivers are significantly increasing with higher over-speedingvalues exceeding the legal posted speed limit on the road. For instance, drivers who exceeded
the speed limit up to 30 kph have a crash rate of 23 crashes per 1,000 drivers during the study
period, however drivers who exceeded the speed limit by 60 kph have crash rates of 46
crashes per 1,000 drivers (i.e. almost double) and drivers’ group of those involved in car
racing on roads that have crash rates of 66 crashes per 1,000 drivers (i.e. 2.87 times morethan the others).

Severe crash rates per 1,000
drivers

70

66

60
46

50

39

40

32
26

30

23

20
10
0
Car Racing

Exceeding
Exceeding
Exceeding
Exceeding
Exceeding
speed limit speed limit by speed limit by speed limit by speed limit up
over 60 Kph
50-60 Kph
40-50 Kph
30-40 Kph
to 30 Kph

Figure 1: Severe crash rates for Class I drivers group

Figure 2 shows the calculated severe crash rates of drivers who belong to Class II violationsgroup. It shows that alcohol usage drivers have the highest crash rates (i.e. about 4.8 times
more than the average rate of all drivers shown in Table 3). On the other hand, crash rates ofdrivers using mobile phones while driving has a relative lower crash rate. This result is not an
accurate representation of its severity level; this is because such violations are difficult to becited by the traffic police specially on the highways where most of sever crashes occur whichleave a relative lower citation records in the violation database that is reflected in lower crash
rate.

538

140
120
100
80
60
40
20
0

Severe crash rates per 1,000
drivers

125
100
66
49

47

41

40

39

34

33

29

29

29

22

Figure 2: Severe crash rates for Class II drivers group

Frequency of Violations Impact and Crashes per Driver

90
80
70
60
50
40
30
20
10
0

77
52

54

38

1

2

3

≥4

Exceeding Speed Limit of more than 60 kph
Violation frequency(a) With severe crash rate

Pecentage of drivers

Severe crash rate per 1000
drivers

The frequency of the violation (i.e., number of repeating the same violation type) by theindividual drivers was investigated for all type of violations during the study period. Due tothe size limitation of this paper, an example of these analyses are presented. Figures 3-a and3-b show an example of the analysis outcomes for the violation titled “Exceeding the speed
limit of more than 60 kph”. These figures show a significant increase of crash rates andpercentages of drivers involved in severe crashes by increasing the frequency of the violation
numbers. Drivers who get four or more violation tickets of this violation have about double
crash rates compared to drivers who get only one ticket.
8.0%
7.0%
6.0%
5.0%
4.0%
3.0%
2.0%
1.0%
0.0%

6.9%
4.8%

5.3%

3.4%

1

2

3

4

Exceeding Speed Limit of more than 60 kph
Violation frequency(b) With percentage of drivers

Figure 3: Crash rates and percentage of drivers with respect to the frequency of the violation(Violation example: Exceeding speed limit by more than 60 kph)

Figure 4 shows the crash rates of the driver’s group based on their records number of all
types of violations. in general, this figure shows that the crash rate of drivers increases withincreasing the total number of traffic violations of individual drivers.

539

Severe Crash Rate per 1000
drivers

46.21

50.00
40.00

35.34
30.36

30.00

24.01

24.80

1 to 56 to 10

20.00
10.00
0.00
11 to 15

16 to 20

> 20

Total violation Frequency of individual driver

Figure 4: crash rates based on total number of violations of the driver

PDO Crash Rate

Figure 5 shows the relationship between the frequency of severe crashes of individual drivers
and PDO crashes records. This figure shows that drivers have more than one severe crashes
were involved in higher PDO crash rates which means the PDO crashes records of the drivers
can be used as indictor for the potential of the driver to be involved in severe crashes.
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0

3.6

3.9

2.7
1.9
1.0

1

1.3

2

3
4
5
Severe crash frequency

6

Figure 5: Frequency of severe crashes of drivers and PDO crashes records

Drivers’ Demographic Characteristics Impact
The calculated crash rate for male drivers is almost very close to that for female (about 26.2
severe crashes per 1,000 drivers). Considering the driver’s age group, Figure 6 shows thecrash rates of different age groups of Abu Dhabi registered drivers. It shows higher crash
rates for very young and very old drivers. This conclusion is supported with the driving
experience of the driver where the mid aged drivers (i.e. with higher driving experience) haverelatively lower crash rates since they became familiar with the road circumstances and hence
drive more safe. However, the older drivers (i.e. drivers with age group of 65 years old andmore) lose their perception/ reaction characteristics which make them more involved insudden crashes.

540

severe crash rate per 1000
drivers

6
4.8

5
4
3

2.6

2.44
1.8

2

1.51

1.45

45-54

55-64

1
0
18-24

25-34

35-44

>=65

Age group (years old)

Figure 6: Crash rate of the driver’s age group

30.0
25.0

24.1

22.6

20.0
15.0
10.0
5.0
0.0
Low educatedHigh educated(a) Education level

Crash rate per 1000 drivers

Crash rate per 1000 drivers

Educational attainment of the drivers showed that the low educated drivers have higher crashrate (24.1 crashes per 1,000 drivers) of severe crashes than for the high educated ones (22.6
crashes per 1,000 drivers) as shown in Figure 7-a. In addition, local drivers showed higher
crash rate (34.6 crashes per 1,000 drivers) relative to other nationalities in residing in Abu
Dhabi as shown in Figure 7-b.
40
35
30
25
20
15
10
5
0

34.6
24.4

UAE local

Other Nationalities(b) Nationality

Figure 7: Crash rate of the driver’s based on education level and nationality

Regression Model Estimation
In this section, a regression model was developed to determine the best predictor variables
that can be used to identify “high-risk” drivers in Abu Dhabi. Based on Highway Safety
Manual (HSM-2010) the negative binomial regression modelling is considered as the bestmodeling approach to estimate the predictors variables of crash involvements. There for thismodel were applied in this study. The negative binomial regression model form to predict the
total crash frequency is shown in Equation 1:
Ln Y = β0 + β1 X1 + β2 X2 + … + βn Xn. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (1)Where, Y is the dependent variable (i.e. number of at-fault severe crashes in our case); X1, X2,… Xn are the predictor variables; and β0, β1, β2, …, βn are the regression coefficients.
The SPSS statistical software package was employed to estimate the model using thecustomized negative binomial with log link function with the option to estimate the541

dispersion parameter rather than setting it to the system’s default value. It accounts for theover-dispersion that is found in the crash data and quantifies an over-dispersion parameter.
Table 4: Model combinations with the investigated predictor variable groups

ModelGroup variables 1
Demographic (age, gender,
nationality, education, yearsof experience)Group variables 2
Speeding Violations(6 types)

Group variables 3
Behavior Violations(14 types)

M1
M2
M3
M4
M5
M6
M7

√

√

√

√

M8

√

√

√

√

PDO
Crashes

√
√
√

√
√
√

√
√

Eight models with different combinations of the examined variables (predictors) weredeveloped. Table 4 summarizes these eight models and the associate examined variables foreach model. For example, it shows that the models M1, M3, and M5 used the variables
croups of speeding violations, historical behavior violations, drivers’ demographic
characteristics, respectively. By accompanied the PDO historical records of the driver tothese three groups of variables the models M2, M4 were developed.
Akaike Information Criterion (AIC) value each model which is a measure of the relative
quality of statistical models are used to select the best fit model. The AIC compares different
models from the same data by adjusting the -2 Log Likelihood statistic for the number ofterms in the model and for the number of observations in the sample and can be calculated asfollows (Gerbers 1999).
𝐴𝐼𝐶 = −2 𝐿𝑛 ( 𝐿 ) + 2(𝐾 + 𝑆) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2)Where, L = Likelihood
K = the number od ordered values for the response variable
S = number of independent variables or covariates
Based on AIC values the best model is the model M7 which used all variables of the threegroups of violation records of the drivers. One possible justification of that the PDO recordsof the drivers not shown in the best model is that in AD any very minor crash is consider as
PDO and that represent a significant number in AD. Table 5 shows the final significant
estimate parameters of the best developed model. As shown in Table 5, all the response
variables are statistically significant at 95% (p-value < 0.05).
Table 5: Results of negative binomial regression model
Dependent variable

Regression Standard
Coefficient
error

Wald
χ2

POdds
value ratio

Odds ratio 95%
confidence limits
Lower
Upper

542

Violation types

drivers’
variables

Dependent variable

Regression Standard
Coefficient
error

Wald
χ2

POdds
value ratio

Odds ratio 95%
confidence limitsIntercept-2.9170.1030802.672 0.000

0.054

0.044

0.066

GenderNationality
Age
Experience-0.2900.395-0.023-0.0240.06390.05130.00350.004620.67259.23241.17127.699

0.000
0.000
0.000
0.000

0.748
1.484
0.978
0.976

0.660
1.342
0.971
0.967

0.848
1.641
0.984
0.985

0.030

0.0149

4.163

0.041

1.031

1.001

1.061

0.027

0.0134

4.070

0.044

1.027

1.001

1.055

0.124

0.026921.370

0.000

1.132

1.074

1.194

-0.0891.253
0.229

0.0332
0.0961
0.04807.130
0.008
170.023 0.000
22.750 0.000

0.915
3.499
1.257

0.857
2.899
1.145

0.977
4.224
1.382

0.309

0.082314.066

.000

1.362

1.159

1.600

0.369
0.094

0.13420.02607.554
13.047

0.006
0.000

1.446
1.098

1.112
1.044

1.881
1.156

Exceed peed
between 50-60kph
Exceed speed
more than 60kph
Reckless andrunning
Mobile use
Alcohol use
TailgatingEnter roadsuddenly
Not using Helmet
Overtaking-related

Regarding the drivers’ demographic characteristics group, gender; nationality; age; andexperience were found to be as significate predictors for estimate crash-prone drivers.
Females, young, local, and low number of years’ in driving experience drivers have high risk
to be involved in severe crashes in the future. From the speeding violations group, exceeding
speed by more than 60 kph, exceeding speed by values 50-60 kph, and reckless and running
violations can be used to define the risky drivers. In addition, from the behavior violationgroup, the following violations were categorized to identify the risky driving behavior;alcohol use, mobile use, tailgating, entering road suddenly, not using helmet and overtakingrelated violations. Accordingly, the accompanied fines and enforcement efforts should beconcentrated in such violations in the future.
CONCLUSION
This paper investigated the variables that predict severe crash involvement of drivers withmultiple crashes in Abu Dhabi. The study conducted crash rate and frequency analyses forabout 20 different drivers’ groups of violations and drivers’ demographic characteristics. In
addition, Negative Binomial Regression modeling approach is used to define the associatedvariables that can be used to predict the number of severe crashes involvements. The data
analysis showed strong relationships between the severe crash rates of the drivers with their
historical records of POD crashes and violations. In addition, females, young, local and low
number of years’ in driving experience drivers have high risk to be involved in severecrashes. The model results showed that 9 violations’ types are the best predictors for driver’s
crash involvements. these violations are: exceeding speed by more than 60 kph, exceeding
speed by values 50-60 kph, reckless and running, alcohol use, mobile use, tailgating, entering
road suddenly, not using helmet and overtaking-related violations.

543

Identifying the characteristics of drivers at increased risk of future multiple crash
involvement would improve the road safety level by anticipating countermeasure actions
against these drivers. To this end, massive enforcement and traffic awareness campaigns haveto be designed based to improve the traffic safety levels and deter the risky drivers fromanticipating in future crashes or violations.
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545

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE
TRACK
AUTHOR(Capitalize Family Name)

Investigating the Impact of Various Climate Change Scenarios on Pavement
Service Life
Adaptation of Road Pavements to Climate Change
POSITIONORGANIZATIONCOUNTRY

Assistant Professor

National Cheng Kung
University

TaiwanCO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

ABDOU

Project Manager

Social Security andHousing FinanceCorporation

GambiaYANG

E-MAIL(for correspondence)

shyang@mail.ncku.edu.tw

KEYWORDS:
Pavement service life, Climate change scenario, Enhanced integrated climate model, Life cycle cost analysis

ABSTRACT:
Climate change has a particular effect on pavement performance. Traffic and environmental loading will cause thepavement to deteriorate over time. The rate of pavement deterioration is then used for future maintenance andmanagement. Modern pavement design methods such as the American Association of State Highway and Transportation
Officials (AASHTO) Guide for Design of Pavement Structures (1993) and AASHTO Mechanistic-Empirical Pavement
Design Guide (MEPDG) are based on preassumed vehicular loading and historical climate conditions. In this study, theimpact of climate change on the pavement service life and life cycle cost analysis (LCCA) was investigated in thenorthern and southern regions of Taiwan by using historical climate and ground water depth data. Two of the pavement
performance models used by the AASHTO (1993) and AASHTO ME were used to predict the service life of a typical
pavement profile of provincial roads under various future climate change scenarios. The results showed that pavement’s
unbound mechanical material properties, structural capacity, and service life are affected significantly by climate change
relative to a baseline profile. The pavement LCC analysis also increases significantly because of the climate change
scenario relative to the baseline climate profile.

546

Investigating the Impact of Various Climate Change Scenarios
on Pavement Service LifeDr Shih-Hsien Yang1 and Sillah Abdou2
1

National Cheng Kung University, Tainan, Taiwan, Email: shyang@mail.ncku.edu.tw
2

Social Security and Housing Finance Corporation, Banjul, Gambia

1.

INTRODUCTION
Traditionally, pavement performance (deterioration) prediction focuses on the impact of applied traffic loading
and assumes that future climate patterns can be simulated from historical data. Today, however, this assumption may nolonger be valid because of the influence of global climate change. Climate change scenarios such as increased
temperature and precipitation may be considered vital in exacerbating the deterioration rate of pavement materials andstructures. Neglecting the impact of extreme events at the design stage may lead to reduced pavement service life andincreased future pavement operation and maintenance cost from the agency’s standpoint.
In the second half of the twentieth century, climate science has observed significant climate change events thatare mainly associated with natural and manmade factors at global, regional, and local levels (1). The fifth assessment
report by the Intergovernmental Panel on Climate Change (IPCC) revealed a rise of 0.74 °C in global mean surface
temperature and an accelerating rate of warming with sea levels rising over the last 100 years (2). The IPCC hasdeveloped long-term emissions scenarios that have been widely used in assessing the impact of climate change. The
scenarios represent various alternative images of the future climate with the influence of driving forces such as
demographic development, socioeconomic development, and technological change on the future of greenhouse gas(GHG) emissions, as covered in the IPCC Special Report on Emission Scenarios (SRES). Four storylines based onthese driving forces produced four sets of scenarios called families A1, A2, B1, and B2 (3). Hsu et al. reviewed
information on climate change at the global and local scale in the Taiwan Climate Change Projection and Information
Platform Project (TCCIP). The project applied statistical downscaling on the 24 IPCC general circulation model
simulations from the fourth assessment report to project future climate change for temperature and precipitation foreach season in Northern, Central, Sothern, and Eastern Taiwan. Their results showed that the annual temperature in
Taiwan increased by 1.4 °C between 1911 and 2009 and that warming has increased significantly at a rate of 0.29 °C
per decade over the last 30 years. The near surface temperature projections for Taiwan under the A1B scenario, which
is a world of rapid economic growth with balance among all sources, indicate that at the end of the twenty-first century,
temperature increases will range between 2 °C and 3 °C. Projections for mean winter precipitation indicate a decreaseof 1%–23%; in summer, an increase of 15%–45% has been observed (4).
Pavement performance is subject to both external and internal factors. The external factors of traffic,
precipitation, temperature, and depth of the ground water table exert a marked influence on pavement performance. Theinternal factors are the materials, and infiltration potential of the overall pavement structure, all of which determine theextent to which the pavement reacts to the external environmental conditions (5). High temperatures from extreme
events affect the aging of bitumen through oxidation and embrittlement, leading to premature surface cracking andraveling, thus reducing the functional life of the pavement. Soil moisture in the surrounding environment frominfiltration by heavy rainfall or flooding through surface cracks weakens the flexible pavement sublayers, rendering
them more susceptible to damage under heavy traffic. Thus, understanding how climate change or extreme events may
affect pavement structures and ultimately their functional life is crucial (6). Li et al. examined the implications ofclimate change on pavement performance by using the Mechanistic-Empirical Pavement Design Guide (MEPDG). Four
GHG emission models representing future policy scenarios (i.e., A1B, A2, B1, and B2) were used to project futureclimate change considering temperature and precipitation for 3 analysis years (i.e., 2030, 2050, and 2100) by using
MAGGIC/SCENGEN software. MEPDG was used to evaluate the relative change between the baseline climate andfuture climate change scenarios (7). Pavement performance prediction can be achieved through performance modeling.
In general, pavement performance modeling can be categorized into empirical, mechanistic-empirical (ME), andsubjective. In the empirical model, certain measured or estimated variables, such as deflection, accumulated trafficloads, and environmental conditions, are related to loss of serviceability or some other measure(s) of deterioration andpavement age, usually through regression analysis. In the ME model, certain calculated responses, such as subgradestrain and pavement layer stress and strain, together with other variables, such as accumulated traffic load andenvironmental conditions, are related to loss of serviceability or some other measure(s) of deterioration throughregression analysis or a model that is calibrated (i.e., the coefficients are determined) through regression analysis (8).
One of the most widely used empirical pavement performance prediction models for flexible pavement is the empiricaldesign equation used in the American Association of State Highway and Transportation Officials (AASHTO) 1993
design guide. The model empirically links pavement performance to various external and internal factors such as547

accumulated traffic loading, soil properties, and environmental conditions. In the past two decades, this empirical model
has been shown to be inadequate for representing the complex failure modes of flexible pavement in the field becauseof its limited ability to predict pavement performance in the field. In addition, the models developed for the AASHTO
Road Test relate key pavement properties and traffic to performance but do not consider the range of climatic effects
that can also contribute to pavement distress (9, 10). To address some of the limitations of AASHTO 1993 design
equation, AASHTO in 2004 launched the MEPDG. This new design procedure incorporates mechanistic principles,
including calculations of pavement stress, strain, and deformation responses, by using site-specific climatic, material,
and traffic characteristics (11). In the ME model, the climatic effects such as temperature, moisture content, and otherenvironmental parameters in the pavement structure and subgrade are considered using an enhanced integrated climate
model (EICM) (12). Richter and Witczak used the EICM to evaluate moisture prediction capability and determined thatthe model could sometimes reasonably estimate the in situ moisture content of unbound pavement materials and that it
might not work well for sites in arid climates (13). Salem performed a sensitivity analysis of the EICM by varying thecrack lengths in the drainage and infiltration model, and the results showed no significant difference in the EICM
volumetric moisture prediction. Thus, the EICM could predict the seasonal variation in the subgrade moisture only
when the seasonal variation of groundwater at each season is known (14).
Therefore, the present study investigated the impact of various climate scenarios on the service life and life
cycle cost (LCC) analysis of provincial and urban flexible pavement roads in Taiwan to develop resilient maintenanceand rehabilitation (M&R) strategies. To achieve this objective, historical climate data collected from the northern andsouthern regions of Taiwan were used as a baseline scenario, and future climate change scenarios projected for 2020 to2039 in Taiwan’s northern and southern regions were compared against the baseline scenario. The EICM was used toestimate the volumetric moisture condition of the unbound layers (base and subgrade) of the pavement structure model.
Pavement service life and LCC were estimated under the historical and predicted climate scenarios by using the
AASHTO 1993 and AASHTO ME performance models.
2.

RESEARCH METHODOLOGY
Two pavement performance models, AASHTO 1993 and AASHTO ME, were employed to predict theperformance of two provincial road pavement sections located in the northern and southern parts of Taiwan. EICM
Version 3.0 was used to predict the climate effect and compute the unbound material mechanical properties undervarious climate considerations. The results were used in the AASHTO 1993 design to predict pavement performance.
The AASHTO ME, which also uses the EICM as a climate tool, was employed to predict the pavement performance
under the same climate considerations to investigate the impact of extreme climate events on the pavement service life.
An LCC analysis was also performed for an analysis period of 30 years.
2.1.

Climate data collection
Two weather stations, one located in Wenshen District (Northern Taiwan) and the other in Yongkang District(Southern Taiwan), were identified for this study. Wenshen District is in the southernmost part of the Taipei Basin. It
lies approximately along the coordinates of 25°N, 122°E (Wenshan-District 2014, May 13) (19). Yongkang District islocated along the coordinates of 23°N, 120°E (Yongkang-District 2014, May 26) (20). The 10-year historical climate
data from 2003 to 2012 for temperature, rainfall, wind speed, sunlight hours, sunrise, and sunset (recorded on an hourly
basis from the two weather stations) were obtained from the Central Weather Bureau. Information on the ground watertable depth variation of Taipei and Tainan Station were also obtained from the Department of Water Resources.
The variation in temperature, ground water depth, and rainfall are illustrated respectively in Figure 1 to Figure
3. Figure 1 shows that, throughout the recorded period, the mean maximum temperature in Taipei is slightly higher thanthat in Tainan. Conversely, the minimum temperature in Tainan is higher throughout the same period. Figure 2 showsthat the average ground water depth in Taipei is 5.0 m, which depicts a relatively constant slope over the period.
Tainan, however, has a considerably lower ground water table. The water depth ranges between 10.63 and 6.00 m. A
low water table was first observed at the beginning of the period, followed by a steady rise to 6 m during 2009, when it
subsequently dropped again steadily. The ground water depth in Taipei is 5.63 m higher than that in Tainan. Finally,
Figure 3 shows that the total annual rainfall in Taipei ranges between 1656 and 3824 mm. In Tainan, the total rainfall is
between 1012 and 3125 mm; during the study period, the highest rainfall was recorded in 2005.
Temperature, º C

TaipeiTainan

32
28
24
20
16
12
0

12

24

36

48

60
72
84
96
Time in Month
Figure 1. Average monthly temperature for Taipei and Tainan.

108

120

548

Ground Water Table, mAnnual Rainfall, mm

TaipeiTainan

12
10
8
6
4
2
0

4500

12

24

36
48
Time in months

60

72

84

96

Figure 2. Average monthly ground water depth in Taipei and Tainan.
TaipeiTainan

3750
3000
2250
1500
750
2003

2004

2005

2006

2007
2008
2009
2010
Year
Figure 3. Total annual rainfall in Taipei and Tainan.

2011

2012

2.2.

Climate scenarios
The extreme climate events assumed in this study are consistent with the climate change report, Climate
Change in Taiwan: Scientific Report 2011, published by the National Science Council and based on the research of the
TCCIP. The extreme climate events for temperature and rainfall were projected for 2020 to 2039 under Scenarios A1B,
B1, and A2 among all the regions of Taiwan. The regional mean changes in temperature in degrees Celsius and rainfall
in percent for the future climate under these scenarios were used at 10th and 90th percentile changes for winter(December, January, and February), spring (March, April, and May), summer (June, July, and August), and autumn(September, October, and November). Six climate scenarios, designated A1B.10, A1B.90, B1.10, B1.90, A2.10, andA2.90, were constructed for each study site (Figure 4to Figure 7).
As described in the SRES (15), the A1 storyline and scenario family simulates a future world with very rapid
economic growth, global population peaking during the midcentury and declining thereafter, and the rapid introductionof new and more efficient technology; by contrast, the A1B scenario is a balance among all the sources considered in
the A1 scenario. The A2 scenario is a heterogeneous world that results in increasing global population; it has slower
economic growth and technological change than the other storylines do. The B1 scenario is a convergent world with thesame global population as that in A1. The B2 scenario is a world where emphasis is on local solutions to economic,
social, and environmental sustainability. The last two numbers in the designations are for 10th and 90th percentile
changes in mean temperature and rainfall, which represent the extreme cases investigated in this study. These changes
were applied to historical climate data (2003–2012) to determine their effectiveness for predicting future climatechange.
Historical

A1B90

B190

A290

A1B10

B110

A210

Temperature, C

25.5
24.5
23.5
22.5
21.5
1

2

3

4
5
6
7
8
9
10
Time in Years
Figure 4. Mean annual temperature for historical (2003–2012) and future climate change scenarios (2020–2039) in
Taipei.

549

Historical

A1B90

B190

A290

A1B10

B110

A210

Temperature, º C

26.5
25.5
24.5
23.5
22.5

5
6
7
8
9
10
Time in Years
Figure 5. Mean annual temperature for historical (2003–2012) and future climate change scenarios (2020–2039) in
Tainan.
Historical
A1B90
B190
A290
A1B10
B110
A210
5000
Annual Rainfall, mm

1

2

3

4

1

2

3

4

3500
2000
500

5
6
7
8
9
10
Time in Years
Figure 6. Total annual rainfall for historical (2003–2012) and future climate change scenarios (2020–2039) in Taipei.

Total Rainfall, mm

Historical

A1B90

B190

A290

A1B10

B110

A210

5000
3500
2000
500
1

2

3

4

5
6
7
8
9
10
Time in Years
Figure 7. Total annual rainfall for historical (2003–2012) and future climate change scenarios (2020–2039) in Tainan.
2.3.

Pavement materials
A typical three-layer pavement system was used as a baseline case in this study. This comprises 15 cm of hot
mix asphalt (HMA) and 30 cm (11.81 in.) of base and subgrade layers. The materials for the pavement were selectedaccording to the AASHTO 1993 and National Cooperative Highway Research Program (NCHRP) 2004 design
specifications. The typical range of values for soil index properties such as percent passing #4, #200 sieves, Atterberg
limit test plasticity index (PI), and liquid limit (LL) (AASHTO T27) were determined from a literature survey. Resilient
modulus of 3,100 MPa was assumed for the HMA. Values of 1.64 and 1.09 Watt/(m)(K) as well as 0.38 Watt/(m)(K)were assumed for the surface absorptivity and heat capacity as well as the thermal conductivity, respectively. Typicalvalues recommended for these properties as Level 3 inputs for the AASHTO ME design analysis (16). Base materials
corresponding to A-1-a of the AASHTO Soil Classification System and material gradation conforming to AASHTO
M147 specifications for road base materials were assumed. Typical value ranges for P4, P200, PI, and LL wereobtained from the literature; the average values were used to estimate the material properties. Among the EICM Level 2
inputs, P200 and PI correlated with the other material properties, namely the specific gravity (Gs), optimum degree ofsaturation (Sopt), and porosity (), in obtaining the gravimetric water content (wopt) and maximum dry unit weight of thematerials under the assumption of standard compaction as per AASHTO T180 (16). Similarly, the material properties
for the subgrade layer as Level 2 inputs were estimated using the aforementioned procedure for the base layer. The
layer material was assumed to be A-6.
2.3.1.

Time series material property for unbound materials
The volumetric water profiles obtained from the EICM analysis under historical and predicted climates wereused to estimate the degree of saturation in the base and subgrade layers over time. The resilient modulus, as thefundamental pavement mechanical material property, was estimated as a function of the degree of saturation in the baseand subgrade layers. Extant predictive models account for the variation in the resilient modulus with the moisture.

550

Through the application of these models, the model in Equation 1 can be selected to analytically predict changes in themodulus resulting from changes in the moisture, and this model is currently implemented in the EICM [21].
Equation 1
𝐿𝑜𝑔[𝑀𝑅 /𝑀𝑅 opt ] = 𝑎 + [(𝑏 − 𝑎)/(1 + 𝐸𝑋𝑃 × (𝛽 + 𝐾𝑠 × (𝑆 − 𝑆opt )))]
where,
a = minimum of log MR/MR opt;
b = maximum of log MR/MR opt;
β = location parameter, obtained as a function of a and b = ln(-b/a);
KS = regression parameter; andS-Sopt = variation in the degree of saturation (expressed as a decimal).
Equation 1, which was implemented by the MEPDG, was used to estimate the time series resilient moduli of
the base and subgrade layers. The 10 years’ monthly resilient moduli values for the base and subgrade layers were thus
obtained under the historical and future climate change scenarios. The time series moduli estimated from historicalclimate data were used to project the resilient moduli of the base and subgrade layers for the 11th year. Thus, themonthly time series moduli of the base and subgrade layers were obtained for the 20-year design period.
Traffic estimation
Typical four-lane urban roads in Taiwan were modeled for this study. Traffic was analyzed according to thetypes of truck commonly used for freight transportation in Taiwan (17). These trucks were then classified using the
MEPDG vehicle class system and redistributed with the obtained truck factors. An average annual daily truck traffic of1500 was assumed, and the distribution factors recommended by AASHTO 1993 for the direction (D) and lane (L) wereobtained as 0.5 and 0.94, respectively. A plot of the cumulative ESALs versus time is shown in Figure 8.
8
ESALs in Millions

2.4.

6

Cummulative ESALs

4
2
0
0

2.5.

24

48

72

96

120
144
168
192
216
MonthsFigure 8. Plot of 18-kip cumulative ESALS versus time for baseline case.

240

Pavement performance evaluation

2.5.1.

Pavement service life estimation using the AASHTO 1993 design method
The pavement structural number (SN) was used as a measure of the overall structural capacity of the pavement
structure at any given period. The objective was to determine the pavement SN at 1-month time intervals for the entire
design life. Structural layer coefficient a1 for HMA was estimated using Equation 2 [22]. The layer coefficient a2 for thebase was estimated from the time series base modulus by using Equation 3, which is provided in the AASHTO (1993).
The SN was evaluated using Equation 4. The initial and terminal present serviceability indices assumed were 4.2 and
2.0, respectively. The SN and ESAL values obtained were used to compute the loss of serviceability ∆PSI for thebaseline, historical, and future climate change scenarios by using the AASHTO 1993 pavement equation. The input
parameters assumed for the equation are 90, −1282, and 0.45 for the reliability, reliability factor, and overall standard
error, respectively. The obtained ∆PSIs versus the ESALs were plotted, and the pavement service life was thus
determined under the baseline, historical, and future climate change scenarios.
In the estimation of the SN and pavement service life, three cases were considered for both test sites. The valueof the drainage coefficient was assumed to vary with the climate scenarios, in which the layer coefficients weremodified according to environmental conditions. Drainage coefficients of 1.0, 1.1, and 0.8 were assumed for the meanchange in the historical, 10th and 90th percentiles, respectively. This assumption premised that the drainage coefficient
will change according to the projected future climate relative to the historical climate. The reason for varying thedrainage coefficient was to simulate pavement exposure to various moisture scenarios. For the 90th percentile
scenarios, the projected rainfall will increase in the future; thus, the same drainage design might not adequately
discharge the water in a short time. This will increase the time of pavement exposure to moisture approaching thesaturation level compared with the historical climate, hence the lower drainage coefficient. By contrast, the 10th
percentile scenarios project less rainfall in the future, resulting in drier pavement conditions and a shorter discharge
time for water. Therefore, in the present study, a higher drainage coefficient was used relative to the historical climate.
Equation 2
𝑎1 = 0.4 × 𝑙𝑜𝑔(𝐸𝐻𝑀𝐴 ⁄3000𝑀𝑃𝑎 ) + 0.44, 0.2 < 𝑎1 < 0.44
Equation 3
𝑎2 = 0.249(𝑙𝑜𝑔10𝐸𝐵𝑆 ) − 0.977
where;551

a1 = structural layer coefficient for HMA;
a2 = structural layer coefficient for the base layer;
EBS = layer resilient modulus; andEHMA = resilient modulus of HMA.
SN = a1D1 + a2D2m2
where,
a1 = structural layer coefficient for HMA;
D1 = thickness of HMA;
D2= thickness of the base layer; and𝑚2 = drainage coefficient.

Equation 4

2.5.2.

Pavement service life estimation (MEPDG) model
The climate files for the historical and predicted climate scenarios prepared for the EICM were converted into
integrated climate model (ICM) climate files. The pavement configuration and unbound material properties described in
the preceding sections for the EICM moisture prediction were assumed for the MEPDG analysis, and these were also
used in the EICM for climate modeling. Vehicle class and an ADTT of 1500 were assumed for the MEPDG traffic
analysis. MEPDG traffic default values were used for the remaining information on traffic. HMA properties were used
for the super-pave binder option at Level 2 inputs. The cumulative percentages retained on 3/4-in., 3/8-in., #4 sieve, andpercent passing #200 sieves were obtained in accordance with the ASTM D3515 gradation specifications for dense
asphalt mixtures. Typical effective binder content, air voids, Poisson’s ratio, and total unit weight of asphalt concreteare 5.0%, 4.0%, 0.35, and 2.35 kg/m3, respectively, as obtained from average historical job mix formula reports.
MEPDG was used to analyze the pavement distress under the historical and future climate change scenarios. The
distress of top-down cracking, fatigue cracking, AC rutting, total rutting, and smoothness, known as the internationalroughness index (IRI), are defined for HMA. The target values set for the distress are given as (a) top-down cracking =190 m/km; (b) fatigue cracking = 25%; (c) AC rutting = 6 mm, (b) total rutting = 20 mm, and (c) IRI =2.69 m/km at areliability of 90.
2.6.

LCC analysis
The service life of pavement depends on various factors including environmental factors such as temperatureand precipitation (18). The typical LCC analysis period ranges between 25 and 50 years. In the present study, an LCC
analysis was performed for a pavement section of 16 km. under baseline, historical, and future climate change scenarios
over a 30-year analysis period. No routine and preventive maintenance activities were assumed to be applied during thepavement service life. Thus, pavement sections were assumed to receive a major rehabilitation at the end of the service
life, and the serviceability was assumed to be reintroduced as a new construction status. The labor and user cost was
assumed to be constant for all the cases and therefore did not affect the analysis. For the purpose of this study, the LCC
analysis considered only the initial construction cost and the cost of rehabilitation at the end of the service life predictedusing the AASHTO 1993 and AASHTO ME performance models.
The initial construction cost was determined from the construction material quantities, such as the HMA, base,and subgrade layers (estimated tonnage), for a section of pavement. Unit prices for the materials were obtained as per
Taiwan’s current unit rates. The pavement was assumed to be rehabilitated to return it to near original condition as soon
as it reaches the end of its service life; this was achieved by restoring the HMA thickness to its original thickness. The
initial and rehabilitation cost at the current dollar value can then be obtained, and the future cost is discounted tocompute the net present value (NPV) as shown in Equation 5. The pavement remaining or the residual value at the endof the analysis period and the LCC under different climate considerations (including the baseline) were thus determinedusing Equation 6 and Equation 7, respectively.
𝑁

NPV = Initial Cost + ∑Rehab. cost 𝑘 [1/(1 + 𝑖)𝑛 ]Equation 5

𝑘=1

where,
𝑖 = discount rate; and𝑛 = year of expenditure.
𝑅𝑒𝑠𝑖𝑑𝑢𝑎𝑙 𝑉𝑎𝑙𝑢𝑒 = 𝐿𝑎𝑠𝑡 𝑅𝑒ℎ𝑎𝑏. 𝐶𝑜𝑠𝑡 × [(𝑆𝑒𝑟𝑣𝑖𝑐𝑒 𝐿𝑖𝑓𝑒 – 𝐴𝑐𝑡𝑖𝑣𝑖𝑡𝑦 𝐴𝑔𝑒)/𝑆𝑒𝑟𝑣𝑖𝑐𝑒 𝐿𝑖𝑓𝑒]𝐿𝐶𝐶 = 𝐼𝑛𝑖𝑡𝑖𝑎𝑙 𝐶𝑜𝑠𝑡 + 𝑇𝑜𝑡𝑎𝑙 𝐷𝑖𝑠𝑐𝑜𝑢𝑛𝑡𝑒𝑑 𝑅𝑒ℎ𝑎𝑏. 𝐶𝑜𝑠𝑡 − 𝑅𝑒𝑠𝑖𝑑𝑢𝑎𝑙 𝑉𝑎𝑙𝑢𝑒
3.

Equation 6
Equation 7

RESULTS AND DISCUSSION

3.1.

Mechanical properties of unbound materials
The material properties of the pavement layers and the resilient moduli of the base and subgrade layers were
estimated using the saturation results. The average resilient moduli estimated for the base and subgrade layers over the
pavement performance period in Taipei were 197 and 49 MPa, respectively. In Tainan, 205 and 54 MPa were estimatedfor the base and subgrade layers, respectively, under the historical climate conditions.

552

Future climate under 10th percentile change
The percentage decrease in the base and subgrade moduli for the A1B.10, B1.10, and A2.10 scenarios relative
to the baseline are shown in Figure 9and Figure 10. The base and subgrade moduli predicted for Taipei were slightly
less than those predicted for the historical climate conditions. By contrast, the modulus values predicted for Tainan forthe base and subgrade layers were higher than those for the historical climate conditions. The decrease in the basemodulus for Taipei ranged between 10.5% and 11.0%. A decrease in the base modulus values between 6.7% and 7.4%
was observed in Tainan. The percent reduction in the subgrade modulus was between 28% and 29.2% in Taipei. Tainan
showed a 22.0%–23.9% decrease. The subgrades the percentage decrease in the modulus for A1B.10, B1.10, and A2.10
ranged between 28.0% and 29.2% in Taipei. In Tainan, the percentage decrease ranged between 23.5% and 24.1%.
Decrease in Modulus %3.2.

Historical

A1B10

B110

A210

A1B90

B190

A290

15
10
5
0

TainanBase
Figure 9. Modulus decrease in the base layer under the historical and future climate scenarios.
Historical
A1B10
B110
A210
A1B90
B190
A290
35
30
25
20
15
10
5
0
TaipeiTainanSubgrade
Figure 10. Modulus decrease in the subgrade layer under the historical and future climate scenarios.

Decrease in Modulus %Taipei

3.3.

Future climate under 90th percentile change
No significant change was observed in the predicted base and subgrade modulus for the A1B.90, B1.90, andA2.90 scenarios in Taipei and Tainan. The base and subgrade moduli predicted for these scenarios were slightly lessthan those predicted for the historical climate conditions. This is consistent because the scenarios represent increasing
rainfall. The percentage decrease in the base moduli was 10.6% for all three future climatic scenarios in Taipei, which
was slightly higher than the moduli predicted for the historical climate conditions. In Tainan, a 6.9% decrease in thebase moduli for the three scenarios was observed, which was slightly less (by 0.2%) than the predicted modulus for thehistorical climate conditions, as shown in Figure 9. For the subgrade modulus, the variations were 1.1% and 0.6% in
Taipei and Tainan, respectively, as shown in Figure 10.
3.4.

Pavement performance prediction by AASHTO 1993 Performance Model
The SNs predicted for the historical and future climate change conditions are presented in Table 1. Higher SNs
were predicted for A1B.10, B1.10, and A2.10 for the historical climate conditions, whereas lower SNs were predicted
for A1B.90, B1.90, and A2.90 both in Taipei and Tainan. However, the SNs predicted for Taipei were lower comparedwith Tainan for both the historical and future climate scenarios. The difference between the SNs predicted for the 10th
percentile change and that predicted for the 90th percentile change was respectively 0.47 for Taipei and 0.49 for Tainan.
These changes reveal little or no variation in the SN between the 10th and 90th percentile changes. For the A1B.10,
B1.10, and A2.10 scenarios, the percent increase in the SN over the historical climate conditions was 7.7% in Taipei
and 7.6% in Tainan. The variations between the 10th and 90th percentile mean changes were 4.1% for Taipei and 3.6%
for Tainan.
Table 1. Average SN predicted for Taipei and Tainan.
Climate Scenarios
HistoricalA1B.10B1.10
A2.10
A1B.90

Taipei
4.17
4.32
4.32
4.33
3.85

Tainan
4.21
4.38
4.37
4.37
3.89

553

B1.90
A2.90

3.85
3.85

3.89
3.89

Pavement service life under baseline and historical climate Scenario
The service life for the baseline design, as predicted using the AASHTO 1993 model, was 20 years. The
pavement service life predicted for the historical climate conditions was 12.3 years in Taipei and 12 years in Tainan, as
shown in Figure 11 and Figure 12, respectively. The service life predicted for Taipei and Tainan was reduced by 7.7
years (39%) and 8.0 years (40%), respectively.
Baseline
Historical
A1B10
B110
A210
A1B90
B190
A290
4.5
4
3.5
3
2.5
2
1.5
0
2
4
6
8
10
12
14
16
18
20
Pavement Service Life in Years
Figure 11. Pavement service life predicted in Taipei.
Serviceability Loss(∆PSI)

Serviceability Loss(∆PSI)

3.4.1.

Baseline

Historical

A1B10

B110

4.5
4
3.5
3
2.5
2
1.5
0

2

4

6
8
10
12
14
Pavement Service Life in Years
Figure 12. Pavement service life predicted in Tainan.

16

18

20

3.4.2.

Pavement service life under the 10th percentile change scenario
The pavement service life predicted for the A1B.10, B1.10, and A2.10 scenarios in Taipei and Tainan are
shown in Figure 11 and Figure 12, respectively. The predicted service life ranged between 13 and 14 years in Taipei
and Tainan, respectively. However, the service life predicted for these scenarios showed a decreasing trend relative tothe baseline case; furthermore, increases relative to the historical climate conditions in Taipei and Tainan wereobserved, as shown in Figure 11 and Figure 12, respectively. Relative to the baseline in Taipei, the pavement service
life was predicted to drop by 32%, 31%, and 29% for the A1B.10, B1.10, and A2.10 scenarios, respectively. In Tainan,
the pavement service life was predicted to drop by 33% for A1B.10 and A2.10 and by 30% for B1.10, as shown in
Figure 13. The variation in the service life reduction was only 3% in Taipei and Tainan. Service life increased relative
to the historical climate conditions by 6% for A1B.10, 7% for B1.10, and 9% for A2.10 in Taipei. In Tainan, the service
life increased by 7% for A1B.10 and A2.10 and 10% for B1.10 relatives to the historical climate conditions. Variationof 3% was observed in Taipei and Tainan.
3.4.3.

Pavement service life under the 90th percentile change scenario
For all climates, the service life predicted for these scenarios was 8.5 years in Taipei and 9.0 years in Tainan.
The predicted service was reduced significantly relative to the baseline and historical climate conditions in both Taipei
and Tainan. Figure 13 shows the service life reduction as percentages for Taipei and Tainan. A 57% service life
reduction was predicted for all the scenarios in Taipei. In Tainan, a 53% decrease in service was predicted for A1B.90
and a 54% decrease was predicted for B1.90 and A2.90 relative to the baseline. In relation to the historical climate
conditions, the service life decreased by 19% for the three scenarios in Taipei. In Taiwan, the service life decreased by
13% for A1B.90 and 14% for B1.90 and A2.90.

554

Pavement service life%

Historical

A1B10
57

60

B110
57 57

A210

A1B90

B190
53

A290
54

54

50
40

38

40

32

31

30

33

29

30

33

20

TaipeiTainanFigure 13. Percent reduction in pavement service life for the historical and future climate conditions relative to thebaseline.
Pavement performance prediction by M-E performance model
Five pavement distresses performance were predicted by AASHTO M-E model under various climate scenario.
The pavement distress predicted for the top-down cracking, fatigue cracking, AC rutting, total rutting, and IRI weresimilar for all the future climate scenarios and historical climate conditions in Taipei and Tainan. The total rutting and
IRI predicted were far lower than their design limits of 19 mm and 2.69 m/km, respectively, for all the cases in Taipei
and Tainan. In all the cases, only HMA rutting and top-down cracking were predicted to have exceeded their design
limits of 6.35 mm and 190 m/km, respectively. The HMA rutting failed at Year 20 for all the climate cases consideredin Taipei and Tainan. However, top-down cracking failure was predicted at less than half of the pavement age in both
Taipei and Tainan, as shown in Figure 14 and Figure 15, respectively. In Taipei, distress failure varied slightly between
99 months (8.0 years) and 104 months (8.5 years) under all the climate scenarios considered in this study. The shortest
pavement service life was predicted for A1B.90. In Tainan, the predicted distress failure was 103 months (8.5 years) for
all the climate scenarios.
Hitorical-TPE
A1B.10-TPE
B1.10-TPE
A2.10-TPE
A1B.90-TPE
B1.90-TPE
A2.90-TPE
Criteria
400
Top-Down Cracking(m/km)

3.5.

200
0

AC Rutting (mm)060

Hitorical-TPE
A1B.90-TPE

8120
Pavement Service Life (month)(a)A1B.10-TPE
B1.90-TPE

180

B1.10-TPE
A2.90-TPE

240

A2.10-TPE
Criteria

6
4
2
0

120
180
240
Pavement Service Life (month)(b)
Figure 14 Pavement distresses prediction for (a) Top-Down Cracking and (b) AC Rutting of Taipei Site by MEPDG
performance model.
Top-Down Cracking(m/km)

060

Hitorical.TAN
A1B.90.TAN

400

A1B.10.TAN
B1.90.TAN

B1.10.TAN
A2.90.TAN

A2.10.TAN
Criteria

200
0
0

60

120
Pavement Service Life (month)
(a)

180

240

555

Hitorical.TAN
A1B.90.TAN

AC Rutting (mm)8A1B.10.TAN
B1.90.TAN

B1.10.TAN
A2.90.TAN

A2.10.TAN
Criteria

6
4
2
0
0

60

120
180
240
Pavement Service Life (month)(c)Figure 15 Pavement distresses prediction for (a) Top-Down Cracking and (b) AC Rutting of Tainan Site by MEPDG
performance model.
LCC analysis
The life cycle cost analysis for all the cases considered in the study was performed in analysis period of 30
years. The performance curves for all cases on which life cycle cost analysis was performed are shown in Figure 16 andFigure 17 for Taipei and Tainan under the AASHTO 1993 model. The total cost of pavement for the different climate
scenarios including the historical and baseline cases are presented in Table 2. The total cost of pavement for thebaseline is NT$152 million. The percent increase in pavement cost for the climate scenarios was determined relative tothe baseline case. The cost of the pavement for the historical climate conditions increased by 54% for Taipei andTainan. The percent increase in cost was 42% for A1B.10 and 38% for B1.10 scenarios in both Taipei and Tainan. The
percent increase in cost for the A2.10 in Taipei was 38% and was 46% increase in cost in Tainan. The percent increasein cost for the A1B.90, B1.90, and A2.90 scenarios was 92% in Taipei and 65% in Tainan, as shown in Figure 18. With
the ME model, the increase in the pavement cost for all the climates in Taipei and Tainan were 92% and 65% of thebaseline cost, respectively. The pavement cost in Tainan was 27% lower than that in Taipei for a similar prediction for
the 90th percentile mean change in the AASHTO 1993 model. The life cycle cost under the MEPDG model is shown in
Figure 19 . The increase in pavement cost for all the climates in Taipei is 92% of the baseline cost and 65% in Tainan.
It is seen that Tainan is 27% lower in pavement cost compare to Taipei similar to the prediction for 90 percentile meanchange in AASHTO 1993 model.
Baseline
Historical
A1B10
B110
A210
A1B90
B190
A290
4.5
4
3.5
3
2.5
2
1.5
0
2
4
6
8
10 12 14 16 18 20 22 24 26 28 30
Pavement Service Life in Years
Figure 16 Pavement life cycles in Taipei
Baseline
Historical
A1B10
B110
A210
A1B90
B190
A290
4.5
4
3.5
3
2.5
2
1.5
0
2
4
6
8
10 12 14 16 18 20 22 24 26 28 30
Pavement Service Life in years
Figure 17 Pavement life cycles in Tainan

Serviceability Loss(∆PSI)

Serviceability Loss(∆PSI)

3.6.

Table 2. Total pavement life cycle costs in millions (NT$)
Climate Scenarios
Baseline
Historical
A1B10
B110
A210

Taipei
152
234
215
209
209

Tainan
152
234
215
209
221

556

A1B90
B190
A290
A1B10
B110
92 92 92

Increase in Cost %Historical
100

292
292
292
A210

250
250
250
A1B90

B190

80
60
40

54

65

54
42

38

42

38

38

A290
65

65

46

20
0
TaipeiTainanFigure 18 Percent increase in pavement cost (AASHTO 1993 model)

Increase in Cost %

100
80

92
Taipei
65

Tainan

60
40
20
MEPDG
Figure 19 Percent increase in pavement cost for all climates (MEPDG model)

4.

CONCLUSIONSThe primary goal of this study was to investigate the impact of various extreme climate change scenarios on
the flexible pavement service life and LCC to develop resilient M&R strategies from the perspective of highway
agencies. During the study, two widely used pavement performance models in pavement design, AASHTO 1993 and
MEPDG, were employed to investigate the service life of a typical three-layered pavement system for Taiwan’s city andcounty roads in the northern and southern regions under various future climate projections. The use of the EICM, whichis the main climatic tool in the MEPDG performance model, was also incorporated into the AASHTO 1993
performance model for climatic considerations. The study revealed that by incorporating the EICM into the AASHTO
performance model, the variation of the unbound material mechanical properties (resilient modulus) and pavement
structural capacity under the various climate changes were addressed. The two models, AASHTO 1993 and MEPDG,
also addressed the pavement service under the various climate scenarios, including the historical climate conditions,
upon which LCC models were established, showing that future maintenance and operations are affected by thechanging climates. Therefore, the framework developed may be a suitable model that can be followed by highway
agencies to incorporate climate change into the planning, design, construction, and maintenance of new and existing
pavement structures.
5. REFERENCES(1) Houghton, J.T., Jenkins, G.J. and Ephraums, J.J., 1990. Climate Change: The IPCC Scientific Assessment,
Cambridge University Press, Cambridge, Great Britain, New York, NY, USA and Melbourne, Australia, 410 pp.
(2) IPCC, 2014: Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth
Assessment Report of the Intergovernmental Panel on Climate Change [Core Writing Team, R.K. Pachauri and
L.A. Meyer (eds.)]. IPCC, Geneva, Switzerland, 151 pp.
(3) Nakicenovic, N., Alcamo, J., Davis, G., De Vries, B., Fenhann, J., Gaffin, S., Gregory, K., Grübler, A., Jung, T.Y.,
Kram, T., and others, 2000. Special report on emissions scenarios, working group III, Intergovernmental Panel on
Climate Change (IPCC). Cambridge University Press, Cambridge, 595pp.
(4) Hsu, Huang-Hsiung and Chou, Chia and Wu, YC and Lu, Mong-Ming and Chen, CT and Chen, Y., 2011. Climate
Change in Taiwan: Scientific Report 2011. National Science Council, Taipei, Taiwan, ROC, 67pp.
(5) Ankit, G., Kumar, P., & Rastogi, R. (2011). Effect of Environmental Factors on Flexible Pavement Performance
Modeling. Paper presented at the 8th International Conference on Managing Pavement Assets Satiago, Chile.
(6) Haas, R., L.C. Falls, MacLeod, D., & Tighe, S. (2004). Climate Impacts and Adaptations on Roads in Northern
Canada. . Paper presented at the Cold Climates Conference,, Regina, AB. 2004.
(7) Li, B.Q., Mills, L., and McNeil, S., 2011. The Implications of Climate Change on Pavement Performance and
Design. University of Delaware University Transportation Center.
(8) Haas, Ralph, 2003. Good technical foundations are essential for successful pavement management, key note paper,
proceedings of MAIREPAV’ 03, Guimaraes, Portugal.

557

(9) Schwartz, C.W. and Carvalho, R.L. (2007). Implementation of the NCHRP 1-37A Design Guide Final Report
Volume 2: Evaluation of Mechanistic-Empirical Design Procedure. MDSHA Project No. SP0077B41, Maryland
State Highway Administration, Lutherville, MD.
(10) Zhang, Z., J.P. Leidy, I. Kawa, and W.R. Hudson. (2000). Impact of changing Traffic Characteristics andEnvironmental Conditions on Flexible Pavement. Transportation Research Record 1730, Washington, D.C., pp.
125-131.
(11) American Association of State Highway and Transportation Officials (AASHTO). (2008). Mechanistic-EmpiricalPavement Design Guide. AASHTO Designation: MEPDG-1. Washington, D.C.
(12) Lytton, R.L., Pufahl, D.E., Michalak, C.H., Liang, H.S., and Dempsey, B.J., 1993. An integrated model of theclimatic effects on pavements.
(13) Richter, C.A. and Witczak, M.W., 2001. Application of LTPP Seasonal Monitoring Data to Evaluate Volumetric
Moisture Predictions From The Integrated Climatic Model. In: Transportation Research Board 80th Annual
Meeting, Washington, DC.
(14) Salem, H., 2004. Monitoring and Modeling Subgrade Soil Moisture for Pavement Design and Rehabilitation in
Idaho Phase III: Data Collection and Analysis, 0010 (May 2005).
(15) Nakicenovic, N., & Swart, R. (2000). Special Report on Emissions Scenarios, Edited by Nebojsa Nakicenovic andRobert Swart, pp. 612. ISBN 0521804930. Cambridge, UK: Cambridge University Press, July 2000..
(16) NCHRP. (2004). Guide for Mechanistic-Empirical Design of new and rehabilitated pavement structures, Final
Report, Part 2 Design Inputs, Chapter 3. Environmental Effects.
(17) Chou, C., 1996. Effect of overloaded heavy vehicles on pavement and bridge design. Transportation Research
Record: Journal of the Transportation Research Board, (1539), 58–65.
(18) Hein, D. K., & Smith, D. R. (2009). Life-Cycle Cost Comparison for Municipal Road Pavements. Paper presented
at the 9th. International Conference on Concrete Block Paving, Buenos Aires, Argentina, 2009/10/18-21
Argentinean Concrete Block Association (AABH) - Argentinean Portland Cement Institute (ICPA) Small Element
Paving Technologists (SEPT).
(19) Wenshan-District. (2014, May 13). In Wikipedia, The Free Encyclopedia. Retrieved 01:19, June 16, 2014, fromhttp://en.wikipedia.org/w/index.php?title=Wenshan_District&oldid=608462398.
(20) Yongkang-District. (2015, May 26). In Wikipedia, The Free Encyclopedia. Retrieved 01:24, June 16, 2014, fromhttp://en.wikipedia.org/w/index.php?title=Yongkang_District&oldid=610179573.
(21) Witczak, M., Andrei, D., & Houston, W. (2000). Resilient modulus as function of soil moisture–Summary of
predictive models. Development of the 2002 Guide for the Development of New and Rehabilitated Pavement
Structures, NCHRP, 1-37.
(22) Hossain, M., Habib, A., and Latorella, T. (1997). Structural layer coefficients of crumb rubber-modified asphalt
concrete mixtures. Transportation Research Record: Journal of the Transportation Research Board, (1583), 62-70.

558

6 Critical Steps to Manage Your Pavement Assets without
Breaking the Bank
By Sui Tan, PE, Program Manager, Metropolitan Transportation Commission

Abstract
With oil pricing falling, it has created ripple effects on businesses. Companies are tightening
their budget and monitoring costs more closely. In managing pavement assets, many agencies
are becoming more cost-conscious on infrastructure investment as well. The worst strategy will
be to defer all maintenance. However, deferring maintenance will only exacerbate the problem
and create larger fiscal potholes.
By following the six critical steps, it doesn’t matter whether you are just about to implement a
new pavement management system or managing an existing system, whether you are in public
sections or private entities, every step is designed to reduce costs, improve cost-efficiency, andpromote infrastructure sustainability. In return, these steps help improve customer satisfaction
and deliver accountability and transparency to motoring public, and minimize lifecycle costs on
managing and maintaining pavement assets.

Introduction
Having a sustainable transportation infrastructure is the ultimate goal for asset managers whoplan, manage, operate, and maintain. However, to reach the goal, managers will have toovercome many obstacles. Over the last 30 years, the growing concern is about financial
sustainability to preserve the current transportation systems. There is an alarmingly increasing
recognition that when budget is tight, short-term decisions are made on investment,
maintenance, and preservation of infrastructure. Pavement asset, the backbone of thetransportation system, as a result, suffered from the lack of long-term sustainability solutions.
Coupled with the continued public demand for transportation services, we are seeing more
potholes in the streets and more damages to our vehicles resulting in higher vehicle operating
costs. Transportation professionals recognize these consequences and have gradually adopted
asset management approach to optimize the public’s return on their investment. However, toeffectively implement a pavement management system (PMS) can be a daunting task if notproperly planned. Hence, it is the objective of this paper to demystify and simplify the businessprocess to manage your PMS.

559

There are six critical steps or business processes that made up the framework of an effective
PMS as shown in Figure 1, namely inventory, condition assessment, needs assessment,
prioritization, investment analysis, and feedback.

Figure 1. Framework of an effective PMS

Step 1: Inventory
To setup an effective PMS, you will need to setup an inventory system of the road network that
supports the agency’s goals and needs. If you are starting from scratch, it is necessary to knowwhat types of records to maintain. Too often, mistakes are made to collect too many attributes
that ultimately impede the implementation and discourage ongoing maintenance of data. Hereare the key questions to ask:
1. What level of agency decision will be supported?
2. Are resources available to support decisions?
There are typically three levels to support pavement management decisions. First, at strategiclevel, decision is made to support the overall long-term sustainability of the pavement
management program. This is where investment decisions and policies are made at the highest
level within an organization. The detail of data at this level is very low. Second, at the network
level, strategies are identified based on agency’s goals. At this level, the overall maintenanceneeds are considered at the entire road network. Typically, at network planning level, multiyearof maintenance and rehabilitation (M&R) programs are developed. Even though the detail of560

data has increased moderately, the required data is still very manageable. For example,
maintenance policy may include just thin asphalt concrete overlay instead of more specifictreatment like 0.75” (19mm) ultra-thin bonded wearing course. Finally, at project level,
decisions made are localized to specific locations and design specifications. Data collected at
this level maybe very detailed. Agencies, large or small, should weigh in on how muchinformation is needed at this level, and the resources to maintain it.
For majority of the agencies, large or small, using PMS that designed as a network-level
planning tool is sufficient. The following guidelines will help pavement managers to determine
the detailed of inventory:

Identify minimum data requirements for network-level decisions
Data collection is costly; collect only what is needed.
Consider PMS software that is easy to use and maintain.

Step 2: Condition Assessment
Once inventory is established, it is imperative to determine the type of pavement rating
protocol to use. It is true that there are many pavement rating protocols in the market. Somehas risen due to local needs, while others are more subjective rating. However, it is important
not to reinvent the wheel by creating a custom rating for in-house use. The problem is this inhouse expert team may retire, change job or be promoted, taking the institutional knowledge
along.
Some main characteristics to consider are:

Distress information provides early intervention of preventive maintenanceRating protocol is supported by recognized organization
Rating protocol is widely used
Rating protocol can be easily adopted for manual and automated surveys

The industry standards are the FHWA’s Distress Identification Manual for the Long-Term
Pavement Performance Program and ASTM D6433- Standard Practice for Roads and Parking
Lots Pavement Condition Index Surveys. The LTPP is geared toward state highways, while ASTM
D6433 is suitable for local municipalities. The ASTM D6433 is based on pavement surface
distress, severity, and quantity. It uses a composite pavement distress index called Pavement
Condition Index (PCI) with a rating scale of 0-100, where 100 means new pavement, while zeromeans pavement needs reconstruction.
As far as conducting the pavement condition survey, agency can choose to do walking survey byusing 2,500 ft2 (232 m2) sample size (Shahin, M.Y., 2005). By using a sampling technique, agency
will reduce substantial effort in resources. For agencies performing in-house survey, the mostefficient use of staff time is after construction season is over. Pavement distress survey training561

is available at the Metropolitan Transportation Commission (MTC) or at the Colorado State
University. For most agencies, it is recommended that roads with heavy traffic such ascollectors and above are surveyed every two years, while low volume roads or parking lots canbe surveyed at four to five-year interval.
If you have heard the saying “I don’t trust the data”, it is possible that the PMS has fallen to the“garbage in, garbage out” symptom, which is the worst enemy of an effective PMS. Hence it isequally important is to establish a data quality management plan. In recent years, there havebeen several publications that discussed about best practices on data quality management(NCHRP Synthesis 401). The Practical Guide for Quality Management of Pavement Condition
Data Collection, published by FHWA in 2013, is probably the best guide available today. This
guide documents the procedures and frequency of pavement survey, quality control for datacollection, and data assurance.
The key takeaways for condition assessment are:Commit to condition assessment at regular interval
For network-level planning, assessment by sampling is the most cost-effective way
Set up a data quality management plan

Step 3: Needs Assessment
It may be easy to come up with a list of streets to fix annually for a small network. When it
comes to developing multiple years of M&R projects, however, the pavement managers that“know the streets like the back of their hands” will be overwhelmed. This is because pavements
deteriorate constantly, by projecting pavement conditions to future years, coupled with traffic,
environmental, social, and economic factors, the decisions are increasingly harder to make. This
is when a PMS software will be useful to develop the short term capital improvement program
and the long term transportation investment plan.
For each treatment setup in the decision tree, trigger rules must be established as shown in
Figure 2, to define when a treatment is triggered once a set of pavement condition is met.
Agency will be able to establish treatment type and trigger values based on local maintenancepolicies. The PMS software should be flexible to setup network-level type of treatment for
preventive maintenance, rehabilitation, and reconstruction.

562

Figure 2. Setting up treatment trigger rules (StreetSaver®)Based on the decision tree established, the PMS tool should be capable of integrating apavement preservation approach (Tan et al, 2011). There will be two lists of streets thatneeded work generated. The first list should consist of streets that require pavement
preservation, including preventive maintenance (PM). This type of treatment is applied topavement in relatively good condition, typically at PCI around 70 as shown in Figure 3. It is acost-effective way to extend the service life of pavement without adding structural capacity.
The other list consists of streets that need minor and major pavement rehabilitation. These
treatments are applied typically for PCI between 25 to 70, while reconstruction for PCI below
25.

563

Figure 3. Decision tree illustrates integration of pavement preservation (StreetSaver®)

Along with the lists, there should be treatment costs to fix these street segments, categorized
by preventive maintenance, minor and major rehabilitation, and reconstruction. This entire
M&R plan, which consists of streets to be treated with costs, constitutes the road maintenanceneeds assessment. It usually includes the entire road network. As such, if M&R is performed, it
will improve the overall network PCI to 80’s, which is considered the state of good repair.
Key takeaways:


Decision tree must be able to support preventive maintenance, minor and major
rehabilitation, and reconstruction
Decision tree promotes pavement preservation

Step 4: Prioritization
In ideal situation, agency will have sufficient funding to address all of its pavement needs. In
reality, however, only a few agencies have adequate funding to meet their needs.
Consequently, many agencies are relying on their PMS to allocate the limited funding in themost cost effective way. It is crucial to understand how the PMS prioritizes. By all means, avoid
PMS that performs ranking since the common approach to ranking is to select the worst
condition of the roads as the highest priority.
Instead, there are plenty of good PMS software provide near optimal solutions. The
underpinning of cost effectiveness is to maximize benefits while minimize costs. The benefit oreffectiveness, as illustrated in Figure 4, is defined as the area under the improved performance
curve. To perform the benefit-cost analysis, the area is divided by cost to derive with the564benefit-cost ratio. Preventive maintenance, which is typically applied at good condition, will
have the highest ratio when compared to reconstruction, when the condition is poor or failed.
In the strict economic sense, PMS that emphasizes on preventive maintenance will have better
condition over longer term, giving better return of investment as it costs less to maintain.

Figure 4. Illustration of cost effectivenessIn summary, the key takeaways are:

Select a PMS that has a strong emphasis on preventive maintenance
Avoid PMS that relies on ranking that is based on priority. Instead, focus on costeffectiveness approach.

Step 5: Investment Analysis
At its most basic level, a PMS software should be able to answer questions such as:What is the existing overall pavement condition?
How much maintenance dollars are currently invested?
How much investment is needed to achieve the state of good repair

What set apart an effective PMS software from an ordinary one is the robustness in investment
analysis. Some of the commonly use of pavement management results are (AASHTO 2012):








Assessing maintenance needs for local, regional, and statewide(http://SaveCaliforniaStreets.org)
Illustrating the impact of funding alternatives
Spatially display the results in GIS maps
Identifying candidate projects for maintenance and rehabilitation
Setting performance-based funding allocation (Romell and Tan 2010)
Setting performance targets (Tan 2015)
Long-term planning for sales tax measures and regional transportation plan of
metropolitan planning organization (MPO) (Plan Bay Area 2040)

565



Sharing regional pavement condition for accountability and transparency (The Pothole
Report 2011)

In the United States, since the last transportation act enacted in 2012, there is an increasingly
focus of performance management on pavement and bridge assets. All state highway agencies
and MPOs are required to set performance targets for these assets. Table 1 illustrates the useof various key performance indicators by MTC in the San Francisco Bay Area to monitor theeffort on pavement preservation (Pavement Preservation Index), asset sustainability (which isalso known as Investment Ratio), and the amount of backlog as compared to the asset value(Tan 2015).
Key Performance Indicators
Current Conditions

CountyAlamedaJurisdiction
Regional Benchmarks
ALAMEDAALAMEDA COUNTYALBANY
BERKELEYDUBLIN

Network
PCI
66
66
71
58
58
87

Network
RSL
18.1
17.7
19.9
14.0
16.2
28.5

Pavement Preservation Performance
A$PM/Lane % Actual
Mile
PM
$
1,336
17%
$
1,271
13%
$
671
18%
$
1,247
10%
$
263
2%
$
3,124
50%

B

% PM
Needs
16%
15%
28%
13%
11%
79%

A/B
Pavement
Preservation
Index
1.06
0.88
0.67
0.78
0.20
0.62

Maintenance and Rehabilitation Investment Level
C

Actual M&R/Lane Mile
$10,400$9,800$3,600$12,700$11,600$6,300D

Needs/ Lane
Mile
$27,000$26,900$16,200$29,800$32,400$5,600C/D

Investment
Ratio
39%
36%
22%
43%
36%
113%

E

F

Table 1: Key Performance Indicators by local jurisdiction (Tan 2015)
Some key takeaways:


Look for PMS software that provides easy to run and yet robust analysis
Time savings in conducting analysis can be refocused on educating the decision makers

Step 6: Feedback
An effective PMS requires a long-term commitment to an agency’s pavement management
program. This includes commitments to personnel resources to manage and upkeep the
program, budgets for condition assessment, and ultimately sustainable investment forpavement needs. The upkeep, which completes an effective PMS framework, is the feedback
loop to an active pavement management program. Unfortunately, this is also one of the steps,
along with condition assessment, that will be eliminated when budget is tight. When thishappens, the database is not kept up to date. This will result in erroneous prediction of
pavement condition, inaccurate M&R work plan, and misguided investment plan. Hence wekeep hearing the plight of “I don’t trust the data”.
Understanding that underlying a PMS software is a work-in-progress database, it is paramountto keep the database current. Here are some of the tasks need to act upon:

E/F

Current
Network
Backlog/
Backlog Asset Value Asset Value(millions)(millions)$5,645$38,814
15%
$32
$229
14%
$55
$647
8%
$9
$41
22%
$77
$298
26%
$4
$180
2%

Verify street segment inventory is accurate, such as functional class, surface type,
length, width.

566





Review decision tree periodicallyUpdate treatment unit costs annually
Reassess data quality management plan periodicallyConclusion and Recommendations
It is true that a PMS software varies significantly in cost, complexity, and flexibility. However,when it comes to implementing a PMS, it does not have to break the bank. The six critical steps
discussed in this paper provide a roadmap to manage a PMS efficiently. Managing a PMS is along-term commitment; it is vital for an agency to identify PMS champion early. Pavement
managers have to evaluate the agency’s needs and goals. They also have to weigh in the levelof staff support – IT, GIS, planning, maintenance, and engineering. By understanding the six
critical business processes, they will be able to manage a PMS effectively, and ultimately attainbuy-in from key holders that provide sustainable funding to meet pavement needs.

567

REFERENCES

Shahin, M. Y. Pavement Management for Airports, Roads, and Parking Lots. Springer Scienceand Business Media, Inc., New York, NY. 2005
Federal Highway Administration: Practical Guide for Quality Management of Pavement
Condition Data Collection, 2013
Nichols Consulting Engineers, Chtd. California Statewide Local Streets and Roads Needs
Assessment, October 2014. (http://www.savecaliforniastreets.org)
Tan, S., Cheng, D., and Hicks, G., “Optimizing Pavement Preservation into a Pavement
Management System.” 8th International Conference on Managing Pavement Asset, November
2011.
Romell, T. and Tan, S. “Regional Asset Management Efforts and a Performance-Based Approachto Local Streets and Roads Funding Allocation.” Compendium of Papers from the FirstInternational Conference on Pavement Preservation, Paper 70, 2010. pp 45–61.
(https://www.pavementpreservation.org/icpp/paper/70_2010.pdf)
Tan, S. “Going Beyond Performance Targets in MAP-21 for Local Agencies”. 9th International
Conference on Managing Pavement Asset, page 6, May 2015
American Association of State Highway and Transportation Officials (AASHTO): Pavement
Management Guide, 2nd Edition, 2012.
Metropolitan Transportation Commission: Plan Bay Area: Strategy for A Sustainable Region,
Adopted July 18, 2013. pp 74-107.
Metropolitan Transportation Commission: The Pothole Report: Can the Bay Area have betterroads? June 2011. p 15.

568

2nd IRF Asia Regional Regional Congress
16 – 20 October 2016
Kuala Lumpur, Malaysia

Establishing Optimal Long Term Funding Allocation Systematic Approachbased on Network Needs & Availability of Funds
By

Alan Roland(PhD Research – in progress)
University of the Sunshine Coast
School of Engineering
Faculty of Science, Health, Education and Engineering
Email: Alan.Roland@research.usc.edu.au or a_r054@student.usc.edu.au
Sippy Downs – Sunshine Coast Region, Queensland - Australia

Research Supervisor: Prof. Mark Porter
Associate Supervisor: Prof. John Yeaman

Word Count: 5,680

Keywords: Asset Management, Funding Allocation, Budgeting Framework, Allocation Mechanisms.

569

1

INTRODUCTION

Road Controlling Agencies (RCAs) around the world are facing continuous challenges sustaining
network funds. Given the fluctuation of market forces and instability of economies around the world.
Effective management of a roads network requires that levels are set at least sufficient to keep the coreof road assets in a stable condition for long term. This requires that ongoing maintenance is funded, andthat adequate provision is made for any strengthening works required. More than this minimum level
will be required if the network is to be expanded or improved. Roads are usually funded through budget
allocations determined as part of the annual government budgeting process.
Roads with different hierarchies and functional classifications may be managed by different roadadministrations. Sometimes they will have their own sources of funds (investments). For others, funding
will come from the national sources. Particularly for roads of lower hierarchy, the provision of funds
will often be shared between national and local / regional sources. It is common for central governments
to fund all work on national or trunk roads. In all cases, mechanisms need to be in place for allocating
and disbursing funds between the different administrations. They need to be simple, transparent andencourage consistency of standards between the different administrations.
2

RESEARCH SIGNIFICANCE & CONCEPT

There is currently no method for the allocation of funding to road network management which considers
the three key elements of deterioration, available funds and political influence. There is also noframework which includes a metric for the consequences of unscheduled influences. This research will
advance the research into funding allocation and distribution research, and examine current practices
with the intention to create a state of the art bugetary framework. This framework will adopt a new
approach to the allocation of all resources, including financial, natural, manufactured, and human, within
a budgetary framework which has a function of various operation and renewal scenarios. It is also
intended that this research will improve the confidence of allocated funds.
The key element of this research study is to develop a model by multi-criteria analysis with adeterministic outcome and a model based on preferential analysis to determine optimality. The data will
be summarised in templates and imported from various sources into the system tool, however data mustbe harmonised and synchronised to ensure compatibility with output files. This research will be uniquein that it will provide the road network owner’s viewpoint and be driven by value for money whilst
meeting the fundamental principles of sustainability, innovation, and risk management.
3

RESEARCH HYPOTHESISThe Alternatives Evaluation and Program Optimisation to Budget Allocation has been considered bythis research and is demonstrated in Figure 1. In this research the budgetary components will be linked
to the overall network performance based on Forward Works programme efficiency and annual
depreciation of assets consumption. This will represent the consumption of assets value over the usefullife versus the political influence to reduce funds on a basis of a lump sum allocation. The proposedsystem will provide various allocation components broken down into categories. This will include
allocations for operation or renewals based on asset functional classification and required level ofservice, or summarised per route or a corridor, and then aggregated for the rest of the network. Hence
different scenarios can be developed as opposed to a single allocated lump sum; Transport Associationof Canada (2013).

570

Figure 1: Alternatives Evaluation and Programme Optimisation
SYSTEM COMPONENTS
Goals and Policies(Reflects Customer Input)

Asset Inventory

Condition Assessment andPerformance Modelling

Alternative Evaluation and
Program Optimisation

Budget/Allocation

Short -and-Long-Range Plans(Project Selection)

Program Implementation

Performance Monitoring(Feedback)Preliminary research has indentified the need to create a tool which is suitable for all levels of roadadministration. The hypothesis is that this tool will significantly affect a ‘planning authorities’ ability
to evaluate the impact of changes to budget, level or service, or a combination of these factors. The
second hypothesis is that this tool requires both qualitative and quantitative measures to be incorporated,
including the cost and level of service of a road network for a multi-year plan, and the functions ofdeterioration, budget and political influence.
Figure 2 illustrates this idea and considers the “Alternatives Evaluation and Programme Optimisation to
Budget Allocation” concepts. This figure has been developed by the researcher as part of the research.
This diagram illustrates that the budgetary components will be linked to overall network performancebased on Forward Works programme efficiency and an annual depreciation of assets model. In
combination, this represents the consumption of asset values over the useful life cycle versus the politicalinfluence to reduce funds on a basis of a lump sum allocation.
Figure 2: Proposed Alternative Evaluation and Programme Optimisation
This will be a unique tool for Road Network Administration
Deterioration (Level of Service)

Available Funding

Change in condition as
a function ofEnvironment or Traffic

Political or stakeholder influence

Projects / Network Schemeo $ per Projecto Safetyo Serviceabilityo Structural Adequacy

IMPACT onooo

Expenditure ($)
Level of Service (Los)
Influence ( Stakeholders)Multiyear forecast of
expenditure & level of Service

Sensitivity Analysis

Output

Min Budget ($)
Optimised Budget ($)
Other Scenarios ($)

571

The research into the designing of this tool refers to the new Canadian Pavement Asset Design andManagement Guide; TAC, (2013) and prioritises the Target Levels of Service which are expressed as
an average condition of all pavement sections for a given network and for specific different roadwayclasses; a similar matrices of various asset types, roadway classifications will be developed using
appropriate indices.
To meet the target network level of service, this research will also use Key Performance Indicators(KPIs). Table 2 illustrates a sample of KPIs recently developed as part of new Canadian Pavement
Asset Design and Management guide; TAC, (2013). However there will be further roadwayclassifications necessary to account for motorways, expressway, and freeways. The table below also
highlights the different levels of actual, desirable and minimum acceptable Level of Service (LoS).
Table 2: Canadian KPIs – (TAC 2013)

Roadway Type

Target or
Desirable(Average PCI for
all Sections)

Minimum Acceptable(Average PCI for all
Sections)

Minimum
Acceptable (PCI for
individual Sections)

Arterial

80

65

55

Collector

70

60

45

Local

60

55

40

The funding authority can choose a level of service and see how KPIs reflect this level of service. In
this way, the funding authority can perform a sensitivity analysis to assess how the budget impacted bydifferent conditions and the optimal operation through a comparison of different budget scenarios
generated by the proposed system.
It is expected, that this research, with the key output of a new system will be equipped with an audit trail
for better management of road networks so that operations, maintenance and rehabilitation areminimised while the design and construction are maximised to full sustainability. Hence, the proposed
alternative evaluation and program optimisation will be focusing on outcomes of delivery and improving
the level of service, while maximising network safety resilient and sustainability. Table 3 illustrates asample of Policy Objectives and Implementation Targets based on KPI’s recently developed as part of
new Canadian Pavement Asset Design and Management guide; TAC, (2013). Accordingly, the research
will be developing a similar matrix and more comperhensive to fit the local conditions for any authoritythat will demostrate the different levels of actual, desirable and minimum acceptable (LoS).
Table 3: Policy Objectives and Implementation Targets Based on KPI’s (TAC 2013)
Policy Objectives

Key Performance IndicatorsImplementation Target

Network
levelofservice(smoothness functionality andutilisation) network condition
Provision of mobility (average
travel speed by road class)Accident reduction (percent)Bridges (% of number with
reduced load postings)







Level of serviceSafetyAsset preservation

Asset value of road network ($)



Recycling of reclaimed materials (asphalt concrete, etc.) - %Emissions levels
a.

Sustainability

Maintain 90% or greater of network infair or better category (e.g. IRI ≤ 2)
Rush hour traffic average speed
minimum of 50% of posted speed
limit
Reduction of fatalities and injuries by
1% or greater annually
Number of reduced load postings toless than 5% of the network
Annual increase in written down
replacement cost of 0.5%or greater
Maintain at 90% or greater
Maintain at levels < 90% of standards

572

The “Optimisation” is another key element of this research which will be based on multi – criteria
analysis (MCA) and takes into account a range of criteria which are both qualitative and quantitative innature and which reflect the economic, safety, serviceability and sustainability characteristics of theprocess outcomes. The proposed system will also involve development of cross asset scoring system
which focus on higher level objectives to optimise budget allocation while improving level of service.
Figure 3 below depicts the concept of broader optimisation, the system tool will incorporate theadvanced state of the art concept of cross asset optimisation; NAMS, (2006).
Figure 3: Cross Asset Optimisation
Economic

SafetyServiceability

Sustainability

Service Delivery Streams

Roads

Road
Structures

ss
Cro

Parking

se
As

sa
mi
pti

n
tio

tO

Others, etc.

Figure 4 below illustrates the ‘Research Optimisation’ concept and depicts the overall concept of thisresearch and also highlights the broader concepts of “Alternative Evaluation and Program Optimisation”
for infrastructure assets. This concept considers the interaction between all network expenditures
whether they are an integral component of operational or capital investment of asset.
Figure 4: Research Optimisation Concept
Budget Optimisation
Growth Augmentation (New Assets)
To accommodate growth

Renewals
Asset
Depreciation

Retain Asset Capabilities

Improvements
Improve Capabilities or Level of Service

Cost of Service

Budget Optimisation

Budget Optimisation

Capital Needs

Maintenance Regime
Optimised to Match Capital

Recurrent(Expense) Needs
Operation & Administration

Budget Optimisation

The proposed system will provide various allocation components and breakdown whether funds areneeded for operation or renewals based on asset functional classification and required level of service.

573

Furthermore, this system also has the ability to summarise by route or a corridor, then be aggregated forthe rest of the network. In this way, different scenarios can be developed as opposed to single allocatedlump sums.
4

BUDGETING ADMINISTRATIVE FRAMEWORK

Modern budgeting systems were developed as a means of exerting legislative control over resource allocation
decisions by the executive. This was achieved by dividing responsibility for and authority over the resource
allocation process between institutions whose competencies and relations were defined in law, supplemented byexhaustive rules and procedures.
Ministry of FinanceSpending Agencies
CabinetResponsible for the management of public expenditure, including the formulation of aconsolidated state budget and accounts, and the management of government’s cash resources.
Responsible for the planning, management and delivery of public services, and the preparationand management of agency budget. Spending agencies are usually headed Ministers,
occasionally by public officials.
Collectively formulates government policy. Implementation of government policy is the
responsibility of individual Ministers. Cabinet approves the Government’s budget.

Legislature

Analyses the Government’s budget proposal and accounts, through the work of specialist
committees, and enacts the budget in law. In Congressional systems, the legislature may amend
the Government’s budget proposal. In Parliamentary systems, it usually may not.

AuditorVerifies compliance with the budget law and procedures regarding the use of public funds. The
Auditor usually reports directly to the legislature, though in some cases may be considered partof the Ministry of Finance and report to Government through the Minister.

5

STRATEGIC BUDGETING

Road administrations are increasingly operating under a unified budget. Sometimes there is no distinction between“Capital and Operational” or any other budget categories. A lump sum budget is awarded and decisions on its
expenditure between different types of works are made by the road administration itself on the basis of policy
framework or needs; Robinson R, Danielson U and Snaith M (1998). Local budget categories may be used toassist in managing funds. While a unified budget will enable the needs of the network to be considered as a whole,
the possibility of optimizing expenditures may not be optimal and could vary year by year. This research proposal
focuses upon the breakdown of roading budget categories, which will subsequently be used to determine a unified
lump sum.

6

LINKING BUDGETS TO BUSINESS OBJECTIVES

When the revenues available to the road sector are significantly less than the amount required to maintain the road
network in a stable long-term condition and to undertake justified improvements, the road agency should prepare
an explicit long-term financing plan showing the size of the financing gap and the options for bridging the deficit.
If a financing gap is indentified changes to the financing plan should also include strategies to reduce the shortfall.
The objectives need to consider the scope for increasing the revenues available to the road sector by simplifying
road user taxes. Other possibilities include restructuring the taxes, reducing tax avoidance, evasion and leakage;
Heggie, I G (2000). This research should assist to in closing the gap and creating a systematic process in a wide
range of scenarios.

7

THE OBJECTIVES & OUTOCMES OF THE RESEARCHThis research will design and demonstrate the implementation of an optimal road funding system tool that willassist in predicting long term roading instrastructure financial plans. The research will deliver a system tool which:Is suitable for an international marketplace (e.g. The World Bank, Investment Authorities) and be
applicable to advanced and emerging economies;
Is compatible for large and small infrastructure networks managed and funded by local, regional, and central
governments;

574



Can make a positive contribution to the technology for funding maintenance management of road networks
within the road reserve;
Is open, flexible and can be customised according to network characteristics. A multi-objective optimisation
process capabiliites will also be incorported.

This move toward consistency requires the development of standard techniques and data systems, within thecontext of a fully integrated road and bridge management system. The system should be capable of accommodating
the types of allocation and fund distribution currently required, including:Development of budget totals based on relating expenditures to changes in overall system performance;
Development of regional distributions through the use of economic analysis that equitably;
Compares the overall value of the investment by jurisdiction; andDevelopment of functional distribution tools to calculate and compare changes in road user costs
associated with various investment strategies.

8

RESEARCH LITERATURE REVIEW

It is important to differentiate between financing and funding. The term funding, as used in this research, refers to
how infrastructure is paid for. Ultimately, there are only two sources of funding for infrastructure, government
investment or direct user charges. This is opposed to financing, which refers to the way in which debt and/or equity
is raised for the delivery and operation of an infrastructure project.
The budget process has two principal components:

To decide how much funds are needed;
To decide how to allocate the funds those are actually awarded.

Under such arrangements, therefore each authority competes for funds and at least in theory, funds are allocatedto finance those expenditures with highest economic or social return, however such allocation are invariably highly
politicized and allocations are often far from economically optimal. Politicians at national level are more likely toreflect general social needs than at the local level, where vested interests tend to have greater influence.
Expenditures for maintenance, in all sectors inevitably lose out to higher profile capital investment projects, which
contribute to the under funding of roading maintenance, as a result roading maintenance expenditures are often
based on historical precedent; each year’s budget is based on that of the previous year, with an additional allowanceto cover inflation. This is a limited and poor basis for budgeting since it is arbitrary.
A better robust approach is for the budget application to be assessed on a rational assessment of economic needthat relates to the objectives specified in the policy framework. One approach to the needs-based budgeting is forbudgets to be based on life cycle costs, upgrading and reconstruction costs and road users costs over the life of theroad by choosing the optimal level of maintenance. If roads are maintained too soon, then the full value of theexisting pavement will not be attained and maintenance costs will higher than any reduction in operating costs,
hence, total transportation costs are higher; conversely, if roads are maintained too late, the consequent
maintenance will be more expensive or the value of asset may be lost. Therefore, the standards and intervention
levels specified in the policy framework should reflect the need for maintenance. If there is to be consistent within
the policy, the road maintenance budget, then the cost of the work needed to correct defects should be funded by
the budget. Some Road Funds are committed to a fixed percentage allocation but this is not necessarily the bestsolution, and cannot always be affected anyway; Chan W T, Fwa T F, ASCE M and Tan J Y (2003).
A review of the funding allocation process used in a number of countries around the world has been undertaken,
such as New Zealand, Australia, North America, Europ, Asia and Africa, it important to note, while this review
may discuss how the government funding agency distributing the fund, the reality compiling a bid by the authority
reflecting how detailed or a sophisticated process being used by the funding authority. Detailed literature review
including references is available however due to limitation of paper submission, only a summay with key highlighs
are provided.

9

OPTIMAL PRACTICE WORLD WIDE – SUMMARY REVIEWFor efficient and consistent allocation of monies, priorities should be on the basis of economic cost-benefit
principles, selecting those projects that demonstrate the highest economic rates of return. In practice the task is notthat simple. Political interests may impose certain regional allocations, and rural roads need to be justified on the575

basis of other criteria because their economic case will inevitably be weak. The process of allocating monies
between types (trunk, district, urban and rural or feeder) is a continuing problem that has not been satisfactorily
been resolved. Some Road Funds are committed to a fixed percentage allocation, but this is not necessarily thebest solution, and cannot always be affected anyway.
Resource allocation decisions are made unilaterally by the Ministry of Finance. In many cases, however,allocations are made in consultation with the Ministry of Transport. The consultation process can assist the
Ministry of Finance in determining the appropriate total level of funding to be made available for road and bridge
improvements. This determination must consider a total maintenance and rehabilitation requirements to support
the desired level of overall system condition and performance for the country road and bridge systems.

10 BUDGET CATEGORIES
Budget Categories, the financial provision of roading network in many countries is divided into:
Capital (Capex) which relate to the construction of new roads, and sometimes the reconstruction, rehabilitation,
strengthening and resealing or renewals of existing roads;
Recurrent (Operational) – the other category is a provision for the regular maintenance of the exisiting roading
network, such as surfaces, off carriagway features, and for dealing with various contingencies, staff cost may also
be paid under this category.
Sometimes the strengthening and renewals may be paid within the recurrent budget. In some roading agencies,
the budget categories have breakdowns into more details such as a budget to maintain road structure, corridor
maintenance, drainage facilities etc.
Where budgets awarded under different budget categories are usually less than bids for the roading agency, thismeans a lack of ability to vary funds from one budget category to another and will prevent the optimal allocationof resources under overall budget constraint.

11 ALLOCATION MECHANISMS
Roads with different hierarchies and functional classifications may be managed by different road administrations.
Sometimes they will have their own sources of funds (investments). For others, funding will come from thenational sources. Particularly for roads of lower hierarchy, the provision of funds will often be shared between
national and local / regional sources. It is common for central governments to fund all work on national or trunk
roads. In all cases, mechanisms need to be in place for allocating and disbursing funds between the different
administrations. They need to be simple, transparent and encourage consistency of standards between the different
administrations. Three basic methods are commonly used for:

Simple Allocation Formula;
Indirect Assessment of Needs;
Direct Assessment of Needs.

Simple allocation formula assigns funds on the basis of pre-defined percentages to different parts of the network.
Such allocation mechanisms are simple and transparent, but over time, are related only weakly to current need or
use of the network.
Indirect assessment of needs; is used where are no reliable data for measuring need directly or where the cost of
doing so would be disproportionate to the size of the budget being allocated. This method is used mostly for the
allocation of budget to low cost/low volume roads, criteria used in the indirect assessment will include for example;The land area covered by the administration;
Road density;
Population;
Industrial / agricultural production or potential.

These factors are weighted accordingly to their perceived importance, this approach provides a pragmatic basis
for allocating funds in appropriate cases that is cost – effective, and acknowledges the socio-political aspects ofthe decision-making.

576

Direct assessment of needs; can be of different degrees of sophistication, as its most comprehensive, it will involve
using the results of a detailed condition survey of all needs to determine work requirements. These are then costed
to derive the budget requirement. This approach requires the use of treatment selection methods such asdeterioration modelling.
Simpler methods; involve deriving norms for expenditure on roads in different hierarchies or of different surface
types. Road lengths in each administration are simply multiplied by the relevant norms to give the budget
allocation. Thus, there are several direct assessment methods. The methods chosen should suit the capacity of thelevel of government concerned. The key is to have clear objectives and then to appraise in a systematic way theextent to which each intervention contributes to realizing these objectives. It is often difficult to change existing
allocation methods because there will be strong resistance from those who will lose out “political interest”. There
may also be pressures to maintain a “regional balance” that may actually distort the optimal allocation of funds.

12 PRACTICAL BUDGETING TECHNIQUESThe purpose of resource allocation is to determine the appropriate total level of capital and maintenance investmentthat is to be made available for road repair and rehabilitation, bridge reconstruction and rehabilitation, and new
construction, usually on an annual basis. Distribution is the manner in which total funds allocated for highway andbridge repair are made available to sub-national jurisdictions, road systems, and types of improvement.
Six identifiable patterns of resource allocation can be identified. The defining characteristic of these six patterns
is the degree of shared responsibility between the Ministries of Finance and Transport (or their equivalents) in the
allocation process.
In the first pattern, the responsibility for allocation, especially for the national road system, is retained ingovernmental hands. For example, the Ministry of Transport in Canada is totally responsible for resource
allocation on the national road network. In Great Britain, the Department of Transport has the responsibility on acentral as well as on a regional level. The procedure for resource allocation in the United States is very much
reflected by the interaction of responsibilities between the Federal and State levels. In New Zealand, thegovernment funding agency (NZTA) taken a leading role in allocating and distributing funds.
In the second pattern governmental jurisdictions are still in charge of allocation, while the distribution procedures
are transferred to national, regional, and local road administrations. Germany, Japan, Norway, Portugal, Spain,
and Switzerland belong to this allocation/distribution category.
In the third pattern, autonomous bodies are involved. This describes the allocation/distribution process in Italy,
with the Autonomous State Roads Administration (ANAS).
Finland and Sweden represent the fourth discrete pattern. Although the financial responsibility remains in thehands of the government, the Road Administrations have a strong impact. This is consistent with the "management
by objectives" philosophy that these countries have adopted.
The fifth pattern related to wealthy governments (economy based on oil & gas revenue), the political decision
basically controls the funding allocation and distribution.
The sixth pattern, developing countries, the overall planning process appears to be inconsistent and very far from
optimal in meeting some sensible framework of objectives.
Typically, the Central Government generally defines the total annual roadway rehabilitation and maintenancebudget. In addition to the initial budget allocation, the central government may also determine the distribution of
those funds by governmental jurisdiction, road system and, in some cases, by major category of road improvement
type, although the involvement of the central road authority varies by country.
Decisions are made using a combination of technical analysis to achieve efficiency in fund allocation, and political,
social, technical and economic considerations to achieve funding equity and balance among competing interestsand political jurisdictions. This combination of technical and political considerations appears to exist in somefashion. As was true with the degree of central government involvement in the allocation process, however, thevariations among countries in the relative mix of technical and political considerations are broad.
Under the political level(s) the managing responsibilities of road administrations differ between countries. Somecountries use "management by objectives", "directed autonomy", or "zero based budgeting" philosophies incarrying out their responsibilities; other countries are more directly tied to the Ministry of Transport which permits
only "limited autonomy" to their road administrations.

577

13 PROPOSED FRAMEWORKThe conceptual framework of the proposed system is outlined below:
Process

Input Data

System Matrices
Setup & Global
ValuesAnalysis &Budget Scenarios

Optimisation

Outputs

Function Requirements







































Define asset data type
Network condition prediction data &Forward works programmes
Asset valuation & economic efficiency determination
Maintenance cost data
Annual budget considering split (Capex vs Opex)
Work categories definitions, classification of activities
Develop and prepare integrated input file
Key analysis factors
Infrastructure Development Index
Budget configuration; operation, maintenance, improvement, new and reconstruction
Calibration of analysis matrix
Infrastructure gaps
Funding assistance rate
Development of Risk Matrix values & risk profile graph
Project implementation performance
Validation of input data (out of range)
Performance-Based Allocation Formula
Economic and customised analysis
Aggregate data into bands
Budget Categories, Approved with Condition, committed allocation
Summarisation of maintenance cost
Perform scenario analysis
Programme review and variations
Definition of critical optimisation factors such as strategic fit, the effectiveness andthe economic efficiency
Budget distribution per category
Alignment of infrastructure projects
Budget scenarios vs. condition
Optimisation vs. committed programme
Final outputs (multi scenarios)
Multi-year forecast of expenditure by activity class
Minimum allocation
Reporting (default, customised, summary, per asset type)
Capex vs. Opex distribution
Optimal scenarios
Audit (review allocated vs. actual resources)
Category review
Trends (increased / decreased) and future spikes

14 SOFTWARE PLATFORM
The research study and the development of the software tool will advance simultaneously as part of the research
project. The research also intends to carry out a pilot testing to ensure a smooth implementation.
System Architecture
The system architecture is depicted in the following chart.

578

Proposed Architecture to Implement System Tool
Final

Various Databases
NMRS, BMS, FWP

Input

Asset Valuation &Maintenance Cost Data

Optimisation

Analysis

Validation & Synchronisation Input file

OutputDefaults &Calibration
Factors

Define Budget
Scenarios

Asset Types &Classification

Economic
AnalysisDefine Optimisation Factors

Review & Audit

Performance Analysis
Network Needs

Run & Get Results

Optimisation Process

Optimised Budget Scheme
Various Report

Synthetic Data
as necessary

Customised
Analysis

Sensitivity Analysis

Minimum
Budget
Allocation579

15 THE WAY FORWARD
The following screen shots illustrate the front end of the system that is currently under development. This front end of the system
reflects the research findings to date. The system platform will be based in various data sources such as valuation, predictivemodelling, long term & annual plans together with other source of data. More details will be presented during the conference as
the study is progressing and further outcomes are achieved.

580

581

16 ACKNOWLEDGEMENTS
The author would like to acknowledge the support and guidance received from the research supervisors, Prof. Mark Porter andProf. John Yeaman.

17 REFERENCES
Allen D P (1996). What should federal policy be regarding the funding of highway maintenance & Transportation Quarterly v50.
Lansdown, VA, USA.
Bloom M S (1997). Emerging issues for transportation: highway infrastructure and financing in the US. Federal Highway
Administration. Washington DC.
Brams S J. and Taylor A D (1999). The Win-Win Solution: Guaranteeing Fair Shares to Everybody.New York: W.W. Norton.
Castells A and Sole-Olle A, (2005). The Regional Allocation of Infrastructure Investment: The Role of Equity, Efficiency and
Political Factors. European Economic Review, 49(5): 1165- 1205.
Chan W T, Fwa, T F, ASCE M, and Tan J Y (2003) Optimal Fund-Allocation Analysis for Multidistrict Highway Agencies.
Journal of Infrastructure Systems.
Chartier G and G Sparks (1998). Managing urban local roads: an asset management approach. 1998 annual conference andexhibition of the Transportation Association of Canada, Ottawa.
De Richcour A B and I G Heggie (1995). African road funds: what works and why. World Bank, Washington DC.
De Silva H and T McHugh (1997). Regional distribution of road funds: an empirical procedure for Western Australia. AustralianTransport Research Forum, Adelaide.
Ferreira D and K Khatami (1996). Financing private infrastructure in developing countries. World Bank, Washington DC.
Fozzard A (2001). The Basic Budgeting Problem, Approaches to Resource Allocation in the Public Sector and their Implications
for Pro-Poor Budgeting, Working Paper 147, Overseas Development Institute 111 Westminster Bridge Road London SE1 7JD,
UK.
Government of India (2012), Annual report 2011 – 2012, Ministry of Road Transport & Highways, New Delhi.
Heggie I G (1995). Managing and Financing Roads: An Agenda for Reform. World Bank Technical Paper No. 275. Washington
DC.
Heggie, I G and Piers Vickers (1998). Commercial Management and Financing of Roads, Technical Paper 409, World Bank,
Washington, DC.
Heggie, I G. (1999). Commercially Managed Road Funds: Managing Roads Like a Business, Not Like a Bureaucracy.
Transportation 26: 87-111.
Heggie I G. (2000). Second Generation Road Funds: Emerging “Good” Practice. World Highways. Vol. 9, Issue No. 8.
Herreiner D K and Puppe C.D (2007). Envy Freeness in Experimental Fair Division Problems. Theory and Decision.
Lee Z, Ford D N, and Joglekar N (2007). "Resource Allocation Policy Design for Reduced Project Duration: A Systems ModelingApproach," Systems Research and Behavioral Science. Vol. 24, No. 6, pp. 551 to 566. Nov-Dec 2007.
Jamieson R G (1998). Private sector funding of roads. Road Engineering Association of Asia and Australasia 9th Conference.
Wellington, New Zealand.
Japan Highway Public Corporation (2004). – NDK, Annual report 1st July 2004.
John W S, Alexander J & Dan P (2011). Providing and Funding Strategic Roads, An International Perspective with Lessons for
the UK, RAC Foundation, ARUP, London.
Kerali H G R (2000). Overview of HDM-4, Volume 1, the Highway Development and Management Series. The World Road
Association (PIARC), Paris.
Malmberg Calvo, C (1998). Options for Managing and Financing Rural Transport Infrastructure. Technical paper 411, World
Bank, Washington, DC.
Mc Cleary W (1991). The Earmarking of Government Revenue: A Review of Some World Bank Experience. World Bank
Research Observer. vol. 6, No. 1.
Shands M (2007). A Synthesis of Research and Resources on Local Road and Bridge Funding for Local Public Works Officials,
Minnesota Department of Transportation - Research Services Section.
Nakagawa D and Matsunaka R (1997). Funding Transport Systems: a comparison among developing countries. Elsevier Science
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National Asset Management Steering Group (NAMS 2006). International Infrastructure Management Manual, International
edition Version 3.0, 2006, Thames, New Zealand.
NZ Transport Agency (NZTA - 2000), The NZTA’s Planning, programming and funding manual, First edition, effective 1
August 2000.
Peter C and Andrew S (2007). ‘The evolution of road funding in South Africa, within its SADC context’. International Seminaron Road Financing and Investment: Ngurdoto Mountain Lodge, Arusha, Tanzania 16-20 April 2007, Tanzania.
Robinson R (1988). A view of road maintenance economics, policy and management in developing countries. Transport andRoad Research Laboratory Research Report No. 145. Crowthorne.
Robinson R, Danielson U, and Snaith M (1998). Road maintenance management concepts and systems. Macmillan Press Ltd,Basingstoke.
Saarinen J, Toivonen T, Mannisto V, and Tapio R (1998). Pavement management in Finland; decision- making from national
policies to project-level programming. Finnish National Road Administration, Helsinki.
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Texas Department of Transportation,.
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Tsunokawa K, and Van Hiep D (2008). “A Unified Optimization Procedure for Road Asset Management.” 6 th ICPT, July 2008,
pp. 1-8.
Wu Z, Flintsch G W, and Chowdhury T (2008). “Hybrid Multi-objective Optimization Model for Regional PavementPreservation Resource Allocation.” Journal of the Transportation Research Board, pp. 28-37.

18 BIBLIOGRAPHY
Biographical note for Alan Roland
Alan is a Chartered Professional Registered Engineer of New Zealand (MIPENZ), (CPEng), (IntPE) and REAAA. Member of
INGENIUM (Association of Local Government Engineers of New Zealand). Alan holds a bachelor degree in Civil Engineering,and Masters Degree in Transportation Asset Management. He has experience almost 30 years in transportation asset management
at both strategic and operational levels; infrastructure development, design, operation and maintenance; development andimplementation of road asset management processes and systems. Alan presented a number of asset management papers at thenational and international workshops and conferences.
Alan has been working with government agencies, consultants and contractors, and currently is working with the Department ofTransport in Abu Dhabi, as the Network Inventory and RAMS Specialist. Alan is currently a PhD candidate working on thisresearch.
Biographical note for Mark Porter
Mark Porter is a Professor of Engineering at the University of the Sunshine Coast, where he is responsible for the developmentof new teaching and research programs in Civil and Mechanical engineering. He is a water resource and environmental engineer
with a strong interest in engineering education and a background in research, teaching and academic management. He is now
overseeing the development of new research programs in asphalt pavement engineering, permeable pavements, and the impactsof climate change on coastal infrastructure.
Mark's achievements include a university Excellence Award for Research (1993) and an Excellence Award for the Design and
Delivery of Teaching Materials (2003) and a national Carrick Award for outstanding contributions to the Enhancement of
Learning (2007 - Learning and Teaching Category: joint winner). He is a Fellow of the Institution of Engineers and held theposition of Chairman for the Sunshine Coast Local Group of EA in 2012-13.
Biographical note for Professor John Yeaman
Professor John Yeaman FTSE, PhD, FIE (Aust) CPEng, RPEQ is the Director of The Queensland Functional Pavement Centre
at the University of the Sunshine Coast and Professor of Civil Engineering Construction.
John has been in the Civil Engineering Materials and Paving industry since 1957 directly involved in new and innovative products
and services for 25 of those years. He built his own business in Pavement Management in which he was the principal engineer
for 30 years.
For the past 3 years his has been an academic heavily involved in Pavement design, construction, operation and renewal
maintenance, contract management and project management.

583

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK

Structural Pavement Design For Saudi Arabian Roads:
Outline of the Proposed ResearchInnovations in Pavements & Materials

AUTHOR(Capitalize Family Name)
Dr. Ibrahim Aldubabe

POSITION
President

CO-AUTHOR(S)(Capitalize Family Name

ORGANIZATION
Advanced Center For
Civil
Engineering
Consultancy

COUNTRY
Saudi Arabia

POSITIONORGANIZATION

Dr. Khaled Galal

Manager: Pavement &Infrastructure Division

Saudi Arabia

Abduhadi Al-Shafi

Assistant Director of the Central
Laboratory

Engineering andResearch
International
Ministry of Transport

Dr. Abdullah Al-Shiha

Professor

King Saud University

Saudi Arabia

Ayed Al-Shehri

Assistant Director of Petroleum
Products Control Department

Ministry of Energy,
Industry and Mineral
Resources

Saudi Arabia

E-MAIL(for correspondence)

COUNTRY

Saudi Arabia

dribrahim@adeceng.com

KEYWORDS:
Pavement, Structural Design, Flexible Pavement, Mechanistic-Empirical Pavement Design, Pavement Layer Thickness.

ABSTRACT:Highways in the Kingdom of Saudi Arabia (KSA) have developed in the last forty years to a state of the art roadway
network. Owing to the fact that KSA is a large country with an area exceeding 2.2 million km2 comprising various
topographical and geological conditions, several temperature zones and a wide range of traffic loading spectrum;
Several highway functional and structural problems have been observed. The major reported defects include permanent
deformation in the form of rutting and cracking in the form of fatigue and temperature cracking. KSA is currently
implementing a national research study aiming to create or adopt a complete structural pavement design system tosatisfy KSA existing conditions including material properties, roadbed characteristics, climate, and traffic loads; theresearch is under progress. This paper will summarize the proposed research plan and summarize the progress so far.

584

Structural Pavement Design for Saudi Arabian Roads:
Outline of the Proposed Research
Dr Ibrahim Aldubabe1, Dr Khaled Galal2, Abduhadi Alshafi3, Dr Abdullah Al-Shiha4
and Ayed Al-Shehri5(1) President, Advanced Center for Civil Engineering Consultancy, Riyadh, Saudi Arabia(2) Manager, Pavement & Infrastructure Division, Engineering and Research International, Riyadh, Saudi Arabia(3) Assistant Director of the Central Laboratory, Ministry of Transport, Riyadh, Saudi Arabia(4) Professor of Statistics, , King Saud University, Riyadh, Saudi Arabia(5) Assistant Director of Petroleum Products Control Department, Ministry of Energy, Industry and Mineral
Resources, Riyadh, Saudi Arabia

1.0 Introduction
Highways in the Kingdom of Saudi Arabia (KSA) have developed in the last 40 years to a state of the art
roadway network. The main objective of Saudi Ministry of Transport (MOT), is to build safe andeconomical successful pavements without major functional or structural defects for the design life of theroad. However, owing to the fact that KSA is a large country with an area exceeding 2.2 million square
km comprising various topographical and geological conditions, several temperature zones and a wide
range of traffic loading spectrum several functional and structural problems in the roads have been
observed. The major reported defects include permanent deformation in the form of rutting and cracking
in the form of fatigue and temperature cracking. The major factors that are affecting the behavior of
highways include materials, temperature, traffic loading and both mix and pavement designs. KSA
government through King Abdulaziz City for Science and Technology (KACST) has launched a twoyears research project to create or adopt a complete structural pavement design system to satisfy KSA
existing conditions including material properties, roadbed characteristics, climate, and traffic loads. This
paper summarizes the research plan and methodology.

2.0 Literature Review
Pavement structural design is a complex process since it must balance selection of a wide range of loads,
materials, layer thickness combinations and climate in one hand and performance with cost on the other.
Traffic loading is a varied mix of vehicles, axle types, and axle loads with distributions that vary withtime throughout the day, from season to season, and over the pavement design life. Pavement materials
respond to these loads in complex ways influenced by stress state and magnitude, temperature, moisture,time, loading rate, and other factors. It should be no wonder, then, that the profession has resorted tolargely empirical methods like the American Association of State Highway and Transportation Officials(AASHTO) guides for pavement design (AASHTO, 1993). Several developments over recent decades
have offered an opportunity for more rational and precise pavement design procedures.

2.1 Review of Flexible Pavement Design Principles
Before the 1920s, pavement design consisted basically of defining thicknesses of layered materials thatwould provide strength and protection to a soft, weak subgrade. Pavements were designed against
subgrade shear failure. Performance became the focus point of pavement designs. Methods based onserviceability were developed based on test track experiments. New design criteria were required toincorporate such failure mechanisms (e.g., fatigue cracking and permanent deformation). The
mechanistic design approach is based on the theories of mechanics and relates pavement structural
behavior and performance to traffic loading and environmental influences.

585

2.2 Empirical Methods
An empirical design approach is one that is based solely on the results of experiments or experience. The
first empirical method used for flexible pavement design date to the mid-1920s when the first soil
classification was developed. In 1929, the California Highway Department developed a method using theCalifornia Bearing Ratio (CBR) strength test. The CBR method related the material’s CBR value to therequired thickness to provide protection against subgrade shear failure. The CBR method was improvedby U.S. Corps of Engineers (USCE) during the World War II and later became the most popular design
method. In 1945 the Highway Research Board (HRB) modified the PR classification. The classification
was applied to estimate the subbase quality and total pavement thicknesses. Several methods based on
subgrade shear failure criteria were developed after the CBR method.
A few design methods were developed based on the theory of elasticity for soil mass. The first one
published was developed by the Kansas State Highway Commission, in 1947. Later in 1953, the U.S.
Navy applied Burmister’s two-layer elastic theory and limited the surface deflection to 6.35 mm. Other
methods were developed over the years, incorporating strength tests. More recently, resilient modulus has
been used to establish relationships between the strength and deflection limits for determining
thicknesses of new pavement structures and overlays. After 1950, experimental tracks started to be used
for gathering pavement performance data. Regression models were developed linking the performancedata to design inputs. The empirical AASHTO method (AASHTO, 1993) is the most widely usedpavement design method today.

2.3 Mechanistic-Empirical Methods
Mechanistic-empirical (M-E) methods represent one step forward from empirical methods. The induced
state of stress and strain in a pavement structure due to traffic loading and environmental conditions ispredicted using theory of mechanics. Empirical models link these structural responses to distresspredictions. Several studies over the past fifteen years have advanced mechanistic-empirical techniques.
Main issues of interest include: Characterization of input parameters such as traffic loading, layer material and subgrade
foundation properties, climate, and other design features.
 Sensitivity of performance models to specific inputs.
 Validation and calibration of the pavement distress prediction models (USA based to KSA
conditions).
 Pavement distress types of interest for the various pavement types were; thermal cracking; load
related (fatigue) cracking; ride quality (IRI); and rut depth in bituminous layers.

3.0 Research Objectives
The main objective of the proposed study is to develop a complete pavement design system (Manual) for
Saudi roads that would take into consideration changes of the materials along with prevailingenvironmental and traffic loading in various regions of KSA; this will be achieved though:(1) Identifying the design governing factors prevailing in Saudi regions in terms of materials,
temperature and traffic loading.
(2) Evaluating the current practice of pavement structural design of Saudi expressways including
design governing factors.
(3) Studying and evaluating the latest pavement design techniques to recommend the most suitable
technique to the local Saudi conditions.
(4) Setting guidelines for pavement structural design including recommendations for suitable
thickness of the bituminous layers and design alternatives to satisfy KSA conditions in terms of
traffic, environment, and materials characteristics.
The findings and recommendations of this research are of great importance to KSA, since billions of
Riyals are being spent to build roads all over the country. On the other hand premature failure is evident
in some Saudi roads which could be attributed to the lack of a proper pavement design technique that isbased on local environmental, traffic and materials conditions and limitations. It is of extreme586

importance in this regard to develop or adopt pavement structural design that will provide an acceptableperformance as well as a balance between initial and maintenance cost to optimize the life cycle cost ofroads in KSA. All government and private parties working in the road industry in Saudi Arabia will
benefit from this research.

4.0 Research Design and Methodology
This research will be conducted in the following Six main tasks:
1) Literature review.
2) Field work and distress surveys.
3) Laboratory work.
4) Pavement design techniques evaluation.
5) Review of Current Practice of Testing and Measurements.
6) Data analysis and recommendations.

Task-1: Literature Review:
Available literature will be reviewed and summarized for the benefit of the project. The research teamwill communicate with KACST to provide any literature review that was conducted in any previous
efforts. However, there has been a lot of recent work in the USA for updating the MEPDG proceduresuch as inclusion of stabilized base layers in the analysis and modeling. Therefore the literature review
will focus on literature published in the last five years. Literature review will cover:
1. Pavement design techniques in use by MOT and other related highway agencies in KSA.
2. Local and International pavement performance studies. This will include reviewing the study thatwas performed by Saudi Aramco in cooperation with the Department of Civil Engineering of King
Fahd University of Petroleum and Minerals entitled “Testing and Evaluation of Sulfur Asphalt
Concrete Mixes and Sulfur Asphalt Test Roads” in December 2009.
3. Pavement design governing factors will include, but not limited to, traffic, climate, material, distressprediction studies. Also, contact area, drainage, and groundwater as these are required inputs for the
MEPDG procedure. Typical tires used in the KSA network will be documented and drainage/watertable conditions will be listed and used as part of the procedure.
4. Local and International traffic loading studies will be reviewed to confirm that estimations in KSA(Traffic Classes) are sufficiently adequate and reliable for use in pavement design.
5. Review of pavement structures and mix design used in local, regional (UAE), and international
highways (USA).
6. Current methods for the design and analysis of pavement structures and international literature on
innovative asphalt concrete mix technologies.
7. The impact of using binder modification like polymers and sulfur (Sulfur Extended Asphalt) on therequired pavement thickness.
8. The research team will review the best method to recover and test aging of binders (AASHTO T164
including methods of centrifuge extraction, reflux extraction, and vacuum extraction).
The findings from literature review and review of International practices will be summarized and used to
identify best practices to be used in this project and make modifications to the work plan, if needed.

Task-2: Field Work and Distress Surveys:
The ultimate goal of this project is to evaluate the effect of pavement thickness on serviceability anddurability of roads in terms of rutting, fatigue cracking, thermal cracking and ride quality (IRI).
Therefore, MOT pavement management system will be utilized to identify existing pavement sections onsome of Saudi expressway network in Central, Western, Northern and Eastern provinces of KSA.
Sections will be identified to cover various geology, materials characteristics, climatic conditions, and587

traffic loads. Selected sections will include good well-performing (control) and poor performing failed
sections. Performance data that the MOT has will be reviewed to select such sections. Test sections will
be selected with different materials including mixes with neat, polymer modified and sulfur extended(SEA) asphalt binder. Each test section will be approximately 1.0 km long and will be selected on an
expressway carrying different traffic loads. A factorial experiment for flexible pavement distresses,
material, layer thickness, traffic loading, environmental conditions, supporting layer and roadbed soil will
be prepared to cover and provide treatment selections for the study.
Sections will be evaluated for pavement distresses such as rutting, cracking and riding quality. Central,western, northern and eastern provinces will be the main areas to be studied in this project; other areasand provinces will be considered as appropriate. In addition to evaluating the selected pavement sections
for the cause of pavement distresses, they will be statistically compared to identify possible correlation
between pavement thickness and those distresses. The collected distress data will also be used tocalibrate the transfer functions and the material damage models in the MEPDG. Moreover, pavement
sections will be sampled and tested to identify common pavement design parameters.

Task-3: Laboratory Work:
Material characteristics will be obtained from samples collected from the selected test sections across the
kingdom and from new materials and mixes including SEA and other different possible combinations ofmaterials that can be used in KSA. Asphalt mixtures will be tested for dynamic modulus, flow number
and rutting resistance. Various variables including air voids, aggregate gradation, performance grade, andpolymer type will be investigated. The subgrade and aggregate base course materials will be evaluatedfor compaction, strength and classification.

Task-4: Pavement Design Techniques Evaluation:
Local and International structural pavement design techniques will be reviewed and employed in thisstudy including American Association of State Highway and Transportation Officials (AASHTO),
Mechanistic-Empirical Pavement Design Guide (MEPDG) and other mechanistic methods.
The research Team will conduct a thorough review of the Mechanistic-Empirical Pavement Design
Guide, including sensitivity analysis of each of the governing factors. Specifically, the review will
indicate how the current calibration and validation of the guide (USA based) will be applicable to KSA
conditions. As the MEPDG requires aging model of bitumen and since the conditions in KSA are very
warm and are almost always sunny conditions, it is necessary to perform a study of oxidative aging
trends in two locations of the Kingdom, one in the coastal region and one in the middle of the country.
The study will include taking cores from pavements at various ages and slicing the cores to study thehardening of bitumen from various depths. This is required to calibrate models in the MEPDG to theconditions of KSA. Also the research will study variation of pavement temperature with depth ofpavement. As asphalt layers are very good insulators and thus the top few centimeters are much warmer
than the lower layers. Although there are models for some other countries such as the US and South
Africa conditions, it is not known how the extreme summer conditions affect pavements in KSA. So it isrequired to study the variation of temperature with depth and adjust the models used in the MEPDG
software if the research team finds them not representatives of the KSA conditions. The pavement
temperature variation with depth study will be carried out at the same location of the study of oxidative
aging.

Task-5: Review Current Practice of Testing and Measurements:
The research team will review the current road sample testing and quality control practice used by MOT
and the Ministry of Municipal and Rural Affairs (MOMRA). This is required to assure that local
laboratories of MOT and MOMRA can provide the required properties and input of the mechanistic
pavement design that will be recommended by the research. Therefore, the team will check what
measurements will be needed and based on that check the laboratories and suggest including all that are
missing.

588

Task-6: Data Analysis and Recommendations:Collected data and information will be analyzed to achieve the research objectives and give the final
recommendations.

5.0 Project Status and Accomplishments
The project started January 2016 and has progressed about six months up to date. In this period the
project accomplishments were as follows:1.

Establishment of the overall work breakdown structure (WBS) to identify all tasks and subtasks
and build up the project plan.

2.

Initial review of the pavement structural design governing factors prevailing in Saudi regions interms of materials, temperature and traffic loading. The research plan was structured to take this
into consideration. This is evident since the research plan will cover four regions and heavy
trafficked roads in KSA. The Experimental design is shown in Figure 1. Pavement sections ofexpressway network in KSA were selected to start the field work, collection of samples anddistress surveys.

3.

The research team after discussion with MOT found that the current practice of pavement
structural design of Saudi expressways is based on the fixed section approach, and no actual
analysis and calculation is done for different projects in various regions of KSA to come up withthe pavement structure based on project level traffic, materials and environment.

4.

The research team has through review and discussion about the latest pavement design
techniques locally, in the GCC and in different parts of the world. At this stage the researchteam and the consultants found that the Mechanistic-Empirical Pavement Design Guide(MEPDG) developed in United States of America (USA) is one of the largest and recent efforts
in the international know how. M-E design procedures “by far” can be classified as the state-ofthe-art and the state-of-the-practice in pavement design. Several M-E procedures are available
worldwide. However, the AASHTO developed M-E design procedure is considered one of themost sophisticated yet easier to adopt M-E procedures. Thus, implementing an M-E design
procedure to develop pavement structural designs in Saudi Arabia is a step forward and strategic
movement in the right direction for KSA Ministry of Transport. Therefore the research teamrecommended using it in Saudi Arabia after doing the necessary calibration and validation for
local conditions.

5.

Start of the laboratory work to build the local material library that is necessary for the successful
implementation of the M-E pavement design.
Distress
Rutting

Cracking
Traffic

Thin
Thickness
thick






Region

Low

High

Low

High

E
C
W
N
E
C
W
N

X1
X5
X9
X13
X17
X21
X25
X29

X2
X6
X10
X14
X18
X22
X26
X30

X3
X7
X11
X15
X19
X23
X27
X31

X4
X8
X12
X16
X20
X24
X28
X32

E = Eastern, C = Central, W = Western, N = Northern regions of Saudi Arabia.
City Sections are: X1, X3, X5, X7, X9, X11, X13 and X15.
Low Traffic less than 20 million ESALs (20 year).
High Traffic more than 20 million ESALs (20 year).
Thin Pavements (15 cm of asphalt layers or less). Thick Pavements (greater than 15 cm of asphalt layers).

Figure-1: Research Experimental Design589

6.0 Acknowledgement
This research project was financially supported by King Abdulaziz City for Science and Technology(KACST) project no. OA-34-1, the research team is grateful to KACST for supporting this importantresearch. Also the team is thankful to MOT and Saudi Aramco and all other agencies and individuals fortheir support and assistance provided to the research.

7.0 References
1.

AASHTO. (1993). AASHTO Guide for Design of Pavements Structures, American Association of State
Highway and Transportation Officials, Washington, DC.

2.

Asphalt-Institute. (1991). Thickness Design - Asphalt Pavements for Highways and Streets. Manual
Series No.1 (MS-1), Asphalt Institute, Lexington, KY.

590

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Performance Evaluation of Developed rejuvenators for Warm-in Place Recycling
Asphalt Pavement

TRACK

Innovations in Pavements & Materials

AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Lim, Chisu

Graduate Student

Chonbuk National University

Republic of Korea

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Lee, Jaejun
Park, Jaeyoung
Kwon, Sooahn
Kim, Yongjoo

Assistant Professor
Graduate Student
Senior Research Fellow
Senior Researcher

Chonbuk National University
Chonbuk National University
KICT
KICT

Republic of Korea
Republic of Korea
Republic of Korea
Republic of Korea

E-MAIL(for correspondence)limchisoo@naver.com

KEYWORDS:
Rejuvenator, R.A.P, Tensile Strength Ratio, Deformation Strength Test, Dynamic Immersion Test.

ABSTRACT:
Recently, the usage of RAP(reclaimed asphalt pavement) has increased as concern with environmental effects. In order
to use RAP for asphalt pavement construction, a rejuvenator is required to improve asphalt mixture properties. The
research team has worked to develop warm-in place recycling asphalt pavement technology. For this research, theresearch team has developed a rejuvenator. To evaluate the developed rejuvenator, the research team has used two typesof rejuvenators for this study. To compare performance of two rejuvenators, three test methods were adopted such as
deformation strength test, tensile strength ratio, and dynamic immersion test.

591

Performance Evaluation of Developed rejuvenators for Warmin place Recycling asphalt pavement
Chisu Lim1, Dr. Jaejun Lee1, Jaeyoung Park1
Dr. Sooahn Kwon2, Dr. Yongjoo Kim2

1
2

Chonbuk National University, Jeonju, Jeonbuk, Republic of Korea

Korea Institute of Civil Engineering and Building Technology, Goyang, Gyeonggi-do Republic of Korea

1. INTRODUCTION
Recently, as environmental issues such as the greenhouse gas emission have been increasing globally, the pavement
construction technology is studying to increase recycling of wasted materials in various ways. One of them, thereclaimed asphalt pavement (RAP) has been actively promoted in order to a cycle of reusing materials that optimizes
the use of natural aggregate. Reclaimed asphalt pavement (RAP) is a useful alternative to virgin materials because it
reduces the need to use natural aggregate, which is a scarce commodity in some areas of the Korea as well as bestpractices for increasing the use of RAP in asphalt pavement mixtures while maintaining high-quality pavement
structures. It also saves the amount of money of new asphalt binder required in the production of asphalt paving
mixtures. Currently, although the amount of recycled asphalt is increased annually in Korea, the amount of usage of
RAP was not comparatively increased. The important issue is that rejuvenator cost is expansive because most of themwere imported. Therefore, in this study we compared the RAP using developed rejuvenator for warm-mix. and verified
the possibility for its application through of conducted the deformation strength test and tensile strength ratio test,
dynamic immersion test.

2. MATERIAL
Asphalt mixture's become susceptible to cracking and fracture as the hardness increases due to over time (Lim et al.,2012). Rejuvenator is the material that makes the ageing asphalt binder restore its physical properties of the recyclingasphalt mixture such as ductility and viscosity in order to maintaining existing aggregate gradation and binder contents.
(Kim et al., 2007). Rejuvenators used in this study is the two types, type1 is developed with adding base oil for decrease
harmful gas emissions and another type2 is current used in pavement market now.

3. EXPERIMENTAL METHODS
3.1 Mix design of R.A.P
In order to evaluate the performance of the two type’s rejuvenator, we carried out mixing, changing the mixing ratio
from 0 to 7.9%. Table 1 shows mix-design of one specimen for estimate to deformation strength and tensile strength.
RAP and rejuvenator were blended at a temperature of 130℃, mixture was compacted by marshall compator. Figure 1
shows two type of rejuvenator. Figure 2 is a reclaimed asphalt pavement extracted from wasted asphalt.

592

Figure 1. Conventional(L) and Developed(R) Rejuvenators

Figure 2. Reclaimed asphalt pavement

Table 1. Mix Design
Recycling Aggregate

Type

Content of Rejuvenator (%)

Coarse Aggregate (g)Fine Aggregate (g)

A

600

600

0

B

600

600

2.4

C

600

600

5.1

D

600

600

7.9

3.2 Deformation Strength Test
Asphalt is generally viscosity-elastic behavior at ordinary temperature. Whereas at a high temperature it has appears theplastic behavior. Therefore analysis of deformation behavior under vehicle load is very difficult. Plastic deformation of
the asphalt such as rutting is mainly generated in the high temperature condition. This rutting-resistance may beapproximately estimated by measuring the deformation strength. Deformation strength of the RAP added Rejuvenator
was conducted in accordance with the test method developed in domestic. After specimen with Diameter of 100 mm, a
thickness of 62.5mm is positioned 60 degrees water bath for 30 minutes, remove the moisture on the surface and load at
rate of 30mm/min and then measure the maximum load and displacement. Substituting the measured load anddisplacement in the following equation, finally the deformation strength was obtained(Byung-Jin Cho et al. 2008).
Figure 3 is a sample of deformation strength test. Figure 4 is a jig for measuring the deformation strength.

where, SD = Deformation strength (MPa)P = Load (N)y = Displacement (mm)Figure 3. Specimen for deformation strength

Fig 4. Measurement jig for deformation strength593

3.3 Tensile Strength Ratio
Generally, water is caused damage to the asphalt pavement and is the cause of reducing durability. Therefore in order toevaluate moisture-resistance of recycling asphalt mixture using the rejuvenator, this study was conducted by measuring
the ratio of tensile strength between the water treated mixture and atmosphere treated mixture with KS F 2398. Afterclassifying 6 specimens compacted by marshall compator into 3 and curing in atmosphere and water at degree of 60℃
for 24 hours, this experiment was carried out in the way measuring tensile strength. Figure 5, Figure 6 each shows
Marshall compactor for making specimen, and Marshall stability tester. Tensile strength ratio(TSR) is obtained bysubstituting the tensile strength of each condition to the following equation.

where, St = Tensile strength (MPa)P = Load (N)t = Thickness of specimen (mm)D = Diameter of specimen (mm)where, TSR = Tenslie strength ratio (%)
Std = Tenslie strength of curing in atmosphere (MPa)
Stm = Tenslie strength of curing in water (MPa)Figure 5. Marshall automatic compactors

Figure 6. Digital stability testing machine

3.4 Dynamic Immersion Test
This experiment was performed to evaluate the resistance of the separation between the asphalt binder with theaggregate when the water is added to the asphalt mixture. The test method was to have asphalt mixture having a
constant size (11mm~8mm ) and distilled water rotated 60 times per minute for 24 hours in test bottle. After that, wemeasured loss amount of weight. Based on the results, scaling resistance of the rejuvenators was evaluated. Figure 7
shows the asphalt mixture and glass bottle including a glass rod and Figure 8 shows the experimental setup.

594

Figure 7. Sample for D.I.T and Experimental equipment
4. TEST RESULTS

Figure 8. Experimental set-up

4.1 Deformation Strength Test
Deformation strength test result for evaluate properties of the plastic is shown Fig 10. As shown in the graph, whenusing a constant ratio rejuvenator was the value exceeding the standardization of warm-mix asphalt pavement. However,
without using rejuvenator, value of deformation strength was 6.9Mpa. This means that asphalt mixture harden with thepassage of time, and rejuvenator acts to soften the binder.

Figure 9. Deformation strength test’s result graph

4.2 Tensile Strength Ratio
The result of tensile strength ratio (TSR) test to measure moisture sensitivity is shown in Figure 10. First, in the case of
the mixture without addition of the rejuvenators, TSR value was 0.69. This value does not reach the domestic
standardization of warm-mix asphalt pavement. However, when using a developed rejuvenator was the value exceeding
the standard value with respect to all the addition ratio(2.4, 5.1, 7.1%). This means that the recycling asphalt mixture
using developed rejuvenator has sufficient resistance to moisture.

595

Figure 10. Tensile strength ratio’s graph
4.3 Dynamic Immersion Test
The result of Dynamic immersion test to evaluate the scaling resistance of asphalt mixtures is shown in Figure 11. The
experiment was conducted according to Europe standard(EN-12697-11). When using specimen without rejuvenator, on
average, a loss of 10g is generated in the whole 150g. However, increases of rejuvenator addition rate to reduce theamount of loss caused by water. Moreover, the newly developed warm-mix rejuvenator has more excellent scaling
resistance over water, compared with conventional rejuvenator. Figure 12 shows asphalt mixture before and after
dynamic immersion test.

Figure 11. Losses of Weight (D.I.T)

(a)

(b)

Figure 12. Asphalt admixture of according to experimental. ((a) before immersion, (b) after immersion)
5. CONCLUSION AND FUTURE RESEARCH WORKS
The following result is a performance to evaluate possibility of application over rejuvenator and propose solutions
about environmental problem. The result of performance testing for recycling asphalt mixture on the indoor test is asfollows.

1. In the result of deformation strength test, addition of rejuvenator on R.A.P had been derived softening ofasphalt binder. According to this response, asphalt mixture's Deformation strength was decreased. This result
represents improvement in the resistance of plastic deformation.
2. In TSR test result performed to evaluate moisture-resistance, in case of using rejuvenator, the TSR values weremore than standardization for warm-mix asphalt pavement. This means that it is possible to improve themoisture sensitivity of the recycling asphalt pavement through rejuvenator.
3. In the result of dynamic immersion test for the scaling resistance evaluation, the resistance of scaling was596

clearly improved in accordance with the increase in addition rate of rejuvenator and newly developed
rejuvenator with polymer is superior to conventional rejuvenator over the resistance of scaling.
ACKNOWLEDGEMENT
This study was conducted under research project (Developed of Eco-Friendly Pavements to Minimize Greenhouse Gas
Emissions) funded by the Ministry of Land, Infrastructure and Transport(MOLIT) and the Korea Agency for
Infrastructure Technology Advancement(KAIA). The authors would like to thank the members of research team,
MOLIT and KAIA for their guidances and supports throughout the project.

REFERENCES[1] Kim, Yeongmin., Lee, Sukkeun., Jeong, Gyudong., Yang, Sunglin., (2007). A Study on Performance Properties ofWaste Asphalt Binder Using Rejuvenator, KICT.
[2] Kim, Yeongmin., Lim, Jeonghyuk., Hwang, Sungdo., Jeong, Kyudong., Lee, Sukken., (2015). Laboratory
Performance Evaluation of Recycled Asphalt Binders with Differing Rejuvenators, KICT.
[3] Lim, Jaekyu., Lee, Jaejun., Lee, Jinwook., Kwon, Sooahn., Hong, Jaecheong., (2012). Evaluation of Properties ofRejuvenator for Warm-Mix Type Recycled Asphalt Concrete, KICT.
[4] Lee, Tackwoo., Park, Seungbum., Cho, Cheonghwi., Chae, Yongjoo., (1999). An Experimental Study on The
Physical Properties of Recovered Asphalt using Recycling Agent and Virgin Asphalt, Chungnam national university of
Korea.
[5] BS EN 12697-11(2012) Bituminous mixtures. Test methods for hot mix asphalt. Determination of the affinity
between aggregate and bitumen.
[6] KSA(Korea Standard Association), (2012) Testing method for resistance of compacted asphalt mixtures to moistureinduced damage.
[7] Cho, Byungjin., Park, Taewon., Doh, Youngsoo., Kim, Kwangwoo., (2008). Determination of Proper Loading
Speed for Deformation Strength Test of Asphalt Concretes.

597

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Maintenance of Infrastructures Using GIS and Point Cloud DataTRACK
AUTHOR(Capitalize Family Name)
Yoshifumi NAGATA

CO-AUTHOR(S)(Capitalize Family NamePOSITIONManager, Inspection
Promotion Division,
Inspection and Repair
Promotion Office,
Maintenance and Traffic
Management Department

ORGANIZATION

Metropolitan Expressway
Co., Ltd., Japan

COUNTRYJapan

POSITIONORGANIZATIONManager, International
Affairs Division, TechnicalConsulting Department
Deputy Director,
Engineering Department

Metropolitan Expressway
Co., Ltd., JapanJapan

Shutoko Engineering Co.,
Ltd.

Japan

Takuji HIRAOKAManager, Marketing GroupELYSIUM Co., Ltd.

Japan

Kiyoshi SUZUKI

Consulting Engineering
Department

Aero Asahi Co.

Japan

Naruhiko KAWADA

Kazuhiro TSUNO

E-MAIL(for correspondence)

COUNTRY

k.tsuno@shutoko-eng.jp

KEYWORDS:
Maintenance, MMS, GIS, Point Cloud, Ledger

ABSTRACT:In recent years, many of the infrastructures that were made in the high-growth period are aging, in Japan. At the sametime, number of maintenance engineers for the infrastructures has been becoming insufficient. In order to solve these
problems, we have developed a computer system to improve efficiency and accuracy of maintenance work on roads andstructures, utilizing GIS (Geographic Information System) and point cloud data. Using this system, variety of data
related to structures such as drawings, inspection results and repair or reinforcing records are managed through a digital
map on the GIS. This system also has the ability to utilize the point cloud data measured by a MMS (Mobile Mappiing
System) for such as creation of 2-D and 3-D CAD data or FEM (Finite Element Method) models, and simulation of
inspection or repair work. Moreover, inspection work can be supported by detecting displacement or damage ofstructures using point cloud data.

598

Maintenance of Infrastructures Using GIS and Point Cloud Data
Yoshifumi Nagata1
Naruhiko Kawada2
Kazuhiro Tsuno3
Hiraoka Takuji4
Kiyoshi Suzuki5
1

2

Inspection Promotion Division, Inspection and Repair Promotion Office, Maintenance and Traffic
Management Department, Metropolitan Expressway Co., Ltd., Japany.nagata1410@shutoko.jp

International Affairs Division, Technical Consulting Department, Metropolitan Expressway Co., Ltd., Japann.kawada106@shutoko.jp
3Engineering Department, Shutoko Engineering Co., Ltd., Japank.tsuno@shutoko-eng.jp
45Marketing Group, ELYSIUM Co., Ltd., Japanhiraoka@elysium.co.jp

Consulting Engineering Department, Aero Asahi Co., Ltd., Japankiyoshi-suzuki@aeroasahi.co.jp

1 INTRODUCTION
In recent years, many of the infrastructures such as bridges and tunnels that were made in the high-growth
period are aging, in Japan. At the same time, number of maintenance engineers for the infrastructures has been
becoming insufficient.
In order to solve these problems, we have developed a computerized system named as “InfraDoctor” toimprove efficiency and accuracy of maintenance work on roads and structures, utilizing the “Geographic Information
System”, hereafter referred to as GIS, and point cloud data. Using this system, variety of data related to structures suchas drawings, inspection results and repair or reinforcing records are managed through a digital map on the GIS. Thissystem also has the ability to utilize the point cloud data measured by a MMS for such as creation of 2-D and 3-D CAD
data or FEM (Finite Element Method) models, and simulation of inspection or repair work. Moreover, inspection work
can be supported to be more efficient and accurate by detecting displacement or damage of structures using point clouddata.
In this paper, various functions of the “InfraDoctor” are introduced and a further development plan of total
management system for infrastructure is shown.
2 OUTLINE OF “INFRADOCTOR”
The “InfraDoctor” has been developed in order to improve efficiency and accuracy of maintenance work on
structures such as bridges, tunnels, buildings and so on, utilizing GIS and point cloud data. This computerized system
consists of some elements listed and explained as follows.
2.1 GIS platform
The “InfraDoctor” has a GIS platform. As the portal of the system, a digital map is shown in the browser on
the computer screen. Through this digital map of the GIS platform, any data on various ledgers can be retrieved easilyand quickly.
The “maintenance ledger” has information concerning number, shape and material of structures andappendages. The “inspection history ledger” has inspection-result records. The “repair-history ledger” has records ofrepair and reinforcement work carried out based on the inspection results. Each data on those ledgers has coordinatesand connected to the digital map. Those data also can be searched using various keywords such as name, type, materialand so on, of the structures. Using other information connected to the searched data, they can be sorted easily and599

quickly for various purposes, such as confirming the quantity and locations of same-type structures or parts, side-byside comparison between inspection results or repair work history, for example.
The point cloud data and the all-around video data to be described later are also managed on the GIS platform
and can be shown on the computer screen by specifying the location from the digital map on the browser.

2.2 All-around VideoThe all-around video images are captured using a vehicle called “MMS” (see Picture 1), which stands for“Mobile Mapping System”, while travelling. The all-around video is recorded as still images at every 4m of interval, if
the MMS is travelling at 60 kilometers per hour. The resolution of an image is about 12 mega pixels.
Using this all-around video, the condition of structures and their surroundings can be confirmed throughcomputer screen without actual investigation at the site. Because the all-around video enables objects on a road to be
seen from not only the direction that the MMS is moving ahead but also any direction from the point of MMS, thecondition of the site can be grasped quickly and precisely at the office. The backside of a sign board can be looked backas seen in Figure 1, or sealing of a tollgate can be looked up, for instance.

Picture 1. MMS.

Figure 1. GIS browser with all-around video image.
2.3 Three-dimensional Point Cloud Data
The MMS mentioned above is installed with 2 laser scanners, and it captures three-dimensional point clouddata while travelling at an ordinary speed same as other vehicles. Those laser scanners emit laser beams a million times
a second and capture the location of an object which reflects the laser beams from the scanner. A laser beam can usuallyreach to an object about 800 meters away from the MMS. The MMS also equipped with a GNSS (Global Navigation

600

Satellite System) antenna and an IMU (Inertial Measurement Unit), and the error of measured coordinates due tovibration or rotation of the vehicle are revised using those devises. In general, degree of error for coordinates of an
object is about 10 centimeters for absolute value of location with respect to the surveying coordinate and a few
millimeters for relative error regarding the position of each point recorded in one measurement, if the target is anexpressway road bridge with the height of about 10m from the surface road. The degree of error, however, is changed
depending on the distance between the target object and the laser scanner, velocity of the MMS, the condition of roadsurface which affects the vibration of MMS, tall buildings or structures which interrupts or reflects radio waves for GPS
antenna from satellites, and so on.
When a structure is modelled in three dimension using point cloud data, the MMS should be driven several
times around the target structure in order to eliminate its blind spot. Therefore, a task called “registration” is required tointegrate those point cloud data groups measured separately. It has been confirmed that an error of a few tens of
millimeters may occur during a registration work. In order to solve this problem, a program which can carry out theregistration work while correcting the error automatically is now under development and being prepared forcommercialization.
The MMS is also equipped with some HD (High Definition) digital cameras and the color data on the image
captured by those cameras can be exported to each point in the point cloud. Because of this color, point cloud looks likea video image as seen in Figure 2 and this makes it easier and more precisely to recognize the shape and positional
relationship of structures.
When the MMS cannot capture all the necessary point cloud of a target structure such as a bridge on a wideriver or in steep mountainous area without roads available, a portable scanner fixed on a tripod, a human carrying typescanner or drone equipped with a scanner can substitute and the point cloud data captured by those different scanners
can be integrated with that from the MMS.

Figure 2. GIS browser with point cloud data.
3 APPLICATIONS OF POINT CLOUD DATA
3.1 Detection of Damage and Displacement
Damage on a concrete surface such as flaking or delamination can be detected using the point cloud, by
measuring the difference of position between measured points and a “standard surface” which is an average plane of theconcrete surface created from the point cloud data. This method is expected as a remote inspection technique for thosedamages where the close visual inspection is difficult and spalled concrete might cause damage on people or cars under
the structure such as bridges on an intersection with heavy traffic or railroads.
In a trial measurement, some flakes on a concrete surface with 3 or 4 millimeters of protrusion were detected
when measured by a scanner on the MMS about 10 meters away (See Figure 3). In this trial, point cloud data measured
in one measurement was used in order to eliminate the error caused by the registration work. More study is needed toacquire higher precision with this inspection method.
It is possible to find displacement, deformation or lack of the appendages, structural members or the structure
itself when subjected to a large external force, such as a large earthquake or tsunami, by comparing a point cloudmeasured after the event with the one formerly recorded.

601

Figure 3. Detection of damage on concrete surface.
3.2 Three Dimensional Measurement
It is possible to measure any size or distance of structures in cooperation with point cloud data and the twodimensional map, on the GIS browser of the “InfraDoctor”. Using this function, it is possible to confirm the locational
relationship between structures where people cannot easily reach or that owned by different organizations and not on
the same drawing. And also, it is possible to confirm the three-dimensional construction space for such as repair orreinforcement work, or a clearance between structure and the traffic space.

Figure 4. Clearance check on point cloud.
This system also has a function to create a contour map by giving a color to each point sequentially different
depending on its position in the height direction. This function is applicable to measurement of inclination or rutting
depth on the pavement surface (See Figure 5), and confirmation of the location of a ponding place or flooding range.

Figure 5. Contour of rutting on pavement.

602

3.3 Creation of Two-Dimensional CAD Data
By cutting the point cloud data in any cross-section, it is possible to create a CAD drawing in two-dimension.
In conventional applications, a drawing is created by manually tracing the outline of the cross-section. On the other
hand, the “InfraDoctor” can automatically generate outlines and make it much easier to complete a drawing. Since eachpoint of the point cloud has coordinates, size and distance measurement can be outputted at any position and a generaldrawing of a structure with the dimensions, as seen in Figure 6, can be generated semi-automatically in a short time.

Figure 6. Two-dimensional CAD data creation (bridge pier).
There are about 700,000 bridges longer than 2 meters in Japan, but original drawings of approximately
300,000 old bridges among them have been lost, allegedly. This situation is surely hindering maintenance work forbridges. As for the appendages and the reinforcing members attached to a structure after completed, drawings are often
not well conserved. Therefore, creating drawings of the current state of the structure using this computerized system
will contribute greatly to the efficient maintenance work.
3.4 Creation of Three-Dimensional CAD Model
It is also possible to create three-dimensional CAD model, shown in Figure 7, in a short time by automaticallygenerating the planar or curved surface of a structure from the point cloud data, using the “InfraDoctor”. Then, a threedimensional FEA (Finite Element analysis) model can be created from the three-dimensional CAD data. This function
is effective to analyze the strength of a structure and to carry out a design of repair or reinforcement, using the shape ofstructures in the current situation with the damage or deformation caused by natural disasters or other external loadings.

Figure 7. 3D CAD model created from point cloud data.
3.5 Three-Dimensional Simulation
The point cloud contains coordinates of any objects in the space measured by the MMS, such as structures
without drawings or owned by different organizations, as explained in §4(2). Various simulations can be carried out
using the point cloud data with integrated CAD data of structural members or vehicles, and so on.
In an inspection simulation using CAD data of inspection vehicle on the point cloud (see Figure 8), forinstance, it is possible to confirm the interference between the inspection vehicle and the obstacles, such as surrounding
structures or appendages. By performing this simulation in advance, it is possible to greatly shorten the inspection timeon site. In addition, a three dimensional simulation is also very effective for construction planning work such as loadinglarge members into a limited space.

603

Figure 8. Inspection simulation.
Using this simulation function, you can see the circumstance on the road just as you are driving a car. This“driving simulation” is effective to confirm the safety of road alignments or traffic control.

Figure 9. Driving simulation.

4 FUTURE DEVELOPMENTS
Various data made or obtained at the time of construction, such as design statements, drawings, material data,
methods or conditions of construction work, inspection results including construction error, repair records before open,
and so on, will be managed on the “InfraDoctor” as the initial data of the structure. It is expected that more timely andaccurate examination for repair or reinforcement of a structure can be executed by understanding the present status in ashort time, using those initial data, the inspection records and the analysis-modelling function explained above, when
any damage or deformation of the structure under use is found.

604

3D modelling

Construction
recordDimension data
Material data

Transfer and integrated management ofinitial condition data.

InfraDoctor- Integrated management of ledgers
on GIS map.
- Support of inspection work.
- Support of inspection planning work.
- Creation of analysis models andinput data.

Structural performance evaluation,
deterioration prediction

Repair and reinforcement
Structural performance evaluation and deterioration
prediction, using programs for material analysis andstructural analysis.

Figure 9. Concept of future development
Also, a study has been started to predict deterioration of structures or materials, by matching inspection datathat is obtained using various new inspection technologies under development with analytical result introduced above,using an “AI” (Artificial Intelligence).

5 CONCLUSION
The “InfraDoctor” is a computer system to support operation and maintenance of structures in many ways, bymanaging various ledger data regarding structures on the GIS platform and utilizing all-around video and point clouddata. In the Metropolitan Expressway Group, this computer system is now under a trial operation in order todemonstrate that the application of this system can make the operation and maintenance work more efficient andaccurate. The result of the trial will be reflected to improve the system further. It is expected that the system contributes
to more efficient infrastructure management not only in Japan but also overseas including Asian countries, in the near
future.

605

ROAD ACCIDENTS IN URBAN AND RURAL AREAS OF TANZANIAAUTHOR: BRUNO KINYAGA

1.

INTRODUCTION

Road traffic injuries claim more than 1.2 million
lives each year and have a huge impact on healthand development. They are the leading cause ofdeath among young people aged between 15 and29 years, and cost governments approximately
3% of GDP. Despite this massive – and largely
preventable – human and economic toll, action tocombat this global challenge has been
insufficient. The third Global status report onroad safety shows that low and middle-income
countries are hardest hit, with double the fatality
rates of high-income countries and 90% of global
road traffic deaths. Vulnerable road users –pedestrians, cyclists and motorcyclists – make up
half of these fatalities, by WHO Global Status on
Road Safety, 2015 Report).
Motorcycles transport commonly known as (bodaboda) in Tanzania has been growing up in the
recently years in both urban and rural areas. Thismeans of transport has been used by a large
number of people in the country due to the facts
that it is the fastest means of transport forsomeone to reach anywhere. Up to June 2014
the number of motorcycles that has beenregistered was about 1.2 Million and currently
it’s about 1.5 motorcycles been registered in the
country.

606

2.

COUNTRY PROFILE

Tanzania is an East African country about 5°
south of the Equator with a population of about
45 million in 2012 (National Bureau of Statistics,
March 2013). Tanzania is a relatively large
country located in East Africa with a total area of
945,087 square kilometers. Tanzania has 30
administrative Regions as well as about 128
districts.
Figure1. Tanzania Map

607

3.

STUDY AREA

The study was conducted in Dar es Salaamregion (Tanzania), where most of people use thismode of transport. The population of Dar es
Salaam is 4,364,541 according to the official
2012 census, increasing at 5.6 percent per annum
from 2002 to 2012.
Study was conducted in three representative
districts (Kinondoni, Ilala and Temeke) within
Dar es Salaam region. The selected districts arewell known in the use of motorcycles transport
service. A large number of respondents involvedin the study areas are those who engaged inproviding the service (motorcyclists) and theusers of the service (passengers).
Table1. Districts of Dar es Salaam Region and its
Population

District

Population(2012)

Area km²

Ilala

1,220,611

210

Kinondoni

1,775,049

527

Temeke1,368,881

656

Total

4,364,541

1,393

608

4.

METHODOLOGY

The study used both qualitative and quantitative
methods of research by conducting physicalsurveying on sample districts. A cross-section
descriptive study was conducted from June to
September 2014 whereby different peopleinterviewed using structured questionnaire. The
Data obtained was entered into a statisticalpackage for social studies (SPSS) program(version 15) for clearing, coding and statisticalanalysis.
5.

FORMULAE

The study covered 289 people obtained throughsampling techniques calculated by using single
population proportion formula,
FormulaN = Z²p (1-p)/E² whereby, N = is the minimum
sample size required
Z= 1.96 at 95% confidence interval
E = is a margin of sampling error rate 5%
P = Proportion of motorcycle crash accidents
victims (25%)
Substituting these values to the equation above;
N= 1.96² * 0.25(0.75)/ (0.05)²; N= 289

609

6.

FINDINGSThis study found that, most of the crashes
occurred

betweenmotorcycles

and

motor

vehicles were (70-80%) compared to otherstudies (50-55%). Crashes between motorcycle
and motorcycle are of (10%) compared to otherstudies (7%), motorcycles and pedestrian (5%)
compared

to

other

studies(10%),

lone

motorcycle (5%) compared to other studies(11%), motorcycles and bicycles (5%) comparedto other studies (3%).
Table2.

Motorcycle

accidents

occurredin

Tanzania from January 2015 to June 2015
compared with accidents occurred from January
2014 to June 2014.
Year

No.

No.

No.

Accidents

DeathsInjuries

2015

4079

1747

4826

2014

3170

1423

3622

610

Figure2. Contribution factors to motorcycle
accidents.
60%
50%
30%

Suspected
use of alcohol
Bad roads

20%

Bad weather

40%

10%
0%

Disobeying oftraffic rules611

Figure4. Age group of motorcyclist’s v/s thepercentage of accidents associated.

100%
Kinondoni

80%

Ilala

60%

Temeke40%
20%
0%
18 -30

31-40

41-50

Figure5. Motorcyclist behavior of carrying morethan one passenger without helmets

612

Table3. Motorcyclists with riding license andwithout license
With
LicenseWithout
License

Kinondoni
(%)
60

Ilala
(%)
70

Temeke
(%)
50

40

30

50

Figure6. Accident mechanism; Motorcycle Motor vehicle Crash

613

7.

ISSUES IMPACTING ROAD SAFETY
IN MOST DEVELOPING COUNTRIESLack of enforcement on road traffic laws andregulations.



Speed management, which lies at the heartof an effective approach to reducing deaths
and injuries, is notably poor in many
countries.



Lack of road safety education to road usersFake licenses “A lot of fake licenses”

CorruptionLack of education for operators

Roads are not perceived as dangerousLack of accident registration(Data Collection
and Management)

Roads continue to be designed and built
without sufficient attention to the needs ofthe most vulnerable road users.

614

8.

CONCLUSION

Road traffic injuries and deaths place a heavy
burden on national economies as well as onhouseholds. In low and middle income countries,
they particularly affect the economically active
age group, or those set to contribute to family,society and the workforce in general.
Unfortunately road safety has not been taken as aserious issue. Probably these problems seem to
be more urgent or important but if we analyze thecost related to the victims, or serious injured
people that will not work anymore or may be
depending on the government helps to live due tothe consequences of the accidents, the road safety
topic becomes more important than they
originally thought.

9.

RECOMMENDATIONSStrictly enforcement of road traffic laws that
instruct the riders to attend pre-riding
courses and to make assurance that they havebeen tested by traffic police before
possessing a riding license.
Conducting several check on alcohol use to
motorcyclists during riding.
Initiate road safety education to road users.




615

ACKNOWLEDGEMENT
This Study is part of the Chartered Institute of
Logistics and Transport International Young
Achiever Award of the Year 2014 and the Henry
Suprrier Award of 2015. The two Internationalrecognition awards I was awarded by theChartered Institute of Logistics and Transport
International for my contribution on road safety
initiatives and the logistics and transport sector atlarge.
It is my pleasure to thank all persons, institutions,and organizations who helped me in one way or
another in every process of this study,
including…
The Chartered Institute of Logistics andTransport (CILT)- International
The Chartered Intitute of Logistics andTransport (CILT)- Tanzania
transaid
Surface andMarine Transport
Regulatory Authority -Tanzania

616

REFFERENCES
Mcharo M. (2012). Motorcycle crash: injuries
patterns and associated factors among patientstreated at Muhimbili Orthopedic Institute (MOI).
Lateef F. (2002). Riding motorcycles: is it alower limb hazard?
Direr M. (August 2014). The impact of
employment and working practices on roadsafety (Case study: Tanzania)
Nantulya V. M. (2002). The neglected epidemic:road traffic injuries in developing countries. BMJ
2002; 324:1139-41.
Kemptson G. Mbathi M. Njenga P. Odero K.
Starkey P. Willilo S. (September 2012) urban
transport service indicators: Tanzania Country
Report.
Lema C. (May 2007). makete integrated ruraltransport project, Dar es Salaam Tanzania.

Barber C. Brader H. Mgonjas E. Turner J.
(January 2014). An investigation into the role oftransport operator associations in shaping
Transport Services in Africa’s rural areas:transaid, Tanzania.

617

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

High Speed Data Collection and Automatic Crack Mapping at the Network Level on the
Bundaberg Region

TRACK
AUTHOR
Pedro YARZA
CO-AUTHOR(S)
Ernesto URBAEZ
Hennie ROUXPeter JENSEN
E-MAILPOSITION
Senior Engineer
POSITION
Senior Engineer
Manager Roads & Drainage
Group Manager Roads & Drainage

ORGANIZATION
Pavement Management Services
ORGANIZATION
Pavement Management Services
Bundaberg Regional Council
Bundaberg Regional Council

COUNTRY
Australia
COUNTRY
Australia
Australia
Australia

pyarza@pavement.com.au(for correspondence)

KEYWORDS:
GIS, profile laser data, pavement distresses, automatic crack detection, integrated assets management

ABSTRACT:
Bundaberg Regional Council (BRC) and Pavement Management Services (PMS) have worked together in the collectionof multiple surface pavement parameters and asset identification of the BRC sealed (over 1,900 km) and unsealed (over1,100 km) networks.
This paper shows how the integrated data collection using multiple systems (laser profiling sensors, 3D pavement
cameras, right of way cameras and a navigation system for georeferencing purposes and integrated asset management),
can benefit road agencies for managing their road network.
In order to visualize the data, PMS proposed a custom tool that synchronises and shows all the collected information.
The data can be visualised at different levels, from road level for the network decisions to distress level for maintenancetasks.
The information is shown using not only images, charts and tables, but also specific tools to show the information
through a web map interface, with capabilities to zoom in at the crack (mostly automatically detected) level on the
pavement images.
This paper shows how the high speed data collection system helped BRC staff for better managing their road networkby assisting them in the decision making process. It also shows the advantages of visualizing the results in an integrated
environment to better understand the relationship between different elements (and associated parameters) that coexist ina local road network.

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High Speed Data Collection and Automatic Crack Mapping at
the Network level on the Bundaberg Region
Pedro YARZA1, Ernesto URBAEZ1, Hennie ROUX2, Peter JENSEN2
1

Pavement Management Services, Sunshine Coast, QLD, Australia
2
Bundaberg Regional Council, QLD, Australia
Email for correspondence, pyarza@pavement.com.au

1 INTRODUCTION
The challenge of managing our road pavement network has become an important and the most critical role for a roadasset manager or an engineer in charge of monitoring pavement network behavior.
This paper showcases the advantages of the high speed road data collection systems with simultaneous collection ofmultiple datasets that provides a comprehensive set of results with homogeneous referencing system. This methodology
will allow review of all the information in an integrated viewer interface, where the relationship between the different
data (e.g. relationship between rutting and fatigue cracking) can be easily seen.
In addition, the integration of the automatic crack detection system has shown a way to improve the consistency andrepeatability of the pavement distress rating at the network level.
2 PROJECT SUMMARY
Bundaberg Regional Council (BRC) and Pavement Management Services (PMS) have worked together in thecollection of multiple surface pavement parameters and asset identification of the BRC road network. It will allow
obtaining a general, but at the same time deeper knowledge of the BRC road network condition that is accessible to the
BRC staff in a simple and centralised way.
2.1 THE REGION AND THE NETWORK
Bundaberg Regional Council manages the road network of Bundaberg Region located in the Wide Bay-Burnett area ofQueensland, Australia, about 360 kilometers north of Brisbane. As a reference it covers a surface of 6,450 km2 and has
a population of around 100,000 people.

Figure 1. Location of Bundaberg region in Australia
The BRC road network measures around 3,000 km and can be split on two types of roads based on their surface: sealed
and unsealed roads. The sealed network comprises of around 1,900 km divided in approximately 4,300 segments andthe unsealed network is about 1,120 km (mainly in rural areas) divided in approximately 1,070 segments. The criteria
used for segmentation is based on intersections with other roads/streets or significant changes in the roadcharacteristics. The location of the sealed and unsealed networks can be seen in blue and orange respectively in Figure 2(left side).

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Figure 2. BRC Road Network. Sealed and Unsealed (left). Planning of Collection (right)

2.2 BRC PROJECT OBJECTIVES
The main objectives of this project were to provide an overall condition of the BRC networks (sealed and unsealed) interms of the data summarised in Table 1 below. That information should be managed in an integrated manner through aviewer interface that simultaneously handles the different collected datasets.
Category

Sealed network

Unsealed network

Surface characteristics

Roughness & Rutting & Texture

N/A

Pavement distresses(visual condition data)

Cracking:(Long. and Trans. Fatigue and Block)
Ravelling - Stripping
Patches
PotholesShape loss
Cross section
Corrugation
PotholesEmbedded stones

Inventory data

Surface, pavement and formation width
Kerbs and channel
Barriers
Traffic signs
Floodways and Bridges
Gates and Grids

Gravel and formation width
Floodways and Bridges
Gates and Grids
Traffic signs

Table 1. Summary of Parameters to be Collected
3 METHODOLOGY
3.1 PROJECT SETUP
Due to the different nature and parameters to evaluate in both networks, the data collection and processing have been
split to be managed independently. PMS used an ARAN system and a 4WD (four wheel drive) fitted with five cameras
for the data collection of the sealed and unsealed networks, respectively.
BRC has provided for both networks GIS data with information regarding the start and end location of each segment. It
was an excellent tool for planning the collection and also for processing and accurately segmenting the resulting dataaccording to the BRC existing segments. The sub division of the networks for collection is shown in Figure 2 (rightside).

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3.2 DATA COLLECTION EQUIPMENT
In order to perform the data collection along the sealed network, PMS ARAN LCMS System (Laser Crack
Measurement System) has been used. This system allows collecting road surface characteristics, in term of visual
defects (right of way video recording), laser data (roughness, rutting and texture), as well as automatic crack detection.
This system incorporates some state of the art sensors needed for collection of the following datasets:High resolution (HD) right of way images both from a front and a rear camera with a frequency of one set ofimages every 5 meters of road (independently of the speed of collection).
Longitudinal profile of both right and left wheel paths obtained by the combination of laser distancemeasurement sensors and accelerometers.
A continuous 3D elevation model of the pavement surface 4 meters wide obtained by an LCMS system with aresolution of 1 pixel per 1 mm2. This system was used for both the automatic crack detection and the rating ofother pavement distresses.
Accurate location (track) of all the collected datasets obtained by an inertial navigation system (INS) based onan Inertial Measurement Unit (IMU), a GPS unit and distance measurement instrument (DMI) that provides
accurate results even when there is no good GPS coverage on some areas.

On the unsealed network, a lighter, rougher and simpler to operate piece of equipment developed by PMS was used. It
is mounted on of a 4WD unit that allows collecting on the harsh environment of the BRC unsealed network. It provides
with a set of distance referenced and georeferenced images every 2 meters of displacement along the road in order to beable to rate the pavement distresses.
This system was comprised of the following components:

A multi camera (5 cameras) system that collects images of the different angles of the road (front and rear).
An integrated high precision DMI (distance measurement instrument).
A differential GPS unit.

The equipment units used for collection on both sealed and unsealed networks can be seen on Figure 3.

Figure 3. PMS Data Collection Equipment. Sealed Network (left). Unsealed Network (right)
3.3 THE DATA COLLECTED
The collected data for the sealed and unsealed networks can be divided in three main areas:
3.3.1 Surface Characteristics (laser data)
The surface characteristics (laser data) are based on the analysis of the longitudinal and transverse profile of the road.
The parameters considered for this particular project included roughness, by means of the calculation of theInternational Roughness Index (IRI) transformed into the Australian roughness value called NAASRA Count; rutting
by measuring the left and right wheel path rutting and texture by means of the evaluation of the MPD (mean profile
depth) on both wheel paths.

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These values provide overall information of the condition of the pavement surface and have the advantage of being
obtained in a completely automated way, so the accuracy and repeatability of the results are assured in properly
calibrated equipment.
Due to the nature of the unsealed road network no laser system was collected and therefore no roughness and rutting
data was processed.
3.3.2 Pavement Distresses (Automated Crack Detection and Visual Surface Condition)
For the sealed network both cracks and other pavement distresses (ravelling, patching and potholes) were identified.
These two types of defects were evaluated differently. For cracking, an automated crack detection system based on 3D
images of the pavement was used. On the other hand, a visual inspection based on the right of way (ROW) images andpavement images was carried out to post rate pavement distresses.
Depending on the criteria of the organizations that manage a road network and also based on the most common defects
that can be found in the road networks, different levels of severities and different classifications have to be consideredwhen setting up a schema for rating the pavement distresses. In this particular project to define the different types of
distresses along the sealed network, several references like the Condition Assessment & Assets performance guidelines
from the IPWEA and the Distress Identification Manual from SHRP/FHWA were used. Based on these documents
BRC and PMS defined a custom rating schema to evaluate the pavement condition. The summary of the ratings andtypes of distresses for the sealed network are shown in Figure 4 (left side).
On the unsealed network the rating of pavement defects was based on the Standard Visual Assessment Manual for
Unsealed Roads by Jones, D & Paige G. The following defects have been considered relevant to the analysis of the
BRC unsealed network: a) Cross Sectional Profile, b) Drainage, c) Potholes, d) Corrugation and e) Embedded stones.
For all these distresses the extension and severity of each of the distresses was evaluated base on the ROW images
collected. Figure 4 (right side) shows a summary of the different distresses and severities.

Figure 4. Distresses Rating Schemas. Sealed Network (left). Unsealed Network (right)
3.3.3 Assets Inventory and Condition Assessment
In addition to the pavement indicators discussed above, the survey included georeferenced inventory of several roadrelated assets (considering the condition of the assets for some of them). The assets that were to be identified aresummarized on Table 1 above.
In order to conduct the inventory, a code of the elements based on the Manual of Uniform Traffic Control Devices, wassetup, and the schema for defining the different condition levels for the rated elements was also prepared.

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3.4 PROCESSING WORKFLOW
PMS developed a database to store and deliver the collected pavement condition data and asset inventory for theunsealed network. In addition, a PMS video player containing all the collected videos of the unsealed network has been
included.
Regarding the sealed network the following methodology summarised the workflow that has been followed.









Preparation Road list for collection
Field data collection
Importing of field data
Segmentation of field data
Data processing:o Laser data processingo Automatic crack detectiono Other pavement distress ratingo Asset inventory elements location and rating
Compilation of results
Preparation of deliverableso Integrated viewero Tabular datao Georeferenced data

Figure 5 below shows one of the tools that have been used for QC the collected data, which is also used for processing
and QC the laser data. Some of the main tasks of this workflow are briefly explained on the next sections.

Figure 5. Processing Software (General View)
3.4.1 Segmentation
One of the most important steps in order to process the information and deliver it with the proper referencing(geographical location and also linear reference [chainage]) is the segmentation of the collected information. PMS and
BRC have used an automated segmentation process that assigns the collected data to the planned collection segment,
rubber-banding (stretching or shrinking) the results to the planned location and chainage references.
Figure 6 shows a sample where the planned collection length is compared to the real collected length (showing an
accuracy of over 99.4% in this particular case). The use of these tools assures the proper location of the collected data
and also allows verifying the quality of the data providing the ability to update any inconsistency that maybe foundbetween the planning and reality.

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Figure 6. Segmentation. Auto Matching Results
3.4.2 Automatic Crack Detection
In order to fulfill the requirements of this project PMS has used a system that automatically detects and classifies thedifferent crack types that can be found in a road network.

Figure 7. LCMS Images. Uses for the Different Types of Images
Figure 7 shows all the different types of distresses that can be identified on the LCMS pavement images, based on boththe 3D range images and the intensity images obtained by the system.
Based on the capabilities of the LCMS system and the distress classification that has been defined to this project, theautomatic processing of the pavement images has been completed.

624

Among the automatic tasks that are done by the crack detection system, the main ones are the following:

Detecting the cracks from the set of 3D images collected by the LCMS equipment
Classifying/grouping the cracks regarding their type (fatigue, block, longitudinal and transverse) and theirseverity (width for linear cracks and density for fatigue and block cracks)
Aggregating the results in order to provide indicators that deliver an overview of the network condition at
different levels of detail (from the crack details to the network level average values)

Figure 8 (top left) shows some samples of the automatic ratings obtained after the automatic crack detection process iscompleted.
Depending on the requirements of different projects, other configurations can be setup, enabling classification of thecracks according to their location along the transverse profile (outer wheel path, between wheel paths and inner wheelpath) or regarding what metrics (length, surface, % of area affected) to be considered when quantifying the results.
3.4.3 Other Distresses Ratings
Other distresses like patching, ravelling or potholes are also manually recorded and rated using both the right of way(front and rear images) and the high resolution pavement images. Some samples of the obtained results can be seen on
Figure 8 (bottom left).
3.4.4 QC and QA Processes of the Pavement Distress Ratings
Further to the automatic image processing algorithms used for detection and classification of the cracks and the
distresses, a manual QA/QC procedure took place in order to assure the quality of the results.
Figure 8 (right) shows the general workflow followed to ensure the quality of the results obtained both at the collectionlevel and also at the automatic distress detection level.

Figure 8. Distress Rating. Automated Crack Detection (top). Rating of Patches (bottom). QC Workflow (right)

625

4 RESULTS
4.1 INTEGRATED MULTI-DATA VIEWER
In order to manage all the information shown in the previous sections, an application for visualising all the road related
information has been developed. This viewer application is a web based viewing platform enabling the efficient
viewing of video and pavement condition data. It allows multiple concurrent users from different locations to access to
all road related information stored in a central repository just by using a web browser (Figures 9 & 10).
The main functionalities of this tool are:








Video player button bar that allows movement sequentially along the collected roads
Image views (right of way and pavement images) with zoom functionality and the ability to overlay detecteddistresses and cracks on top of pavement images (with identification of cracks attributes)
Configurable charts and tables synchronized to the remaining views with the summary of the collected data
(Roughness, Rutting, Pavement Distresses, etc.) at different aggregation levels.
Synchronized interactive map view showing the position of the current location and the current trackcollected by the different pieces of equipment
A dashboard for overall network comparison of the different parameters obtained for the entire road network.
A set of measurement tools that allow to interactively measure and record areas and lengths of the different
elements that can be identified on the right of way images (lane width, barrier height, patch areas, etc.)
Front, Rear and Pavement images (with overlaid crack maps). Roughness chart and table. Map view.

Figure 9. Viewer Application

Figure 10. Viewer Application. Width measurement (left). Surface measurement (right)

626

4.2 RESULTS SUMMARY
In summary, the following data and information has been collected, processed and delivered to BRC for better
managing and understanding their sealed and unsealed road networks.
Sealed network:

Roughness, Rutting, Texture and Pavement Distresses data has been compiled over 1,820 km of sealed roads.
Over 30,000 asset elements have been identified and geolocated.
Over 16,000 width measurements have been made on the sealed network.

Unsealed network:

Pavement distresses have been rated for over 1,150 km of unsealed roads.
Over 2,700 assets (inventory) elements have been identified and geolocated.
Over 3,500 width measurements have been made on the unsealed network.

Besides the results being shown in the integrated viewer described above, some of the obtained datasets (mainly theassets/inventory data) has been provided as georeferenced information for using on the BRC assets management tools.
Also some other information that is also shown in the viewer such as surface characteristics and pavement distresses
have also been provided in georeferenced tabular format (at 10 meter interval and segment level) for using on the BRC
pavements maintenance plans.
5 CONCLUSIONS
The main purpose of this paper was to present the capabilities of the high speed pavement data collection to assist BRC
staff to better manage their road network and the decision making process.
It has also been shown how the use of automatic crack detection systems can improve the accuracy and repeatability ofthe pavement distress ratings that are performed on a road network.
Finally, the paper showed the advantages of using specialized, but at the same time simple to use, viewing software thatshows the results of a data collection on a road network, by showing the information in an integrated environment thatallows for a better understand the interrelations between different evaluated parameters that coexist at any spot on a
local road network.

REFERENCES-

AUSTROADS (2007). Guide to Asset Management Part 5B: Roughness. Austroads, Sydney.
AUSTROADS (2007). Guide to Asset Management Part 5C: Rutting. Austroads, Sydney.
DTMR (2003). Manual of Uniform Traffic Control Devices, Department of Transport and Main Roads,
Brisbane.
FHWA (2003). Distress identification manual for the Long-Term Pavement Performance Program. FHWA,
Virginia.
IPWEA (2015). Condition assessment and asset performance guidelines – Practice Note 9 2015 – Road
Pavements (Visual Assessment). IPWEA, Sydney.
Jones, D. (2000). Draft TMH12 Pavement Management System: Standard Visual Assessment Manual for
Unsealed Roads, Council for Scientific and Industrial Research Transportek, Pretoria

627

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

The Impacts of Climate Change on Transportation
Safety and Their Consequences

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Emre DEMIR

Assist. Prof. Dr.

Antalya International University

TurkeyCO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Beste CUBUKCUOGLU

Assist. Prof. Dr.

Antalya International University

TurkeyE-MAIL(for correspondence)

Emre.Demir@antalya.edu.tr

KEYWORDS:
Road safety, climate change, transportation, pavement materials

ABSTRACT:The previous researches have shown the contributions of transportation design and construction to climate change.
Therefore, it is almost unquestionable that the climate is affected by such activities, and further studies are required inorder to observe the consequences of climate change on transportation safety and passenger health. For instance; sudden
rain falls, quick icing which are common incidents due to the changes in climate of a particular region may cause
crashes, injuries, and increase of mortality more than the planning stage predictions of pavement design. Anotherexample would be unexpected wind flow direction shifts which may risk landing/take off of a passenger aircraft. In
overall, this paper interprets the impacts of climate change on transportation safety and hence its economic assessments.
The evaluations and discussions of this work are highlighted with the use of case studies and various observation
techniques.

628

The Impacts of Climate Change on Transportation Safety
and Their Consequences
Assist. Prof. Dr. Emre Demir*, Assist. Prof. Dr. Beste Cubukcuoglu
Antalya International University, Antalya, Turkey
Emre.Demir@antalya.edu.tr*
Beste.Cubukcuoglu@antalya.edu.tr

1 INTRODUCTION
It was both at national and international level agreed that some degree of climate change is now
unavoidable regardless any future reductions in emissions. This statement was also stated by theIntergovernmental Panel on Climate Change (IPCC) (IPCC 2007). It is clear that the increase of detrimental
impacts of global warming and hence all other related climate change phenomena are all related toanthropogenic activities. The usage of fossil fuels causes the release of greenhouse gases. Transportation
network is one of the biggest sector which causes the highest greenhouse gas (GHG) emissions. It is apparent
that even a slight increase in GHG emissions cause an increase in global warming. An increase of 1.3 °F(0.74 °C) was observed in global average surface temperature since 1850. The researchers have always been
focusing on the detrimental effects of materials used or the GHG emissions caused by the Transportation
sector. However, a little attention was paid on the fact that global warming and hence climate change also
influence the quality, durability and safety of the road designs and hence the materials used. Therefore, asignificant decrease in the road safety is expected due to the detrimental impacts of the climate change on theroad pavements.
The awareness of the negative effects of climate change on road safety has been increasing for thelast few years. Many researchers have been working actively on these effects, their causes and hence
consequences (Qiao 2015; Amponsah-Tawiah & Mensah 2016; Taylor & Philp 2015; Rattanachot et al.
2015). It was found by the researchers that the unexpected changes in temperature mostly due to climatechange have reduced the long-time performance of flexible pavements. The increase in temperature orseasonal hot/cold extreme temperatures are found to be the main reasons of aggravated flexible pavement
mostly at regions where extreme hot/cold climatic conditions are observed (Qiao et al. 2013; Tighe et al.
2008).
This research study is an on-going extensive work which focuses on the road safety which is mainly
caused by the changes in climate in Turkey. As it can be seen in Figure 1, major defects such as changes inasphalt flux and major cracks throughout the highways are the main cases that were observed all over thecountry, mainly caused by unexpected climatic conditions due to changes in climate.

Figure 1: Various pictures taken in Antalya highway and Çanakkale-İzmir interstate highway (En Son Haber,
2015)

629

The materials and methods used in pavement design and their negative impacts in climate change
are discussed as already done by many other researchers in the literature. Not last but least, the impacts ofclimate change on road safety and hence its long-term performance will also be evaluated within this work.
At first, a specific region of Turkey namely Antalya, which has been experiencing unexpected severe
climatic conditions during the last few years, will be investigated and analyzed using a few techniques as
discussed within this paper. The cost of the influences of climate change on this region in discussion will also
be evaluated and an estimated cost analysis will be undertaken. Recommendations in order to avoid trafficcrashes due to the changes in climate and decrease the number of deaths and/or injuries will be given to thenational authorities as part of this study.

2 THE IMPACT OF CLIMATE CHANGE ON ROAD SAFETY
Even though over speeding is accepted to be the major cause of road traffic accidents worldwide, it
is worthwhile to discuss the detrimental impacts of climate change on road safety. It is clear that climatechange influences the quality of road design and hence reduces the safety of roads.
While evaluating the influences of climate change on road safety, transportation safety factors must
be taken into account. They are the factors that the roadway designers consider in order to minimize thenumber of crashes at a particular part of a road network (Reynolds et al. 2009; Oh & Mun 2012;
Rzeznikiewiz et al. 2012). For example, vehicle speed limits, distance and straightness of network paths areimportant considerations (Demir 2013). Transportation safety factors are not only based on the design but
also the weather conditions (indirectly the climate change) affects the safety factors at a road section. For
example, after or during a precipitation, wet pavement increases the number of crashes at a particularsegment of a road (Kou 2005; Caliendo et al. 2007; Pardillo Mayora & Jurado Pina 2009) and the number offatal crashes increases dramatically if the rate of precipitation increases (Eisenberg 2004; Wang et al. 2011).
There are studies for mechanical improvements to reduce the stoppage time in such wet conditions (Mazze etal. 1999); however the increase of the crashes due to a precipitation at a particular highway section orjunction is a common result unfortunately. Wet pavements near the road intersections may cause stop
violations (i.e. failure to stop a vehicle) (Rettling et al. 2003). Stop violations at unsignalized intersections
cause a great amount of rear-end crashes. Stop violations ending up with rear-end crashes are also
contributed by pavements containing snow and ice accumulation near the intersection (Rettling et al. 2003).
Moreover, poor drainage systems on a highway segment may lead to crashes related to wet pavement
conditions (Wu et al. 2015). Optimizing drainage locations may reduce the number of crashes due to wet
pavements. In addition to rear-end collisions at signalized intersections, the other types of collision in traffic
may occur due to the sudden change of weather. For example, poor visibility of traffic signals because of
sudden and heavy precipitation, and following the leading vehicles on a roadway in such poor visibility
conditions may cause crashes too (Broughton et al. 2007; Mitra & Utsav 2011). Especially fog and sudden
heavy rain cause the reduction of visibility on a roadway. Also if the sunshine arises suddenly after a rainfall,
wet pavement and water accumulations may reflect the sun light like a mirror. This kind of unexpectedreflections, especially during sun rise and sunset times, may reduce the visibility and risk the safety ofdriving (Sun 2010; Churchill et al. 2012).
In addition to the unexpected weather condition changes, according to the researches undertaken
pavement cracking and pavement roughness was observed due to the climate change including longitudinaland fatigue cracking (Kim et al. 2005). This additional impact on the performance of pavements brings aneed of an additional maintenance for road safety. Changes in solar radiation, air temperature, and dew-pointtemperature play a significant role for the near-surface temperatures of road pavements (Gui et al. 2007).
They not only change the stability of the road materials, but also affect the safety for road users. Paving
materials mix design has to be considered while the geometric design of a road pavement is planned (Tighe etal. 2000; Meagher et al. 2012). Thus pavement safety measurements, criteria, and maintenance program andmethods could be developed against the climate change of a region. All these will end up an increase inbudget to maintain the level of performance at a constant level to provide full safety for the users.
Several studies at national level were undertaken in different countries to measure the cost of theeffects of climate change on road infrastructure. For instance, according to Schweikert et al. (2015) researchstudy, the national-level climate cost impact in South Africa was estimated to be in between US$116.8
million and US$228.7 million annually by year 2050 if no action is taken (Schweikert et al. 2015).
To mitigate the number of crashes is really vital in order to reduce the costs. The crashes caused byclimate change may give rise to loss of many lives and injuries which have monetary costs too. According to
the National Safety Council (NSC) in the United States for year 2011 data, the average comprehensive costs630

by injury severity are very high (NSC 2013). For example, the cost of a death is $4,459,000 while anincapacitating injury cost is $225,100. Further, possible injury cost is $27,200 and no injury cost is $2,400 asshown in Table 1.
Table 1. Average comprehensive costs by injury severity
AVERAGE COMPREHENSIVE COSTS BY
INJURY SEVERITY
Injury Severity
Cost ($)
Death
4,459,000
Incapacitating Injury
225,100
Possible Injury
27,200No injury
2,400
Compiled from NSC (2013)
Such high amount of values would be considered with an application of Cost Benefit Analyses when
deciding on installation of transportation safety measure alternatives related to climate change. Countermeasures, evaluation of safety programs, and allocating resources would be considered with the reality ofclimate change. Also construction costs, additional maintenance costs, enforcement and emergency
management costs would be reevaluated bearing climate change in mind.
On a global scale, shifts in tourism and agricultural productions are also linked to the increase intemperature due to climate change. These unexpected changes in tourism sector and agricultural productions
end up some shifts in passenger and freight transport (Koetse & Rietveld 2009). On top of that a focus onroad and rail transport infrastructures is needed to see the changes in quality and long-life durability of thetransportation systems due to the climate changes and vice versa.
Based on the above mentioned discussions it is clear to understand that the impact of climate changeon transportation systems and vice versa requires some cost-benefit analyses to see which method ortechnique would be appropriate to apply to achieve a less costly, environmental friendly and less impacted
systems from climate change.
Therefore, one of the main aim of this research study is to undertake studies at national level tomeasure the cost of the effects of climate change on road safety and being able to evaluate and compare thenational cases with other nations worldwide.

3 FINDINGS AND DISCUSSIONS
3.1 THE USE OF PROPER MATERIALS IN ROAD DESIGN
The main materials used in road pavement design may be listed as asphalt, cement and aggregates.
Aggregates are mainly used in road buildings. However, even the extraction of aggregates has a directcontribution into the climate change. Moreover, heavy lorry traffic on unsuitable roads will cause permanentand long-term pavement cracks. The use of finite natural resources in order to produce aggregates also will
have direct impact on sustainability. Therefore, the right choice of materials to be used in road designs isrequired in order to reduce their negative impacts on climate change and vice versa. Luckily, there are a few
alternatives available in order to replace virgin aggregates. The impacts of unused materials on climatechange may be reduced by replacing them with other alternative materials e.g. recycled aggregates. The
impact of road design on climate change and vice versa is linked to the materials used and the way of
production. The amount of materials required for road design is extremely high since the paved surfaces cancomprise a really high rate of land cover all over the world. For instance, in urban regions of the UnitedStates, land cover by paved surfaces may comprise up to 45%. These roads are mostly designed with energy
intensive products made up from either Portland cement or petroleum-based asphalt (bitumen). The longterm durability of materials used in the pavement design is quite important in order to preserve the roadsafety and also to reduce the cost. Therefore, a right type of material should be chosen by considering all
factors including the unexpected climatic conditions due to global warming and hence changes in climate.

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3.2 EVALUATION OF TECHNIQUES AND STANDARDSTo help avoid or mitigate collisions due to slippery surface and poor visibility, there are suggestions
to apply or traffic instruments to install for precaution. In order to decrease the wet pavement area which
creates slippery surface overlaying pavement to change friction course, chip seal or slurry seal approaches,grooving pavement surface, providing adequate drainage, drainage locations optimization, setting appropriate
speed limit, using slippery when wet sign might be applied (Sun 2010; Chen et al. 2014; Wu et al. 2015). In
order to decrease the number of crashes due to poor visibility affected by fog, heavy rain, glare from sun, etc.
the following precautions might be applied (Sun 2010). For example, installing and improving warning signs,
installing thicker signal lenses allowing more visibility from further distances, installing signal visors,
relocating and adding signals, removing sight obstructions, setting appropriate speed limits might be thesolutions.
One of the most common applications in order to mitigate the number of crashes on roadways isusing Traffic Control Devices (TCDs) (Stamatiadis et al. 1991; Zhang et al. 2014). For example, signs, roadmarkings on pavement and delineators, signals, and temporary traffic controls regulate traffic give warnings
and provide guidance to drivers. Standards are needed to set a single form for all drivers, pedestrians,
cyclists, and so on. Standards in the United States are publicized in a manual titled Manual on Uniform
Traffic Control Devices (MUTCD). The minimum standards of TCD’s are set in MUTCD to provide
guidance and ensure the uniformity of TCD’s (MUTCD 2016). In Turkey, MUTCD standards are used asbase to set up a manual for the traffic regulations in the country. The Department of Traffic Safety controlled
by the General Directorate for Highways is responsible for this purpose and the most of the MUTCD
regulations are used as basement to arrange TCD’s for the Turkish highways, arterials, and streets. Since
climate change affects the weather also in Turkey, adaptation to this change in terms of transportation safety
is also important in this country. The manual might be reviewed and examined according to the new climate
conditions. For example, there are parts in the manual about the change in driver behavior to adjust the speed
while driving a private vehicle. The article mentions that the traveling speed on the roadway is mostly up to
the drivers if congestion effects are neglected (General Directorate for Highways 2014). Drivers prefer theirtravel speed based on the condition that they feel safe. There are specific conditions affecting on adjusting
traveling speed by drivers. These are, for instance, weather conditions, wetness/moisture conditions onpavement amount conditions related to snow, ice, mud, sand on pavement, of the light at the environment,time of the day. As can be seen from the manual publicized by the Department of Traffic Safety, suchconditions are extremely related to the weather and climate change.

6 CONCLUSIONS AND FUTURE WORKAs it was already mentioned within the main body of this paper, this is an on-going research projectand only a very few observations and investigations were mentioned in this paper. Antalya has been chosen
as a pilot study area in Turkey to get some idea about the detrimental impacts of climate change on roadsafety. When all the required data is completed, it will allow the researchers to have some valid data about
the general condition of the road network in Turkey mainly in Antalya. This will allow us to makerecommendations on what should be done in transportation sector to reduce the negative impacts of climatechange on road safety.
The General Directorate for Highways in Turkey and its subdivision the Department of Traffic Safety
would take the changes in climate into account to review the regulations nationwide. As mentioned earlier,
the Department of Traffic Safety is responsible for following up the recent upgrades in technology anddevelopments in science to improve the safety in transportation. After confirmations of new applications
related to climate change (e.g. improving the visibility of pavement markings, and the quality of pavement
design (including the right choice of materials to be used), signalization materials and so on), traffic safety
regulations might be changed in the manuals for transportation safety. Finally, the Department of Traffic
Safety would implement the new techniques in order to mitigate the number of collisions in traffic.

632

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Preliminary report for IRI changes after KUMAMOTO earthquake Japan, byusing Smartphone roughness measurement

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRYYAGI, KoichiCEO

BumpRecorder Co., Ltd.

Japan

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

E-MAIL(for correspondence)yagi@bumprecorder.com

KEYWORDS:
IRI, response type measurement, pavement maintenance management, smartphone, accelerometer

ABSTRACT:The Kumamoto earthquake was occurred in Japan on April 14th 2016. After this earthquake, road damage investigation
was done that is roughness condition IRI measurement over 3,000km roads. This preliminary report is written for thisinvestigation results.
As for this IRI measurement, response type measurement was done by using a smartphone built-in an accelerometer /GPS and a commercially available car, instead of the inertial profiler. This method is simple, easy and low-cost. So it
can immediately measure IRI of whole disaster areas under the damaged rougher road. Measurement results are drawn
on online maps. It includes roughness current status and comparison with past status before an earthquake.

635

Preliminary report for IRI changes after KUMAMOTO
earthquake Japan, by using Smartphone roughness
measurement
YAGI, Koichi1
1

BumpRecorder Co., Ltd., Tokyo, Japan
Email for correspondence, yagi@bumprecorder.com

1 INTRODUCTION
In Japan, Kumamoto earthquake was occurred on April 14 and 16, 2016, at the west end side of Japan. It was
the quite large twin earthquake. In Figure shows the location of Kumamoto prefecture. And Figure 2 shows its seismic
intensity map. The first shock occurred at 21:26, April 14 and it recorded moment magnitude Mw6.2. The second main
shock was occurred at 01:25, April 16, whose magnitude was Mw7.0 bigger than first one. Of course, there wereseveral aftershocks followed the initial quake. In a series of seismic activities, the first shock is usually the biggest one,but at this earthquake, the second main shock was the biggest, which was quite unusual. In the first main shock, many
houses, buildings, bridges and roads were damaged. As you know there are many earthquakes in Japan, for example
Kobe Earthquake 1995, Chuetu Earthquake 2004, and the Grate East Japan earthquake 2011. So in Japan, buildings etc.
have seismic performance. For this reason, at the first main shock in Kumamoto, many of them have damages to someextent but it was not serious for residents’ safe. At that time, I thought it was a large earthquake, but it could be undercontrol. However, after the second shock, many structures had already lost enough seismic performance. Many
structures were completely destroyed. As the result, 49 peoples died in Kumamoto earthquake. Ａat the Grate East
Japan earthquake 2011, more than 20,000 people died because of the tsunami attack at some pacific coastal areas, notbecause the quake. Its wave was higher than 35m. At Kumamoto earthquake, more peoples died by quake damages.
That was a large quake. Over 137 thousand houses were destroyed by the quake. Of cause it was affected not only tohouses, but also to roads and pavements.
Previously, as for pavement inspection, only the human visual inspection used to be applied. In this case, theresult is not quantitative, which is difficult to compare with other inspections. Also the use of an inertial profiler isdifficult, because of its high costs and the possibility of the breakdown caused by bad road conditions after anearthquake. On the other hand, the response type roughness measurement by using smartphone is one of the solutions tothese problems. It can measure quantitative data by using a car that is tougher than an inertial profiler. After two weeks
from the main shock of Kumamoto prefecture roughness measurement was done the whole prefecture. Driving distancewas up to 3,100km.

Figure 1. Location of Kumamoto prefecture

Figure 2. Seismic intensity map
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2 SMARTPHONE TYPE ROUGHNESS MEASUREMENT
A smartphone application named BumpRecorder was used for IRI roughness measurement of the road damage
inspection from Kumamoto earthquake. The measurement principle was reported at 1st IRF Asia Regional Congress.
An essence of this method is as follows.
Smartphone is on the vehicle dashboard. It is located over the vehicle suspension. So a recording acceleration
is easily influenced by vehicle model and driving speed. As the result, measurement results are not stable. To increasemeasurement stability, vibration frequency analysis is applied. Figure 3 is drawing calculation steps.

Figure 3. Roughness measurement method

At first, using FFT, vehicle suspensions resonant frequency and damping ratio are estimated. Even if recorded
acceleration is including several resonant frequencies, suspensions movement is a main vibration, so it's resonant
frequency can be found around 1.5[Hz] easily.
Next, using this spring parameters, the equation of motion of one mass spring model is calculated. This model
appears in Figure 4. An equation (1) is an equation of motion for this model. In this equation, Lz is a sprung verticalmovement, "u" is an unsprung vertical movement, "ω" is an angular frequency, "h" is a damping ratio. "ω" is definedby equation (2). In this equation, "f" is a resonant frequency. Here, "h" and "f" are used for previous FFT result.
And finally, an unsprung movement "u" is assumed that it is equal to road longitudinal profile, and it iscalculating the Quarter Car simulation, then IRI will be calculated.

Figure 4. One mass spring modelz  2h( L z  u)   2 ( Lz  u)  0
L(1)

  2f(2)

Previously, the response type roughness measurement uses correlation equation between IRI and sprung
acceleration. That is IRI class 3. And correlation equation is calculated by a test drive result of each vehicle model
before measurement drive. On the other hand, BumpRecorder calculates longitudinal profile first, and then QC
simulation is applied. That is IRI class 2. And it is not required a previous test drive. That is because calculation
parameters of spring constant and damping ratio are estimated form acceleration data of measurement drive.

637

3 SQUARE MESH SECTION FOR IRI SECTION
To calculate IRI, calculating the section is important. Usually, this section is defined by a road location
markers e.g. kilo-post data. But it is not convenience. Because kilo-post data is prepared for a main road, but not for
many roads. When not using kilo-post data, the measurement GPS data is separated in a certain distance for example
each 100m, which is easy in calculation. But unfortunately, GPS data has an error, when it wants to compare current
IRI with previous IRI, it is expected that each IRI section is not same, and a comparison check is difficult.
To improve the situation, "Square Mesh Section" is proposed. It can pick up the same section for same
location, anytime, anywhere, only by using GPS data. Square shape mesh is defined by the longitude and the latitude on
the earth. When it is driving to cross over one mesh, a section between an entry point and an exit point is used in IRI
calculation section. It is drawing in Figure 5.

Figure 5. IRI calculation section
In detail, East West length of Square Mesh is defined by 1/8192=2-13 length for each 1 degree of the longitude.
It is about 10m around Japan located around latitude 35 degrees. And North South length is the same width as East
West width. For each square shape mesh, Square Mesh Code is a pair code for the longitude and the latitude. An
equation (3) defines longitude code of LonCode, and an equation (4) define latitude code of LatCode. LonCode and
LatCode are integer.

LonCode = int(

longitude
)
213

(3)

1
1+ sin(latitude) a´ a ) = int(log´ )cos(latitude)
1- sin(latitude) 2(4)

LatCode = int( òHere, “ a ” is defined for LatCode is 1 when LonCode is 1. That is as follows equation (5).

a = 469,367.1234(5)In Addition, an expand mesh is defined, because it usually wants to use longer section to calculate IRI. An
expanding mesh is defined by 2 times, 4 times, 8 times, 16 times width of original mesh one. Square Mesh code isdefined by array of (MeshSize, LatCode, LonCode). It shows in Figure 6.

Figure 6. Definition of the Square Mesh Code638

4 MEASUREMENT CONDITIONS AND RESULTS
Figure 7 shows roughness measurement roads. It is around Kumamoto prefecture, collected after Kumamoto
earthquake. This map has 200km long for south to north, and 260km width for the west to the east. The brown line
indicates measurement roads which have over 3,100km long. Measurement roads are located around the epicenter,
referred to Figure 2.

Figure 7. Roughness measurement road aroundKumamoto prefecture

Figure 2. Seismic intensity map (reshown)

Figure 8 and Figure 9 were taken in Mashiki Town during roughness measurement driving. Mashiki Town islocated at the Kumamoto earthquake epicenter, and it had biggest damages. Figure 8 indicates a left house originallywith two floors, but its ground floor is collapsed down. Figure 9 shows a left house also damaged, its ground floor andwall. that is dangerous to pass its side, so, the left turn lane was closed.
Figure 10 and Figure 11 shows the then Mashiki Town too. Here, pavements are peeled. In Figure 11, on theright hand side of the road, the water drain is floating up, as the result there are bump steps on this intersection.
Figure 12 and Figure 13 shows the then Aso City. It is located at the north east of the epicenter. As for the big
bum step of Figure 12, in order to it, the pavement is peeled and graveled. Figure 13 shows a temporally bump step signfor drivers safety, which is continued about 7km long. Driving speed is slowed down.

Figure 8. House collapse at Mashiki Town

Figure 9. House collapse at Mashiki Town

639

Figure 10. Pavement peeling at Mashiki Town

Figure 11. Pavement peeling at Mashiki Town

Figure 12. Bump step and pavement peeling at Aso City

Figure 13. A bump step sign at Aso City

Figure 14 indicates the roughness measurement result around Mashiki Town, located near the epicenter. On
this map, the line color indicates road roughness, which is the Japanese roughness standard index "Flatness Index" like
IRI. light blue lines means most flat conditions, blue, green, brown lines do rougher roads, and red lines mean the mostrough roads. In addition, triangular shapes indicate bump steps. Large triangular means large bump steps. This map
indicates current roughness situations. However, according to this map, it is a little bit difficult to understand whichroughness and/or bump step is affected by the earthquake. That is because some roads have been rough before theearthquake, for example around manholes, or bridges, etc.

Figure 14. Current roughness and bump step distribution map

640

5 ROUGHNESS COMPARISON BETWEEN BEFORE AND AFTER EARTHQUAKE
BumpRecorder Co., Ltd is measuring road roughness with the global IRI and the Japanese standard "Flatness"from 2011. Figure 15 indicates the measured roads by BumpRecorder application that has already spread all over Japan.
So the roughness data before the Kumamoto earthquake happened was already acquired. Using this data, roughness
comparison is done between before and after the Kumamoto earthquake.

Figure 15. IRI measured road in Japan by BumpRecorder application

Figure 16 shows the roughness comparison results. In this figure, the line width indicates roughness by theJapanese standard index, "Flatness Index" which is like IRI. The bold line indicates rougher road and the thin line does
flat roads. Red lines show the data after the earthquake. Blue lines are overwrapped on red lines for the data alreadyacquired before the quake. When the roughness situation is the same between before and after the quake, the both lines
are the same width. Then only blue lines can be shown. When the road has damages by this earthquake, red lines
become wider than blue lines, as the result, the red color can be shown on this map. It is easy to understand the disaster
effect on the roads.
Compared with Figure 14, current roughness drawing, Figure 16 of the before and the after comparison iseasily understood where the quake has damaged. For example, the green arrow point has a bump step, but it is not thequake affect, which is recognized by Figure 16, but difficult to see by Figure 14.

Figure 16. Roughness comparison between before andafter earthquake

Figure 14. Current roughness (reshown)

Figure 17 and Figure 18, show he roughness comparison result of wider areas around Mashiki Town. Figure 17
has 20km width for the west to the east, and Figure 18 shows 40km width. Look at this figure, road damages are
spreading out the south west direction.

641

Figure 17. Roughness comparison around Mashiki Town
and neighbouring cities and town

Figure 18. Roughness comparison around central
Kumamoto

Figure 19 shows the current roughness distribution map of Aso City located at the north east from theepicenter. In this city, after the earthquake, there is measurement data on many main roads. But there is only few datafor before the earthquake. For this reason, Figure 20 shows the fact that two roads can only be made roughness
comparison map. According to this result, the regular and frequent measurement is very important to understandpavement situations.

Figure 19. Current roughness distribution at Aso City

Figure 20. Roughness comparison at Aso City

7 CONCLUSIONS
Kumamoto earthquake occurred on April 14 and 16, 2016. The epicenter was in Mashiki Town, and the areastrongly damaged by the quake was spreading south west and the north east area from the epicenter. After theearthquake, IRI data was collected from over 3,100km roads in a week. During the inspection, smartphone typeroughness measurement application was used. It is easy and low cost to collect roughness data, so it is possible tocollect long distance in a short period.
Current roughness data is useful for the pavement maintenance management. However, because the road structure is not
sometimes flat, for example manholes and/or abuts of bridge etc., roughness becomes large. That is not damaged by theearthquake. To understand the affect by the earthquake clearly, roughness comparison has been done by using previous
measurement data, which enabled us easily to understand where has been damaged. Unfortunately, in some places, forexample in Aso City, creating roughness comparison distribution map was impossible because of lacking previous data,
which clearly indicates the importance of frequent measurement. It is very important to understand current roadconditions. The existing method of inertial profiler is difficult to use because of the high operation cost.
Smartphone type roughness measurement is a powerful tool to collect roughness data. It is easy and low cost.
At Kumamoto earthquake, smartphone roughness measurement clearly indicates the possibility to collect roughness
data immediately in a short period.

642

8 REFERENCESREFERENCESYAGI Koichi, Collecting Pavement Big Data by using Smartphone, 1st IRF Asia Regional Congress 2014
TOMIYAMA Kazuya, et.al, Lifting Wavelet Transform for Distress Identification Using Response-Type Profilers,
Transportation Research Board 93rd Annual Meeting, 14-3520
Shahidul Islam et al., Measurement of Pavement Roughness Using an Android-Based Smartphone Application,
Transportation Research Board 93th Annual meeting 2014, 14-5481.

643

Energy Usage and Greenhouse Gas Emissionsof Pavement Preservation Processes for
Asphalt Concrete Pavements
Jim Chehovits ¹ and Larry Galehouse ²

ABSTRACTUse of pavement preservation treatments extends the remaining service life of asphalt concrete pavements. These
treatments typically include spray applied surface seals, thin overlays, crack treatments, chip seals, slurry seal/micro
surfacing, surface recycling and others. Each preservation treatment reduces damaging effects of aging anddeterioration of the pavement surface layer and helps protect the integrity of the underlying pavement structure. If
proactive preservation treatments are not used, pavements deteriorate more rapidly and require major rehabilitation
with structural overlays or reconstruction much earlier.
Every type of pavement strategy requires a series of energy using processes that impacts greenhouse gas
emissions. Pavement rehabilitation and reconstruction require large amounts of energy to obtain and process raw
materials, transport, mix and apply the final product, while pavement preservation processes require much lessenergy to apply the final product to the road surface. This paper presents information on energy usage per unit areaby comparing pavement life extensions of pavement preservation treatments to typical design lives of reconstruction
and rehabilitation techniques. Results show that pavement preservation treatments have significantly reduced
energy use and greenhouse gas emissions compared to traditional rehabilitation and reconstruction strategies.
KEYWORDS
Pavement Preservation, Energy Usage, Sustainability, Green House Gasses, Asphalt Concrete Pavement¹Crafco, Inc. 420 N Roosevelt Ave., Chandler, AZ 85205²National Center for Pavement Preservation 2857 Jolly Road, Okemos, MI 48864
INTRODUCTION
Construction, rehabilitation, and maintenance of highway pavements require obtaining, processing, transporting,manufacturing, and placement of large amounts of construction materials. These activities use substantial amountsof energy and generate green house gasses (GHG). Differing philosophies have existed, and still exist, on the proper
approach of managing, rehabilitating, and maintaining pavements. Methods range from one extreme of allowing thepavement to deteriorate and then reconstructing; to using preservation treatments to minimize effects of aging andmaximize pavement life. Vastly different amounts of energy are consumed with different construction,
rehabilitation, and preservation techniques. These various techniques also provide differing amounts of pavement
design lives and life extensions. For each preservation treatment the life extension can be compared to the requiredenergy and GHG emissions to determine an annualized energy use and GHG emission level. To minimize energy
and GHG emissions over the life of the pavement, treatments can be chosen as having the lowest annualized energy
use and GHG emissions.
LITERATURE REVIEW
Energy use and GHG emissions for the construction industry have been receiving increasing attention in recent
years. The terms “Green”, “Sustainable Development”, “Environmental Impact”, “Energy Efficiency”, “Global
Warming”, “Green House Gases”, and “Eco-efficiency”, are becoming more widely recognized and used.
For buildings, the Leadership in Energy and Environmental Design (LEED) system has been developed toaid in design and construction to minimize environmental impacts. The LEED-ND (for Neighborhood
Development) system includes some basic paving considerations in the analysis for multi-unit developments (US644Chehovits, Galehouse

Green Building Council, 2008). The Greenroads system has been developed as a method to assess roadway
sustainability. Greenroads enables owners, consultants and contractors to make informed decisions by providing asustainability performance metric for roadway design and construction. The system defines roadway sustainability
attributes, provides a system for evaluation of roadway sustainability, and includes a collection of sustainable
design and construction practices. The system includes 11 project requirements, including items ranging fromhaving pavement preservation and environmental maintenance plans to construction quality control and life cycle
cost analysis. Credit can be given for several pavement technologies including warm mix asphalt, cool pavements,
and quiet pavements, to name a few. Additional voluntary credits are available that can be added to produce a
final Greenroads score. The score can be used for tracking and evaluating roadway project and system
sustainability (Greenroads, 2009). BASF has developed an Eco-efficiency analysis method that can be applied tomany products or systems (Uhlman, 2009). The process considers and evaluates six aspects of a system including
raw materials, land use, energy consumption, emissions, toxicity potential, and risk potentials. This procedure has
been used to compare eco-efficiency of several paving processes including hot mix overlays, micro-surfacing, andchip seals (Wall, 2004). Cold mix systems, such as micro-surfacing were found to use less energy and to be more
eco-efficient than hot-mix asphalt concrete, and emulsion chip seals were found to require less energy and be more
eco-efficient than hot-applied chip seals. The publication “Road Rehabilitation Energy Reduction Guide for
Canadian Road Builders” (Canadian Construction Association, 2005) was developed to provide information on
methods to reduce energy usage during road construction and maintenance operations. Suggestions are provided for
reducing energy use during plant operations and construction operations. Chappat and Bilal (2003) reported an indepth analysis of energy consumption and GHG emissions of over 20 different paving product types by ton ofmaterial placed. Their comparisons show that PCC paving materials and processes demand the most energy,
followed by hot mix asphalt (HMA) paving. The report also showed that cold in-place recycling (CIR) is the least
energy intensive process. Dorchies (2008) reported on software that has been developed to quantify energy use and
GHG emissions for various pavement structures based on material types and quantities. Terrel and Hicks (2008)
analyzed energy use for hot in-place recycling (HIR) and determined the process utilizes less energy than hot mix
asphalt (HMA) paving.
Miller and Bahia (2009) in a report on sustainable pavements revealed that proactive
maintenance is the least energy intensive process because minimal improvements are made to the pavement
structure and surface course. The authors suggest that cold process patching and surface treatments are the mostenergy efficient.
Extensive analysis of energy use and GHG emissions for the major construction processes was frequently
mentioned in the literature review. For preventive maintenance processes, there is limited reporting of energy use
and GHG emissions for several treatments with suitable conclusions. However, available reports do not always use
the same base data and analysis methods, so comparisons between processes cannot readily be made.
ENERGY USE AND GHG EMISSIONS FOR CONSTRUCTION MATERIALSWhen determining energy use and GHG emissions of various preventive maintenance treatments, the first issue is todetermine the components of the process to measure. Some comparisons have been reported which only consider
parts of the process, such as manufacturing or product placement. These comparisons can lead to misleading
conclusions. A more accurate and realistic measure of energy use and GHG emissions of a specific type of work, is
to begin with obtaining the raw materials from the earth and adding all the operation steps, such as transport, refining,
manufacturing, mixing and placement. Table 1 was compiled by Chappat and Bilal (2003) of energy consumption
and GHG emissions for various construction products. The following discussions of energy use for materials andprocesses are based on information from Table 1.

645

Chehovits, Galehouse

Table 1
Energy Use and GHG Emissions for Pavement Construction Materials(Chappat and Bilal, 2003)
Energy consumed and greenhouse gases emitted during the manufacture of one ton of finished product fromextraction (quarry, oil deposit, etc.) until the sale at the production unit (refinery, cement plant, etc.)
Product
BitumenEmulsion 60%
CementHydraulic Road Binder
Crushed Aggregates
Pit-Run Aggregates
Steel
Quicklime
Water
Plastic
Fuel
Production of Hot Mix Asphalt
Production of Warm Mix Asphalt
Production of High Modulus Asphalt
Production of Cold Mix Plant
Surface milling of Asphalt for RAP
In-situ Thermo-Recycling
In-situ Cold Recycling Stabilization
In-situ Soil Cement Stabilization
Laying of Hot Mix Asphalt
Laying of Cold Mix Materials
Cement Concrete Road Paving
Lorry Transport (km/t)

Energy(MJ/t)

CO2(kg/t)

Data Source

4,900
3,490
4,976
1,244
40
30
25,100
9,240
10
7,890
35
275
234
289
14
12
456
15
12
9
6
2.2
0.9

285
221
980
245
10
2.5
3,540
2,500
0.3
1,100
4.0
22
20
23
1.0
0.8
34
1.13
0.8
0.6
0.4
0.2
0.06

Eurobitume
Eurobitume
Athena & IVL
CED
Athena & IVL
Athena & IVL
Athena & IVL
IVL
IVL
IVL
IVL
IVL
IVL
IVL
IVL
IVL
Colas MM
IVL
IVL
IVL
IVL
IVL
IVL

Materials
Most materials used in asphalt pavement construction, rehabilitation, and maintenance processes consist of
aggregates, of various gradations, and asphalt binders of different performance grades. The total energy used is
obtained by starting with the raw material extraction and progressing to transportation and processing/refining.

Aggregates
Energy consumption for aggregate production includes the quarrying, hauling, crushing, and screening. Energy
consumption for aggregate production ranges from 25,850 to 34,470 BTU/t (30 to 40 MJ/t), and GHG emissions
range from 5 to 20 lb CO2/t (2.5 to 10 kg CO2/t).
Asphalt646

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Energy consumption for asphalt binder production includes crude oil extraction, transport, and refining. Energy
consumption for asphalt binders has been determined to be 4.2 mmBTU/t (4900 MJ/t), and GHG emissions are 570
lb CO2/t (285 kg CO2/t). For asphalt emulsions, energy consumption is 3.0 mmBTU/t (3490 MJ/t) and GHG
emissions are 442 lb CO2/t (221 kg CO2/t).
Manufacturing
Manufacturing includes all steps involved with handling, storing, drying, mixing, and preparation of materials for
installation. Energy consumed varies depending on the specific material or product type. Typical manufacturing
products for highway use include hot mix asphalt (HMA), cold mix, crack sealant, and drying surface dressing
aggregate. Production of HMA consumes 237,000 BTU/t (275 MJ/t) and produces 44 lb CO2/t (22 kg CO2/t).
Warm mix asphalt production, as reported in Table 1, consumes 201,000 BTU/t (234 MJ/t), approximately 15%
less than HMA. It is noted that there are several warm mix asphalt processes for which energy use varies depending
on required production temperatures. Cold mix asphalt production only requires 12,000 BTU/t (14 MJ/t) because of
not needing to heat the aggregate to elevated mixing temperatures.
Transport to Work Site
The produced construction materials must be transported to the work site. Energy consumed on transport varies
with the distance and the quantity of material moved. Transport energy has been reported as 1,250 BTU/t-mile (0.9
MJ/km-t) with 0.2 lb CO2/t-mile (0.06 kg CO2/km-t).
Placement and Construction
Placement and construction consists of all activities required to install the materials or products. This includes
traffic control, site and product preparation, compacting, finishing, clean up, waste disposal, etc. The highest energy
consuming process for placement is hot in-place recycling (HIR) at 393,000 BTU/t (456 MJ/t) with 68 lb CO2/t (34kg CO2/t) of GHG. This is due to the required heating to soften and reclaim the existing pavement. Placement ofasphalt concrete and cold mixes require between 5,170 and 7,750 BTU/t (6 to 9 MJ/t) with 0.8 to 2.2 lb CO2/t (0.4 to
1.1 kg CO2/t) of GHG. Placement energy for PCC is the lowest at 1,900 BTU/t (2.2 MJ/t) with 0.4 lb CO2/t (0.2 kg
CO2/t) of GHG.
Total Energy Use and GHG Emissions
Tables 2 and 3 are summaries of total energy use and GHG emissions for raw materials, manufacture, transport, andplacement of various construction products (Chappat and Bilal, 2003). The data shows that Portland cement
concrete pavements use the highest energy consumption at approximately 860,000 BTU/t (1000MJ/t) with thehighest energy demand being required for manufacture of the cement. Asphalt concrete utilizes less energy at
586,000 BTU/t (680 MJ/t), with the majority of energy being required for manufacture of the asphalt cement andheating during the hot mix production process. Processes that use unheated aggregate and cold applied binders
utilize the least amount of energy per ton.
Table 2
Total Energy Use for Pavement Construction Materials (Chappat and Bilal, 2003)
Energy Consumption (MJ/t) for Each Type of ProductProduct

Binders

Aggregates

Manufacture

Transport

LayingTotal(MJ/t)

Bituminous ConcreteRoad Base Asphalt ConcreteHigh Modulus Asphalt Concrete

279
196
284

38
36
38

275
275
289

79
75
79

9
9
9

680
591
699

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Warm Mix Asphalt Concrete
Emulsion Bound Aggregate

294
227

38
37

234
14

80
81

9
6

654
365

Cold Mix Asphalt
Cement-Bound Materials
Cement-Bound Materials & AJ
Aggregate w/Hydraulic Road Binder
Aggregate w/Hydraulic Road Binder & AJ
Cement Concrete Slabs without Dowels

314
200
203
50
54
598

36
32
32
29
29
40

14
14
14
14
14
14

86
67
67
61
61
84

6
6
6
6
6
2.2

457
319
323
160
164
738

Continuous Reinforced Concrete
Untreated Granular Material
Soil Treated In-situ w/Lime + Cement
Thermo-Recycling
Concrete Bituminous w/10% RAP
Road Base Asphalt Concrete w/20% RAP
Road Base Asphalt Concrete w/30% RAP

1,100
0
63
98
250
157

29
40
0
4
35
33

14
275
275

81
68
7
12
73
64

2.2
6
12
456
9
9

1,226
113
81
570
642
538

137
98
105

39
25
4

275
275
-

58
47
15

9
9
15

510
454
139

Road Base Asphalt Concrete w/50% RAP
Emulsion In-situ Recycling

Table 3
Total GHG Emissions for Pavement Construction Materials (Chappat and Bilal, 2003)
Greenhouse Gas Emissions (kg/t) for Each Type of ProductProduct

Binders

Aggregates

Manufacture

Transport

LayingTotal(kg/t)

Bituminous ConcreteRoad Base Asphalt ConcreteHigh Modulus Asphalt Concrete

16
11
17

9.4
7.6
9.4

22.0
22.0
23.1

5.3
5.3
5.0

0.6
0.6
0.6

54
47
55

Warm Mix Asphalt Concrete
Emulsion Bound Aggregate
Cold Mix Asphalt
Cement-Bound Materials
Cement-Bound Materials & AJ
Aggregate w/Hydraulic Road Binder

17
14
20
39
40
10

9.4
9.4
9.1
5.7
5.7
5.1

20.5
1.0
1.0
1.0
1.0
1.0

5.3
5.4
5.7
4.5
4.5
4.1

0.6
0.4
0.4
0.4
0.4
0.4

53
30
36
51
51
20

Aggregate w/Hydraulic Road Binder & AJ
Cement Concrete Slabs without Dowels
Continuous Reinforced Concrete
Untreated Granular Material
Soil Treated In-situ w/Lime + Cement
Thermo-Recycling

10
118
188
0
12
6

5.7
9.6
5.1
9.6
1.0

1.0
1.0
1.0
-

4.5
5.6
5.4
4.5
0.5
0.8

0.4
0.2
0.2
0.4
1.1
34.2

22
134
200
15
14
42

Concrete Bituminous w/10% RAP

15

8.6

22.0

4.9

0.6

51

648

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Road Base Asphalt Concrete w/20% RAP
Road Base Asphalt Concrete w/30% RAP

9
8

7.8
7.0

22.0
22.0

4.3
3.9

0.6
0.6

44
41

Road Base Asphalt Concrete w/50% RAP
Emulsion In-situ Recycling

6
7

5.2
1.0

22.0
1.1

3.1
1.0

0.6
0.4

37
10

ENERGY CONSUMPTION AND GHG EMISSIONS FOR CONSTRUCTION, REHABILITATION, AND
PRESERVATION PROCESSES
Different types of pavement construction, rehabilitation, and preservation operations consume different amounts ofenergy. Energy use and GHG emissions per ton of product provide only a relative comparison of products. The
specific pavement structure or work type together with the actual quantities of materials must be evaluated to moreaccurately compare energy use and GHG emissions for construction, rehabilitation and preservation. Dorchies(2008) performed several comparisons for different structured pavement sections, and determined that for different
structures yielding the same structural performance, energy use and GHG emissions can vary as much as 80%.
For some pavement preservation treatments, including thin HMA overlays and HIR, energy use and GHG
emissions are available. There have been some specific comparisons perfomed for various types of chip seals and for
micro-surfacing. No references could be found for fog sealing and crack treatments. To provide uniform
comparisons, the information developed by Chappat and Bilal (2003), from Tables 1, 2, and 3 was used to calculateenergy use and GHG emissions for typical preservation treatments. Energy use and GHG emissions were calculated
per unit area of the pavement surface, using typical quantities of raw materials for each treatment. Preservation
treatments considered include the HMA overlay, HIR, chip seal, micro-surfacing/slurry seal, crack fill, crack seal andfog seal. For some treatments, several different application rates of the treatment were considered. Table 4 shows
calculated energy use and GHG emissions for these pavement preservation treatments. The analysis of energy use
and GHG emissions considered the entire process for each treatment including raw materials, transport, processing,mixing and installation as appropriate . Further details on energy determinations are listed in the following
discussions for each treatment type.
For comparative purposes, Table 5 shows energy and GHG emissions fortypical pavement construction and rehabilitation work types.
Table 4
Total Energy Use and GHG Emission for Pavement Preservation Treatments
TREATMENT

DETAILS

ENERGY USE

GHG EMISSIONSBTU/yd2

MJ/m2

lb/yd2

kg/m2

1.5” (3.8 cm) thickness

46,300

59

9.0

4.9

2.0” (5.0 cm) thickness

61,500

77

12.3

6.7

1.5” (3.8 cm) thickness;
50/50 Recycle/New

38,700

49

7.0

3.8

2.0” (5.0 cm) thickness;
50/50 Recycle/New

51,300

65

9.0

4.9

8.9

0.9

0.5

Hot Mix Asphalt

Hot
In-place
Recycling (HIR)

Chip Seal

0.44 g/yd2 (2.0 L/m2) Emulsion,
7030
38 lb/yd2 (21 kg/m2) Aggregate

649Chehovits, Galehouse

0.35 g/yd2 (1.6 L/m2) Emulsion,
5130
28 lb/yd2 (15 kg/m2) Aggregate

6.5

0.7

0.4

Type III, 12% Emulsion,
24 lb/yd2 (13 kg/m2)

5130

6.5

0.6

0.3

Type II, 14% Emulsion,
16 lb/yd2 (8.7 kg/m2)

3870

4.9

0.4

0.2

Crack Seal

1 lin.ft./ yd2(0.37m/m2),
0.25 lb/ft (0.37 kg/m)

870

1.1

0.14

0.08

Crack Fill2 lin.ft./ yd2(0.74 m/m2),
0.50 lb/ft (0.74 kg/m)

1860

2.0

0.25

0.14

0.05 gal/yd2 (0.23 L/m2),
50/50 Diluted Emulsion

250

0.4

0.04

0.02

0.10 gal/yd2 (0.46 L/ m2),
50/50 Diluted Emulsion

500

0.8

0.07

0.04

0.15 gal/yd2 (0.69 L/ m2),
50/50 Diluted Emulsion

750

1.2

0.12

0.07

Slurry Seal /Micro-surfacing

Fog Seal

Table 5
Energy Use and GHG Emissions for
Asphalt Concrete Pavement Construction and Rehabilitation
TREATMENT

DETAILS

New Construction

Major Rehab
Hot Mix Asphalt

Major Rehab
Warm Mix Asphalt
1
2

ENERGY USE

GHG EMISSIONSBTU/yd2

MJ/m2

lb/yd2kg/m2

4” (100 mm) HMA over6” (150 mm) Aggregate 156,820
Base 1

198.5

24.1

13.1

4” (100 mm) Overlay 2

112,800

142.8

20.9

11.3

3” (75 mm) Overlay 2

84,600

107.1

15.6

8.5

4” (100 mm) Overlay 2

108,500

137.3

20.5

11.1

3” (75 mm) Overlay 2

81,400

103.0

15.3

8.3

Data from Dorchies (2005)
Data from Chappat and Bilal (2003)

650

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The following are descriptions and findings of the pavement preservation work analyzed:
Hot Mix Asphalt (HMA) Overlay
Thin HMA overlays, placed approximately 1.5 to 2.0 inches (3.8 to 5.0 cm) thick, are commonly used as a pavement
preservation treatment. GHG data are calculated based on using a 140 lb/ft3 (2240kg/m3) in-place density. Results
are shown in Table 7 for both a 1.5 and 2.0 inch (3.8-5.0 cm) thickness. The 1.5 inch (3.8 cm) thickness uses 0.079
t/yd2 (86 kg/m2) and the 2.0 inch (5.0 cm) thickness uses 0.105 t/yd2 (114 kg/m2). The analysis used an energy useof 586,000 BTU/t (680 MJ/t) for the entire process.
Hot In-Place Recycling (HIR)
HIR consists of heating, removing and remixing of one inch of the existing pavement surface followed byinstallation of a new one inch thick asphalt concrete overlay producing a two inch (5.0 cm) thick treatment. For
comparison purposes a 1.5 inch (3.8 cm) total thickness is also shown. Energy use basis is 491,000 BTU/t (570
MJ/t). Data are calculated using a 140 lb/ft3 (2240 kg/m3) in-place density.
Chip Seal
Two chip seal treatment designs were analyzed. First, a high quality design using 0.44 g/yd2 (2.0 L/m2) of asphalt
emulsion with 38 lb/yd2 (21 kg/m2) of aggregate. The second design, a lesser binder application rate of 0.35 g/yd2 (1.6
L/m2) with a smaller aggregate gradation of 28 lb/yd2 (15 kg/ m2). Energy use is calculated including emulsion andaggregate raw materials, transport, and installation.
Slurry Seal/Micro Surfacing
Two slurry seal/micro-surfacing treatment designs were analyzed. First is a typical Type III aggregate, with 12%
emulsion and a 24 lb/yd2 (13 kg/m2) application rate. The second design is a typical Type II aggregate, with a 14%
emulsion and a 16 lb/yd2 (8.7 kg/m2) application rate. Energy use is calculated including emulsion and aggregate
raw materials, transport, and installation.
Crack Seal
Crack sealing was calculated for a typical pavement cracking density on the basis of one foot of crack sealing per
square yard. This density is equivalent to one full length longitudinal crack per lane, and full width transverse
cracks spaced at 36 feet (11.0 m). This crack pattern , for a typical lane mile produces 7,040 linear feet (2,146 m)of cracking for the area of 7,040 yd2 (5,867 m2) which is one linear ft/yd2 (0.365 m/m2). An installation rate of 5,000
pounds (2268 kg) per day is used. The application yields four linear feet per pound of sealant, producing an
installation amount of sealant 0.25 lb/yd2 (0.136 kg/ m2). Energy use is calculated including raw materials,
manufacturing, transport, field heating, reservoir cutting, and installation.
Crack Filling
Crack filling was calculated for a typical pavement cracking density of two feet of crack filling per square yard.
This density is equivalent to a crack pattern of two full length longitudinal cracks, and full width transverse cracks
spaced at 18 feet (5.5 cm). This crack pattern, for a typical lane mile produces 14,080 linear feet (4,292 m) of
cracking for the area of 7,040 yd2 (5,867 m2), which is 2 linear ft/ yd2 (0.73m/m2). An installation rate of 5,000
pounds (2268 kg) per day is used. The application yields four linear feet per pound of sealant, producing an
installation amount of sealant 0.50 lb/yd2 (0.272 kg/m2). Energy is calculated including raw materials,
manufacturing, transport, field heating, and installation.

651

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Fog Seal
Fog sealing is calculated for three different application rates; 0.05, 0.10, and 0.15 g/yd2 (0.23, 0.46, and 0.69 L/m2)
of a 50/50 water diluted asphalt emulsion. Energy use is calculated including raw materials, manufacturing,transport, and installation.
New Construction: Hot Mix Asphalt (HMA) Pavement
The structural section for the pavement is 4 inches (100mm) of HMA placed on 6 inches (150mm) of compacted
aggregate base course. Energy is calculated including raw materials, heating, mixing, transport, placement, andcompaction.
Rehabilitation: Hot Mix Asphalt (HMA) Pavement
Both a 4 inch (100 mm) thick HMA overlay and a 3 inch (75 mm) thick overlay were investigated. Energy is
calculated including raw materials, heating, mixing, transport placement, and compaction.
Rehabilitation: Warm Mix Asphalt Pavement
Both a 4 inch (100mm) thick warm mix asphalt overlay and a 3 inch (75mm) thick overlay are examined. Energy is
calculated including raw materials, heating, mixing, transport placement, and compaction.
ANNUALIZED ENERGY USE AND GHG EMISSIONS FOR CONSTRUCTION, REHABILITATION
AND PRESERVATION PROCESSES
Pavement preservation treatments proactively address the pavement needs and are performed to prolong pavement
life. There have been several studies that determined the amount of life extension provided by various pavement
preservation treatments. The resulting life extensions have varied widely and are dependent on many factors
including environmental factors, timing, treatment design, existing pavement distress, traffic levels, and quality of
construction. The range of pavement life extensions for properly design and constructed preservation treatments areshown in Table 6. Pavement life extensions provided by preservation treatments range from one year for fog
sealing, up to ten years for thin HMA overlays and HIR. The energy and GHG data must be normalized for the
expected pavement life extension to appropriately compare energy use and GHG emissions of preservation
treatments. The normalization is accomplished by dividing unit area energy and GHG data from Table 4 by the life
extensions in Table 6 to produce annualized results. The annualized results for pavement preservation treatments
are shown in Table 7 and for new construction and rehabilitation work types in Table 8. In Table 7. the ranges forenergy use and GHG emissions are due to the ranges of life extension times listed in Table 6.
Table 6
Pavement Life Extensions Provided by Pavement Preservation Treatments
TREATMENT TYPE

LIFE EXTENSION

Thin HMA Overlay

5 – 10 years

Hot In-Place Recycling

5 – 10 years

Chip Seal

3 – 6 years

Slurry/Micro Surfacing

3 – 5 years

Crack Sealing

1 – 3 years652

Chehovits, Galehouse

Crack Filling1 – 2 years

Fog Sealing

1 yearTable 7
Annualized Total Energy Use and GHG Emission For Pavement Preservation Treatments
Treatment

Details

Pavement Life Energy Use
Extension
per Year

GHG Emissions
per Year

BTU/yd2

MJ/m2

lb/yd2

kg/m2

1.5” (3.8 cm) thickness

5 – 10 years

4,660 – 9,320

5.9 - 11.8

0.9 - 1.8

0.5 - 1.0

2.0” (5.0 cm) thickness

5 – 10 years

6,080 - 12,160

7.7 - 15.4

1.2 - 2.4

0.7 - 1.3

1.5” (3.8 cm) thickness;
50/50 Recycle/New

5 – 10 years

3,870 – 7,740

4.9 - 9.8

0.7 - 1.4

0.4 - 0.8

2.0” (5.0 cm) thickness;
50/50 Recycle/New

5 – 10 years

5,130 - 10,260

6.5 - 13.0

0.9 - 1.5

0.5 - 1.0

0.44 g/yd2 (2.0 L/m2) Emulsion,
38 lb/yd2 (21 kg/m2) Aggregate

3 – 6 years

1,170 - 2,340

1.5 - 3.0

0.15 - 0.3

0.08 - 0.10

0.35 g/yd2 (1.6 L/m2) Emulsion,
28 lb/yd2 (15 kg/m2) Aggregate

2 – 5 years

1,026 - 2,565

1.3 - 3.3

0.14 - 0.35

0.08 - 0.2

Type III, 12% Emulsion,
24 lb/yd2 (13 kg/m2)

3 – 5 years

1,026 - 1,710

1.3 - 2.2

0.12 - 0.2

0.06 - 0.10

Type II, 14% Emulsion,
16 lb/yd2 (8.7 kg/m2)

2 – 4 years

968 - 1,935

1.2 - 2.4

0.10 - 0.20

0.05 - 0.10

Crack Seal

1 lin.ft./ yd2(0.37m/m2),
0.25 lb/ft (0.37 kg/m)

1 – 3 years

290 - 870

0.4 - 1.1

0.05 - 0.14

0.03 - 0.08

Crack Fill2 lin.ft./ yd2(0.74 m/m2),
0.50 lb/ft (0.74 kg/m)

1 – 2 years

930 - 1,860

1.0 - 2.0

0.13 - 0.25

0.07 - 0.14

0.05 gal/yd2 (0.23 L/m2),
50/50 Diluted Emulsion

1 year

250

0.4

0.04

0.02

0.10 gal/yd2 (0.46 L/ m2),
50/50 Diluted Emulsion

1 year

500

0.8

0.07

1.04

0.15 gal/yd2 (0.69 L/ m2),
50/50 Diluted Emulsion

1 year

750

1.2

0.12

0.07

Hot Mix Asphalt

Hot
In-place
Recycling (HIR)

Chip Seal

Slurry Seal /Micro-surfacing

Fog Seal

Table 8653

Chehovits, Galehouse

Annualized Energy Use and GHG Emissions for
Asphalt Concrete Pavement Construction and Rehabilitation
Treatment

New Construction

Major Rehab
Hot Mix Asphalt

Major Rehab
Warm Mix Asphalt

Details

Design Life

Energy Use
per Year

GHG Emissions
per Year

BTU/yd2

MJ/m2

lb/yd2kg/m2

4” (100 mm) HMA over6” (150 mm) Aggregate 20 years
Base

7840

9.9

1.2

0.7

4” (100 mm) Overlay

15 years

7500

9.4

1.3

0.8

3” (75 mm) Overlay

12 years

7050

8.9

1.3

0.7

4” (100 mm) Overlay

15 years

7210

9.2

1.3

0.8

3” (75 mm) Overlay

17 years

6780

8.5

1.3

0.7

The annualized energy and GHG data for pavement preservation treatments ranges from 250 BTU/yd2-yr(0.4MJ/m2-yr) for a 0.05 g/yd2 (0.23 l/m2) fog seal application upwards to 12,160 BUT/yd2-yr (15.4 MJ/m2-yr) for
2.0 inch (5.0 cm) of HMA overlay. Annualized results for the new construction and rehabilitation work types range
from 6,780 to 7,840 BTU/yd2-yr (8.5-9.9 MJ/m2-yr). The results group into three categories. The first category
includes the thin HMA overlay, HIR, new construction, and rehabilitation, have the highest annualized results
ranging from 3,870 to 12,160 BTU/yd2-yr (4.9-15.4 MJ/yd2-yr) energy and 0.9 to 2.4 lb/yd2-yr (0.4-1.3 kg/m2-yr) of
GHG. The second category includes chip seal, micro-surface, and crack fill at 930 to 2,565 BTU/yd2-yr (1.0-3.3
MJ/yd2-yr) energy and 0.13 to 0.35 lb/yd2-yr (0.07-0.20 kg/m2-yr) of GHG. The third and final category includes
fog sealing and crack sealing with 250 to 870 BTU/yd2-yr (0.4-1.1 MJ/m2-yr) energy and 0.04 to 0.14 lb/yd2-yr(0.02-0.08 kg/m2-yr) of GHG.
The annualized energy and GHG emission results in Table 7 show that the different pavement preservation
treatments provide a year of life extension with differing energy requirements and GHG emissions. Each type of
pavement treatment will not always be appropriate for all pavements, distresses, traffic, climate, desired results, etc.
CONCLUSIONS
Comparisons of energy use and GHG emissions for the construction, rehabilitation and preservation of asphalt
concrete pavements are calculated and compared. Results show that on an annualized basis, different process types
require differing amounts of energy per year of pavement life. New construction, major rehabilitation, thin HMA
overlay, and HIR have the highest energy use and range from 5,000 to 10,000 BTU/yd2-yr (6.3-12.6 MJ/m2-yr).
Chip seals, slurry seals, micro-surfacing, and crack filling utilize lower amounts of energy per year of extended
pavement life and range from 1,000 to 2,500 BTU/yd2-yr (1.3-3.3 MJ/m2-yr). Crack seals and fog seals use the least
amount of energy per year of extended pavement life at less than 1,000 BTU/yd2-yr (1.3MJ/m2-yr).
Energy use and GHG emissions for the different products depend primarily on the type and quantity ofmaterials placed per unit area. Products that use lower amounts of asphalt per unit area and products that do not
require heating of aggregate use the least amounts of energy. Additionally, products having the lowest quantity of654

Chehovits, Galehousematerial applied to the pavement per unit area utilize less energy, simply because not as much material needs to be
produced, processed, transported and installed. To minimize energy use and GHG emissions over the life of apavement, all preservation treatments should be utilized as appropriate to the maximum extent possible for the
existing pavement conditions.
REFERENCES
Dorchies, P.T. (2008). The Environmental Road of the Future: Analysis of Energy Consumption and Greenhouse
Gas Emissions. The 2008 Annual Conference of the Transportation Association of Canada, Toronto, Ontario
Chappat, M. & Bilal, J. (2003). The Environmental Road of the Future: Life Cycle Analysis, Energy Consumption
and Greenhouse Gas Emissions, Colas Group.
Miller, T. & Bahia, H. (2009). Sustainable Asphalt Pavements Technologies, Knowledge Gaps and Opportunities.
Modified Asphalt Research Center, University of Wisconsin Madison
Terrel, R.L. & Hicks, R.G. (2008). Viability of Hot In-Place Recycling as a Pavement Preservation Strategy, Report
Number: CP2C-2008-106. California Pavement Preservation Center, Chino, California.
Uhlman, B. (2009). Principals of Eco-Efficiency Analysis in Construction Applications. ARRA-AEMA-ISSA
Annual Meeting, Palm Springs, California. February 17-21, 2009.
Canadian Construction Association (2005). Road Rehabilitation Energy Reduction Guide for Canadian Road
Builders; Ontario
Wall, C. (2004). Eco-Efficiency Analysis of Chip Seals, BASF Corporation Report.
US Green Building Council (2008). Leadership in Energy and Environmental Design (LEED). Green Building
Rating System, Washington, DC
Greenroads (2009). University of Washington & CHS M Hull655

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

The Effect of Rejuvenators on the Properties ofRepetitive Recycled Asphalt

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)

Michito KONNO
CO-AUTHOR(S)(Capitalize Family Name
Kazunari HIRAKAWA
Shouichi AKIBA
Yousuke KANOUE-MAIL(for correspondence)

POSITIONManager

POSITIONORGANIZATIONTaisei Rotec corporation

COUNTRYJapan

ORGANIZATION

Senior Researcher
Taisei Rotec corporation
Professor
Nihon University
Assistant Professor
Nihon University
michito_konno@taiseirotec.co.jp

COUNTRY
Japan
Japan
Japan

KEYWORDS:
Rejuvenator, RAP, Repetitive recycled asphalt, Chemical composition

ABSTRACT:The technology for recycling usage of reclaimed asphalt pavement (RAP) has been spread widely in 1980’s and now,
it is authorized in Japan. However, it is not found that the properties of repetitive recycled asphalt,which compared withthe property of virgin asphalt mixture, will be effected or not, including the extent of influence. The RAP is estimated tobe recycled repetitively and continuously from now on. This study was conducted with aiming to present the suitablerejuvenator, throughout the research of the effect on the properties of recycled asphalt with different types ofrejunvenator.
As the results, it is found that the properties of asphalt which is experienced aging and rejuvenation repetitively, would
be influenced by the chemical composition of rejuvenator and the ratio of RAP content.

656

The Effect of Rejuvenators on the Properties ofRepetitive Recycled Asphalt

Michito KONNO
Taisei Rotec corporation, Manager
Email michito_konno@taiseirotec.co.jp

Kazunari HIRAKAWA
Taisei Rotec corporation, Senior Researcher,

Shouichi AKIBA
Nihon University, Professor,

Yousuke KANOU
Nihon University, Assistant Professor

1 INTRODUCTION
In Japan, the research about recycle use of reclaimed asphalt pavement (RAP) had been started in
1970s.In the 1980s and 1990s, the guidelines and the laws for the recycling technology of the pavement weredeveloped and enforced. After this, full-scale recycling came to be carried out.
By for now, the recycling technology of RAP is widely spread as a general technology. The rate ofrecycled hot mix asphalt to the total shipments of hot mix asphalt is increasing year by year, in 2013 hasreached 75%. In the future, the RAP with experience of recycled repeatedly multiple times will slide into
increasing.
In Japan, many studies for the recycling asphalt about the effect on physical and chemical properties
in terms of the kinds or the components of rejuvenator have been conducted. It is included recycled asphalt
and recycled asphalt mixtures.
However, almost all of these studies were limited on the first recycling of asphalt and the mixture.
The physical / chemical properties of repeated recycling asphalt and/or the desirable rejuvenator on theassumption that it is repeatedly reproduced were not clear.
Based on the background above, the series of laboratory tests were conducted aiming to confirm thatthe effect on the properties of repeated recycling asphalt /asphalt mixture. In this study, the rejuvenator thathas large saturation component widely used in Japan was applied. This paper is including the results of thesetests.
It should be noted that in this study, the RAP was prepared with accelerated aging by heat in thelaboratory after produced with a newly material (hereinafter, the virgin mixtures). Then comparing theproperties of recycling asphalt mixtures and recycled asphalts

2 OVERVIEW OF EXPERIMENTS
2.1 Procedure of Experiments
The procedure of experiments in this study is shown in figure 1. In the experiment, repeated aging
and recycling of the mixture in the laboratory, physical/chemical properties at the each of aging and recyclingasphalt and mechanical properties of recycled asphalt mixture were confirmed.
In the accelerated deterioration, the aging time was set the penetration is reduced to 20 ( in the aging
procedure, target penetration was 20). In the recycling of asphalt, the rejuvenator was added to make thepenetration of aged asphalt to be recovered up to 70 (in the recycling procedure, design penetration was 70).
And also the mixing ratio of RAP in this study was carried out at 60%, taking account for the
average of the RAP mixing ratio of each region of Japan to be approximately 30 to 60% (JAMA 2014).

657

Hot mix asphalt (HMA) produced byan asphalt mixture plant
Measurement of HMA or recycled HMA
properties
Measurement of asphalt recovered from
HMA or recycled HMA properties
Penetration，Softening point，Carbonyl index(FT-IR)，
Composition analysis(TLC-FID)
Accelerated deterioration using the
hot air circulation dry oven

4 times・110 degree Celsius，84hr(target penetration=20)
Design of recycled asphalt mixture
using rejuvenator

Adding rejuvenator(Additive rate=11.7%)※Design penetration=70
Production of the Recycled
Hot Mix Asphalt at Laboratory

Additive rate of RAP=60%

Figure.1 Procedure of experiment

2.2 Materials
The asphalt mixture used in the experiment is dense graded asphalt mixture (the maximum aggregate
size is 13mm) with paving petroleum asphalt 60/80 (hereinafter, original asphalt). The optimum asphalt
content is 5.3%. The basic physical properties of original asphalt is shown in Table 1.
In addition, the rejuvenator applied in this study is widely using and commercially available in Japan
which has a large saturation components. The properties of rejuvenator is shown in Table 2.

Table.1 The properties of original asphalt

Density

Penetration

3

Softening Point ductility at 15

g/cm

1/10mm

℃

cm

1.038

70

47

100+

Table.2 The properties of rejuvenator

Density3

Composition(%)

g/cm

asphaltene

resin

aromatic

saturation

0.966

0

6.3

26.6

67.1

3. DETAILES OF EXPERIMENTS
3. 1 Evaluation of extracted asphalt
The asphalt extracted from the virgin mixture and the recycled mixture (recycling one to four times)
were performed physical properties testing and chemical properties tests described below.
It should be noted that extracting asphalt from the mixture, was carried out according to the "G029asphalt recovery test method (JPI-5S-31-1988)".

658

3.1.1 Physical Properties Tests
Penetration test and softening test were conducted as physical properties tests
3.1.2 Chemical Properties Tests
a. Asphalt composition analysis test by Thin-Layer Chromatography/Flame Ionization Detector(TLC / FID)
methodAsphalt composition components were analyzed by (Ltd.) LSI Medience Co. Iatroscan (MK-6s) thinlayer chromatography using a (below, TLC / FID method).
The TLC / FID method, four components separation operation the asphalt in rod-shaped thin
adsorption layer on the (TLC), is an analytical method that combines methods (FID) for each of thecomponents is ionized in a hydrogen flame detector. The conditions such as the solvent used are shown in
Table 3.
Table.3 TLC/FID Method
Item

Condition

Adsorption layer

Bar-like thin-layer adsorption layer (carrier: silica gel)
Flame ionization detector (FID detector. The organic component is burnt
in a hydrogen flame, detecting the occurrence ion current)

Detector

After spotting the asphalt on the adsorption layer,(1) hexane (developing distance 10cm)(2) toluene (developing distance 5cm)
(3) in dichloromethane + methanol mixture (95: 5)

Operation(Developing distance 2cm)
Of the deployment in the order, it separated into four components.
After drying, the respective concentrations were measured by FID
detector, determine the concentration ratio.

b. Infrared absorbance measurement
To quantitatively evaluate the progress of the oxidation reaction, oxygen as an index of oxidative
degradation of the asphalt by using JASCO Co., Ltd. Co., Ltd. of FT / IR-4000 Fourier transform infrared
spectrophotometer (FT-IR) the behavior of the increase-containing functional group (carbonyl group) were
measured.
Specifically, by measuring the infrared absorbance of the asphalt, the peak around 1700 cm-1
attributable to the stretching vibration carbonyl group, and the peak around 1600cm-1 attribute to the C = C
stretching vibration which is not affected by deterioration were analyzed.
With the ratio of these two peaks, carbonyl index (hereinafter, CI) was determined. Measurement
conditions of FT-IR, are shown in Table 4.
Table.4 Measurement conditions of FT-IR
Item

Condition

Absorption spectrometry

On KBr crystal, formed by transmission measurements the thin filmof the sample using a solvent
CI 

Carbonyl index (CI)log( I o1 / I1 )log( I o 2 / I 2 )I1 ,I 2 ： transmittance of the peak spectrum in the vicinity of eachof 1700cm-1 and 1600cm-1
Io1,I 02 ： each transmittance of the background corresponding to
the wave number659

c. Molecular weight distribution measurement by gel permeation chromatography
In the measurement of molecular weight distribution, in order to grasp the difference in molecularweight distribution of the asphalt during deterioration, it was measured molecular weight distribution using
gel permeation chromatography (GPC). The GPC equipment and operating conditions used are shown in
Table 5.
Table.5 Conditions of GPC equipment
Item

Condition

Equipment

LC-10ADvp (Shimadzu Corporation)

Detector

Refractive index detector (Shimadzu RID-6)

ColumnTSKgel GMHHR-L（ Tosoh）

Mobile phasetetrahydrofuran (THF)

Mobile phase temperature

20℃

Mobile phase flow rate

1mL/minConcentration

1.1wt%

The amount of sample

20μL

3.2 Mechanical Properties test of asphalt mixture
Mechanical properties of the virgin mixture and recycled mixture was performed split test (JARA2010) and the wheel tracking test (JARA 2007). Each tests were conducted each at the virgin mixture, at firsttime recycled mixture, and at third time recycled mixture.
3.2.1 Accelerate deterioration of asphalt mixture
Accelerated deterioration of the asphalt mixture was carried out using a hot-air circulating drying
oven is a device which has become popular in view of the convenience in Japan.
Promote deterioration, asphalt mixture was aged for 84 hours in a hot air circulation drying oven at
110 C. Aging procedure in detail is, break-laying mixture 7.5kg of the state that are not compacted to 36 ×24cm bat, covering the single the surface so as not to be exposed to as much as possible direct hot air in thewide aluminum foil, the edge of the aluminum foil bat as folded.
It should be noted that the curing time of this time (84 hours) is decided so that the penetration of
extracted asphalt from the mixture after the deterioration becomes to 20.
3.2.2 Preparing procedure of recycling asphalt mixture
The deteriorated mixture was used as RAP, and reproduced as recycled asphalt mixture, mixing withrejuvenator, new aggregates and new asphalt in a vertical mixer in laboratory.
The reproduce procedure is shown below.
[1] Curing recycled aggregate (RAP) with the hot air circulation drying oven at 165°C for 3 hours[2] Mixing recycled aggregate (RAP) with the vertical-type mixer for 30 seconds[3] Mixing after adding a predetermined amount of rejuvenator for 90 seconds[4] Mixing after introduce a predetermined amount of new aggregates for 30 seconds[5] Mixing after pouring a predetermined amount of put a new asphalt (at 160 ℃) for120 seconds[6] Discharge the mixture from vertical mixer[7] Prepareing the specimen for each tests (for the split test , wheel tracking test) by a suitable compaction
machine.
4. RESULTS
4.1 Results of Asphalt
4.1.1 Physical Properties
a. Penetration test

660

The penetration test results are shown in Figure 2. Asphalt promoted deterioration is recycled to be adesign penetration 70 at each stage. Therefore, even when the deterioration and recycling are repeated aplurality of times, the penetration of the asphalt recovered from the mixture after recycled and after
accelerated aging are approximately about 20 and 55, respectively.
Therefore the targeted aging and recycling process were seemed to be repeated.

Penetration (1/10mm)

70
60

50
After Recycling40

After Aging

30
20
10
1st
Original Virgin
Asphalt HMA

2nd

3rd

4th

After Aging/
After Recycling
Figure.2 Penetration

b. Softening Point test
The softening point test results are shown in Figure 3. Softening point, aging and recycling tended tobe higher in accordance repeated, indicating that the temperature sensitivity of asphalt become dull.

70
Softening point (℃)

65
60

55
50
After Recycling

45

After Aging40
1stOriginal
Asphalt

Virgin
HMA

2nd

3rd

4th

After Aging/
After Recycling

Figure.3 Softening Point

4.1.2 Chemical Properties
a. Asphalt composition analysis test by TLC / FID method
The composition analysis test results of the extracted asphalt from the mixture after the accelerated
deterioration are shown in Figure 4. And Figure 5 shows the composition analysis test results of the asphalt,
which was extracted from the recycled asphalt mixture. From Figure 4, the composition of the asphalt, which661

was extracted from the mixture after the accelerated deterioration, when the accelerated deterioration of times
increase, decrease asphaltene and aromatic content, saturated component and resin content tended to increase.
On the other hand, as shown in Figure 5, as in the analysis of the asphalt after accelerated
degradation and is repeatedly recycled, decrease asphaltene component and the aromatic content, saturated
component and resin content tended to increase.
This means that if the recycled aggregate (RAP) content rate of 60% cannot be compensated by the
new asphalt, and consider to be affected by the chemical composition of the rejuvenator.

100

Ratio(%)

80
60
40
20

Saturates

Aromatics

ResinsAsphaltenes

0

RAP Content = 60%

Original Asphalt

Virgin HMA

Recycling 1st

Recycling 2nd

Recycling 3rd

Recycling 4th

Figure.4 Chemical compositions after accelerated deterioration

100

Ratio(%)

80
60
40
20
Saturates

Aromatics

ResinsAsphaltenes

0

RAP Content = 60%

Original Asphalt

Virgin HMA

Recycling 1st

Recycling 2nd

Recycling 3rd

Recycling 4th

Figure.5 Chemical compositions after recyclingb. Infrared absorbance measurement
The carbonyl index (CI) from the infrared absorbance measurement result of the extracted asphalt
from each mixture is shown in Figure 6. The CI of asphalt after accelerated deterioration, has tended to662

increase with increasing aging number. Also, the CI of asphalt extracted from recycled mixture has tended toincreases with recycling number.
It should be noted that, in studies in Japan (Nitta 2011), CI of asphalt, if recycled aggregate (RAP)
blending ratio of about 30%, but small changes even if they are played repeatedly, is a change in accordancewith recycled aggregate (RAP) compounded rate increases It indicates that there can be large, but it can besaid that the results of this study are consistent with it.
1.4
1.2
1.0
CI

0.8
0.6

0.4
0.2
0.0

After Aging
Original Asphalt

After Recycling

Virgin HMA

1st

2nd

3rd

4th

Figure.6 The CI extracted asphalt from aging/recyclingc. Molecular weight distribution measurement by gel permeation chromatography
The molecular weight distribution measurement results of the extracted asphalt from repeatedrecycling in the recycled aggregate blending ratio of 60% is shown in Figure 7.
From results when it becomes much aging number of iterations, a large difference was observed in the peaknear a retention time 7.0 ~ 7.2min (molecular weight of about 104), is a tendency that the components oflarge molecular weight increases were observed.
This trend, since it is the same as the tendency of the CI as shown in Figure 6, the increase inmolecular weight in this experiment is considered to have large effect of oxidation. Also, recycled aggregate
blending ratio 60% since less is new asphalt to be added at the time of recycling, it is considered acomponent of increased aging and molecular weight by oxidation asphalt indicating that tends to beaccumulated.
180,000
Original Asphalt
Recycling 2nd
Recycling 4th

160,000

Recycling 1st
Recycling 3rd

140,000

Intensity

120,000
100,000

80,00060,00040,00020,000
0

6

7

8

9

10

11

12

13

retention time(min)Figure.7 Molecular weight distribution of recycling asphalt663

4.2 Results of Asphalt Mixturea. Split test
Figure.8 shows the result of Split test for virgin mixtures, once, and 3times recycled asphalt mixtures.
From the results, split coefficient of 60% recycled aggregate blending ratio tended to increase in accordancewith the recycling number.
Therefore, it is considered that when it is recycled repeatedly a plurality of times using rejuvenator
contains saturations rich, recycled aggregate blending ratio of 60% recycled mixture would became hard andthe fatigue resistance would decrease .

Split Coefficient (MPa/mm)

1.0
0.8
0.6
0.4

0.2
0.0

Virgin HMA

Recycling 1st

Recycling 3rd

Figure.8 The result of split testb. Wheel tracking test
Figure 9 shows the result of wheel tracking test for virgin mixtures, once, and 3times recycledasphalt mixtures. From the results, the dynamic stability of 60% recycled aggregate rate became to be larger
than the one of virgin mixture. However, the dynamic stability didn’t tend to increase in accordance with therecycling number large differences views even increased was observed.
Therefore, recycled aggregate blending rate of 60% of the recycled mixture is considered to tend to
become hard even in a relatively high temperature range.

Dynamic Stability (time/mm)

1,200
1,000
800
600
400

200
0
Virgin HMA

Recycling 1st

Recycling 3rd

Figure.9 The result of wheel tracking test664

5. CONSIDERATIONIn this study, it is shown that the physical and chemical properties of the recycled asphalt andrecycled asphalt mixture, which is repeated recycling with rejuvenator of saturation rich, behave to change
slowly. In the case of the recycled aggregate blending ratio of 60%, since the amount of fresh asphalt being
added to recycling mixture is small, physical and chemical properties of recycling asphalt are easy to receive
the influence of the properties of the old asphalt and rejuvenator.
Consequently it is considered that the physical and chemical properties of recycled asphalt canbecome a thing that is different from the original asphalt. Therefore, in recycling the mixture repeatedly withrejuvenator of saturation rich, it will be suitable less recycled aggregate blending ratio.
However this study is as far as the case of using rejuvenator of saturation rich, it is not clear that theeffect of rejuvenator component on the properties of repeatedly recycled asphalt or asphalt mixture.
In the future, it is needed to establish the suitable recycling method through comparing the propertiesof the recycled mixture and recycled asphalt in the case of repeated aging and recycling by using different
rejuvenators.

6. CONCLUSION
The conclusion of this study is following.
[1]Repeatedly recycled asphalt has a softening point higher it becomes temperature sensitive resistancetended to decrease.
[2]For the composition of repeating recycled asphalt, the asphaltene and the aromatic tend to decrease
according to increase the recycling number.
[3]The CI of repeatedly recycled asphalt tends to increase according to the recycling number.
[4]The molecular weight distribution of asphalt repeated aging and recycling, according to a recycling
number count increases, has a tendency that power of a large component (retention time 7.0 ~ 7.2min) to be
increase. It is the same as the tendency of CI increases, it is seemed that the increasing in molecular weight inthis experiment is considered to have large effect of oxidation.
[5]From the results of split test and wheel tracking test for the repeatedly recycling mixture, it is considered
to become "hard",and "low fatigue resistant".
[6]Recycling with the rejuvenator of saturation rich for the recycled aggregate blending ratio 60% , since lessis new asphalt to be added at the time of recycling, it is considered a component of increased aging andmolecular weight by oxidation asphalt indicating that tends to be accumulated.
[7]In recycling the mixture repeatedly with rejuvenator of saturation rich, it will be suitable less recycled
aggregate blending ratio.

References
Japan asphalt mixture Association, synthetic material Statistics Annual Report, 2014.
Road Association, Paving playback Handbook (2010 edition), 2010.
Road Association, Pavement Investigation and test methods Handbook, 2007.
NITTA, Study on the development and life cycle assessment of the recycling technology in asphalt paving,
Public Works Research Institute, Public Works Research Institute Report No. 217, 2011.

665

SLAMET MULYONO & MAX ANTAMENG

1. Introduction
Implementation of Performance based Contract through a pilot project at 5 places not too successful, because
the Government through regulations that there is still not adapting best practices such as those written in
documents or document World Bank Latin America. The handling pilot project even though his contract was
already reaching out in terms of the length of the road into the scope of the km's contract, but the contract still
adapting attention focused only on roughness only not as an output contract. Based on World Bank, Gunter Zacs
review found the following:
1.

The existence of the fact that the implementation of the pilot project for the Performance Based Contract
fail to adapt the international best practices

666

2.

3.

The existence of a common perception that already in place, That the current focus to construct road will be
only pave, no consideration to take into account another three important components of the road such as
Drainage, Shoulder, and other road equipment
During preservation implementation in 2015, it was found that out of 91% of the length of the nationalroad carried out a preservation with using force account. Only 9% of the total length of the national roadwhich was done by means of a contract.

There is a need to improve this current practices, and the most eligible short time solution will be to eliminate
both no. 2 and 3 above to approach the objectives on no. 1.
The Development Framework of institutional side can be drawn as follows:

Diagram 1 Current Issues, transitional period and End objectives, source: Writer (2016)

Below diagram shown us effort has been taken by the Government of Indonesia to achieved Performance BasedContract thru several stages:667

Simplified and reduced
several complicated process 4Long Segment as an Indonesian Way to achieved Performance Based Contract

International
experiences on
PBC done by
severalmultilateral
donorsModification 3

Adapted to 1
Pilot Project PBC
in Indonesia

Obstacles 2

Introduction ofLong Segment

Several weakness
on planning, andimplementation

6

Standard Road
thru Pilot Project5
Data Management

Long Segment is
the Indonesian
Way to achieved
PBC ideal.

Career Planning

Diagram 2 Long segment as an Indonesian way to achieved PBC, source: writer668

2. KPI’s of National Road Sector at the end of 2019
Discussion on Performance-Based need to discuss opportunity, and the opportunity was there since 2015 is the
beginning of the national strategic plan for the Ministry and also medium-term development plan 2015-2019.
The Key Performance Index set by Government on Road Sectors as follows (existing road 47.017 km length):
•
•
•
•
•
•
•
•

National road stability from 94% to be (good + Fair) 98%
Regional Road Stability (good + fair) from 60l% to 70%
Average travel time in main corridor from 2.6 hours/100 km reduce to 2.2 hours/100 km
3,057 km Widening
15 km Fly Over / Under pass
2,650 km new roads
1,000 km toll road
500 km support for regional road

From the above KPI’s, that are directly related to the preservation of the road i.e. national road stability (good +fair) to 98%. All efforts have to fulfil the target which is already mentioned in the Strategic Plan. Since there isalso finance constraints, needs an effective approach, as well as a systematic attempt to hit KPI’s byimplementing Performance Based Contract to increase level of efficiency, thru the transition period policy withLong Segment, Road Standard, and multiyear budget.

3. Existing Condition of National Road Sector 2015
Existing National Road condition can be seen as follows:
Table 1 National Road Condition in Indonesia, sources: DG Highways 2015
Pave

Not Paved
Length%(Km)

Road
Length(Km)

Length(Km)%

SUMATERA

13,709.85

13,451.19

98.11%

JAWA

6,534.62

6,534.62

100.00%

0.00

0.00%

KALIMANTAN

7,620.01

6,656.42

87.35%

963.5912.65%SULAWESI

8,792.82

8,297.53

94.37%

495.29

5.63%

PAPUA
BALI, NTB, NTT MALUKU DAN MALUT

3,963.11
6,396.87

2,206.27
5,478.57

55.67%
85.64%

1,756.84
918.3044.33%
14.36%TOTAL INDONESIA

47,017.27

42,624.60

90.66%

4,392.67

9.34%

Islands

258.65

1.89%

As can be seen from table 1 that islands outside Java, part of the road still unpaved, even in Papua, the numberof roads that unpaved reached almost half of the total length of the road. This happened, since Government
policy on road is always related to the number of traffic pass thru that road. If the number of traffic or AADT
below the standard, then imposed Minimum Service Standards, like in Papua, where in this case the number of
AADT, is stil far below the spesification.

669

Table 2 National Road Condition in Indonesia, sources: DG Highways, 2015

Table 2 shows the trend of National Road Condition from 2005 up to 2014, Blue color show the “Good” road,Red color refer to “Fair” Road, while green color is the light damage and purple means “heavy damage”
Due to budget constraints, in the past, the Government has to focus only on Pave alone at the time and thenprioritize on the length of the road or length of road course. Minimum service standards that are on the Road
sector, due to the accessibility aspects, leading to areas like Papua, still much in the way that there is no cover.
At a time when the volume of traffic had already stepped forward on certain limitations, then the mobility aspectof becoming a benchmark in the development of the road, the road becomes such standards established by Act
No. 38/2004, on the road. It's just that, in fact, the situation, build roads just focus on asphalt cover and limited
to the road course, it seems to be true for all national roads, few are aware that the road is not just a road but
including drainage and other road equipment.

4. Unsuccess story on Pilot Project on Performance Based
Maintenance System
DG Highways Indonesia has conducted trials Performance Based contract since 2000’s by the Directorate
General of Bina Marga, in early 2009, established that the concept of the PBC can be started as pilot project in2010 in two sections in Java: Ciasem-Pamanukan and Demak - Trengguli. By 2012, another 3 road project
established: (1)Semarang-Bawen, (2)Bojonegoro-Padangan, Padangan-Ngawi, and (3) Sei Hanyu – Tb Lahung(Central Kalimantan).
Unfortunately, the result of the review found that the implementation of the pilot project is still undeniably
contract input, not PBMC, whereas the government still have to face the risk, while on the best practices, otherway around, the private sectors has the responsibility of initiation of PBC. There are several issues related to the
PBC, such as:• Difficulties of Hybrid Performance Based Contract• Regulatory issues• Quality management• Unpredictable maintenance• Measurement and payment of hybrid670

In implementing the pilot project performance based contract, the main one is the quantity or length of the
project. Refer to the South Africa, one contract was reached 100 km, then in Indonesia should be around 50 s/d
100 km/contract. Another important point on construct PBC, is the launching of Standard Road, which isincluding pavement, (2) Drainage; (3) Shoulder and (4) other road equipment.
Almost all ASEAN countries have switched on the Long Term Contract including Performance Based Contract,
Countries like Malaysia, Singapore, and Thailand have introduced long term comprehensive contract, which wecall as Performance Based Contract. While at the same time we still deal with input and small contracts. To do
the reform from far left to far right, has to be done in several stages, the unsucess story of PBC, approved that.

5. Transition Period to achieved Performance Based Contract thru
long segment included Standard Road
Each country has a different approach in carrying out the organization of the road, as well s Indonesia, in termsof conducting Performance Based Contract. Although the model of Each country has a different approach incarrying out the Organization of the road, as well as Indonesia, in terms of conducting of Performance BasedContract. Although PBC model documents available everywhere (World Bank, ADB, Latin American
experiences). Learning from the result of pilot project, need to achieve the objectives thru several stages. Below
are the things that are done as a policy transition towards performance based contract: Standard road, Long
Segment

a. Standard Road
Awareness of standard road need to be socialized as standard which must be met on road construction. Basedon the Regulation (PP No. 34/2006) has referred to those parts of the road, which should always exist in theplanning. Standard means: not only Pavement alone, it has to be in place: Shoulder, Drainage, and other Road
Equipment. From the economic point of view, ignoring Drainage, which cost around 7 up to 10% of the totalroad construction, will cause the early rate deterioration of Road. This is due to the number and duration of rainthat pooled the asphalt. The Pilot Project of Road Standard implemented in 2015, implemented in each
Preservation Project Manager as long as 1 km, per Project Manager. Project Manager will decide which part oftheir road will be as a pilot project. Once that particular road become pilot project, it has to be fulfil with at least
Drainage, Shoulder, and detail of road equipment as mentioned on the regulationb. Long Segment
Concept of long segment launch in mid-2015 is based on the recent findings, that 91% of preservation funds
was done thru force account while 9% use annual small contract. Transition policy is needed, thru theintroduction of long segment as an effort to eliminate/minimize force account. The Rationale of applying andintroduction of “Long Segment" based upon:
a.
b.
c.
d.

Awareness of the good road maintenance needs
Approximately 98% of national roads need maintenance
Inadequate funding to carry out the maintenance of optimum path resulting in national road conditions
vary in the short-short segments
Effectiveness (administer) vs. efficiency (best value)

The Definition of Long Segment as follows: The Long Segment is a way to handle road preservation within theboundaries of one long segment which is can be more than one road section(Sources: Min of PUPR decree No.
19/PRT/M/2011) which was implemented with the aim to obtain a uniform road condition. In Organizing theLong Segment, include the following activities: Widening, Reconstruction, Rehabilitation and Road
Maintenance.
In the year 2016, the introduction of Long Pavement is still limited and is done thru the technical aspects whichis condition that is available. One example: to design a long segment of the job picture is done with theincorporation of the roads will be DED merged so the length of the segment, and is done with a focus on
maintenance and assigned based on quantity approach techniques associated with the condition that is available.
One example: to design a long segment of the job picture is done with the incorporation of the roads will be
DED merged so the length of the segment, and is done with a focus on maintenance and assigned based on
quantity.

671

Whereas in fiscal year 2017, scheduled so that each province is putting together a one (1) contract of long-termpreservation (Long Term Preservation contract), that would later form the multiyear long program over a periodof 3 years budget
Long Segment definition include the following:(1) Road package with the length from 100 to 200 km(2) Within multiyear budget(3) Combination of three program: Preventive Maintenance, Rehabilitation and Reconstruction
Contractors and consultants involved in long segment, it must be prepared and understand the root of the
problems of structural damage in order for selected preservation technology on time. One contract for 100 up to
200 km is not new in the world, there are a lot of country already doing so. This long segment insist thecontractors to change from “executor” into “Road Manager”, means that work very carefully
The objective of the implementation of long segment on preservation of the road is to achieved uniform
standard with stable condition and fulfil road standard with the following detail:1. Minimized and eliminate road with a severe damaged condition
2. To Prioritize Road with bad condition until all the long segment addressed by optimizing capacity as
long as the budget available
3. The First priority is a very bad road with reconstruction treatment and have the technical life around 5
to 10 years, while took another section (due to budget constraint) in holding treatment.
4. The second priority will be to handled light damage road with rehabilitation
5. Widening will be done simultaneously with pavement (rehabilitation and reconstruction)

Diagram 3 Program of Handling Long Segment, sources: DG Highways 2015

Some provisions in the implementation of road preservation with the long segment concepts are:1.

The contract System is a contract unit price with most of the work: lump sum at the end of the period(after it refund conditions) for the segment of road maintained

2.

No Guarantee for the Routine maintenance Work

3.

Reconstruction and rehabilitation work guarantee around 2 years.

672

Diagram 4 KPI 1 and 2, source: Writer673

6. Conclusion
Firstly, starting from 2016, again to remind all the stakeholder of preservation to do a fundamental changes,
where for building road, it has to refer to Ministerial PUPR decree No. 19/PRT/M/2011 in connection with
Road Standard and should be implemented as a guidelines to build road in Indonesia. The concept also lead to
introduce new motto: Apparatus Care Standard (APS) and become part of the Standard Operational Proceduresin implementing preservation of National Road. To implement this, by 2016, it will be done pilot project, 1
PPK/1 km.
Secondly, start from 2016, introduced and implemented the Long Segment concept, with around 100 up to 200
km road length per contract package, and this contract will be consists of comprehensive procurement
procedures. By introducing this policy, government try to eliminate and minimized the force account and also
implementing combination of treatment between routine, periodic, rehabilitation and improvement within acontract. In 2016 still in transition, but in 2017 will be done systematically.

674

References:
1.
2.
3.
4.
5.
6.
7.
8.
9.

Ministerial decree PUPR No. 19/PRT/M/2015 on Long Segment
World Bank, 2010, Performance Based Contract: Review and analysis
Ditjen Bina Marga, 2014, Study on Road Preservation and Survey
Ditjen Bina Marga 2014, study on Key Performance Index of Road Sector
Edward James, Callum McDonald, Paul Hambleton, Robin Dunlop, 2014, Some issues for PBC
implementation in Indonesia
Anik S Bhandari, 2014, Capacity Building in delivering and Managing Performance Based Road
Contracts
SRIP/PPIAF, 2005, Introducing performance Based Maintenance Contract to Indonesia
Waskita Karya, 2014, Kontrak berbasis Kinerja
Rowan Keyle, 2014, Principles and Lessons of Performance Based Contract675

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Motorcycles Gap Acceptance At Merging Point Of Egress And Ingress Of Exclusive
Motorcycle Lane In Malaysia

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Norfaizah MOHAMAD
KHAIDIR

Research Officer /Master Student

Malaysian Institute of Road
Safety Research (MIROS) /University Putra Malaysia(UPM)

Malaysia

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Nusayba MEGAT JOHARI

Research Officer

Malaysian Institute of Road
Safety Research (MIROS)

Malaysia

E-MAIL(for correspondence)

norfaizah@miros.gov.my

KEYWORDS:
motorcycle safety, exclusive motorcycle lane, access, gap, gap acceptance

ABSTRACT:
Motorcycle accidents contribute up to 60% of the traffic fatalities in Malaysia. To increase motorcycle safety, exclusive
motorcycle lanes (EMCL) have been built with the aim to segregate them from other (larger) vehicles. Egress (path of
exiting) and ingress (path of entering) are hazardous locations on EMCL where motorcyclists are required to makecritical decision whether to join or leave a traffic stream. The important factor they will need to consider is theavailability of a gap between two vehicles that, in the motorcyclist’s judgement, is adequate for them to complete themaneuver. Poor gap acceptance decisions will increase likelihood of accident to occur. Findings from the study revealthat gap acceptance for motorcyclist is lower than 1 sec. This paper presents findings in regards to a better
understanding of the gap acceptance of motorcyclists and guides the way for safer design solutions for EMCL.

676

Motorcycles Gap Acceptance At Merging Point Of Egress
And Ingress Of Exclusive Motorcycle Lane In Malaysia
Norfaizah Mohamad Khaidir1, Nusayba Megat Johari2
1,2

Malaysian Institute of Road Safety Research (MIROS), Kajang, Selangor, MALAYSIA
1
University Putra Malaysia (UPM), Serdang, Selangor, MALAYSIA
Email for correspondence, e.g. norfaizah@miros.gov.my

1 INTRODUCTION
Access into and out from the exclusive motorcycle lane (EMCL) is provided through egress andingress section. Egress is a path of exiting from the motorcycle lane whilst ingress is a path of entering into
the motorcycle lane. Similar to intersection, interaction area (merging and diverging) of egress and ingress is
expected to be one of the risky locations on both EMCL and adjacent main carriageway. Here, motorcyclists
are required to make multiple decisions such as to leave or join the traffic stream, slow down or stop to
observe for oncoming traffic and many more. Knowing the fact that motorcyclist will lose stability at speed
below 5 km/h, most of them refuse to stop to complete the maneuver.
The most important factor a motorcyclist will need to consider when joining the traffic stream is theavailability of a gap between two vehicles. Acceptance gap is the gap available that in the motorcyclist’s
judgement, is adequate for them to complete the maneuver. Acceptance or rejection of available gap between
two vehicles on the intended traffic stream has serious consequences on safety. Poor gap acceptancedecisions will increase the likelihood of accident to happen.
The size of gap in traffic stream is one of the main parameter in capacity analysis. Capacity isimportant to determine the performance of the road network. Generally, capacity at access point predominates the overall capacity of the road network (Amin & Maurya, 2015). Significant volumes of joiningor leaving traffic at access point will cause interruptions and capacity reduction. Therefore, incorrect
estimation of the capacity at the design stage will lead to inappropriate design decision. If large gap isassumed, the road will be over-designed causing negative value of infrastructure investment. It also will
reduce facility efficiency and adversely affecting the road system. On the other hand, if small gap is assumed,
it can force motorcyclists to make gap acceptance decisions in a dangerous manner. Hence, the study on gap
acceptance decision among motorcyclists will contribute to the new knowledge for EMCL design.
Gap acceptance parameter forms a crucial part in many microscopic traffic simulations. Even thoughmost of the simulation software has provided default value for gap acceptance, it still allows the modeller toadjust to more relevant values to suit onsite motorist behaviour. In addition, most of the default value
provided in simulation software is for car and it is expected that the default value will not simulate onsite
condition accurately for motorcycles behaviour. Sensitivity testing of the simulation model of six ways
roundabout in Birmingham reveals that the observed gap acceptance value showed a better level of fit toonsite condition compared to default values (Kay, Ahuja, & Cheng, 2006). Kay et al added in their findingsthat gaps accepted by heavy vehicles differ from light vehicles. Therefore, findings from this study cancontribute to more motorcycle research and the application of microscopic simulation in the future.
At present, to the best knowledge of the author, no published works examining gap acceptance formotorcycles has been found in the literature. Based on the above point of view, a need exists to adopt greater
understanding of motorcyclists’ gap acceptance behaviour. The aim of the study is to determine gap
acceptance value for motorcyclists at merging point of egress and ingress of EMCL. Findings obtained fromthis study will help fill in the gap in existing motorcycle research and will improve the safety of Malaysian
motorcyclists.

677

2 SCOPE AND LIMITATIONThe study started in July 2014 and ended in March 2016. Data collection was conducted in Augustand September 2015. The study was conducted at six (6) egress locations and six (6) ingress locations along
the main arterial road, Federal Road 2. Three (3) main types of data collected for the study are; gap
acceptance time, classified vehicle speed and classified vehicle volume. All data were collected during peakand off-peak period on normal weekday (Tuesday, Wednesday and Thursday) where no abnormal traffic
composition was observed.
The limitation to the study is that the data collection was restricted to only merging point of egress
and ingress. Other external effects that may occur on the traffic exiting/entering the exclusive motorcycle
lane were not included in the study.

3 LITERATURE REVIEW
3.1 Motorcycle Safety
Motorcyclists are categorized as one of the vulnerable road users due to the low ability to sustain
severe injuries in the event of a traffic collision. Abdul Manan & Várhelyi, (2012) in their study highlightsthat Malaysia has the highest road fatality risk (per 100,000 population) among the ASEAN countries andmore than 50% of the road accident fatalities involve motorcyclists. Motorcyclists are prone to injuries due tothe fact that helmets and type of clothing worn are the only possible protection gear for them.
Number of registered motorcycle in Malaysia shows an increasing pattern since it was first
introduced to the local market in mid of 1970’s (Road Transport Department Malaysia, 2014). Malaysians
choose to ride motorcycles due to several factors including it being the cheapest and fastest mode of travelingthat these small vehicles allow for. Less petrol and less space requirement for parking make it more favorable
for Malaysians working in the city center like Kuala Lumpur (Industry Research Department, 2015).
The increase of motorcycle volume consequently leads to the increase of road exposure, one of thepossible reasons for the high injuries and fatalities on road. This is supported by crash statistic from year
2002 to year 2012, where motorcycle fatalities rose approximately 22% from 3,429 to 4,178 fatalities (Royal
Malaysia Police, 2013). Motorcycle accident in Malaysia is an epidemic issue because it cuts out more thanhalf of road accident fatalities.
3.2 Motorcycle Facility
There are two (2) types of motorcycle lane in Malaysia i.e. exclusive motorcycle lane (EMCL) andnon-exclusive motorcycle lane (NEMCL). EMCL differ from NEMCL where it was built separately from thetraffic carriageway. The NEMCL on the other hand make use of road marking to separate motorcycle fromother vehicle types. Both type of motorcycle lane has shown benefit in reducing the number of motorcycle
crashes. As reported by Radin Umar et. al., (1995), the first EMCL constructed on Federal Road 2 wasproven to reduce approximately 34% of motorcycles fatalities excluding accident occurring on the main
carriageway.
Radin Umar & Barton, (1997) proved that the preliminary Benefit to Cost Ratio (BCR) of providing an
EMCL ranges from 3.3 to 5.2 depending on assumptions used in calculating the motorcycle accident costs
and the capacity of the exclusive motorcycle lane. Their study indicated that even though the cost forprovision of exclusive motorcycle lane is high, the benefit is at least three times higher than the construction
cost whereby resulting in a cost effective approach to tackle motorcycle safety problems in Malaysia.
Carriageway in Malaysia is based on a mixed traffic system where motorcyclists have to share the road withlarger vehicles resulting in a differential cruising speed and mixed flow conflicts. Previous study showed thatvehicles travelling with large speed variance were more likely to be involved in an accident (Hauer, 1971). If
motorcycles were segregated from other larger vehicle, the mixed traffic flow risk can be managed
efficiently. However, to date, the total length of motorcycle lane provided on Malaysian road are still low.

678

3.3 Gap Acceptance
Highway Capacity Manual (HCM, 2000) defined gap as the space between the vehicles on the majorroad at an unsignalised intersection while gap acceptance describes the completion of a vehicle’s movementon minor road into a gap. In addition, HCM defined the critical gap as the minimum time interval between
the front bumpers of the second of two successive vehicles in the major road that will allow the entry of one
minor road vehicle. The capacity of minor road of an unsignalised intersection rely on the possibilities tohave enough gap between vehicle on the major road to cross the conflict space safely (Amin & Maurya,
2015). HCM (2000) also explained that gaps sizes required by the minor road depends on the major roadtraffic stream, available sight distance, the length of time the minor road vehicle has been waiting at
intersection, and the driver characteristics (driver’s eyesight, reaction time, age, etc.).
Laberge et. al., (2006) highlights that in observing the gap size, drivers must have a sense of how
fast the approaching vehicle is traveling, how far away the vehicle is and how soon it may arrive at theintersection. Drivers may accept gaps that are less safe when they overestimate the arrival time of
approaching vehicles. Previous study found out that the gap acceptance has significant correlation withdriver’s age. Older drivers seems to accept greater median gap and take longer time to cross the intersection
than younger drivers (Alexander, Barham, & Black, 2002). HCM, (2000) outlined critical gaps ranging from
5.0 seconds for major road to 6.5 seconds for minor road and AASHTO, (2001) recommends a minimum
threshold of 7.5 seconds for a left-turn maneuver. However, this is based on the passenger car’s behavior andno study has been found on the motorcyclist’s behavior towards gap acceptance.

4 METHODOLOGYThis section discusses the methodology applied in conducting the study. Field data collection was
conducted in order to obtain data needed to evaluate and quantify the gap acceptance for motorcyclists.
4.1 Identification of Study Location
Site reconnaissance was conducted on the exclusive motorcycle lanes along the Federal Highway(F2) in the state of Selangor (30km per direction) and the Shah Alam Highway (KESAS) (20km perdirection). Drive-through video recording was conducted on the EMCL and on the main carriageway. The
video recording was used to assess the road environment and to simulate a motorcyclist’s/motorist’s
riding/driving experience. The video was also used to help in identifying suitable locations to conduct the
study.
Egress and ingress were grouped into the five (5) types based on the category sets in previous study
conducted by Norfaizah, Abdul Manan, & Nusayba, (2015). The five (5) groups of typical types of egress
and ingress are listed in Table 1. Two (2) locations for each type of egress and ingress was selected for study
locations as summarised in Table 2. The Type 1 (Type E1 and Type I1) and Type 5 (Type E5 and Type I5)
egress and ingress was excluded from this study due to insufficient number of location. This left twelve (12)locations i.e. six (6) egress and six (6) ingress selected for this study as shown in Table 2.
Table 1. The five (5) types of egress and ingress identified from previous study
Type

EgressIngress

Type E1 or Type I1
Entry angle 90 degree,
length of slip lane < 15m

679

Type E2 or Type I2
Presence of auxiliary lane
for acceleration anddeceleration on the
motorcycle lane
Type E3 or Type I3
Entry angle <90 degree,
length of slip lane <15m

Type E4 or Type I4
Entry angle <90 degree,
length of slip lane >15m

Type E5 or Type I5
Skewed access that gives
impression of a seamlessconnection between
motorcycle lane and themain carriageway.
Table 2. Selected study locations
TYPE
Egress Type 1 (E1)
Egress Type 3 (E3)
Egress Type 4 (E4)
Ingress Type 1 (I1)
Ingress Type 3 (I3)
Ingress Type 4 (I4)

LOCATIONKESAS – Subang Jaya
KESAS – Taman OUG
Padang Jawa
Subang Airport
Amcorp Mall
Ke Bulatan Kayangan
Susur Batu Tiga
Petronas Shah Alam
Seksyen 7
Setia Jaya
Susur NPE
Dari Bulatan Kayangan

ID
E1-01
E1-02
E3-01
E3-02
E4-01
E4-02
I1-01
I1-02
I3-01
I3-02
I4-01
I4-02

4.2 Data Collection
Accurate and sufficient data play a critical role in the success of any conducted study. Field datacollection was conducted at twelve (12) locations, comprising of six (6) locations at egress and another six(6) locations at ingress. To collect the required data for this study, a video camera was used. The video
camera was mounted on a special pole at the height of 3 m and was positioned to capture the motorcyclist
exiting or entering the exclusive motorcycle lane as well as the oncoming traffic, simultaneously. Figure 1
depicts the position of mounted video camera.
Video recording was conducted for two (2) hours of morning peak (7.00 am – 9. 00 am) and two (2)hours of morning off-peak (10.00 am – 12.00 am). A total of 48 hours of video playback is obtained for data
extraction and analysis. Data collection was conducted during weekdays (Tuesday, Wednesday andThursday). Data collection was not conducted during bad weather or during unusual traffic conditions (e.g.

680traffic congestion due to roadway maintenance, crashes incident, police enforcement activity or public
holiday).
Three types of main data collected are gap acceptance time together with the details (as listed in
Section 4.3), classified vehicle speed, and classified vehicle volume. Gap acceptance time and classified
vehicle volume data was retrieved from the video recordings while vehicle speed data was collectedmanually on site using speed radar gun. The placement of speed observer officer is illustrated in Figure 1 andfour (4) types of speed data collected are:i. Speed on EMCL at 100 m to 200 m away from the egress/ingress merging point
ii. Speed on EMCL at the egress/ingress pointiii. Speed on main carriageway at 100 m to 200 m away from the egress/ingress merging point (speed
for different types of vehicles on slow lane only)
iv. Speed on main carriageway at the egress/ingress point (speed for different types of vehicles on slow
lane only)

Figure 1. The illustration on the location for data collection
4.3 Data Retrieval
The video recording was analysed in the office. The types of data were retrieved from the video are:i. Motorcycles arrival and departure time at egress and ingressii. The time when conflicting vehicle crosses the point where it conflicts with the entering/exiting
motorcycles.
iii. Accepted/rejected gap
iv. Motorcycles entering or exiting exclusive motorcycle lane from stand still position or floating.
A customised video play program used to retrieve data from the video was created using Language
C#. This is to increase the accuracy of the data. With the program, research assistant was asked to press
specific keys on computer when vehicles reached designated locations. The program generated a uniquetimestamp marking the position of the vehicles.
4.4 Data Analysis
The analysis of this study was done in two parts, i.e. analysis of gap acceptance decision and speed
study. It is expected to disseminate the findings in terms of revealing the motorcycle gap acceptance, speed
distribution, cross tabulation of gap acceptance based on egress and ingress type and travel period (peak or
off peak). Microsoft Excel, SPSS, XLSTAT and Wizard software was used to help in the data analysis.

5 RESULT AND DISCUSSION
5.1 Gap Acceptance by Location

681

Table 3. Gap acceptance and rejection characteristic by location
ID

E1-01
E1-02
E3-01
E3-02
E4-01
E4-02
I1-01
I1-02
I3-01
I3-02
I4-01
I4-02

ACCEPTANCESAMPLEMINMAX TIME
SIZE
TIME
378 (98.95%)
0.000
57.310120 (96.77%)
0.000
40.538515 (95.72%)
0.000
43.854617 (99.68%)
0.000
32.687865 (100%)
0.000
23.142567 (93.87%)
0.000
33.61322 (84.62%)
0.210
12.455212 (97.25%)
0.078
45.402968 (88.97%)
0.110
46.6611045 (95.78%)
0.060
36.3592065 (99.85%)
0.112
40.160148 (99.33%)
0.014
33.203

SAMPLE
SIZE
4 (1.05%)
4 (3.23%)
23 (4.28%)
2 (0.32%)37 (6.13%)
4 (15.38%)
6 (2.75%)
120 (11.03%)
46 (4.22%)
3 (0.15%)
1 (0.67%)REJECTION
MAX TIMEMAX TIME

0.662
0.786
0.000
0.270
0.207
0.361
0.283
0.158
0.154
0.548
0.266

30.1872.836
14.3233.463
22.462
1.559
4.608
3.232
36.4301.508
0.266

Table 3 lists the sample size, minimum and maximum time of gap acceptance and rejection collected
at 12 locations of study area. The percentage of rejection gaps amongst motorcyclists is apparently low. The
high percentage of gap rejection was observed at ingress type of I1-01 (15.38%) and I3-01 (11.03%). Basedon the site observation, ingress I1-01 and I3-01 located just after a curve section where the observation on theoncoming motorcyclist is limited to the entering motorcyclist at ingress. This was seen to trigger
motorcyclists to stop and reject small gaps. In addition, there is no shoulder provided on the EMCL to allow
for comfortable lateral clearance.
It was perceived that motorcyclist accept minimum gaps time of zero (0) seconds at egress locations
most probably due to availability of sufficient lateral clearance between edge line and vehicle on the intendedlane (main carriageway). The narrow paved shoulder provided on the main carriageway also offers additional
space for motorcyclists to merge into the main traffic.
Cumulative frequency distribution of gap acceptance and rejection type was illustrated in Figure 2.
It was found that most motorcyclists tend to reject gap smaller than 1.75 seconds (45%). However, it wasinteresting to note that the percentage of motorcyclist accepting gap below than 0.25 seconds was 7.06% (572samples).

Figure 2. Gap acceptance and rejection time cumulative relative frequency distribution

682

The gap acceptance cumulative relative frequency distribution was plotted by egress and ingress
type as shown in Figure 3 (egress) and Figure 4 (ingress). Generally, the graph indicates that gap acceptanceat each location was unique and not correlated with the egress and ingress design. As explained in section
4.1, for each egress and ingress design, two locations were selected for data collection. The similar gap
acceptance trend was only observed for egress type E3 and ingress type I3.

Figure 3. Gap acceptance cumulative relative frequency distribution by egress location

Figure 4. Gap acceptance cumulative relative frequency distribution by ingress location

683

5.2 Gap acceptance by time period
The gap acceptance was also tabulated to see the effect of time period on gap acceptance behavior as
illustrated in Figure 5. It was found that motorcyclist accept smaller gap time during peak period as compared
to off peak period. This was parallel with findings by Kyte, (1994), where sites with higher traffic volumes
are likely to put pressure on drivers to accept shorter gaps.

Figure 5. Gap acceptance time cumulative relative frequency distribution by time period
5.3 Speed study
In addition to the gap acceptance analysis, this study also included the effect of speed on theexistence of egress and ingress section on EMCL and the main carriageway (MC). The analysis wastranslated into graph as shown in Figure 6 (EMCL) and Figure 7 (MC) showing mean approaching speed(speed at 100-200 m from the egress or ingress) and mean merging speed (speed at merging area).

Figure 6. Mean speed on EMCL at approching of egress and ingress and at the merge area684

Based on the data analysis on EMCL, approaching speed is higher compared to at merging area at
all study location accept at location I1-02. Based on observation, ingress location of I1-02 is near the curvearea and thus a lower mean speed was observed mainly because motorcyclist has reduced the speed tomaneuver the curve safely. At location E3-02, E4-01, I3-01 and I4-01, no significant speed reduction wasobserved at merging area.
Whilst on the main carriageway, it was observed that vehicles do not reduce the speed at merging
area for location I3-01 and I3-02 and no significant reduction was observed at location I1-01 and I1-02. The
speed at merging area of MC at location E1-01 was unable to be collected due the presence of enforcement
activity during data collection. Speed of vehicles on MC were mostly not affected or interrupted at ingress
section, compared to egress section.

Figure 7. Mean speed on MC at approching of egress and ingress and at the merge area

6 CONCLUSIONS
The research in gap acceptance decision among motorcyclists at merging point of egress and ingressof EMCL is long overdue. It is significant to improve the infrastructure for motorcycles and increase the levelof safety. By knowing the gap acceptance, not only can the design parameter for EMCL be known, but it also
opens up opportunities to further explore research on motorcycle infrastructure and behavior. This in longterm can help to reduce the number of motorcycle fatalities due to road accidents.
These conclusions can be drawn from this study:i.

Motorcyclists accept minimum gaps time of zero (0) second at egress location due to the availabilityof sufficient lateral clearance between edge line and vehicle on the intended lane;
ii. The percentage of rejection gap time for motorcyclists was low (3.46%);iii. Most motorcyclists tend to reject gap time smaller than 1.75 seconds (45%);
iv. Gap acceptance was unique at each locations and not correlated with the design type;v. Motorcyclist accept smaller gap time during peak period as compared to off peak period; andvi. Significant of speed reduction at merging area of egress and ingress can be observed on both EMCL
and MC at most locations.
For safety reason, it is suggested that the design of egress and ingress should consider the provision of taperlane or auxiliary lane so that entering or exiting motorcycles have ample time to adjust their speed with the685speed of intended traffic. This is due to the reason that motorcycle have high probability to accept small gaps
up to zero (0) seconds which may increase the likelihood of accident.

7 ACKNOWLEDGEMENTS
The authors would like to express gratitude to those who give their support and valuable information
towards completion of this report. Special mention goes out to Assoc. Professor. Law Teik Hwa, Professor
Dr. Wong Shaw Voon, Dr. Siti Zaharah Ishak, Alvin Poi Wai Hoong, Azzemi Aziz, Mohd Saifullah Mohd
Sohi, Zulfadhli Sharifudin, Mohd Khairil Embi, Suriani Bajuri and members of Road Engineering andEnvironment Research (REER) Centre, for their support and advice.

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Lane in Malaysia. REAAA Journal, 1–6.
Road Transport Department Malaysia. (2014). Tabulated Number of Motorcycle Registrations. Retrieved
February 1, 2014, from http://www.jpj.gov.my/statistik-pendaftaran-motosikal
Royal Malaysia Police. (2013). Laporan Tahunan PDRM 2012. Kuala Lumpur.

686

2nd	
  IRF	
  Asia	  Regional	
  Congress	
  &	
  Exhibition	  October	
  16-­‐20,	
  2016	
  –	
  Kuala	  Lumpur,	
  Malaysia	
  PAPER TITLE

Cracking performance evaluation of asphalt mixtures using semicircular bending
test: Experimental evaluation and Box-Behnken optimization

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Gourab SAHA

Doctoral Research
ScholarIndian Institute ofTechnology Kharagpur

India

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Krishna Prapoorna
BILIGIRI

Assistant Professor

Indian Institute ofTechnology Kharagpur

India

E-MAIL(for correspondence)krishnapbiligiri@gmail.com

KEYWORDS:
Cracking, asphalt mixture, fracture resistance, semicircular bending test, performance optimization

ABSTRACT:
Owing to the increasing popularity of asphalt rubber gap-graded (AR-Gap) mixtures, a long-term cracking performanceof AR-Gap demands a fundamental fracture characteristics evaluation. Since the working principle of the gap-gradedmixture is distinct from the conventional dense-graded asphalt mixture, it is important to understand the fracture
mechanism of the AR-Gap mixtures. In addition, a better performance of AR-Gap mixture in terms of cracking
necessitates an optimized design with a combination of mixture-variants; and understanding the effects of potential
contributing factors to the fracture characteristics. Thus, the objective of this study was to understand the cracking
performance mechanism of the different AR-Gap mixtures using mechanical fracture tests, that included determinationof fracture resistance (KIC) using static semicircular bending (SCB) test at varying mixture variants and temperature
combinations. A total of eight AR-Gap mixtures were prepared to comprehensively assess the effect of three factors:
temperature, asphalt content, and air voids. Further, the experimental data was statistically analyzed to understand theeffect of predictor variables on KIC using analysis of variance (ANOVA) test. It was found that temperature and asphalt
content significantly influenced the fracture resistance of the AR-Gap mixtures. An optimization study was carried out
using Box-Behnken technique to assess the level of the three factors; to capture which of them was a better cracking
performance indicator. The optimization solution indicated that low level of temperature and air voids, in association
with intermediate level of asphalt content resulted in optimized cracking performance evaluation. Furthermore, thefracture mechanism of AR-Gap mixture was analyzed using fundamental load-time relationship and compared to theconventional dense-graded asphalt mixture. It was noticed that occurrence of cracking in the AR-Gap mixture tookapproximately twice that of the time taken for the dense-graded one. Overall, this study helped understand the fracture
characteristics of AR-Gap based on fracture mechanics principles, and developed a rational methodology to evaluate thecracking performance both reliably and rationally.

687

Cracking performance evaluation of asphalt mixtures using
semicircular bending test: Experimental evaluation and BoxBehnken optimization
Gourab Saha1 and Krishna Prapoorna Biligiri2*
1

Doctoral Research Scholar, Department of Civil Engineering, Indian Institute of Technology Kharagpur,West Bengal 721 302, INDIA, Email: mr.gourabsaha@gmail.com
1

Assistant Professor, Department of Civil Engineering, Indian Institute of Technology Kharagpur, West
Bengal 721 302, INDIA, Email: krishnapbiligiri@gmail.com
Email for correspondence: krishnapbiligiri@gmail.com

1 INTRODUCTION
Cracking is one of most fundamental failure modes in the flexible asphalt pavements. Although the cracking
constitutes a wide variation of distresses in the flexible pavement, a categorical classification of cracking includes aload-associated and thermal-derived failure in the mainstream cracking performance analysis. In general, the loadassociated fracture behavior is closely pertinent to the fatigue performance; while the thermal-derived fracture isassociated with the study of the low-temperature thermal performance of the asphalt mixture. Thus, a long-term
cracking performance of the asphalt mixtures demands a fundamental evaluation of fracture behavior using fracture
mechanics principles.
In the last few decades, the use of asphalt rubber gap-graded (AR-Gap) mixtures has been very popular due toits better performance over conventional dense-graded (DG) asphalt mixtures. A wealth of literature can be found on
the cracking performance evaluation of AR-Gap mixture on the premise of conventional mechanistic approach, where
the analysis pivots the stiffness and strain parameters to sketch the cracking performance. It is noteworthy that thestone-to-stone contact between the aggregates is the key factor that demarcates the working principle of DG asphalt and
AR-Gap mixtures. With this background, it can be understood the AR-Gap is designed with higher air voids and asphalt
content in comparison with the DG asphalt mixes. Thus, the cracking mechanism of AR-Gap employs a distinct
evaluation approach to understand the mechanism of the cracking performance. Furthermore, it is also important tounderstand the level of asphalt content and air voids to obtain the optimized cracking performance of the AR-Gap
mixture.
Although there are several fracture parameters available, fracture toughness (KIC) provides simple but acomprehensive understanding of the fracture behavior of the asphalt mixture. In recent times, Semi-Circular Bending(SCB) test has been utilized by many searchers (Molenaar et al. 2003, Birgisson et al. 2008, Li and Marasteanu 2010,
Minhajuddin et al. 2015, Saha and Biligiri 2015, Saha and Biligiri 2016) successfully to evaluate fracture characteristics
of asphalt mixtures. This objective of this study was to evaluate the cracking performance using a statisticaloptimization: Box-Behnken Design (BBD) and investigate the fracture mechanism of different AR-Gap mixtures on thebasis of KIC using the SCB test. The scope of the study includes (Figure 1):
Cracking performance
evaluation
Experimental
investigation

Statisticaloptimization

Static SCB test

ANOVA

KIC determination

BBD design

Fracture mechanism
Load-time
relationship

BBD response
model
Cracking performance
optimization

688

•
•
•
•
•

Figure 1. Research framework
Determination of fracture toughness of various AR-Gap mixtures at varying temperature using static
SCB test method
Formulation of BBD orthogonal matrix and perform an optimization analysis
Comparative analysis of cracking performance of various AR-Gap mixtures
Recommend an optimized level of variables to obtain the best cracking performance of AR-Gap
mixtures
Investigation of fracture mechanism of AR-Gap in contrast with DG asphalt mixes

2 BACKGROUND TO THE BBD OPTIMIZATIONBBD is a second-order response surface approach to optimize the response based on incomplete factorial
design. The formulation of BBD employs consideration of treatment level combination within the central-zone insteadof extreme ranges. Since the operational principle of BBD is distinctive from the full factorial design, and response
surface approach; it is more efficient due to the less number of experimental runs as well as the elimination of extreme
levels of treatment combinations. A detail on the BBD can be found in the literature (Ferreira et al. 2007). In this study,a three-factor BBD was formulated, which encompassed 12 base-experimental runs with two replicates totaling 24
experimental runs. The orthogonal matrix of the BBD design is presented in Table 1. Note that -1, 0, and 1 indicate thelow, medium, and high level of the factors, respectively.
Table 1. Orthogonal matrix of BBD for three factors

Experiment
runs
1
2
3
4
5
6
7
8
9
10
11
12

X
-1
1
-1
1
-1
1
-1
1
0
0
0
0

Factors
Y
-1
-1
1
1
0
0
0
0
-1
1
-1
1

Z
0
0
0
0
-1
-1
1
1
-1
-1
1
1

3 MATERIALS AND EXPERIMENT PROGRAM
A total of eight AR-Gap mixtures were prepared using crumb rubber modified binder: CRMB-60 and Arizona
gap-graded aggregate prescribed in (Way et al. 2012). Superpave gyratory specimens, (height 120 mm and diameter
150 mm) were prepared using varying asphalt contents (AC) and gyration levels to achieve the different air voids (AV).
The gyratory specimens were sliced into two discs of height 50±2 mm and then, each disc was cut centrally to obtaintwo semi-circular discs. Subsequently, a central notch of 15 mm was introduced at the mid-point of the base along the
thickness direction. A total of 24 semi-circular specimens were prepared with two replicates to suit with the orthogonal
matrix shown in Table 1. As a next step, an SCB test was conducted on 24 specimens at three temperatures, namely 5,
15, and 25 oC using Universal Testing Machine (UTM) in accordance with AASHTO TP 105, and KIC was calculatedusing Equation (1) as summarized in Table 2. The test specimens were conditioned for four hours prior to the testing. A
notched-SCB sample and the experimental setup along with the specimen are shown in Figure 2.
𝐾!" = 𝜎! 𝜋𝑎×𝑌!

(1)

689

Load
cell

(a)

Loading(b)

Supports(c)
Figure 1. (a) Notched- SCB specimen, (b) experimental set-up of SCB test, and (c) cracked specimen after the
SCB test
Table 2. Experimental matrix

T

AC

AV

KIC (MPa. √m)

(oC)
5
25
5
25
5
25
5
25
15
15
15
15

(%)
6
6
8
8
7
7
7
7
6
8
6
8

(%)
8
8
8
8
7
7
9
9
7
7
9
9

Rep_1
0.601
0.143
0.529
0.103
0.626
0.099
0.509
0.139
0.303
0.268
0.340
0.329

Rep_2
0.643
0.133
0.567
0.108
0.644
0.125
0.617
0.135
0.390
0.321
0.287
0.322

Where:
KIC
σo
P
D
L
a

= fracture toughness, MPa. √m= P/(D*L)= failure load (MN)
= Specimen diameter (m)= Specimen thickness (m)= Notch length (m)YI= geometric factor = 4.782 + 1.219!
!

+ 0.063  𝑒

!.!"#

!
!

4 RESULTS AND ANALYSESThe BBD experimental matrix and statistical analysis were conducted using MINITAB® 17.0. As mentioned
earlier, three factors: temperature (T), asphalt content (AC), and air voids (AV) were varied at three levels with two690

replicates per combination. The BBD was considered to investigate the difference in the fracture properties of various
AR-mixtures at 95% confidence interval. The statistical analysis of BBD is explained next.
4.1 ANOVA RESULTS
As the first step of BBD, ANOVA test was performed to understand the primary effect of the factors on thefracture properties of AR-Gap mixtures. The results obtained from the ANOVA are presented in Table 3. The null andalternative hypotheses considered in this process were as follows:
Ho : µT = µAC = µAV
H1 : At least one of the mean not equal
If the P-value of the factor shows a value less than 0.05, the null hypothesis can be rejected. As observed inTable 3, T and AC produced P-value less than 0.05, which indicated that the null hypothesis could be rejected. Hence, it
can be concluded that T and AV had a significant effect on the KIC of the AR-Gap mixtures. In contrast, AV did not show
any significant impact on fracture performance in the range under consideration. Furthermore, the interaction effects
were also checked to assess the behavior of the response variables with respect to the interactive factors. It was foundthat the interaction and quadratic effects did not produce any significant impact on the KIC of the AR-Gap mixtures.
However, it can be concluded that AC and T showed a significant effect on the KIC in the range under consideration.
Table 3. ANOVA results

Factors
T
AC
AV

DF
1
1
1

Adj SS0.87990.00530.0006

Adj SS0.87990.00530.0006

T-stat809.484.89
0.57

P-value< 0.05< 0.050.461

Model decision
Significant
Significant
Insignificant

T2

10.00440.0044

4.05

0.062

Insignificant

AC2
T*AC
T*AV
Total

1
1
1
23

0.00030.00090.00480.917510.00030.00090.0048

0.27
0.79
4.37

0.611
0.389
0.054

Insignificant
Insignificant
Insignificant

4.2 EFFECT ANALYSESAs the next step, it was deemed important to analyze and understand the results obtained from the ANOVA
test. Since there was no significant interaction effect, the only main effect would provide a complete understanding
towards the KIC of AR-Gap mixtures. Essentially, the main effect explains the effect of an independent predictor
variable averaging across all its levels on the dependent variables. Figure 2 shows the main effect of T, AC, and AV on
the KIC.
As observed in Figure 2, KIC decreased with increasing temperature. This phenomenon can be explained by theviscoelastic properties of the AR-Gap mixtures. An increase in the temperature reduced the stiffness of the mixtures,
which in turn reducing the cracking resistance. As a result, the mixture at higher temperature failed under a lower
magnitude of load due to the reduced viscosity of the mixtures. It is also important to observe the linear reduction of KIC
with respect to the temperature. It can be expected that the BBD model (discussed in Section 4.3) established in thisstudy would predict the KIC with respect to temperature without any quadratic and interaction with any other variables.
Concurrently, KIC was initially found to be not varying with increasing asphalt content (AC: 6-7%) and then, it
reduced with further increment in the asphalt content (AC: 7-8%). The initial stable plateau of KIC indicated the KIC in
the range of 6-7% of AC was not sensitive to the change in the AC. It can be understood that an increase in the AC
increased the adhesion between the aggregates in the mixture-matrix. But after reaching a certain level (here: at 7% ofAC), an increase in AC did not help improve the adhesion, rather it provided a lubrication effect along the aggregate
boundaries. Hence, KIC dropped with further increment in AC. On the other hand, AV produced an insensitive change in
AC. Similar findings were also noticed from the ANOVA results discussed in Section 4.1. Although it is an establishedpoint that air voids affect the mixture performance significantly, the impact of AV was not clear in the analysis. It may
be because of the fact that the potential effect of AV on the cracking performance of AR-Gap mixtures based on the KIC
was lower than the other variables and their associated levels and thus, the cracking performance was governed by theother factors. However, a reduction in KIC was noticed with increasing AV. Since an increase in AV creates bigger air

691

void pockets in the mixture-matrix, the stress concentration at the tip increases. As a consequence, fracture resistancedecreased with higher AV in the AR-Gap mixtures.
T

AC

AV

0.6

KIC (MPa √m)

0.5

0.4

0.3

0.2

0.1
5

15

25 6

7

8 7

8

9

Figure 2. Main effect on KIC
4.3 BBD RESPONSE MODEL
Development of a BBD response model is the crucial step in the process of statistical optimization. The model
was constructed using three variables with three factors based on the general regression concept. The model presents the
KIC as the output variable as a function of T, AC, and AV including the main and interaction effects. It is noteworthy thatthough the interaction and quadratic effects were not found to be significantly contributing to the fracture resistance of
the AR-Gap mixtures, the model included these effects to achieve better accuracy. The model accuracy was measured
by the goodness of fit, R2 = 0.9545 indicated that a good agreement between the measured and the predicted values.
KIC = 1.80 - 0.0602 T - 0.041 AC - 0.1541 AV + 0.000332 T2 - 0.0086 AC2 + 0.00103 T*AC + 0.00244 T*AV
+ 0.0159 AC*AV(2)
Where:
KIC

T
AC
AV

= Fracture toughness, MPa. √m= Temperature, oC= Asphalt content, %= Air voids, %4.4 KIC optimization
As a final step to optimize the response of KIC, BBD optimization was carried out on the basis of the BBD
model. It is important to understand the relationship of the fracture performance of the asphalt mixtures with theparameter used for the analysis prior to the optimization process. Since KIC indicates the fracture toughness of the
mixtures, it is expected that higher fracture toughness augments the fracture resistance of the AR-Gap mixtures. With
this background, an optimization goal was set to maximize the KIC in order to optimize the cracking resistance of the
mixtures. In this process, all the variables were kept to an initial setting to find the optimized solution to achieve theoptimization goal. The optimization summary is shown in Figure 3.

692

Figure 3. Optimization plot of KIC
It can be observed that KIC was found to have maximized at a lower level of temperature (T), and air voids (AV)and intermediate level of asphalt content (AC). The lower temperature increased the fracture resistance as explained in
Section 4.2. Also, 7% of AC produced the maximum response that supported the findings obtained from ANOVA
results. The optimization process adopted in the study can be utilized to optimize the fracture resistance of various typesof asphalt mixtures including different asphalt binders and aggregate gradations.
5 FRACTURE MECHANISMS
As mentioned earlier, one of the tasks of the study was to investigate the fracture mechanism of the AR-Gap
mixtures. To understand the difference in the fracture mechanism, the load-time history was recorded from the dataacquisition system of UTM and then, plotted with a comparison with a DG mixture as shown in Figure 4. A
conventional DG mixture was prepared with a view to compare and contrast the cracking mechanism of the twodifferent mixture types. One DG gyratory specimen was prepared, and SCB sample geometry was prepared using the
aforementioned procedure discussed in Section 3. Note that AR-Gap and DG mixtures, which were used forcomparison purpose, were prepared with same air voids, 7%, and with AC of 5 and 7%.
As observed, the DG mixture showed a rapid increment in load within a short span of time, whereas the ARgap mixture slowly increased the load magnitude. It was also interesting to note that AR-Gap mixture resulted in failureload, under which the sample sustained some time. On the other hand, the DG mixture showed a sudden drop in theload after reaching the peak load. It revealed important information regarding the distinct fracture pattern of the two
mixtures. A hold in peak load magnitude explains that although AR-Gap mixture failure took place at the peak load, it
still offers a resistance against the crack propagation. The AR-Gap mixture continued to take the additional load, which
worked against the residual crack resistance. It is possibly due to the fact that the presence of the crumb rubber
modifiers in the AR-gap mixture endured the viscoelastic characteristics, which in turn rendered a viscoelastic bonding
between the asphalt binder and the aggregates. Since the DG mixture was prepared using a virgin binder (viscosity
graded VG-30); there was no endured elasticity observed during the specimen fracture. Furthermore, the failure of thespecimen after the peak was also found to be distinctive where AR-Gap mixture took a longer time to completely fail ascompared to the DG mixture. It provides additional information regarding the complete cracking of the two types ofasphalt mixtures. DG mix completely cracked with a rapid reduction in load within a very short span of time whereas
the AR-gap mixture showed a prolonged cracking performance with a slow reduction rate of load. Overall, it can beconcluded that though the AR-gap mixture would initiate the crack at a comparatively lower load than the DG-mix,
AR-Gap mixture would provide a better cracking performance than the DG asphalt mix due to endured viscoelastic
effect of the AR-Gap mixture.
5

Failure time:
4

AR-Gap ≈ 2* DG

Load, kN

3

2

DG mix
AR-Gap mix

1

0
0

20

40

60

Time, sec

80

100

Figure 4. Load-time relationship and fracture mechanism693

6 CONCLUSIONSThe objective of this study was to optimize the cracking performance and understand the fracture mechanismof the AR-Gap mixtures. A total of eight AR-Gap mixtures were used to investigate in respect of their cracking
characteristics with three factors: temperature, asphalt content, and air voids at three levels. A significant contributionof the study was to formulate a statistical algorithm: Box-Behnken design to assess the effects of variables on cracking
performance. The major findings of the study are as follows:•••

Fracture toughness determination: the study determined the fracture toughness of eight AR-gap
mixtures at three temperatures using SCB test method. Then, the test results were statisticallyanalyzed using ANOVA. The statistical findings showed that temperature and asphalt content had asignificant impact on cracking performance. Overall, it was found that the SCB test procedure wasfound to be very promising candidate test to distinguish fracture behavior of AR-Gap mixtures evenfor a minor change in the mix-composition, such as: asphalt content.
Box-Behnken optimization: A response model was developed as a part of the study to perform thestatistical optimization. The accuracy of the model was excellent (R2 > 0.95) indicating an excellent
prediction of the response variable: KIC. Further, the optimization results concluded that higher
fracture resistance could be achieved with lower temperature, intermediate asphalt content, and low
air void levels.
Fracture mechanism: the study discussed the fracture mechanism of AR-Gap and demarcated themechanical differences in cracking process of the DG asphalt mix. It was found that the occurrence offailure load for AR-Gap took approximately twice the time required for the DG-Gap mix. A sustained
peak-load hold was also reported for AR-Gap mixes, which revealed a residual cracking resistanceafter the crack initiation has taken place.

Although the study considered fracture toughness to evaluate the cracking performance of AR-Gap mixturees,a similar methodology can be utilized using other fracture parameters as assessors. However, more research is definitely
needed on this subject to extend the understanding for the other types of materials, including various asphalt binders
and aggregate gradations.

ACKNOWLEDGMENTS
The authors gratefully acknowledge the Government of India Ministry of Human Resource Development Departmentof Higher Education for their financial support vide Indian Institute of Technology Kharagpur Institute Scheme forInnovative Research and Development research project grant number IIT/SRIC/CE/CAM/2014-15/36, dated 22 April
2014.

REFERENCES
AASHTO TP 105-13. (2013). Standard method of test for determining the fracture energy of asphalt mixtures using
the Semicircular Bend geometry (SCB), American Association of State and Highway Transportation Official.
Birgisson, B., Montepara, A., Romeo, E., Roncella, R., Napier, J.A.L., and Tebaldi, G. (2008). Determination andprediction of crack patterns in hot mix asphalt (HMA) mixtures, Engineering Fracture Mechanics, 75 (3), 664–673.
Ferreira, S.L.C, Bruns, R.E., Ferreira, H.S., Matos, G.D., David, J.M., Brandao, G.C., Silva, E.G.P., Portugal, L.A.,
Dos Reis, P.S., Souza, A.S., and Dos Santos, W.N.L (2007). Box-Behnken design: an alternative for the
optimization of analytical methods. Analytica Chimica Acta, 597(2), 179-186.
Im, S., Ban, H. and Kim Y.R. (2014). Characterization of mode-I and mode-II fracture properties of fine aggregate
matrix using a semicircular specimen geometry, Construction and Building Materials, 52, 413–421.
Li, X.J. and Marasteanu, M.O. (2010). Using semi circular bending test to evaluate low temperature fracture
resistance for asphalt concrete, Experimental Mechanics, 50 (7), 867–876.
Mohammad, L.N., Wu, Z. and Aglan, M.A. (2004). Characterization of fracture and fatigue resistance on recycled
polymer-modified asphalt pavements, in: Proceedings, 5th International Conference on RILEM, 375–382.

694

Minhajuddin, M., Saha, G., and Biligiri, K.P. (2016). Crack propagation parametric assessment of modified asphalt
mixtures using linear elastic fracture mechanics approach, Journal of Testing and Evaluation, ASTM International,
USA, 44 (1S), 1–13.
Molenaar, J.M.M., Liu, X. and Molenaar, A.A.A. (2003). Resistance to crack-growth and fracture of asphalt
mixture, in: Performance Testing and Evaluation of Bituminous Materials ptebm’03. Proceedings of the 6thInternational RILEM symposium held Zurich, Switzerland, 14–16.
Saha, G and Biligiri, K.P. (2015). Fracture damage evaluation of asphalt mixtures using Semi-Circular Bending test
based on fracture energy approach, Engineering Fracture Mechanics, 142, 154-169.
Saha, G and Biligiri K.P. (2016). Fracture properties of asphalt mixtures using semi-circular bending test: A stateof-the-art review and future research. Construction and Building Materials, 105, 103-112.
Way, G.B., Kaloush, K.E. and Biligiri, K.P. (2012). Asphalt-Rubber Standard Practice Guide, 2nd Edition., Rubber
Pavements Association, Phoenix, AZ, 2012.

695

2nd	
  IRF	
  Asia	  Regional	
  Congress	
  &	
  Exhibition	  October	
  16-­‐20,	
  2016	
  –	
  Kuala	  Lumpur,	
  Malaysia	
  PAPER TITLESTATISTICAL EVALUATION OF CRUMB RUBBER MODIFICATIONPROCEDURE IN ASPHALT BINDER MODIFICATIONTRACKAUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Veena VENUDHARAN

Doctoral Research
ScholarIndian Institute ofTechnology Kharagpur

India

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Krishna Prapoorna
BILIGIRI

Assistant Professor

Indian Institute ofTechnology Kharagpur

India

E-MAIL(for correspondence)krishnapbiligiri@gmail.com

KEYWORDS:
Asphalt binder, Crumb rubber, Binder modification, Statistical analysis, Factorial design

ABSTRACT:The objective of the study was to investigate the effect of various mixing/blending factors in the modification procedureof the asphalt binders. The scope of the study included crumb rubber modification of three base binders at various levelsof crumb rubber dosages and digestion times. The evaluation of various factors was conducted on the basis of advanced
rheological characterization using the Dynamic Shear Rheometer (DSR). The statistical evaluation was performed atvarious levels of factors using 33 factorial design on two asphalt binder performance assessors: Strategic Highway
Research Program (SHRP) rutting parameter, G*/sinδ; and energy dissipation parameter, tanδ. Further, the main andinteraction effects of the factors were also examined to comprehensively understand the improvement in performance ofasphalt binder towards high pavement temperature rutting distress. The ANOVA and factorial design results indicatedthat all the three factors including, base binder, digestion time, and CR dosage significantly influence the performance ofthe crumb rubber modified (CRM) binder. It was also found that the interaction effect of all three factors was significant
in developing a better performing CRM binder with enhanced rutting resistance at higher temperatures. Higher levels ofbase binder viscosity, digestion time, and CR dosage produced the CRM binders with higher G*/sinδ and lower tanδ
indicative of improved rutting resistance of the material. It is envisioned that this study will provide a necessary
understanding towards binder modification procedure for achieving a superior performing asphalt binder.

696

Venudharan, and Biligiri

STATISTICAL EVALUATION OF CRUMB RUBBERMODIFICATION PROCEDURE IN ASPHALT BINDER
MODIFICATION
Veena Venudharana and Krishna Prapoorna BiligiribaDoctoral research scholar, Department of Civil Engineering, Indian Institute of Technology Kharagpur, West
Bengal 721 302, INDIA; Email: veena.venudharan@gmail.combAssistant Professor, Department of Civil Engineering, Indian Institute of Technology Kharagpur, West
Bengal 721 302, INDIA; Email: krishnapbiligiri@gmail.com
Email for correspondence: krishnapbiligiri@gmail.com

1 INTRODUCTION
The innovations in sustainable development have encouraged researchers to consider several recycling
techniques to develop better performing pavement materials and design practices. In this context, the use of crumbrubber (CR) from truck/car scrap tires has received positive response across the world due to its superior pavement
performance characteristics. The addition of CR improves the binder resistance at various climatic conditions and hightraffic. Thus, the advantages of crumb rubber modified (CRM) binders are multifold, which includes usage of wastematerial leading to a sustainable environment and better long-term pavement performance. In the last few decades,
research studies have shown that the addition of CR derived from scrap tires blended into a virgin binder resulted in
improved resistance to rutting, fatigue cracking, and low-temperature thermal cracking (Neto et al. 2003, Way 2003),
and thereby reducing the thickness of the asphalt overlays and reflective cracking potential (Amirkhanian 2003).
The performance of CRM binders highly depends on the production parameters and raw material properties.
The production parameters include mixing speed, temperature, and time (also known as digestion time); also, rawmaterial properties including base binder characteristics as well as CR properties and dosages. Researchers have studied
the interaction of CR with bitumen (Abdelrahman and Carpenter 1999, Airey et al. 2004, Jeong et al. 2010); the effectand significance of digestion time while blending (Neto et al. 2006, Presti and Airey 2013); influence of CR properties(Peralta et al. 2010, Celauro et al. 2012, Kovaľaková et al. 2013, Guillamot et al. 2013); and effect of mixing
temperature (Subhy et al. 2015).
The improvement in the properties of CRM binders is chiefly due to the swelling of CR particles in binders,which absorb oils and resins to form a viscous compound similar to asphaltenes and thereby, increasing the viscosity of
the CRM binders. Thus, the performance of CRM binder depends on the amount of CR particles (CR dosage), thepresence of oils and resins (base binder), and interaction time between CR particles and binder (digestion time). In thisdirection, several studies investigated the effect of binder modification. But, the significant influence of each of themixing parameters and their interaction effects on the improvement of the asphalt binder’s strength and viscoelastic
properties imparted by the modifiers with the compatible dosages at their interfacial level plays a decisive role towards
the overall rutting performance characteristics of the binders. Thus, it is deemed important to understand the effect ofeach mixing parameter in developing a better performing CRM binder with improved strength and resilient properties.
2 RESEARCH OBJECTIVE AND SCOPE
The objective of this research study was to statistically evaluate the effect of various mixing parameters on theperformance of CRM binders. A total of eighteen laboratory binders (three base binders × three CR dosages × threedigestion times) were used in the study. The scope of the effort included:• Laboratory preparation of CRM binders at three dosages (10, 20, and 30%) and three digestion time intervals (30,60, and 90 minutes) using three base viscosity-graded binders (VG10, VG30, and VG40)• Evaluation of the binder rheological characteristics using temperature-frequency oscillation test
• Formulation of factorial design on Strategic Highway Research Program (SHRP) parameter, G*/sinδ anddissipation energy parameter, tanδ
• Statistical evaluation of mixing parameters: base binder, CR dosage, and digestion time
3 MATERIALS AND EXPERIMENTAL PROGRAM
3.1 Materials
A blender-stirrer combination was employed to produce the eighteen laboratory blended CRM binders with
VG10, VG30, and VG40 as base binders and with CRM dosages of 10, 20, and 30% by weight of each of the virgin

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Venudharan, and Biligiri
asphalt binders. The CR gradation used was Type-B gradation as specified by the Arizona Department ofTransportation (ADOT) and shown in Table 1 (Way et al. 2012). CR was added to the base binder, which wasmaintained at 170-180 oC, and then blended for 30, 60, and 90 minutes at 2000 rpm to achieve a homogeneous CRM
binder matrix. The designations of all the eighteen CRM asphalt binders used in the study are given in Table 2.
Table 1. Crumb rubber gradation (Way et al. 2012)
SIEVE SIZE, mm
CUMULATIVE PERCENT PASSING, %
2.36
2.00
100
1.18
65-1000.600
20-100
0.425
0.300
0-45
0.150
0.075
0-5
Table 2. CRM binder designations
BASE BINDERCRUMB RUBBER DOSAGE, %DIGESTION TIME , min

DESIGNATION

VG10
VG10
VG10
VG30
VG30
VG30
VG40
VG40
VG40
VG10
VG10
VG10
VG30
VG30
VG30
VG40
VG40
VG40
VG10
VG10
VG10
VG30
VG30
VG30
VG40
VG40
VG40

10
20
30
10
20
30
10
20
30
10
20
30
10
20
30
10
20
30
10
20
30
10
20
30
10
20
30

30
30
30
30
30
30
30
30
30
60
60
60
60
60
60
60
60
60
90
90
90
90
90
90
90
90
90

3V1R1
3V1R2
3V1R3
3V3R1
3V3R2
3V3R3
3V4R1
3V4R2
3V4R3
6V1R1
6V1R2
6V1R3
6V3R1
6V3R2
6V3R3
6V4R1
6V4R2
6V4R3
9V1R1
9V1R2
9V1R3
9V3R1
9V3R2
9V3R3
9V4R1
9V4R2
9V4R3

3.2 Experimental Program
For rheological evaluation, all the eighteen CRM binders were subjected to temperature-frequency oscillation
test using a Dynamic Shear Rheometer (DSR) as shown in Figure 1. The oscillation test was conducted on unaged andshort-term aged binders over 10 – 0.1 Hz (a total of 21 frequencies) and for a range of 46 – 82 oC (with 6 oC increments
totaling seven temperatures). The tests were performed at 12 and 10% controlled strain rate for unaged and short-term
aged binders, respectively. Subsequently, the results from the oscillation test were used to estimate the upper
Performance Grade (PG) temperatures for both the unaged and short-term aged asphalt binders as per ASTM D7175-05(2005). In this process, the SHRP rutting parameter: G*/sinδ was used to identify the PG upper temperature inaccordance with ASTM D7175-05 (2005).

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Venudharan, and Biligiri

Figure 1: Dynamic Shear Rheometer (Kinexus DSR+)
4 RESULTS AND ANALYSES
4.1 Oscillation Test
The oscillation test on all the asphalts provided complex shear modulus (G*), and phase angle (δ) at all
temperature-frequency combinations. G* is the ratio of peak stress to peak recoverable strain, and δ is the lag between
stress and strain pulse in a viscoelastic material. From the oscillation test results, G*/sinδ were estimated. G*/sinδ of all
the asphalt binders was considered to classify the binders based on the PG at upper temperatures. SP-1 guideline (1997)
defines PG upper temperature as the highest temperature at which the magnitude of G*/sinδ > 1.0 and 2.2 kPa forunaged and short-term aged binders, respectively. Table 3 summarizes the estimated PG upper temperature range of thevarious asphalt binders used in the study.

DESIGNATION
VG10
VG30
VG40
3V1R1
3V1R2
3V1R3
3V3R1
3V3R2
3V3R3
3V4R1
3V4R2
3V4R3
6V1R1
6V1R2
6V1R3
6V3R1
6V3R2
6V3R3
6V4R1
6V4R2
6V4R3
9V1R1
9V1R2
9V1R3
9V3R1
9V3R2
9V3R3
9V4R1
9V4R2
9V4R3

Table 3. Range of PG upper temperatures
PG UPPER TEMPERATURE, oC
BASE BINDER
MODIFIED BINDER
58 – 64
58 – 64
64 – 70
58 – 64
64 – 70
64 – 70
58 – 64
64 – 70
64 – 70
64 – 70
70 – 7670 – 7658 – 64
64 – 70
64 – 70
64 – 70
64 – 70
64 – 70
70 – 7670 – 76
76 – 82
58 – 64
64 – 70
64 – 70
64 – 70
64 – 70
70 – 7670 – 76
76 – 82
76 – 82tanδ @ 1.59 Hz &
64 oC
58.53
25.56
9.95
19.20
8.38
4.91
18.06
5.29
3.94
8.07
4.72
2.43
7.91
5.19
3.55
7.19
3.21
2.56
3.92
4.36
2.43
6.41
4.51
3.38
6.14
2.57
2.42
3.73
2.85
2.36

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Venudharan, and Biligiri
It can be observed that the inclusion of CR escalated the PG upper temperature of CRM binder with respect tothe base binders. With the addition of 20 and 30% CR into the base binder, the PG upper temperature increased by twolevels (with an increment of 6 oC per level) for all the base binders. The increase in digestion time increased the PG
upper temperature indicative of an increase in the binder strength with more digestion time. The influence of the basebinder properties on PG upper temperature of CRM binders can also be observed from the oscillation test results. CRM
binders with stiffer VG40 base binder produced higher PG upper temperature followed by CRM binders with softer
VG30 and VG10 as base binders. The highest PG upper temperature range was observed for 9V4R2 and 9V4R3
binders.
The oscillation test results indicated that the rutting performance of the asphalt binders improved when it was
blended with CR. Since the PG upper temperatures were measured by the SHRP parameter: G*/sinδ, which explains thestiffness and phase lag simultaneously, it can be also inferred that the CR inclusion in the virgin binders augmented thestiffness of the CRM binders significantly (approximately 1.6 – 1.8 times the stiffness of the virgin binders).
Table 3 also provides the dissipation energy parameter, tanδ for all the eighteen binders. tanδ aids inevaluating the rutting resistance of the asphalt binders on the basis of the energy concept. As observed, all the CRM
binders produced very low magnitude of tanδ in comparison with the virgin binders. It is important to note that higher
magnitude of tanδ indicates more relative dissipation energy, and thereby there is a very high possibility that the asphalt
binder will dissipate more energy during a loading cycle. Hence, lower the tanδ, better is the rutting resistance of theasphalt binder. tanδ of the virgin binders was approximately 50-100 times more than that of the CRM binders indicativeof the fact that virgin binders showed higher dissipation energy, and in turn would be more prone to rutting. Further, an
increase in the digestion time and CR dosages also resulted in lower tanδ indicative of improved rutting resistance.
From the G*/sinδ and tanδ results, it can also be inferred that all the three parameters including the base binder
characteristics, digestion time, and CR dosages affect the performance of the CRM binders. A statistical analysis was
carried out on the oscillation test results, namely G*/sinδ and tanδ to appreciate the significance of each parameter on
the CRM binder performance as discussed next.
4.2 Statistical analysis: Factorial design
In essence, the analyses of G*/sinδ and tanδ encompassed three factors: base binder, digestion time, and CR
dosage. All factors consisted of three levels: base binder – VG10, VG30, and VG40; digestion time – 30, 60, and 90
minutes; and CR dosage – 10, 20, and 30%. A 33 factorial analysis was designed to investigate the main and interaction
effect of each factor with the knowledge gained from (Montgomery, 2013). The interaction effect with second degree
was considered in the analyses and the higher order interactions were neglected for simplification purposes. The factors
and level details of the factorial design are summarized in Table 4.
FACTORS
Base binder
Digestion time, min
CR dosage, %Table 4. 33 factorial design
LEVELS
VG10
VG30
30
60
10
20
Replicates = 2
Total samples = 3×3×3×2 =36

VG40
90
30

Factorial analysis was conducted using the statistical software MINITAB® and the ANOVA results arepresented in Tables 5 and 6. A two-tailed ANOVA was done at a confidence interval of 95%. The p-value for all themain and interaction effects was less than 0.025 indicative of the significant impact of the factor on the binder
performance parameters, G*/sinδ and tanδ. As observed in Tables 5 and 6, all the main effects and interaction effects of
the all the treatments (base binder × dosage; base binder × digestion time; and dosage × digestion time) produced a pvalue < 0.01, thus indicating the significant contribution of all the factors on the output parameters. The details of thesignificant effects of the main and interaction factors are explained later in Section 5.

SourceBase binder
Digestion time
CR Dosage
Base binder × Digestion time
Base binder × CR Dosage
Digestion time × CR Dosage
Error
Total

Table 5. ANOVA for G*/sinδ
DF
Adj. SS
Adj. MSF-value
2
179700360 89850180 2525.21
210813088
5406544151.95287844797 43922398 1234.43
4371372492843126.09
452796304 13199076
370.964274512168628019.29
35124534435581
53 338858737

p-value
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01

Model findings
Significant
Significant
Significant
Significant
Significant
Significant

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Venudharan, and Biligiri

SourceBase binder
Digestion time
CR Dosage
Base binder × Digestion time
Bae binder × CR Dosage
Digestion time × CR Dosage
Error
Total

DF
2
2
2
4
4
4
35
53

Table 6. ANOVA for tanδAdj. SS
Adj. MSF-value
68.01
34
24.55
155.3877.69
56.08
239.57
119.78
86.46
23.32
5.83
4.21
40.87
10.21
7.37
103.55
25.88
18.69
48.49
1.385
679.2

p-value
<0.01
<0.01
<0.01
<0.01
<0.01
<0.01

Model findings
Significant
Significant
Significant
Significant
Significant
Significant

5 EFFECTS OF VARIABLES
As discussed in the earlier Section, the ANOVA results provided an idea of the significant treatments of theexperiment. As a next step, the practical understanding of this analysis was evaluated by understanding the individual
factor effects (also known as main effects), and the interaction effects of the treatments. The main and interaction
effects with regard to G*/sinδ and tanδ are shown in Figures 2 and 3, respectively.
5.1 Main effects
The main effect of a variable is basically the influence of the independent input variable on the dependent
variables. The effect of each variable is evaluated by considering the difference between the levels of the variable of all
the significant treatments with respect to the response variables. The pattern of response variables was further
interpreted to understand the in-between difference in the factors.
As observed in Figure 2(a), G*/sinδ increased with stiffer base binder. The viscosity grading of binders
indicates that VG40 has higher viscosity followed by VG30 and VG10. Thus, VG40 can be considered and is the stiffer
binder out of all the three base binders. As observed, G*/sinδ increased from softer VG10 base binder to harder VG40
base binder. The base binder significantly influenced the stiffness of the CRM binder. The main effect of the basebinder was steep with a similar slope indicative of the significant influence of the base binder on G*/sinδ in bothsegments from VG10 to VG30 and VG30 to VG40.
Figure 2(b) presents the main effect relationship of tanδ with all the three factors. It can be observed that tanδdecreased with stiffening of the base binders. The magnitude of tanδ decreased from softer VG10 base binder to harder
VG40 base binder. The innate viscoelastic properties of the base binder significantly influenced the performance
improvement in CRM binders. The slope of the main effect plot of the base binder with tanδ was observed to be steeper
and thereby indicating the significant influence of the base binder on the dissipation energy parameter, tanδ of the CRM
binders.
Figure 2(a) also presents the main effect of digestion time on G*/sinδ. The G*/sinδ magnitude increased withincrease in the digestion time. Increased time for CR and binder interaction results in homogeneously blended CRM
binders. A steeper slope was observed when the digestion time was varied from 30 to 60 minutes and comparatively
flatter slope was seen for G*/sinδ when the digestion time was varied from 60 to 90 minutes. With the increase indigestion time, the rate of improvement in binder performance reduced as indicated by the slope of the plot. Figure 2(b)shows the main effect of digestion time on the dissipation energy parameter, tanδ. tanδ decreased with an increase in
the digestion time indicative of better rutting resistance of the CRM binders at higher digestion time. A homogeneous
CRM binder obtained at higher digestion time provides sufficient stiffness and elasticity that is not achieved at lower
digestion time. It can also be observed the slope of the main effect segment from 60 to 90 minutes was flatter than 30 to
60 min segment, indicative of a reduction in the rate of improvement in tanδ.
The main effect of the third factor, CR dosage on the output dependent variables, G*/sinδ and tanδ are alsopresented in Figures 2(a) and (b), respectively. From Figure 2(a) it can be observed that G*/sinδ increased with increasein the CR dosage. The addition of CR particles in asphalt binder triggers the swelling of CR particles by absorption of
the asphalt binder components and aiding in the improvement of stiffness and viscoelastic properties of the binder. The
increase in the concentration of CR particles increased the proportion of the swelled CR particles in the binder leading
to a stiffer CRM binder with improved elastic behavior. Similarly, increase in CR dosage resulted in a decrease of tanδmagnitude as observed in Figure 2(b). The addition of CR improved the elastic property of the CRM binder,consequently reducing the phase angle of the binder. Phase angle reduction led to a decline in dissipation energy andincrease in binder’s resistance to rutting.
Overall, it was observed that G*/sinδ increased with an increase in the base binder viscosity, digestion time,and CR dosages. Further, it was also observed that tanδ magnitude decreased with increase in the base binder viscosity,
digestion time, and CR dosages. It was also found that all the three factors significantly affect the binder parameters,
G*/sinδ and tanδ. Although the individual consideration of the different variables provided a preliminary understanding
regarding the dependency of the various treatments with response variables, the analysis of the interaction effects of all
the treatments was necessary for better understanding of the CRM characteristics, which are discussed next.

701

Venudharan, and Biligiri

Figure 2. Main effect of variables on (a) G*/sinδ and (b) tanδ
5.2 Interaction effects
As discussed in Section 4.2, all the interaction effects produced a significant effect on G*/sinδ and tanδ. A
brief discussion on the interaction effects of two-degree factorial is provided here. Figures 3(a) and (b) depict theinteraction effects of the variables on G*/sinδ and tanδ. As observed, Figure 3(a) presents the interaction effect of thebase binder × digestion time on G*/sinδ. As shown, base binder × digestion time interaction significantly affected theG*/sinδ magnitude. For all digestion times, the G*/sinδ increased with base binder viscosity. For VG10, the variation in
G*/sinδ at varying digestion times was insignificant compared to the VG30 and VG40 base binders. Further, for VG30
and VG40, a significant difference was found between 30 and 60 min digestion time and comparatively reduced thedifference between 60 and 90 min digestion time. Figure 3(b) shows the interaction effect of base binder × digestion
time on tanδ. A drastic variation in tanδ was found between 30 and 60 min digestion time for all the three base binders.
In contrast, tanδ variation in a lower degree was observed between the digestion times of 60 and 90 min. The results
showed that after 60 min, the improvement in the parameters for all the base binders was negligible.
Figure 3(a) also presents the interaction effect between base binder × CR dosage on G*/sinδ. It was observedthat G*/sinδ increased with increase in the CR dosage for all the base binders. At 10% of CR dosage, it can observedthat there was very less variation in the G*/sinδ of CRM binders with VG30 and VG40 as base binders. With theincrease in CR dosage, a significant variation in G*/sinδ was observed for all the base binders indicative of the
improvement in binder rutting resistance and concurrently with an increase in the CR dosage and base binder viscosity.
A similar outcome was observed for the interaction effect of tanδ between base binder × CR dosage as shown in Figure3(b). tanδ magnitude decreased with the increase of both base binder viscosity and CR dosage. The variation in tanδ
was higher between 10 and 20% CR dosage for CRM binders with VG10 and VG30 when compared with CRM binders

702

Venudharan, and Biligiri
with VG40 base binder. Note that VG10 and VG30 contain a higher proportion of low molecular weight binder
components, and thus CR swelling will be more in CRM binders with VG10 and VG30 base binders.

Figure 3.Interaction effects of variables on (a) G*/sinδ and (b) tanδThe interaction effect between digestion time × CR dosage on G*/sinδ is shown in Figure 3(a). Very lessvariation of G*/sinδ with digestion time was observed at 10% CR dosage, indicative of the presence of fewer CR
particles in the binder. At 20 and 30% CR dosage, an increase in G*/sinδ was observed with increase in the digestion
time. Higher time intervals of CR and binder interaction lead to more CR particle swelling, and thus producing CRM
binder with improved rut resistance. From Figure 3(b), it can be observed that both digestion time and CR dosage
significantly influenced the tanδ parameter. It was observed at 20 and 30% CR dosages, the reduction in tanδ wascomparatively less at a digestion time of 90 min, indicative of CR swelling saturation. At digestion times of 30 and 60
min, a significant variation in tanδ was observed at all CR dosages.
6 CONCLUSIONSThe objective of the study was to investigate the effect of various mixing parameters on the performance of
CRM binders in respect of the binder rutting parameter G*/sinδ and dissipation energy parameter tanδ. The three
mixing parameters considered in the study were: base binder, digestion time, and CR dosage. Further, all the threefactors consisted of three levels. Thus, a total of eighteen CRM binders were employed for the investigation.
From the factorial design and ANOVA, it was found that all three factors significantly affected both binder
performance parameters, G*/sinδ and tanδ. As the factors individually and simultaneously affect the binder’sperformance, main effects and also the interaction effects were studied. Main effects of factors and interaction effects
between the factors indicated the variation of output parameters with change in the levels of each factor. The increase in703

Venudharan, and Biligiri
all the three factors increased the CRM binder’s G*/sinδ and decreased the magnitude of tanδ. Though the performanceof binder improved with digestion time, it was found that the difference in performance between 60 and 90 min was lessindicative for obtaining saturation threshold. Thus, it can be concluded that stiffer base binder with higher CR dosage
mixed at higher digestion time will result in a homogenous CRM binder with enhanced rutting resistance.
Even though this study investigated the influence of mixing parameters on the rutting resistance of asphalt
binders modified with crumb rubber, it is deemed important to understand the effect of mixing parameters on thefatigue and low temperature thermal cracking resistance of asphalts due to crumb rubber modification. Also, it isnecessary to understand the effect of different crumb rubber gradations on the viscoelastic behavior of the CRM
binders. Therefore, more research is definitely needed in this direction to characterize the CRM binders and othermodifiers such as polymers, and fibers, etc.
ACKNOWLEDGEMENTS
The authors gratefully acknowledge the Government of India Department of Science and Technology for theirfinancial support vide Science and Engineering Research Board (SERB) research project grant number DST No:
SERB/F/2670/2014-15 dated 17 July 2014.

REFERENCES• Abdelrahman, M., & Carpenter, S. (1999). Mechanism of interaction of asphalt cement with crumb rubber
modifier, Transportation Research Record: Journal of the Transportation Research Board, (1661), pp. 106-113.
• Airey, G., Rahman, M., & Collop, A. C. (2004). Crumb rubber and bitumen interaction as a function of crude
source and bitumen viscosity, Road materials and pavement design, 5(4), pp. 453-475.
• Amirkhanian S. N. (2003). Establishment of an Asphalt-Rubber Technology Service (ARTS), Proceedings,
Asphalt Rubber 2003 conference, Brasilia, Brazil.
• ASTM D7175-05. (2005). Standard Test Method for Determining the Rheological Properties of Asphalt
Binder Using a Dynamic Shear Rheometer, American Society for Testing and Materials International,
Pennsylvania 19428-2959, United States.
• Celauro, B., Celauro, C., Presti, D. L., & Bevilacqua, A. (2012). Definition of a laboratory optimization
protocol for road bitumen improved with recycled tire rubber, Construction and Building Materials, 37, pp.
562-572.
• Guillamot, F., Goujard, L., Simard, D., & Boulangé, L. (2013). Influence of interface energy on compatibility
between ground tyre rubber and bitumen used in asphalt pavement, Road Materials and Pavement Design,
14(2), pp. 372-383.
• Jeong, K. D., Lee, S. J., Amirkhanian, S. N., & Kim, K. W. (2010). Interaction effects of crumb rubber
modified asphalt binders, Construction and Building Materials, 24(5), pp. 824-831.
• Kovaľaková, M., Fri?ová, O., Hronský, V., Ol?ák, D., Mandula, J., & Salaiová, B. (2013). Characterisation of
crumb rubber modifier using solid-state nuclear magnetic resonance spectroscopy, Road Materials andPavement Design, 14(4), pp. 946-958.
• Montgomery D. C. (2013). Design and Analysis of Experiments, 8th ed., John Wiley & Sons, Chicago.
• Neto D. S. A., Farias M. M., Pais J. C., Pereira P. A., & Picado S. L. (2003). Behavior of asphalt-rubber hot
mixes obtained with high crumb rubber contents, Proceedings, Asphalt Rubber 2003 conference, Brasilia,
Brazil.
• Neto, S. A. D., Farias, M. M., Pais, J. C., Pereira, P. A., & Sousa, J. B. (2006). Influence of crumb rubber anddigestion time on the asphalt rubber binders, Road Materials and Pavement Design, 7(2), pp. 131-148.
• Peralta, J., Silva, H. M., Machado, A. V., Pais, J., Pereira, P. A., & Sousa, J. B. (2010). Changes in rubber due
to its interaction with bitumen when producing asphalt rubber, Road Materials and Pavement Design, 11(4),pp. 1009-1031.
• Presti, D. L., & Airey, G. (2013). Tyre rubber-modified bitumens development: the effect of varying
processing conditions, Road Materials and Pavement Design, 14(4), pp. 888-900.
• SP-1. (1997). Performance Graded Asphalt Binder Specification and Testing. Asphalt Institiute Superpave
Series No. 1, Lexington, KY.
• Subhy, A., Lo Presti, D., & Airey, G. (2015). Rubberised bitumen manufacturing assisted by rheologicalmeasurements, Road Materials and Pavement Design, pp. 1-21 (DOI:10.1080/14680629.2015.1079549).
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Rubber Research, Proceedings, Asphalt Rubber 2003 conference, Brasilia, Brazil.
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Pavements Association, Tempe, United States.

704

STRATEGIES FOR ROAD SAFETY IN THE CARIBBEAN– EXPLOITING THE LOWEST HANGING FRUIT

Terrence FLETCHERIRF FELLOWCHAIRMAN – CARIBBEAN ASSOCIATION OF ROADS

tfal2020@gmail.com

Challenges have been experienced worldwide in the effective and successful implementation of the fiveE’s of Road Safety. One of the major challenges is related to National Financial considerations. This
problem has been a persistent one in the Member Countries of the Caribbean Community CARICOM. It
is easy to conclude that the lowest hanging fruit are associated with Pillar 4 – Road User Behavior – alongwith the E’s associated with Education, Enforcement, Encouragement and Evaluation. The Pillar of
infrastructure and the E of Engineering are universally known to attract the highest capital costs. This
has indeed been the experience of most CARICOM Territories. The paper will attempt to analyze theexperiences in this regard from selected CARICOM Territories, confirm or otherwise the benefits to be
derived by exploiting the low hanging fruit and recommend modified strategies that could be adopted by
all Caribbean Territories and Latin America.
KEYWORDS
Road Safety Economics Education Fatalities

705

1

INTRODUCTION AND BACKGROUND

1.1

A History of the Caribbean Association of Roads
The Caribbean Association of Roads was launched in the Caribbean in 2008 in Tobago. Its
membership is open mainly to Road and Highway Engineers and other Practitioners in the
fourteen Territories of the Caribbean Community – CARICOM. Its focus in the Caribbean
continues to be

1.2•

Road Safety•

Road Maintenance•

The innovative financing of Road Projects

Background
Road safety must be the priority of every road user. Regard for human life should be theunspoken code that guides every driver, cyclist and pedestrian. Our task is to find innovative
ways to have this conversation with the travelling public in as many ways as are needed todrive the message home. This paper will attempt to analyze effective methods that haveworked in the Caribbean context. It will explore effective low cost ways for engaging road
users in the discussion. This dissertation will explore old methods that worked in the past withnew eyes and new ideas for the future. If we wish to change road user behavior in anaffordable Engineering Environment, we must start with Education, continue with
Encouragement, carry out Evaluations, and when all else fails deter errant behavior with
Enforcement.

1.3

The UN Decade of Road Safety
In 2011 the UN Decade of Road Safety was launched. Most of the countries of the United
Nations body committed themselves to inter alia, influencing the reduction of road fatality rate
at the end of the decade to 50 percent of what it was at the commencement.
In early 2016, the new United Nations Sustainable Development Goals (SDG) were approved.
They included a new goal to reduce the 2015 level of fatalities by 50% in 2020. This is far
more challenging than the original Decade of Action goal mentioned previously.

1.4

Caribbean Road Fatality Trends
Table I below shows the annual trend in road fatalities and road fatality rates per 100,000 of
population for eight selected territories in the CARICOM Caribbean. From the numberspresented, it is noted that both Trinidad and Tobago, and Suriname have demonstrated
encouraging downward trends over the first half of this decade. Barbados has maintained its
position of being the only country so far to sustain its single digit status. Hopefully some ofthe others will get there in another year or two.

706

2011

2012

2013

2014

2015

2016 -Projected

Jamaica

304

264

306

296

390

350

Jamaica

11.7

10.1

11.8

11.4

14.0

12.5

Trinidad

191

193

151

140

150

150

Trinidad

14.7

14.8

11.6

10.0

11.0

11.0

Guyana

115

110

108

146

125

135

Guyana

15.3

14.7

14.4

19.5

16.7

18.0

Suriname

85

80

76

75

58

55

Suriname

17.0

16.0

15.2

15.0

11.6

11.0

Barbados

23

28

23

20

22

20

Barbados

8.4

10.2

8.4

7.3

8.0

7.3

Saint Vincent

4

6

7

9

25

15

Saint Vincent

3.7

5.5

6.5

8.2

22.7

14.0

Belize

57

64

51

60

87

85

Belize

16.7

18.5

14.6

10.0

25.1

24.9

TABLE I
Trends in annual road fatalities and road fatality rates – 2011 to present
Note: Road Fatality Rates expressed in deaths per 100,000 of population

707

1.5

Development Banks and Economic losses to a country due to Road Fatalities

1.5.1

The Inter American Development Bank
Various formulae have been developed in the past to assess the negative economic impacts toa country as a result of road fatalities. A recent IDB developed formula postulates that theeconomic loss to a country resulting from a single road fatality is approximately 70 TIMES THE PER CAPITA GROSS DOMESTIC PRODUCT FOR THE COUNTRY
For a country with a per capita GDP of US$ 10,000, this equates to a loss of US$ 700,000 per
fatality.
It should be noted that the current IDB Road Safety Strategy is aligned under the five pillarsof the “Decade of Action” with the intention of implementing concrete actions – andmeasureable results – that contribute towards meeting the target set by the United Nations of
reducing the number of road accident fatalities by 50% by 2020. Specifically, the Bank seeks
to:
A. Incorporate road safety components into all transportation operations;
B. Promote transport operations exclusively focused on improving the countries’ road safety;
C. Facilitate regional and cross-regional dialogue among the governments; andD. Place road safety as a priority in the political agenda of the region’s governments; andE. Create a culture of change and civil responsibility in the subject of road safety by raisingawareness among the population of the negative impact they will suffer whileirresponsible traffic attitudes and behaviors persist in society.

1.5.2

The Caribbean Development BankIn March 2012, the Caribbean Development Bank responded to a request from the Government of
Belize which resulted in the CDB currently assisting in the financing of a multi-sectoral Road Safety
intervention that includes infrastructure improvements and capacity building for agencies involved inroad safety management. The budgetary cost of this program is approximately US$5M.
More recently, the Government of Guyana benefitted from a modest sum of US$200,000 for a School
Road Safety Education Program which formed a small component of a US$35M Highway Project.

708

3

DISCUSSION

3.1

The Highest Hanging Fruit
We can consider some of the highest hanging fruit on the road and highway safety tree to be

3.2•

Divided Highways•

Anti Collision Devices•

Roundabouts and Overpasses

The Higher Hanging Fruit
Some examples of higher hanging fruit not incurring capital costs as high as the highest
hanging fruit would be

3.3•

Highway Lighting•

Traffic Signing•

Road Marking

The Lowest Hanging Fruit
3.3.1

Road Safety Education from Kindergarten to University•

Kindergarten
The Guyana Red Cross Society has designed and is promoting a coloringbook for preschool children. The book graphically depicts the do’s anddont’s of Road Safety and is full of illustrations for the kids to color.

•

Primary
School Traffic Patrols should play an integral part in all Primary Schools in
CARICOM Territories.

•

Secondary
Secondary School Pupils should be encouraged to take part in Radio andTelevision Quizzes on Road Safety.

•

Tertiary
Final Year Projects should be developed based inter alia on statisticalanalyses of traffic accident black spots.

•

Defensive Driving

709

CARIBBEAN ASSOCIATION OF ROADSDEFENSIVE DRIVING TIPS

DO A DEFENSIVE DRIVING COURSEDRINK RESPONSIBLY
DRIVE WITHIN THE SPEED LIMITAVOID DISTRACTIONSDON’T DRIVE WHEN DROWSYWEAR YOUR SEAT BELTTAKE EXTRA CARE IN BAD WEATHERDON’T FOLLOW TOO CLOSELYLOOK OUT FOR THE OTHER GUYCHECK YOUR VEHICLE REGULARLYPRACTISE DEFENSIVE DRIVING

710

3.3.2The Stakeholders of the Lowest Hanging Fruit.

Many effective stakeholders of Road Safety Public Awareness already exist in our society. The secretis to employ these stakeholders in a smart way. Some of these stakeholders are briefly discussed below.

•

National Road Safety Councils
Currently there are four NRSCs actively in operation in the CARICOM Caribbean. These are locatedin Guyana, Trinidad and Tobago, Barbados and Jamaica. The oldest and most dynamic of the four
exists in Jamaica. (Public Awareness role of NRSCs + Umbrella Body). (Initiatives for CARICOM to
get its Health Desk to include Road Safety on its Agenda)•

Youth Groups for Road Safety
Young people all over the Caribbean are involved as the perpetrators and victims of a substantial
number of serious and fatal road accidents. Within the last year or two, the territory of Belize has
introduced an entity Belize Youths for Road Safety (BYOURS) which has dynamically interacted with
the Belizean Society in organizing a number public awareness related road safety programs.

•

Insurance Companies
Members of CAR have engaged Insurance Companies of several territories of the Caribbean who havespasmodically shown interest in investing in curbing road casualties. Profits of Insurance Companies
are reduced as Road Accident and Fatality Rates increase.

•

Safety Companies
JARIC – is a Trinidad based company providing Environmental, Safety and Health Services in theSouthern Caribbean. including, inter alia, fleet training in Defensive Driving, First Aid & CPR. In thecurrent decade they have successfully organized several Road Safety Conferences in the Southern
Caribbean.

•

Chambers of Commerce
In Guyana, the Georgetown Chamber of Commerce has partnered with the Police Traffic Department
and donated a number of Speed Guns in their interest in making the roads safer.

711

•

Newspapers
The two Excerpts shown below are examples of reporting which effectively stimulate heightened roaduser public awareness.

Hit-and-run results in seventh road fatality of theyear
BY: LOOP NEWS
15:38, February 23, 2016

Eyewitnesses said that Alimoenadi was run over by either atruck or tanker after his moped had fallen on the road. They said
that the driver who struck Alimoenadi continued on without
stopping. He has yet to report to the police.
By the time police were on the scene, Alimoenadi had alreadydied. He marks the seventh road fatality of this year.
An autopsy will be conducted and Richelieu police will continue
to investigate the case.

Excerpt I*TRINIDAD AND TOBAGO**Carapichaima man dies in accident*
By ALEXANDER BRUZUAL Friday, September 17 2010

*THE ROAD fatality rate climbed once again on Wednesdaynight when a 50-year-old Carapichaima man was killed in an
accident, bringing the number of road deaths for the year to 144,
12 less than the figure of 156, for the corresponding period lastyear.
Excerpt II

712

•

Billboards
The Suriname population is informed on a weekly basis by several suitably placed Billboards with
updated Fatality Statistics. These have proven over the years to be a very effective public awareness
tool.

•

Radio and Television Stations
A Radio and Television Station in Guyana is preparing to host a monthly Road Safety program
highlighting road fatality statistics, speed gun demonstrations, and defensive driving techniques.

•

Social Media
Facebook and other Social Media are gaining in popularity as effective safety tools of masscommunication among road users .

•Funding Agency Contributions and Experiences

It is encouraging to note the modest investments of the Regional Banks in Road Safety as described inparagraph 1.5. Once other stakeholders continue to become more aware of the impressive magnitude of
economic losses to the country resulting from Road Accidents, we can expect to see an increase in thelevel of investments focused on the soft solutions.
•

Enforcement
Table II presents the relationship between numbers of Traffic Enforcement Personnel and Populations
in eight CARICOM Territories. Although o detailed scientific analysis is possible at this time, thenumbers suggest that there should be the recruitment of additional personnel in several countries. The
cost of the additional personnel could be expected to be covered by the reduction in economic losses
resulting from a smaller number of accidents.
Population‘Rate’ per 100000

GUYANA

220

75000025

SURINAME

85

50000017

TRINIDAD AND TOBAGO

500

1400000

35

BARBADOS

40?

27500015

SAINT LUCIA

2016000013

SAINT VINCENT

2012000017

JAMAICA

300

2800000

12

BELIZE

60?

33000018

TABLE II
Relationship between numbers of Traffic Enforcement Personnel and Populations in 8 CARICOM Territories.

713

5

CONCLUSIONS

5.1

Development Banks
Both the Inter American Development Bank and the Caribbean Development Bank are
currently actively involved in investing in Road Safety initiatives as part of their Highway
Investment portfolio in the Caribbean. This laudable initiative needs to be further pursued in
the future.

5.2

Trinidad and Tobago and Suriname are two territories of the CARICOM Caribbean whichhave been exhibiting continuing encouraging downward trends in Road Fatality Rates inrecent years.

5.3

The traditional media have been playing an important role in heightening Public Awarenessabout Road Safety matters in some Caribbean Territories.

5.4

The Social Media can play a major role in stimulating Public Awareness in Road Safety
matters.

714

6

RECOMMENDATIONS
6.1

Public Relations activities on Road Safety via Radio Stations TV Stations, the printed Media,
Facebook and other Social media should be substantially increased.

6.2

The concept of dynamic Youth Groups for Road Safety should be embraced and effectively
implemented throughout the Caribbean.

6.3

Defensive Driving Programs in the CARICOM Caribbean should be extensively proliferated.

715

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

EVALUATION OF AUTHORISED LEFT (ALT) TRAFFIC CONTROL:A CASE STUDY IN KUALA LUMPUR

TRACK
AUTHOR(Capitalize Family Name)HO Jen Sim
CO-AUTHOR(S)(Capitalize Family NamePOSITION
Research Officer

POSITIONORGANIZATION
Malaysian Institute of Road
Safety Research
ORGANIZATIONCOUNTRY
Malaysia

COUNTRY

POI Wai Hoong, Alvin

Research Officer

Malaysian Institute of Road
Safety Research

Malaysia

AIN Amirul

Senior Traffic Engineer

Kuala Lumpur City Hall

Malaysia

E-MAIL(for correspondence)jsho@miros.gov.my

KEYWORDS:
Include up to 5 keywords
LTOR, Authorised Left Turn, Efficiency, Safety

ABSTRACT:The abstract should be written in English, readily understandable to most readers and may contain up to maximum of
500 words. Authors are invited to use Times New Roman Size 10 and the full type width of the page (single column).

Different forms of Left Turn on Red (LTOR) traffic control have been operated in Malaysia for several years. However,
the efficiency of LTOR in improving traffic flow at junctions has yet to be proven as no study has been conducted thus
far. Due to demand for its implementation nationwide, this practice was gazetted under the Malaysian Road Transport
Act and was reintroduced as Authorised Left Turn (ALT). Due to some safety concerns, MIROS had produced aguideline for the installation of this traffic control for use by the local authorities in 2012. This study was undertaken toassess the ALT from the efficiency perspective such as, violation rates and vehicle delay (LOS). Data were collected atthree junctions, before and after ALT installation. The results showed that ALT slightly improved the capacity. Most of
the left turn on red movements violated the ALT rule of which motorists need to come to a complete stop before
performing ALT. Multiple Regression Model suggests that types of vehicles, conflicting vehicles and total approachvolumes significantly affect the ALT violation rates. Based on the findings, it can conclude that the provision of ALT
traffic control improves the junction capacity at certain degree without prominent detriment to the safety. It is
recommended to install ALT traffic control at junctions which fulfil the criteria outlined in the guideline. It is alsosuggested to constantly monitor the performance of ALT as the behaviour of motorists change over the time which inlong run would expose other road users to the risk of collision.

716

Evaluation Of Authorised Left (ALT) Traffic Control: A Case
Study In Kuala Lumpur
Ho Jen Sim1, Alvin Poi, Amirul Ain
1

Malaysian Institute of Road Safety Research, MALAYSIA
jsho@miros.gov.my

1 INTRODUCTION
Left Turn On Red (LTOR) or Right Turn On Red (RTOR) traffic control has been implemented in the UnitedStates since 1937 (Green, 1980) and is widely adopted in many countries today. This traffic control scheme allows avehicle on the left turn lane (LTOR under left-hand drive traffic system) to turn left after stopping and giving way to
oncoming vehicle / pedestrian. The objective of this scheme is to increase the operating efficiency at junctions.
Nevertheless, the benefits and the deficiencies are still being debated today. Though studies have proven that it
improves traffic capacity, it is at the same time creating safety problems.
LTOR traffic control has been implemented in several states in Malaysia for years but not without safetyissues. Many have complained about the non-standard sign used and safety issues with regard to near-misses between
vehicles and pedestrian. A Task Force was set up in 2011 to examine the feasibility of this provision. Based on the
preliminary findings, a technical guideline on the implementation of LTOR in Malaysia was produced by MIROS(Alvin et al., 2012). Due to the high demand, the Authorised Left Turn (ALT) traffic control has been widely provided
at several signalized junctions in Kuala Lumpur.

2 LITERATURE REVIEW
Right Turn On Red (or left turn on red in countries with left-hand traffic) traffic control was introduced in the
United States in the 70’s as part of an effort to conserve energy. In fact, it started as early as in 1924 in New York City
but was terminated in 1937 though it had significantly contributed in fuel saving and improved traffic capacity(Preusser et al., 1981). Throughout the periods until the 70’s, the implementation of RTOR was limited due to issues
related to its overall benefits and the negative impact it has on the safety of road users. The turning point was after the
Arab Oil Embargo from 1973-1974 and when the Energy Policy and Conservation Act was passed in 1975 which
required the states to develop an energy conservation plan to source funding from the Federal Government. Since thenthe implementation of RTOR was fast gaining popularity and by 1977 almost all states permit RTOR at manysignalized junctions. Nevertheless, there were various types of RTOR rules: Totally Prohibited, Generally Prohibited
except signed to allow, Generally Permitted except where signed to Prohibit and Totally Permitted.
In view of the varying rules governing the implementation of RTOR, there is a need to have a national policy
and guidelines to be adopted. Several studies were then conducted. In general, Mamlouk (1976) found that RTOR
consist of 19.5% of total right turns and 1.5% LTOR were out of total left turns. Important factors that affect RTOR
movements were signal type, city size and availability of exclusive right turn lanes. Conflicts between the turn on red
vehicles with cross traffic did not cause significant problem and also it did not cause significant hazard to pedestrians.
Other findings include 1.3 seconds travel times per vehicle (9%) saved in central business districts and an average of
7.7 seconds travel times per vehicle (39%) saved in rural areas as well as 0.3 to 1.7 hours travel times per vehicle saving
if accumulated on a year basis (McGee et al., 1976 as cited in Preusser et al., 1981; Clark et al., 1983). Based on thesefindings, the FHWA suggested that the generally permissive rule be adopted as the national policy. A set of national
uniform guidelines in prohibiting RTOR at hazardous junction was then developed based on the generally permissiverule.
On the other hand, the opponents claimed that pedestrian safety had been compensated by the RTOR. Zador(1980) showed a significant increase in pedestrian crashes during the period 1974-1977 when RTOR was implemented
in six of the states. Overall, the implementation led to an increment of 57% in single vehicle-pedestrian crashes.
Similarly, Preusser (1981) in another study before and after RTOR implementation showed an increase in pedestriancrashes in New York (45%), Wisconsin (86%), Ohio (66%) and New Orleans (96%). On the other hand, South Carolina
and Alabama reported no significant evidence that pedestrian crashes increased as a result of RTOR. Clark et al. (1983)717

in their analysis indicated that the proportions of crashes involving pedestrians at RTOR junctions and at the control
sites did not differ significantly in both the states.
Singapore has adopted sign permissive LTOR traffic control in 1997 with a GIVE WAY sign to regulate theleft turning vehicles. Due to majority of motorists failing to come to a complete stop and give way to pedestrian and oncoming vehicles, the LTOR traffic control was changed from a standard “GIVE WAY” sign to “STOP Before Turning”
sign. The revised operation is that motorists can turn left on red after a complete stop and give way to on-coming
vehicles and pedestrians. A study by Ho (2003) showed that LTOR in Singapore has resulted in time saving and better
capacity for left-turning traffic. However, the study had not proven the risk of accident between left turn on red vehicle
with pedestrian or on-coming vehicle.
In Malaysia, LTOR has been adopted by several local councils in different parts of Malaysia without a national
standard guideline. Realizing the potential time savings as well as the safety deficiencies, a Task Force led by MIROS
was set up in 2011 to look into the feasibility of nationwide implementation. MIROS has therefore carried out apreliminary study in Kuala Lumpur to assess the various road characteristics and outline installation criteria in line withexisting road design guidelines. Based on the outcome of the study, the LTOR traffic control was adopted in the Road
Transport Act and renamed as Authorised Left Turn (ALT). A technical guideline on the implementation of ALT in
Malaysia had been published in 2012 to ensure the uniformity of ALT installation in the country (Alvin et al., 2012).
The guideline contains the criteria for selection of appropriate junction, the design requirements of ALT sign and bestpractice with regard to the installation of the sign.

3 DATA AND METHOD
A before-after study design was adopted to evaluate the ALT implementation at three junctions (with a total ofeight approaches) installed by the Kuala Lumpur City Hall (DBKL). Several months of baseline data were collectedprior to the installation of ALT using video cameras recordings. Video cameras were located at the opposite direction of
ALT approach to allow the extraction of parameter such as turning movement, approach stopped vehicles and conflictfrom the video. The recordings were conducted 3 days a week (Monday, Wednesday, Friday) during morning peak (2hours), morning off-peak (1 hour), evening peak (2 hours) and evening off-peak (1 hour). The after period was
conducted within two to three months after the ALT installation.
The three junctions namely Persiaran Alam Damai, Jalan 21/154 and Jalan Dutamas 1 were assessed for the
traffic operation performances during before and after ALT installation periods. The three junctions represent thedifferent level of road hierarchy. Two study hours were identified: 7am – 8am during morning peak and 10 am – 11 am
during off peak. Afternoon off peak and evening peak traffic operations were also collected but they are not discussed
in this paper as the traffic patterns did not differ much from the morning sessions.

3.1 Study Measures
Parameters such as traffic volume by types, vehicle queues at left turn approach and ALT violation rates wereextracted from the video. Violation in this case refers to vehicles turning on red without stopping at the stop line. The
total left turning volumes consists of left turn on green vehicles and ALT vehicles.

3.2 Analytical Model
Multiple Linear Regression models were developed to examine the influence factors on ALT violation rates.
Violation rates in this study refer to the left turn vehicle which fail to stop before performing turn on red. It is
mandatory for ALT vehicles to stop before making a turn on red. Review of literature noted that several factors such as
approach lane, volume and median contribute to traffic violation. These suggested variables were included in the modelby using the IBM SPSS programme to determine their contributing effect in influencing the ALT violation rates.
Stepwise regression method was used to remove the variables that were not significant.

718

4 RESULTS
Persiaran Alam Damai is a collector road thus high traffic volumes were observed. The traffic volumes for
before and after ALT installation had somewhat similar profiles. About 4400 vehicles were recorded during themorning peak which saw a reduction by about 35% after the morning peak. Majority of the traffic were passenger
car/MPV/van (55% - 88%) while motorcycle comprised of 12.5% to 43.5%.
About 1400 to 1600 vehicles per hour were recorded during the morning peaks for both before and after ALT
installation at Junction Jalan 21/154. The passenger car/MPV/Van accounted for 75% - 90% while motorcycle made up
of 8% to 25%.
Jalan Dutamas is located in the Kuala Lumpur city centre and traverses shopping centres and government
offices. High traffic volumes were observed at this junction. About 3000 to 3200 hourly traffic during the datacollection periods (before and after periods). There was no significant difference in the traffic volume during the two
periods of time. Of the total volumes, motorcycle consists of 10% - 33% while passenger cars/van represented 65% 89% of the traffic.

Figure 1 Hourly traffic volume at the study sites during before and after periods

Table 1 presents the percentage of motorcycles and passenger cars turning on red phase during before and after
ALT installation periods. It was shown that even before the installation of ALT, there were substantial number ofturning on red movements at the junctions. A simple Chi-Square was then performed to examine if the ALT had
increased the turn on red opportunity. Nevertheless, no significant changes in the turning on red movement between thetwo periods at all the junctions.

Table 1. Percentage of left turn on red movements and Chi-Square analysis
Motorcycle (%)
Persiaran
Alam
Damai
Jalan 21/15
Jalan
DutamasMorning Peak

48

38.6

Off Peak

40.8

24.7

Morning Peak

49.2

66.5

Off Peak

45.6

63.3

Morning Peak

38.4

71.65

Off Peak

51.9

59.4

Chi-Square
Test

Chi-Square
Test

Car (%)
6

2.8

9.5

0.7

Not
significant

22.4

30.2

18.6

38.3

Not
significant

2.8

9.25

6.7

5.4

Not
significant

Not
significant
Not
significant
Not
significant

The output of LOS performance at the junctions by using SIDRA did not show much improvement after the
installation of ALT. As the SIDRA software evaluate the junction as a whole, the time savings by certain type of
vehicle such as motorcycle might not be reflected in the results. Nevertheless, there were evidences of capacity
improvement for motorcyclists on sites. Table 2 presents the average total vehicle queues at the junctions during before

719

and after. The capacity at Jalan Dutamas during morning peak and at Jalan 21/15 during off peak increased slightly but
a simple Paired t test did not indicate any significant changes in the capacity.

Table 2. Paired t test results for average total queues at each junction for before and after ALT installation period
JunctionTime

BeforeAfter

Difference

Paired-t test

Persiaran
Alam
Damai
Jalan
21/15

MP

74.97

75.67

0.70

t=0.0226, p=0.492

Off peak

62.83

67.03

4.20

Jalan
Dutamas

MP

15.80

16.47

0.67

Off peak

14.67

13.27

-1.40

MP
Off peak

32.13
19.63

26.90
24.67

-5.23
5.03

t=0.3424, p=0.3823
t=-0.5021, p=0.3327

Table 3 presents the total interaction and unsafe interaction observed at the junctions during before and after
ALT installation. A simple Chi-square analysis was performed to evaluate the effect of the ALT and it shows that there
was no significant evidence to prove that ALT increase the traffic risk to the road users. Nevertheless, it should be
noted that the observation was conducted within 3 months of ALT installation. The behavior of road users might bechanged over the time. Hence it is still inconclusive to justify the effectiveness of ALT.

Table 3. Chi-Square analysis for unsafe interactions
Junction
Persiaran
Alam Damai

Jalan 21/15

Jalan
DutamasTime
MorningPeak
Off PeakMorningPeak
Off PeakMorningPeak
Off Peak

PeriodBeforeAfter
BeforeAfter
BeforeAfter
BeforeAfter
BeforeAfter
BeforeAfter

Total Interactions
160
184
30
47
20
18
20
19
103
133
25
39

Unsafe Interactions
45
75
10
21
8
9
6
8
36
61
12
19

Chi-Square Test
Not significant
Not significant
Not significant
Not significant
Not significant
Not significant

Statistical modeling of ALT violation data was conducted. Multiple Linear Regression models was developed to
examine the influence factors on ALT violation rates. Violation rates in this study refer to the left turn vehicle which
fail to stop before performing turn on red. It is mandatory for ALT vehicles to stop before making a turn on red. Review
of literature noted that several factors such as approach lane, volume, median and others contribute to traffic violation.
Table 4 lists the attributes used in the Multiple Linear Regression analysis of ALT vehicles turning without
stopping which was set as the dependent variable. Independent variables include the followings and it is noted that only
motorcycle and car were included as the rates of violation by other vehicles were too little. Other factors such as lane
width, turning radius, topography, cycle length, land use are not studied in this project.

720

Table 4. Variables considered in Multiple Linear Regression Analysis
Variable Description
Day of week

Data Format
MondayWednesday
Friday7 am – 8 am
8 am – 9 am
10 am – 11 am
3 pm – 4 pm
5 pm – 6 pm
6 pm – 7 pm
Car
Motorcycle
Exclusive
Shared lane
Total volume of the oncoming vehicles
Total approach volume of the left turning vehicles
Presence of protected left turn green arrow:
Yes
No
Number of receiving lane
12Time of day

Type of vehicle
Lane configuration
Oncoming vehicle
Total approach volume
Left turn green arrow

Receiving Lane

Table 5. Results of Multiple Regression analysis
Variable
Constant
Day of week
TIme of day
Type of vehicle
Lane configuration
Oncoming vehicles
Total approach volume
Left turn green arrow
Receiving Lane
* Significant at α = 0.05

B
-14.246
0.271-0.14439.5980.914-0.031-0.030-1.4291.703

Std. Error
9.755
0.768
0.932
2.436
2.779
0.008
0.007
2.744
3.615

t
-1.4600.353-0.15416.2550.329-3.874-4.366-0.5210.471

p-value
0.146
0.725
0.878
0.000*
0.743
0.000*
0.000*
0.603
0.638

The overall model as shown in Table 5 was found to be significant (p-value = 0.00 for F statistics = 37.79). The
results of the analysis suggest a relatively strong relationship as explained by the model R 2=0.655 with three significant
explanatory variables. It is expected that type of vehicles (motorcycle and car) was significant in influencing the rates ofviolation given that the ease man oeuvre of the motorcycle in traffic stream. As expected, conflicting vehicles affect theviolation rates as the volumes of oncoming vehicles reduce the chances of turning during the approach red phase.
Higher approach volumes would have higher volume of ALT.

5 DISCUSSION AND CONCLUSIONS
In general, the provision of ALT did not create serious conflict for the motorists (based on site observation). As
there was no pedestrian movement at the junctions, this study was unable to assess the effect of ALT on pedestriansafety. Furthermore, no accident crashes at the junction was recorded and it is too early to judge the safety impact of
ALT at the moment.
The provision of ALT traffic control at the study sites seems to have some potential gains in traffic capacity
though the LOS output (by SIDRA software) was not apparent. The difference of left turning movements between
before and after periods was significant at some approaches. This may be due to several constraints such as shared lane,
single receiving lane and side parking that have reduced the opportunity for left turning. Besides, it was also observed721

on site that substantial vehicles chose to stop for green light may be due to the absence of ALT flashing amber. By andlarge, the results brought to the conclusion that it improves the traffic capacity without apparent increase of conflict.
On the other hand, it is also important to highlight that the provision of protected left turn green arrow can be
hazardous to the motorists. This is because the left turning drivers may not always be aware of the actual activation or
end of the protected right turn green arrow. The driver may continue to turn left at the same speed as if green arrow isonset. In the situation where there is right turning vehicle at high speed, collision might occur and the degree of severity
would be very serious due to high speed.
Modeling of factors influencing the percentage of left turn on red movement by using Multiple Regression
analysis suggests that the conflicting volume and approach volume are important in deciding the turning opportunity.
High conflicting volume would reduce the opportunity of ALT movement even increase the risk of collision. On theother hand, high volume of ALT traffic in a relative moderate conflicting traffic stream can improve the stopped delay
time. It is also as expected that type of vehicle was significant in the model. Motorcycle with a smaller physical size iseasier to maneuver through the left turn bend.
In short, the provision of ALT traffic control improves the junction capacity to a certain degree withoutprominent detrimental safety effects.

REFERENCES
Alvin Poi WH, Ramizam NZ, Muhammad R, Jamilah MM, & SV Wong (2012), A Technical Guideline on
Implementation of Authorized Left Turn (ALT) in Malaysia, MCP 03/2012, Kuala Lumpur: Malaysian Institute ofRoad Safety Research.
Clark J. E., Maghsoodloo S., and Brown D. B. (1983). Public good relative to right turn on red in South Carolina andAlabama, Transportation Research Record 926, Washington D. C., pp 24-31.
Green, F.S. (1980). Left turn on red. Road Research Unit, National Roads Board, New Zealand, Research Projet DC/4,
Road Research Bulletin.
Ho J. S. (2003). A study of left turn on red (LTOR) traffic control at signalized junctions in Singapore. Master Thesis,
Nanyang Technological University, Singapore.
Mamlouk, M.S. (1976). Right turn on red: Utilisation and impact. Report JHRP 76-17. Joint Highway Research
Program, Purdue University, West Lafayette, Ind.
McGee, H.W., Stimpson, W.A., Cohen, J., King, G.F. and Morris, R.F., (1976). Right Turn On Red, Vol. J, Alan M.
Voorhees and Associates, McLean, Va., Final Technical Report, FHWA-RD-89, Federal Highway Administration,
Washington, D.C. (cited in Clark et al., 1983).
Preusser D. F., Leaf W. A., DeBartolo K. B. and Blomberg R. D. (1981). The effect of Right-Turn-On-Red onpedestrian and bicyclist accidents, U.S. Department of Transportation, Report No. DOT HS 806 182.
Zador, P. (1980). Adoption of right turn on red: effects on crashes at signalised intersections. Insurance Institute forHighway Safety, Washington, D.C.

722

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
Masahiko IWAMA
CO-AUTHOR(S)(Capitalize Family Name
Tamotsu YOSHINAKAE-MAIL(for correspondence)

Advanced Use of Solar Heat-blocking Pavement Technology

Adaption of Road Pavements to Climate Change
POSITION
Research Engineer

POSITIONManager

ORGANIZATIONNIPPO Corporation

ORGANIZATIONNIPPO Corporation

COUNTRYJAPAN

COUNTRY
JAPAN

iwama_masahiko@nippo-c.jp

KEYWORDS:
Climate change; Solar heat-blocking pavement; Reduction in surface temperature; Repair; Small scale application.

ABSTRACT:In recent years, there is growing awareness on environmental issues due to global warming. In addition, urban areas
have been suffering from emerging issue called “Urban Heat Island” which significantly affects pedestrians as well asasphalt surfaces in terms of temperature. In order to tackle the problem, Solar Heat-blocking Pavement technology wasdeveloped to gain the following effects: the reduction of surface temperature and the prevention of pavement
deterioration. This paper describes the recent development of the technology and its practical effects throughexperiments and case studies. The following conclusions are drawn from this study. With regard to the performance, thefield results indicate that the reduction in surface temperature by use of the solar heat-blocking pavement isapproximately 16°C. In terms of application, innovative coating method is highlighted in order to make the technology
user-friendly, as well as environmentally friendly.

723

Advanced Use of Solar Heat-blocking Pavement Technology
Masahiko Iwama1, Tamotsu Yoshinaka1
1

NIPPO Corporation Research Insititute, Japan
iwama_masahiko@nippo-c.jp

1 INTRODUCTION
In recent years, there is growing awareness that temperatures have been rising worldwide due to the emerging
issue of global warming and climate change. This kind of problem has become more pronounced, especially in Japan,
where the air temperature during recent summers has tended to set new records, the surface of asphalt pavements may
reach 60°C or more, the number of patients requiring ambulances due to the summer heat (i.e. heatstroke) has been
increasing, and all in all, the increase in temperatures during summer has become a serious problem. Also, as asphalt
pavements cover approximately twenty per cent of urban areas, it is considered to be a factor in the “urban heat island
phenomenon” which significantly affects the thermal comfort of pedestrians. Past study suggested that dark asphalt
paving absorbs solar rays, including invisible solar radiation (Pomerantz et al.). According to Yoder and Witzak (1975),
rising temperatures from the paving surface affect the properties of the surface layer. Therefore, bearing in mind these
problems, reduction in the surface temperature has become increasingly important in terms of sustainability as well as
the environment.
Pomerantsz et al. (2000, 2003) indicated that making urban surfaces whiter to reflect both visible and infrared
rays (i.e. sunlight) is the most practical way of mitigating surface heat. However, out of consideration for driver’s vision,
darker surfaces (e.g. grey) would be preferred as they are more familiar. In addition, taking into account the workabilityon the existing pavement, surface treatment with a painted coating is one way to deal with the issue on the existing
surface. For these reasons, a new surface treatment technology called “solar heat-blocking pavement”, which aims to
reduce surface temperatures, has been developed in Japan.
The aim of this paper is to highlight the fundamental study of the solar reflective coating technology on
pavements, and addresses practical effects through experiments and field applications.

2 SOLAR HEAT-BLOCKING PAVEMENT
2.1 BASIC CONCEPT
Solar reflective technology was originally developed to mitigate the rising temperature of building roofs(Yoshinaka, 2003). Pomerantz et al. (2000) suggested that sealing a reflective material onto the surface layer contributes
to both a reduction in surface temperature and the mitigation of surface damage due to ultraviolet rays. As a result, a
reduction in surface temperature during summer was expected by applying this technology to asphalt paving.
The function of this technology is based on the higher reflectivity of near-infrared rays and lower reflectivityof visible rays. In practice, the reflectivity of solar rays and infrared rays are represented by albedo (Yoshinaka, 2005).
Albedo is defined as the ratio between incoming and reflected solar rays. A higher albedo means that the surface layer
has a higher reflectivity for infrared rays, whereas a lower albedo indicates that infrared rays are absorbed into thesurface layer, thus increasing the surface temperature. In order to prevent the surface layer from absorbing infrared rays,
which contribute to its heating, paint-based materials with a higher albedo were coated onto the existing paving (seeFigure 1).
Solar radiation
Low reflection for the visible rays

High reflection for the near infrared rays

High albedo and dark coloredsurface treatment materials
Asphalt
Component of
hot mix asphalt

Aggregate
Hollow ceramic particle(a)(b)
Figure 1. Solar Heat-blocking Pavement: (a) Photograph, and (b) Schematic image

Highly reflective pigment724

2.2 PROPERTIES OF SOLAR HEAT-BLOCKING PIGMENT
In order to examine the albedo characteristics, a comparison was made between three surfaces: solar heatblocking pavement, conventional pavement (i.e. dense-graded asphalt pavement) and normal paint material. The test
was conducted in accordance with the Japanese standard, JIS A 5759 (1994). In this case, the colour for both the solar
heat-blocking pavement and the normal paint is grey, whilst that of the conventional pavement is black.
Figure 2 shows the comparison results. As shown in the figure, there are clear differences between the solar
heat-blocking pavement and conventional painting materials. Conventional painting material has almost the same or aless reflective ratio across the entire wavelength. However, in the case of the solar heat-blocking pavement, thereflective rate for near-infrared rays in the wavelength is much higher than others. This indicates that the solar heatblocking pavement has higher albedo, despite the fact that the normal paint material is the same colour as the heatblocking pavement.

Albedo (%)

100

Visiblerays

Near infrared rays

80

60

Solar Heat-blocking Pavement (Grey)

40

Normal paint materials (Grey)

20

Straight asphalt 60/80(Black)04001000 1200 1400
1600 1800 2000
500600 800 1000
1500
2000 2200

Wavelength (nm)Figure 2. Albedo characteristics of solar reflective pigment
2.3 STRUCTURE OF THE COATING LAYER AND CONSTRUCTION METHOD
The coating layer is about 1.0-mm thick. The coating layer consists of three components: prime layer, second
layer and non-skid sand (see Figure 3). Firstly, the prime layer is applied to cover the existing surface; then the non-skidsand is sprayed on immediately after the primary coating to ensure skid resistance; and finally, the second layer isapplied as the coloured surface and to sandwich the non-skid sand. After curing for an hour, the site can be reopened totraffic. The coating and spraying work is normally performed with a specialist spray gun as shown in Figure 4. The
material specification generally used for this pavement is as follows:Size of non-skid sand particles: 0.5 ~ 1.7 mm;
Density of non-skid sand: 0.5 kg/m2;
Density of coating: 0.4 ~ 0.6 kg/m2 in each layer.

Second layer
Prime layer

Nonskid sands are sandwithed between two layers
Coating thickness
Approx. 1 mm

Porous Asphalt Pavement

Figure 3. Structure of Solar Heat-blocking Pavement

Figure 4. Application725

3 SURFACE PROPERTIES
3.1 SKID RESISTANCE
Skid resistance is a factor affecting the serviceability of paving. It is also closely related to traffic accidents,
especially on rainy days. Therefore, non-skid sand is sprayed on immediately after coating with the solar heat-blocking
material. For confirmation purposes, the skid resistance of both coated porous asphalt and uncoated porous asphalt
surfaces were measured using a Dynamic Friction tester. The results are shown in Table 1.
Table 1. Skid Resistance Results
Dynamic
Friction

Test speed

Porous asphalt paving

Solar Heat-blocking Pavement

40 km/h

0.60

0.62

(μ)

60 km/h

0.55

0.56

Tests were conducted as per ASTM E1911 (2002). From this result, it was found that the skid resistance valuesof the two surfaces are almost identical. Therefore, it can be said that an appropriate amount of sand needs to be sprayedon to ensure skid resistance.
3.2 STRIPPING RESISTANCE
Considering the service state, the coating layer of solar heat-blocking pavement should be strong enough andhave good bonding to the original asphalt surface. In order to investigate these factors, two types of laboratory
stripping-resistance tests (Torsion test and rebelling test) were conducted. A schematic representation of the test
equipment is shown in Figure 5.

Image
analysis(a)(b)

Computer
Surface state after the test
Figure 5. Stripping resistance test (torsion test) (a) Schematic of the equipment, and (b) Image analysis
Photo

For torsion test, a test was conducted, following the laboratory stripping-resistance test method for solar heatblocking pavement material (Minegishi & Ueno 2010). A test load was applied to the specimen by turning the tire left
and right. A summary of the test parameters is presented below:

Loading condition: Turning the tire left and right
Test temperature: 20°C
Test load: 686 N
Number of cycles: 650

For rebelling test, a test was carried out in accordance with the testing procedure for solar heat-blocking
pavement materials (Minegishi & Ueno 2014). The test is the same as conventional rebelling test (see Figure 6).
However, it was conducting by the following conditions:






Test temperature: 20°C
Testing duration: 180 seconds
Type of testing chain: Cross chain
Testing speed for wheel: 200 cycles/min.
Testing speed for specimens: 66 cycles/min.

726

(a)

(c)

(b)

Figure 6. Stripping resistance test (Rebelling test) (a) Overview, (b) Wheel with chain, (c) Specimen after the test.
After the tests, a digital image of the specimen’s surface was taken with a digital camera. Then, the stripping
resistance of the solar heat-blocking layer is evaluated using computer image analysis which can record the stripped
area of the surface. The result is shown in Table 2. As can be seen the table, compared to the performance criteria set by
one organization, the coated layer demonstrates strong adhesion to the existing surface. As a result, a longer life cycle
can be expected for solar heat-blocking pavement.
Table 2. Stripping Test Results for solar heat-blocking pavement
Test
Stripping area rate (%)
Performance requirement
Stripping test
6%
Less than 40%
Labeling test
7%
Less than 20%
Note: Stripped area rate = (stripped area/wheel contact area) 100
3.3 AGGREGATES POP-OUT
The bonding between each aggregate is important factor affecting the durability of pavement. However, asasphalt is thermo-plastic material, it is vital that asphalt pavement is strong enough for torsional shear stress, especiallyat curved section on the road. Considering the strong coating layer, Solar Heat-blocking Pavement might be acountermeasure for this problem because it makes the surface possible both reduction in surface temperature andreinforcement of surface layer. In order to confirm this effect, laboratory torsional tests were conducted, in accordancewith Japanese Standard (2008) (see Figure 7).
Figure 8 shows the test result. As can be seen in the Figure, Solar Heat-blocking Pavement is strong enough totorsional shear stress, compared to conventional pavement. Particle loss rate for conventional pavement gradually
increased during the test, whereas that of solar heat-blocking pavement was almost zero percent after the test.
Therefore, it can be said that solar heat-blocking pavement is highly effective for improvement of surface durability.
Loading

Tes t load（686N）
R otation Speed（10.5 roations/minutes）
Sol id Tire

Da maged area

After testLos s ofa g gregates
Loading

Test temp.:50 CSpecimen（300×300×50 mm）

Damaged depth

Aggregates pop-out(b(a)
Figure7. Schematic of torsional test (a) Overview,(b) Loss of aggregates)Particle loss rate (%)

15

10Conventional
Pavement
Solar Heat-blocking
Pavement

5

0
0

30

60

90

120

Testing time (minutes)

Figure 8. Torsional test results727

4 EFFECT OF TEMPERATURE REDUCTION
In order to examine the effect of temperature reduction, conventional pavement (i.e. dense graded asphalt
pavement) and solar heat-blocking pavement were compared in the field. The traffic classification of the field is morethan 250 and less than 1000 vehicles/day for heavy traffic. Figure 9 shows the temperature of the two surfaces. It can beseen that the maximum surface temperature of the solar heat-blocking pavement was approximately 42C, whilst that ofconventional pavement was around 58C; the difference between the two surfaces was about 16C. Therefore, the resultclearly shows the advantage of the solar heat-blocking pavement in reducing the surface temperature in summer.

Figure 9. Effect of temperature reduction
Figure 10 compares the surface temperatures of both solar heat-blocking pavement and dense graded pavement
through a thermographic image at a site. As can be seen from the thermographic image, the surface temperature of thesolar heat-blocking pavement was 35C, whilst that of dense graded pavement was 48.3C. Therefore, it is immediately
evident that solar reflective coating can effectively reduce the surface temperature.

(a)

(b)

Figure 10. Reduction in surface temperature(a) Photographic image, and (b) Thermographic image
Left: Solar Heat-blocking Pavement, Right: Dense graded pavement
5 DEVELOPMENT OF REPAIR KIT
5.1 CONCEPTThe area of Solar Heat-blocking pavement has reached to 1700,000 m2. Some of the construction sites haveexperienced more than ten years in service, whereas other sites have had buried piping work immediately after
construction. In such case, larger machined unit which is used for large scale application was also taken to the repair
site even small area (See Figure 11).

(b)(a)
Figure 11. Small scale repair and conventional application train (a) repair area, (b) application machine728

In order to avoid such inconvenience, the development of the repair kit for solar heat-blocking pavement wasstrongly demanded to meet the public demand. In particular, the repair kit for solar heat-blocking pavement wasdeveloped to meet the following demands: good workability and easy to handling. Figure 12 shows the repair kit
developed. As can be seen in the Figure, the kit contains the following materials:Softener and hardener for the paint;
Non-skid sands; andHandy roller for application(b)(a)
Figure 12. Repair kit for solar heat-blocking pavement (a) Softener, hardener and non-skid sands, (b) Handy roller.

5.2 APPLICATION
Solar heat-blocking pavements can be constructed by applying the developed solar reflective pigment toexisting surfaces. The repair kit for solar heat-blocking materials uses MMA based resin. In general, MMA-typematerial is suitable for heavy traffic roads as quick curing and strong adhesion to the surface are required. The
application is conducted by the following procedure:






Clean the existing surface,
Apply hardener as 1st layer, then Apply softener as 2nd layer,
Spray non-skids,
Apply hardener as 3rd layer, then Apply softener as 4th layer andSpray non-skids.

The kit can be applied to the repair area of 1.0 m2. The coating work is conducted by hand. The kit andapplication work are shown in Figure 13.

(a)

(b)

(c)
st

Figure 13. Application of the repair kit (a) Application of 1 layer, (b) Application of 2nd layer, (c) spray non-skid sand.

729

5.3 DURABILITY
The repair kit is used to the solar heat-blocking surface which is tore off in service. Therefore, it should be
durable enough to snow removal action as well as traffic loading. In order to confirm the durability for these actions,laboratory stripping and raveling tests. The stripping area was evaluated after the tests. The results is shown in Table 3.

Test
Torsion test
Labeling test

Table 3. Stripping area results for the repaired solar heat-blocking surface
Stripping area rate (%)
Performance requirement
5%Less than 40%
1%
Less than 20%

From the results, it can be said that the surface coated by the repair kit is strong enough to traffic loadings.
Despite the fact that the coating was conducted by dividing the surface layer into four layers, the coated layer has thesame performance as conventional product. This means that hardener and softener reacts well to make the coating layer.
5.4 ODOR
Solar reflective material contains Methyl Methacrylate (MMA) resin. If applying solar heat-blocking material
in urban areas, there are some concerns that the smell of the material may affect people living nearby. Therefore, theemission of odors should be minimized as much as possible during construction.
In such case, a less odorous type of material (i.e. odor-reduced resin) can be selected as the solar heat-blocking
material rather than conventional material. In order to evaluate this effect before construction, odor testing is conductedin accordance with laboratory odor measurement method (Minegish et al. 2010). The test equipment is shown in Figure
14.
Test cabinet

Odor sensor

Air flow
Specimen
Figure 14. Odor testing equipment (Minegishi et al. 2010)
As can be seen in the above photo, solar heat-blocking material is set in the cabinet; the odor of the materials is
measured using an odor sensor. The maximum value of the odor is recorded during the measurement. The detailed test
conditions are shown below:






Air flow: 0.14 L/s (wind velocity: 0.2 m/s)
Test duration: 20 minutes
Measurement value: Odor level
Test temperature and humidity: 20°C, 50%
Specimen mass: 1.0 g

Table 4 shows the measurement results. These results clearly show the difference between conventional andodor-reduced materials. The odor level for the conventional material is about four times that of the odor-reduced type.
Also, the odor-reduced material meets the requirements set by the organization. In addition, the same surface
performance as conventional material has been confirmed for the odor-reduced material. Therefore, it is possible toapply the repair kit for solar heat-blocking pavement even in urban residential areas.

Table 4. Odor level of repair kit for solar heat-blocking material
Types of Solar Heat-blocking Pavement

Odor level

Repair kit for Solar heat-blocking pavement

203

Conventional solar heat-blocking material

889

Performance requirement
Less than 300

730

6 CONCLUSIONSThis paper presents the development and application of Solar Heat-blocking Pavement. Based on the field
results, the following conclusions can be drawn:With regard to improvement of durability, the solar heat-blocking surface contributes to improving the surface
layer since the technology makes the surface possible both reduction in surface temperature and reinforcement of
surface layer.
With respect to the performance of solar heat-blocking pavement, the surface temperature is reduced byapproximately 16C compared to conventional dense-graded asphalt paving due to the curtailment of solar
radiation.
In terms of small scale repair, the performance of the repair kit developed in this study is almost identical withconventional solar heat-blocking pavement.

REFERENCES
Pomerantz, M., Pon, B., Akbari, H., Chang, S-C. (2000) The Effect of Pavements’ Temperature on Air Temperaturein Large Cities. Lawrence Berkeley National Library, LBNL-43442.
Yoder, E.J. and Witzak, M. W. (2000) Principles of Pavement Design. New York, NY, Wiley and Sons, 1975.
Pomerantz, M., Akbari, H., Harvey, J.T. (2000) Cooler Reflective Pavements Give Benefits Energy Savings:
Durability.
and Illumination. Lawrence Berkeley National Library; LBNL-45370.
Pomerantz, M., Akbari, H., Chang, S-C., Pon, B. (2003) Examples of Cooler Reflective Streets for Urban HeatIsland Mitigation: Portland Cement Concrete and Chip Seals. Lawrence Berkeley National Library, LBNL-49283.
Yoshinaka, T., Kinouchi, T. and Fukae, N. (2003) Study on high performance of solar radiation reflective
pavement, Proc. of 25th Japan Road Conference. No. 09P04 (in Japanese).
Yoshinaka, T. (2005) Study on Pavement Technology targeting improvement of Atmospheric Thermal Environment.
D.Eng Thesis, Nagaoka Institute of Technology (in Japanese).
Kinoshita, K. (1998) A Solar radiation reflective paint to improve the efficiency of cooling and heating. Industrial
Material; 46-5: 35-38 (in Japanese).
Kinouchi, T., Yoshinaka, T., Fukae, N., Kanda, M (1994) Development of Cool Pavement with Dark Colored High
Albedo Coating. American Meteorological Society, 5th Conference on Urban Environment, 2004; No 4.7.
JIS A 5759 Adhesive films for glazing.
ASTM E1911-98 (2002) Standard Test Method for Measuring Paved Surface Frictional Properties Using the
Dynamic Friction Tester.
Minegishi, J. and Ueno, S. (2010) Performance Requirement for Durability on Surface of Solar Heat-blocking
Pavement. Annual Report of Civil Engineering Support & Training Center, Tokyo Metropolitan Government: pp.
41-50 (in Japanese).
Ueno, S. and Minegishi, J. (2014) Evaluation Method for Flaking Resistance Performance of Solar Heat-blocking
Pavement. Annual Report of Civil Engineering Support & Training Center, Tokyo Metropolitan Government:
pp.31-42 (in Japanese).
Japan Road Association (2008) Method for Particle Loss Rate by Torsional Shear Stress Test, The Performance
Evaluation of Pavement, (in Japanese).
Minegishi, J. and Ueno, S. (2010) Evaluation of Odor of Solar Heat-blocking Pavement Material, Annual Report ofCivil Engineering Support & Training Center, Tokyo Metropolitan Government, pp.51-58 (in Japanese).

731

THE EFFECTIVE USE ON EXPRESSWAY TO REDUCE
TRAFFIC ACCIDENTS IN TOKYO METROPOLITAN AREA
Arata MOTOKI(Mr.) 1
1

Central Nippon Expressway Company Limited, Nagoya, Japan
Email for correspondence, a.motoki.aa@c-nexco.co.jp

1. INTRODUCTION
The Ken-o Expressway, Tokyo’s ring road, was opened to the public on June 2014. Since theexpressway connects the heavy-traffic intercity expressways, it has been regularly suffering from severe
traffic congestion arising from traffic concentration. Once congestion occurs, the traffic accident riskincreases at the tail of traffic jams, leading to serious traffic accidents.
Under the circumstances, it was concerned about the increase in traffic congestion and traffic
accident due to expressway network expansion on October 2015.
Since the widening of expressway was impossible in the urban area, it was necessary to select the mosteffective measure from some countermeasures in the limited ROW.
Therefore, we carefully analyzed the ETC probe data to identify the factors causing the congestionin the first step, we selected and carried out the most effective congestion solution.
In this paper, we would like to describe the congestion solution.

2. OVERVIEW OF KEN-O EXPRESSWAY
The Ken-O Expressway is one of ring roads in Tokyo Metropolitan area, which is planned about
40-60 km away from central Tokyo.(Figure 1) This Expressway is expected to make traffic smooth,
improve the roadside environment, encourage closer connections among cities, and to become an alternate
route at the time of disaster. As of 2016, about 80% of the expressway has been completed, the traffic
volume has been increasing year by year. In this section, a daily traffic is 30,000 vehicles per day on one
lane.
Due to this heavy-traffic, it has been regularly suffering from severe traffic congestion at thejunction of two Expressways.

732

Figure 1. Location map of The Ken-O Expressway

3. MATERIALS (FACTOR OF CONGESTION)
The cause of traffic congestion at the Junction, mainly comes from over capacity arising from traffic
concentration. According to the analysis of the ETC probe data, it was confirmed that the following two
factors contribute to traffic congestion additionally.

Factor-1 Decline in traffic speed at the junction and small in traffic capacity
At the time of traffic concentration, it has been suffering from severe traffic congestion because of
the decline in speed at the Junction as well as small in the traffic capacity. (Figure 2.)

Figure 2. Decline in traffic speed at the Junction733

Factor-2 Decline in traffic speed on the 6% uphill ramp
6% uphill ramp has contributed to the decline in the traffic speed of large vehicles at the Junction.
(Figure 3)

Figure 3. Decline in speed on 6% uphill ramp

4. METHODS (CONGESTION SOLUTION)
It was confirmed that the best solution is to prepare for the split lane by analyzing the factor of
traffic congestion. By introducing this solution, it was considered that traffic capacity will increase andrecovery effects of reduced speed are expected.
But, in this case, the targeted section is located on bridges in urban area, it was necessary to takethe solution in a limited ROW. Therefore, we have selected the solution of “temporal split lanes” without
losing safety and required performance.
Moreover, we also improved how to merge the ramp with main lanes while keeping smooth andsafety roadways.

(1) Width of main lane and shoulder
In order to ensure the two lanes in the one-lane-operated ramp, we narrowed the main lane widthfrom 3.50m to 3.25m, the right shoulder width from 1.0m to 0.38, and the left shoulder width from 2.50m
to 0.38m respectively. (Figure 4)
Even though the cross section in this portion does not satisfy the law with respect to the roadstructure, the road structure, two-lane operation, was adopted because this would be the temporal
operation until the completion of expressway network and ensures the width required for snow removal
and construction works. We prioritized reducing traffic congestion and accidents in this plan.

Figure 4. Width of main lane and shoulder734

(2) The modification of merging section with the main lanes
Even if two-lane operation is adopted, it was expected that another traffic congestion occurs at themerging section with the main lane. Therefore, we decided to improve the structure of not only themerging section but also the main lanes. Of three measures proposed, we decided to proceed with the plan
3 described below from the comprehensive point of view including the reduction of traffic congestion.
(Figure 5)

CASE-1. 2 main lane & 2 junction lane
This road structure cannot ensure the required length of the lane for acceleration.

CASE-2. 1main lane (right side) & 2 junction lane
There is a possibility to occur another traffic congestion at the merging section of main and ramp
lanes, because of the increase in the length of merging section.

CASE-3 1MAIN LANE (LEFT SIDE) & 2 JUNCTION LANE
The probability that another traffic congestion occurs in the merging section is low because of theincrease in the length of merging section.

Figure 5. Merging section with the main lanes735(3) Traffic forecast
If the traffic capacity in one lane would be set to 1,530 vehicles by hour, demand traffic volume
would be estimated to 1,625 vehicles by hour after the measures of traffic congestion by using bothdemand time factor on no-congestion days and real traffic volume on congestion days.
Therefore, when we introduce two lanes in the ramp, if 95 vehicles or more by hour shift up to themerging section with the main lane, the traffic congestion is not considered to occur.

5. INPLEMENTATION OF SOLUTION
It was necessary to review the speed limit from the current 50km/h to 40 km/h, because the solutionof traffic congestion is provisional. Therefore, we decided to implement various accident measuresaccording to the traffic congestion solutions.
The major accident measures are as follows.
1. Improvement of the lane mark2. Installation of additional warning sign

6. RESULTS
Even though the average traffic volume in the section increased by about 4,000 vehicles by day, no
traffic congestion have occurred at all. The result shows that the effect of improvement is sufficient.

(1) Comparison of traffic volume and congestion
Even though the average traffic volume in the section increased by about 4,000 vehicles by day, no
traffic congestion have occurred at all. The result shows that the effect of improvement is sufficient.

Figure 6 Comparison of traffic volume and congestion736

(2) COMPARISON OF TRAFFIC CAPACITY
According to the verification on the traffic capacity in the section, the traffic capacity at the time oftraffic congestion has dramatically increased from 1,530 vehicles by day to 2,000 vehicles by day.

Figure 7.Traffic capacity of lanes(3) TRAFFIC VOLUME OF CHANGING LANE
The comparison of traffic distribution at the two sections in the two-lane ramp shows effective lanechange, clearly indicating the increase in traffic capacity.
In addition, it was observed that 15% of the traffic is shifted in the merging section. The result is beyond
our estimations. It is inferred that this contributes to the resolution of traffic congestion.
<section-1 → section-2>

Figure 8.utilization ratio (two-lane ramp)<section-2 → section-3>

Figure 9.utilization ratio (merging section)

737

7. REPTATION OF THE USER
We carried out user survey to understand the effect of the traffic congestion solutions. The resultshows the solutions provides the improvement of traffic congestion in not only expressway but also local
roads. We are also receiving a favorable opinion from the local residents.

8. CONCLUSIONS
These solutions can be useful examples, in which we analyzed and identified the causes of thedecline in traffic speed, and implemented the effective and temporal solutions in the maximum use of thecurrent road structures under the incomplete expressway network.
This case has provided big effects by minimum time and low cost. No traffic congestion has
occurred in the targeted section as of June 2016.A similar type of traffic congestion at another ramp near
the section is observed. Another solution is needed while considering a different gradient and traffic flow.
We hope that this solution will become one of the guidelines for similar types of traffic congestion solution
while reflecting the measures against current issues and their effects.

738

“URBAN TRANSPORT SOLUTIONS/ BRT VS TRAM”
María Concepción Ortega
IDOM Ingenieria y Consultoria S.A.U.
Av. Zarandoa Etorbidea. 48015 Bilbao, Vizcaya
Tel: +34944797600
Corresponding autor: cortega@idom.com

1.

INTRODUCTION

Urban transport project are much more than transport systems. They are not only a public means of mobility;
its urban and social relevance can involve profound changes in the cities in which it is located.
Public transport is also a social tool to promote equity, providing affordable transportation to access services
and opportunities otherwise not reachable for low-income population.
In addition, they will be under operation during decades. Any decision should taken by a huge analysis tosolve mobility problems in cities, processing capacity of historic urban zones, the possibility of structuring
new urban development and boost the life of cities and considering the benefits and the cost during the whole
life of the project.
Public transport generates a series of direct Impacts for passengers and cities to take into account:

Passenger’s Benefits:- Accessibility: Time travel savings- Economical: Vehicle cost savings (parking, fuel and maintenance)- Health: Increases people physical activity, Reduces people stress, Reduces number oftraffic accidents, Reduces costs with public health careCity’s Physical Benefits of reducing car traffic:- Reduces energy consumption and CO2 emission- Facilitates better walking and cycling conditions- Improves urban life quality: enhance public spaces, less sound pollution

The present paper analyzes those aspects that should come to decide best way of transport in a city: BRT and
TRAMS by a decision maker in each city. It presented the objectives, methodology, similarities anddifferences between BRT and TRAMs, in order to find best option to each case.
2.

OBJECTIVES AND GOALS FOR THE IMPLEMENTATION OF A BRT/TRAM IN A CITY

The objectives and main challenges in the implementation of a new transport system in a city should be:







CONECTIVITY AND INTERMODALITY: Enhance land public transport connectivity acrossurban conurbations and access, especially where the population density is higher, in a high quality
and integrated service transport network includes, not only the public transport, but also “last/firstmile transport”. The analysis of private cars, taxis, bicycles, parking lots, etc. it is very important foran efficient transport.
ACCESIBILITY: Ensure affordable and accessible public transport services by enhancing industry
structure.
URBAN INTEGRATION IN A SAFETY WAY: Implementation of the urban transport solution
has social and urban relevance and can involve important changes to the city in which they arelocated. Urban integration and alignment design will be carry out to exacting international
standards, considering all national and international safety and security regulations and in fullcoordination and integration with all other modes of transport, existing and planned for the future.
A SUSTAINABLE INFRASTRUCTURE (TRANSPORTATION COMPONENT) Enhancing safetylevels of public transport. The strategies must focus on reducing accidents, incidents and improve
passenger’s confidence in the efficiency of the system.

739



QUALITY OF LIFE: Reduce congestion, noise and vibration, pollution, and increase quality of life
for the city, benefits for passengers and for citizens.

To establish an efficient and attractive way of transport for the citizens and provide the basic network for theplanned future development we need to think main characteristics that differentiate BRT or TRAM services
from other local bus services including:








higher service frequency along the corridors
higher operating speeds
limited key stops along the BRT corridorstransit priority measures – queue jumps, traffic signal priority, segregated lanes
distinctly branded high capacity vehicles
enhanced passenger stations
enhanced/integrated local feeder service

To reach this functional requirements decisions on design of the network, in the definition of the vehicles,alignment, station, and user facilities will be very important and constitute the fundament for the success of
the BRT / TRAMWAY and its acceptance by the citizens, users and non-users.
3.

MASS TRANSPORT MODES: BRT´S/ TRAMWAYS

The new trams and BRTS, through the application of technological advances, have become a new form of
public transport with a high level of performance for its accessibility, low noise, speed, regularity, comfort
and ecology.
Generally the definition of modes are related to capacity and demand, but other issues has consequences inthe definition of the right mode to implement in a city.
Below is a typical definition of different transport mode, starting in less capacity and growing up.

740

Características

Tramways

BRTs

Conventional
Buses

Capacity Passengers/ hour

3.000-10.000

2.000 - 5.000< 3.000

Commercial speed (km/h)

20-28

12-20

12-18

Accesibility

Low floor

Low floor

None

Investment average Million Euros/ km/ Km (*)

8-30

6-16

4-8

Average between stops(meters)

400-800

400-800

400

Length of life of vehicles

30-35 years

10-12 years

10 years

Table 1. Comparison between transport modes (Speed (km/h) versus Capacity (passenger/hour))(*) This average varies depending on country, project and length of the line.
The capacity increase put the TRAMWAYS as a mode of efficient transport way with a significant reduction
in operational costs compared to BRTs or conventional buses.
The implementation of a modern tramway system in the cities had to face the challenges of mitigate thetraffic congestion, noise reduction, CO2 emissions reduction, and to contribute to the development of cities
and the recovery of pedestrian spaces (dusty historical buildings by pollution from cars, filled squares cars
and parked cars were usual in several cities.)
The design of modern tramways project should be focus on aspects as: safety and environmental aspects;
Mitigation measures; noise and vibration (track and rolling stock design, Emissions); Conditions ofaccessibility at station areas and rolling stock; Safety; urbanization, signaling and operation; Compatibility oftram with priority traffic lighting; Tram-compatibility with other modes of transportation during theconstruction and design phases (temporary site, pedestrian and bicycle path alternatives, traffic detour, bus
stops); Configuration of Power-supply system (power substations, redundant configuration, rush; special
feeding system for areas without power lines; fail-safe systems, insulation and protection to third parties(land network); Travel information systems and ticketing.
BRT is also a high capacity and an efficient transport way if the demand is in the range described. Same thantramways industry has developed several technology that can offer great capacity, comfort and environmental
solutions.
We can find in the market different BRT solution based on Diesel, CNG and electrical vehicles.
Taking the consideration of electrical vehicles we could reach the goal to reduce and minimize pollution and
CO2 in the city.

Electrical - Quito

Diesel - Bogota

CNG - Jakarta

741

Tram -Vitoria

Metro - Bilbao

Optical guidance system - Castellón de la
Plana

Cable- Oaklanairport

Figure 1. Different types of mass transit modes
4.

BRTs versus TRAMWAYS

To compare each system we will divide the analysis in eight topics that need to be considered in theimplementation of the line: Vehicles
 Permanent Way
 Stops / Stations
 Power supply Workshops and Depots
 Operation and Maintenance costs
 Investment cost
4.1. Vehicles
It is difficult to compare vehicles because of the very different natures of light rail and BRTs, but attached aremain differences: BRTs is subjected to road vehicle oriented legislation and standards, contrary to TRAMWAY which
is submitted to a legislation and standards identical or that derive from railway standards.
 Usually much higher requirements for trams in regards with comfort, safety, reliability,
availability…. This concerns for example the great surface of glass, the large driver’s cab and theequipment redundancy of trams
 The materials and technologies employed in trams have a much longer life duration than for BRTs
(approximately three times)
 Bidirectional vehicles in tramways nor in BRTs,
 More capacity in tramways than BRTs A common basis for comparative studies is often the numberof places available for passengers. In this paper, it is included the number of square meters available
for passengers, because the number of places available is depending on many factors such as:- Percentage of seats (usually between 15 to 40%)
- Number of square meters per seats (usually 1,4m2 per seats in trams but only 1,15m2 perseats in busses)- density of standing passengers (Normal load is defined as 6 pax/ m2m2 in busses and only
4 pax/m2 in trams)- exchange rate (ratio of door openings over vehicle length)742

Type of vehicle

Dimensions

Long Trams
Medium Tram
Long BRTs
Small BRTs

44 x 2,4 m
32 x 2,4 m
18 x 2,5 m
12 x 2,5 m

Square meters available
for passengers
90
64
38
24

Table 2. Type of Vehicles and dimensions Source: LibertinEnergy demand is clear difference between TRAMS and BRT (if we include all types not only
electrical ones) The tram is clearly much better than busses in regards with sustainable development,
notably because:- it uses electricity, which reduces pollution and all its consequences- it is renewed once every 30-40 years instead of once every 15 years- the energy consumption is lower. The small running resistance of the wheel-rail contact andthe regenerative braking. Even if heavier, the tram consumption is four times less kWhconsuming than a bus per passenger (with occupancy rates of 50%) and 24 times less perpassenger than a car (with an average occupancy rate of 1,2 people per car).

4.2. Permanent way
BRTs and TRAMWAYS will be implemented in a segregated lane with some areas where shared traffic
could appears, but in both cases some investment is required if we look for a high capacity system.
Main differences will be in alignment requirements: Tramways will go in a horizontal minimun radio over 20-25m (1 m or 1,435 m gauge) and BRTS could reach 12 m radios.
About maximum slope iron wheels limits to 8,5 % for tramways meantime BRT could reach 12%.
BRT
Not necessary special infrastructure. Typical sectionof a carriage way
If there is not electrical BRT, less special ducts(multitubular ) are needed.
Not possible green surface
Relocation of existing utilities could be not required
thinking that BRT could change the alignment incase of a disruption of service

TRAMWAY
Necessary a special infrastructure: track slab, rail
fixation or embedded system
Multitubular ducts required for electrical supply anddrainage works of the rails
Possible green surface
Relocation of utilities is considered to avoid any
disruption during operation because of any failure inutilities

4.3. Stops /Stations
The design of the stops or station is a tailor-made solution for the city, considering climatic and operational
conditions. Accessibility is always priority in the design incorporating latest technology in travel information
systems and ticketing, as we consider the correct contact interface between the user and the urban light rail
solution to be essential for the system to be effective, safe and attractive.

743

Many things should be decided: Stops can be close (platform doors) or open
 Central or lateral platform.
 Equipment: benches, shelters, passenger information system Fare collection system at stop or on board
Some differences comes from vehicle differences: Elevated platform from the pedestrian way to fit with vehicles floor (accessibility) Length of platform: BRT needs shorter platform than tramway because length of vehicles.
 Tramways run in both directions and have doors at both sides, BRT must be manufactured withdouble doors if needed.

Figure 2. Type of stations/stops BRTs
4.4. Power supply
In BRT vehicles energy demand established huge differences the type of vehicles. Here we compare
electrical BRT. Buses can based the energy on batteries, rapid charge on stops or a overhead contact line
during the line.
Tramways based their energy in overhead contact line, but also newest technology were developed freecatenary systems based on embebed and protected third rail, ultra capacitors, batteries and recharging points
at stops. In this last case tramways has a rapid charge (less than 30 seconds) in comparison with buses (4-6
minutes).
4.5. Signaling / Traffic priority
A goal for a high capacity and efficient mode of transport is the travel time and commercial speed. To reachthis goal traffic priority is required in BRTs and TRAMWAYs.
A special signaling and on board systems to be installed and need to be connected with CMC and traffic
control Centre.
Tramways will required additional signaling and control for the switches devices and maneuvers zones.

744

4.6. Workshops and Depots
Functional definition of workshops and depots are engaged to operational drive.
BRT is able to run outside the permanent way. Tramway can not run without infrastructure. BRT is able to
avoid obstacles in the infrastructure and to be implemented in a less radius than a tramway.
Tramways needs rails and maintenance pits at workshop
BRT is similar to a typical bus and does not need same special equipment as tramways
BRT needs less space at depot than tramway (for same fleet size)
BRT workshops and depots are cheaper than Tramways ones.
4.7. Investment costs
Investment is generally divided in costs of:- Infrastructure (including road works, utilities relocation, tracks, stations, signaling, communications,ticketing and information to passengers, energy)- Vehicles- Depot and maintenance facility
In infrastructure investment there are many differences between each city and lines. Infrastructure budget
depends on length of the line, number of stops and additional works included in the investment (utilities
relocation and urban roads can be third part of the infrastructure budget). Generally a TRAM line is more
expensive than a BRT but length of life of components are longer. For these reason a total analysis should bedone to compare BRT and TRAMWAY projects.
For example for a BRT line in London for two lines of 12,5k m and 14 km had an investment of 381,8
million dollars, this means $14,4 million/km.

BRT line for TEOR line in Rouen buget split was 29,5 million Euros for 66 vehicles and 135 million Eurosfor infrastructure of 29,8 km length , that means 6,4 million Euros ($ 7,5 million/km).
TRAMWAYS are more expensive in chapters of vehicles, depot, energy and tracks as initial investment, but
reduced budget for maintenance during the length of life of the vehicle (2- 3 times a BRT life)

Type of vehicle

Dimensions

Average priceEuros

Long Trams
Medium Tram
Long BRTs
Small BRTs

44 x 2,4 m
32 x 2,4 m
18 x 2,5 m
12 x 2,5 m

2800000
2200000
450000300000

Average priceEuros per square metre
available for passengers
31000
24000
12000
13000

Table 3. Type of Vehicles and prices (Source: Libertin)
The higher ratio for trams results from:- the higher level of equipment provided (intercom, dot matrix display …)- very small series in comparison with busses

745

4.8.

Operation and maintenance costs

To analyze the costs attributable to the operation and maintenance, emphasis is on those that are mostcharacteristic of this service, such as: Operational personal cost (drivers, managers, PMC controllers, etc. …)
 Cost maintenance Cost of energy to traction
Trams however provide economy in operation:- lower energy consumption – 4 times less per square meter available, the price of the “fuel” being
approximately 0,1 per kWh in both cases –- lower driving costs because of the higher vehicle capacity
Choosing best way of transport between BRT and tramway should based in addition to capacity and demand
approach to mean characteristic.
Following figure from London transport Authority showed a curve for London transport systems thatcomparing operational cost per passenger and km per year for three different transport modes (bus, BRT, andTramway) we could see that in different ranges of demand each mode is more efficient.

Figure 3. Type of Vehicles and prices (Source: ATM London)
This exercise is made for London city but should be done in each city in planning phases in order to compare
and analyze each mode according demand prognosis to choose best mode in each case.
5.

CONCLUSIONS

Different characteristics and economical ratios clearly reflect the importance of the different industrial
environment of busses and trams. As a consequence, it is recommended to use more systematically the
analysis BRT versus Tram comparison to detect areas where technical solutions for BRTs should betransferred to TRAMS (and reciprocally) and areas, where the specification for trams should be relaxed.
One method to define the transport mode should integrate the analysis of growth city, the expansion of thetransport system; innovation; life quality, greater interaction using the attractive high design specification
service and; sustainability, conscious of the environment and the economy of the project.

746

Nowadays BRTs and TRAMs reach this topics. In order to find the best solutions taking into account all thegoals of the project the strategy for accomplishing this: The realization of a comprehensive transport study (Integrated Transport) which analyses existing
bus lines and the possible restructuring (location of stops, areas served) to achieve an efficientsystem compatible with the tram system or a BRT.
 Use of demand analysis software like VISUM; EMME or others to model networks and calculate
demand prognosis for each mode and corridor.
 Operational analysis to propose frequencies, fleet size and operational and maintenance cost.
 Preliminary study of the corridor, location of stations, transport technology and fleet size should bedone to calculate investment works for each system.
 Financial and economical analysis for length of life of each system BRT and TRAM in order tocompare total cost and benefits of each mode to estimate most appropriated.
 Comparison of each mode taking into account main challenges:- Urban integration- Transport efficiency: operational and maintenance cost analysis during whole life
- Passengers and non-passengers benefits

REFERENCES[1] Cambridgeshire County Council, Cambridgeshire guided Busway[2] ETS, Study of elements in addition to transportation tram Vitoria –Gasteiz, 2015
[3] FastTrack. Delivering Successful BRT in the UK, Urban transport system in small and medium sized
cities, 2006
[4] Hondious, H. 1998. “What is Light Rail?.It’s origins, today’s state of the art and its importance throught
the world”, Railway Technical Review, 1, 1998, pp 2-11.
[5] Libertin, Draft_Topic_Report_Bus versus trams.doc[6] London Transit Authority, London’s Bus Rapid Transit (BRT) – The Business case for BRT. Way
Ahead[7] Siemens, Optiguide Transportation Systems. A single guideline: quality of service[8] Veolia Transport, TEOR – BRT in Rouen, Urban Transport system in small medium size, 2006.

747

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Wheel load running tests on the embedded expansion Joint using high-flexibility
stone mastic asphalt

TRACK

Asset Management

AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Ayaka Ishii

engineer

Hanshin Expressway

Japan

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

Yoshinori Obata

engineer

Hanshin Expressway

Japan

E-MAIL(for correspondence)

Ayaka-ishi@hanshin-exp.co.jp

KEYWORDS: embedded expansion joint, high-flexibility Stone Mastic Asphalt, wheel load running test

ABSTRACT:The embedded expansion joint is applied on the pre-stressed Concrete Bridge in urban areas in Japan for noise
reduction and run stability. Conventionally, gussasphalt is used for the base course of the embedded expansion joint.
However, gussasphalt is constantly damaged under low temperature condition; therefore, improving durability of thebase course is highly demanded. Under this situation, it has been studied to develop new embedded expansion joint
using high-flexibility stone mastic asphalt, instead of a conventional gussasphalt in Hanshin Expressway in Japan.
In this study, wheel load running tests simulating an actual viaduct are conducted, in order to compare the fatigue
resistance of three embedded expansion joint types using gussasphalt, using whole and partially high-flexibility stone
mastic asphalt. This paper describes the improvement of fatigue resistance of the embedded expansion joint.

748

Wheel load running tests
on an embedded expansion joint
using high-flexibility stone mastic asphalt
Ayaka Ishii1
1

Hanshin Expressway Co.Ltd, Osaka, Japan
Email: ayaka-ishi@hanshin-exp.co.jp

Yoshinori Obata2
2

Hanshin Expressway Co.Ltd, Osaka, Japan
Email: yoshinori-obata@hanshin-exp.co.jp

1 INTRODUCTION
Generally, to improve trafficability in Japan, embedded expansion joints are used for replacing the old
expansion joints of prestressed concrete bridges, with a span length below 25 m and joint movement below 20 mm.
However, these embedded expansion joints have a durability problem because of damage occurring over a few years
after their repair. The primary source of the defects in such expansion joints is considered to be the gussasphalt used in
the base course. Therefore, high-flexibility stone mastic asphalt (SMA) is adopted as the base course in new designs.
In this study, simulation of wheel load running tests on an actual viaduct was performed to compare the fatigue
resistance of three types of embedded expansion joints: (i) joints with base course made of gussasphalt, (ii) joints withbase course completely made of high-flexibility SMA, and (iii) joints with base course partially made of high flexibility
SMA. This paper describes the improvement in fatigue resistance of these embedded expansion joints.

2 HIGH-FLEXIBILITY STONE MASTIC ASPHALT
High-flexibility SMA uses a special polymer-modified asphalt binder, which is very flexible at low
temperatures. According to several previous studies, high-flexibility SMA is superior to gussasphalt in terms ofresistance to cracking by repeated wheel load, especially at low temperatures. In addition, using glass-fiber sheets underthe base course for reinforcement can enhance the durability of the embedded joints.
Examinations were conducted to compare the high-flexibility SMA and gussasphalt. Bending strength test was
performed to characterize asphalt bending stiffness. Bending fatigue test was performed to characterize asphalt bending
resistance by repeated load. Penetration with crack test was performed to characterize crack resistance of the basecourse by repeated wheel load, as shown Figure 1.

Figure 1. Penetration with crack test by wheel load
The result of the bending strength test is shown in Figure 2(a). SMA has a better performance than gussasphalt
with respect to both bending strength and fracture of strain at −10°C. In addition, SMA is more flexible thangussasphalt. The result of the bending fatigue test is shown in Figure 2(b). This test was conducted under different
temperatures of 0, 5, and −10°C. The SMA was observed to have a better performance than gussasphalt for every
temperature.

749

Based on the result of the penetration with crack test, compared with gussasphalt, high-flexibility SMA has
superior resistance to cracking by the repeated wheel load, especially at low temperatures, as shown Figure 6(a). To
further enhance the durability, glass-fiber sheets were used under base course for reinforcement, in which case theresistance to crack is higher than when using no reinforcement, as shown Figure 3(b).
Gussasphalt

High flexibility SMA

1.E+06

High flexibility SMA

15

1.E+05

Number of times

bending strength（MPa）(Temp -10°C)

20
10Gussasphalt

5
0
0

10
20
fracture strain(×10-3)

1.E+04

1.E+03
1.E+02
1.E+01
1.E+005℃

0℃
Test temperature-10℃

Figure 2. Test results: a) bending strength and fracture of strain by bending strength test at −10°C,b) Bended fatigue test.

Gussasphalt
High flexibility SMA

No reinforcement
With reinforcement

1.E+05
Number of times

Number of times

1.E+05
1.E+04

1.E+03
1.E+02
1.E+01

1.E+00

1.E+04
1.E+03

1.E+02
1.E+01

1.E+00
0℃

10℃
25℃
40℃
Test temperature

10℃

25℃
40℃
Test temperature

Figure 3. Test results: a) Penetration with crack test,b) compared with the effect of rein forcing material

3 SPECIMENS FOR WHEEL LOAD RUNNING TEST
The wheel load running test was conducted on the structures of three embedded expansion joints. One of thesethree structures is Type A conventional embedded expansion joint. A conventional embedded joint, shown in Figure 4,
uses gussasphalt and an expanded metal, as the base course. A sliding sheet (PM-N sheet) is placed between
gussasphalt and the concrete slab for reducing frictional resistance. Gussasphalt was cast via human construction
because of small-scale site work.

5000
500

4000

500

Fixing section

Expansion section

Fixing section

Base course

Surface course

Fixing anchor of expanded metal

Expanded metal
Sliding sheet(PM-N)

35
40
Gussasphalt

Expansion gap

Figure 4. Type A conventional embedded joint.

The other two structures are new structures that using high-flexibility SMA in the base course.
The SMA of Type B structure, shown in Figure 5, is cast via machine construction for quality control. The
SMA of Type C structure, shown in Figure 6, is cast via human construction and is used in maintenance work because
the traffic regulation time is short, and the construction spot is small.

750

Figure 5. Type B embedded expansion joint cast via machine construction.

Figure 6. Type C embedded expansion joint cast via human construction

4 WHEEL LOAD RUNNING TESTS
Wheel load running tests were conducted using a device shown in Figure 7 to evaluate the rut, surface
condition, and strain. The test load was set to 69 kN, adding 40% impact load to 49 kN of design load. The test loadincreased as the test construction was not damaged. It was tested 140,000 times for 69 kN, 160,000 times for 83 kN,
and 200,000 times for 98 kN load.

Figure 7. Wheel load running test device

5 EVALUATION OF RUT
A rut from each type of embedded expansion joint was evaluated to confirm the pavement damage. Ruts were
measured at a point 300 mm from the embedded expansion joint, as shown in Figure 8. The results are shown in Table751

1. It was observed that the ruts from all three types of embedded expansion joints were undamaged because ruts
measurements are small.

Figure 8. Rut measurement positions

Table 1. Results of rut measurements

Type A
Type B
Type C

Left wheel
1.3 mm
1.5 mm
1.6 mmRight wheel
1.8 mm
1.8 mm
2.1 mm

6 PAVEMENT CONDITION
The surface condition of the pavement after the wheel running test. It was performed 200,000 times is shown in
Figure 9. Potholes and cracks were found in the Type A embedded expansion joint. However, the Type B and Type C
embedded expansion joints were mostly undamaged.
Test structures were dismembered to confirm the condition inside the pavement. The Type B and Type C
embedded expansion joints were not damaged. However, the Type A embedded expansion joint showed small cracks
rising from under the base course and moving towards the top surface, as shown in Figure 10.

Figure 9. Surface condition of the pavement.

752

Figure 10. Cracks inside the pavement

7 MEASUREMENT OF STRAIN
Strain sensors were set at three points: surface and upper part of base course and under side of the base course,
as shown in Figure 11. In order to examine the change in strain, strain distribution graphs were plotted on the basis of
the results of the strain measurements. As shown in Figure 12, strain distribution upper part of base course in Type A
embedded expansion joint changed from tensile strain to compressive strain. This result shows that damages in theconventional embedded-joint occur between the surface course and the base course. Strain distribution in the Type B
and Type C embedded expansion joints are shown in Figures 13 and 14, respectively. Type B is the most stableembedded expansion joint. The Type C embedded expansion joint is initially stable like Type B, but the strain sensor on
the surface of the Type C embedded expansion joint was broke after the wheel running tests were conducted 160,000
times. In addition, strain distribution of the Type C embedded expansion joint changed in a way similar to that observed
for the Type A embedded expansion joint when the wheel running test was conducted 180,000–200,000 times. It showsthat the damages in the new embedded joints are similar to those observed in the Type A embedded expansion joint.
Considering the abovementioned results, high durability is expected in the two new embedded expansion joints,
especially Type B.

Figure 11. Position of the strain sensors

Figure 12. Results for the strain distortion of the Type A embedded expansion joint.

753

Figure 13. Results for the strain distortion of the Type B embedded expansion joint.

Figure 14. Results for the strain distortion of the Type C embedded expansion joint.

8 CONCLUSION
The findings of this study are as follows.
1. The wheel running tests show that the damage to the surfaces of the new embedded expansion joints
was lesser than that to surfaces of the conventional embedded expansion joint. In addition, the test
construction of the new embedded expansion joint was no damage.
2. Cracking inside the pavement in the case of a conventional embedded joint was confirmed.
3. Strain distortion in the conventional embedded joint caused more damage between the surface courseand base course with increasing number of load running tests. In addition, a similar tendency wasobserved in a new embedded expansion joint fabricated via human construction.
4. Machine construction of high-flexibility SMA resulted in quality.
Our results show that the new embedded expansion joints, which were fabricated using high-flexibility SMA,
possess high durability when used in the all base course in maintenance work.

REFERENCES
Hanshin Expressway Co.Ltd. (1994). Design and construction manual of embedded expansion joint.
Yuuki Iguchi et al. (2014). Modified research of embedded expansion joint Paper presented at the 69 th Annual
Conference of the Japan Society of Civil Engineers, University of Osaka, Osaka, 10-12 September 2014.

754

2nd IRF Asia Regional Congress & Exhibition
October 16‐20, 2016 – Kuala Lumpur, Malaysia
PAPER TITLE

Network Evaluation of Flood Impact for Rural Highway Management

TRACK
AUTHOR(Capitalize Family Name)
Thanit WITTHAYAMET
CO-AUTHOR(S)(Capitalize Family Name)POSITION
Civil Engineer

POSITIONORGANIZATION
Department of Rural Roads

COUNTRY
ThailandORGANIZATIONCOUNTRY

Koson JANMONTA

Civil Engineer

Department of Rural Roads

ThailandJom TEERAWANIT

Civil Engineer

Department of Rural Roads

ThailandKoonnamas
PUNTHUTAECHA

Civil Engineer

Department of Rural Roads

ThailandNoppadol SIANGBOON

Civil Engineer

Department of Rural Roads

ThailandKlahan TARUGSA

Civil Engineer

Department of Rural Roads

Thailand

E-MAIL(for correspondence)

Koson.te@gmail.com

KEYWORDS:

Network vulnerability, Highway Management, Scenario Analysis, Priority Ranking

ABSTRACT:This practical paper presents the network analysis under flood situation for rural highway. It proposesa guideline for highway management both pre and during a flood crisis. This general guideline may
be adopted and applied in any area in Thailand. The road network modelling is an important tool toevaluate the vulnerability and sensitivity of the network under various scenarios such as that all mainroad links are submerged, etc. The result is shown as volume-capacity-ratio and is considered withthe other considerations such as the primary function of each link, its flooding history, probability offlood occurrence, the present traffic volume to be affected, etc. A case study in Nakhon Sawan
province is presented to demonstrate the applicability of the proposed framework. The finds shade
light to prepare and improve the highway network in the province and its vicinity so that the crisis
could be proper tackled and relieved.

755

Network Evaluation of Flood Impact for Rural Highways
Management
Thanit Witthayamet1, Koson Janmonta1, Koonnamas Punthutaecha1, Jom Teerawanit1,
Noppadol Siangboon1, Klahan Tarugsa1
1

Department of Rural Roads, Bangkok, Thailand
koson.te@gmail.com

1. INTRODUCTION
After the flood events in 2011, it had brought a severe loss to the country, many roads were cut off, and people
were suffered from the events. This was significantly affecting the enormous economic value, the Department of Rural
Roads (DRR) was affected with more than 1,000 roads in 64 provinces with a total value of approximately 9,000 million
baht. DRR is responsible for rural highways and serve with conveniences and safety. Especially in the event of flooding,
DRR is taking part in reducing the economic loss, helping suffered people and resolving the crisis quickly and effectively
with respect to the government policy. DRR has realized that this duty is very important therefore DRR has been
studying and preparing to set guidelines and tools to take in action during the flooding event so that the staff can perform
more effectively.
1.1.1 STRAHNET Network
The United States has imposed a citywide strategy (STRAHNET: Strategic Highway Network) to provide astable road for using in the logistics when a natural disaster occurs, for example; natural disaster, war etc. (asshown in Figure 1). It contains the road with multi-agency including inter-state higway and State Highway.

Figure 1 STRAHNET

2756

2. GUIDELINE TO TACKLE FLOOD EVENTS
Department of Rural Roads has set guidelines to deal with floods, which consists of two phases before andduring the floods as shown in Figure 2

Collecting flooded road data
Evaluating Flooding Impact

Before Flood Events
Prioritising Road from Severity
Prepare suitable solution

Data Collection
Monitoring water runoff

During Flood Event
Select suitable flood protection
Check Structural capability

Figure 2 Guideline to tackle flood events
Guidelines for planning preparation to tackle floods during the events are shown in Figure 3.
3. NAKHON SAWAN REGION
The topography of this province is mostly flat, the west end area is mountainous and forest areas and theeastern tip is a highland slopes down to the lowland areas is the center of the province. There are rivers that flow into
the province in the north, including Ping and Nan Rivers. (Yom River join Nan River at the upper area of theProvince) and these rivers join together into one river called Chao Phraya River. Therefore, this province which has
two large rivers, during the raining season there is a large amount of water flows into many areas of the province,
especially in 2011 the flooding that occurred causing a lot of damages.
4. ASSESSMENT OF FLOOD AREA
Assessment of flood area are considered from causes of the flooding. There are three factors that are the maincauses, amount of rain fall on the area, water runoff from the upper area and sea water level. These factors havecritical effect differently to each area such as in Nakhon Sawan, water runoff from the upper area and the rain that fellin the area were the most important factors, but the impact of the sea level was not considered. On the other hand,
Bangkok Province has all three flooding factors affecting flood event. It can be concluded that the province locates in
the upstream areas has the main factor that caused flooding is the amount of rain water that falls in the area. The
province which locates in the middle of the basin, the water runoff from the upper area and the amount of rain would
be the most important factors. Finally, for the province in the upper watersheds, particularly flat area near the sea has
all three factors causing the floods. Thus, in a study to determine ways to assess the risk of flooding in the area, it
depends on the location and topography of the area of interest are important.
The main areas affected by water runoff from the northern are the central areas and the areas towards the eastof Nakhon Sawan, for the west area of the province and the eastern tip, which is the area higher level than the centralarea, the cause of flooding occurred mainly due to the amount of rain fall in the. It can be concluded that the causes ofthe flooding in Nakhon Sawan are water runoff from the upper area and rainwater that falls in the area.

3757

Considered Information
 Area Information
 Road Information
 Flood Information
 Traffic Information
 Irrigation Information

Risk of Flooding in each Area

Role of the Road

 Check flood history in the area
 Divided area by causes of flooding Country Policy Strategy
 Major/Minor Roads
 Evacuation Route POI.
 Social
 Economy

Rain

Water Runoff

Gauge Station
 Water

Obstacles

Runoff Check
Station Obstacles

Traffic Volume
 Traffic information
 Other traffic information
Score

Sea Water
 Level

Sea water
Level

Score

Sensitivity Analysis
Analyse scenario from any modelConsider any change oftraffic in the area

Flooding on the road
 Previous record of flooding

Score

Score

Score

Prioritising the Road
Apply any Factor
Total Score

ResultPreparation to tackle floods
Group 1 Severe Impact: Survey the area
 Consider Connectivity of the road
 Preparation for long term protection
 Preparation for temporary protection

Group 2 Moderate Impact

Group 3 Small Impact
 Announce to people in Preparation for temporary protection
the area Preparation for evacuation

 Preparation for Evacuation

Figure 3 Guidelines for planning preparation to tackle floods during the events

4758

4.1 Rainfall
Data collection from rain gauge stations located in the province and neighboring in total of 67 stations haveshown in Figure 4. It was found that the average rainfall is 1044.1 mm / year, with a range between 524.9 to1545.0 mm / year. The analysis of rainfall found that the amount of precipitation annually average of 1044.1 mm,
most rain was falling between May and October which is 87.57% of the average annually rainfall, or equivalent to914.3 millimeters of rainfall, while the remaining percentage of 12.43% or 129.7 mm rainfall was occurred during
November to April. Also an analysis of the highest rainfall period from 1 day to 3 days for applying in determining
the repeat amount of rain water of heavy rain in the area from 2 years to 1,000 years which can be summed up thehighest rainfall at any period of the rain gauge stations located in the province and neighboring areas.
4.2 Runoff
The runoff gauge stations are located in the province and neighboring stations with a total of 25 locations asshown in Figure 5. The area can reserve rain water from 457 to 120,693 km2 with the range of average annual
runoff per unit area is between 3.483 to 32.045 liters/sec/km2. For the river runoff station Banphotphisai (P.17) was
unusually high during the dry season, which is caused due to the release of water for irrigation and power
generation of the Bhumipol reservoir in Tak. Nan River station at Koei Chai (N.67) had similar situation from
Sirikit reservoirs which released water for cultivation during the dry season. This is quite different from thevariability of river runoff at Wang River Station (CT.4) and the Yom River (Y.5), which has no reservoir to control
the flow. Thus it was seen that the amount of water flowing down from the north, part of it, was controlled by twolarge reservoirs. However, such a large number of uncontrolled runoff from the rain in the south of the reservoir,
Yom and Wang rivers. The runoff is a major cause of flooding in the central area of the province. Local floodingthat had occurred in the past seven years since 2005 to 2011 is shown in Figure 4, it can be seen that there are 3
zones of flooding, which are;• Zone 1 West Bank.
• Zone 2 Central Lowlands.
• Zone 3 Eastern tip.
The cause of local flooding zones 1 and 3 are mainly due to rainfall in the Northern Province itself, and flows
into the high central area of the province itself. The cause of the flood zone 2 was water runoff from the Ping and
Nan rivers.

Nakhon Sawan Area

Flood Zone

Figure 1 History of flooding in Nakhon Sawan during 2005-2011

5759

5. THE MODEL OF ROAD NETWORK
Road Network analysis was done by applying models of road network using a computer program. It was doneby replication traffic on the road network.
5.1 subarea and road network
The study area covered the province and neighboring areas according to its economic and social conditions.

Province
Lopburi
Singburi
ChainatNakhonSawan

Uthai Tani
Kampengphet

PhichitPhetchabun

Figure 5 Case Study Area

Population Density (Person/km2)

Ave. Population Density (Person/km2)

Figure 6 Population Density in the Case study area
6760

5.2 Landmarks
Various locations in the area and important role during the floods are as follows.
• Health centers and hospitals of 22.
• Police Station 23• Evacuation centers 49• Fire Station 8• Army Base
• Bus Terminal• Nakhon Sawan Railway Station etc.

Figure 7 Migration point in Nakhon Sawan

Road
Highways
Rural Rd.
OthersPCU (vehicles/day)Figure 8 Traffic Volume on the rural road network

7761

6. IMPACT ASSESSMENT OF ROAD NETWORK
Road Network analysis to assess the severity of the impact of floods in each area was able to manage the
network effectively and prepare for the flood and managed network during the incident. The factors used indetermining factor divided into 3 groups.
(1) Road Category(2) Cause of flooding.
(3) Traffic Volume
6.1 Factors and scores
Assessment of the impact was made by the following factors and weighted accordingly in each area. In thisstudy, recommended for general use, as shown in Figure 9.

Flooding

Role of the road
Strategic Road

Flood History

Evacuation Road+

Major/Minor Road

* Wi

Traffic Volume++
Risk Area
to Flood

Traffic Volume

* Wi

* Wi

+
Sensitivity* Wi

Total Score

Priorotised Road

Figure 9 Guideline for scoring and weighting factors
The analysis will have to consider the scores, weighted factors and adjusted as appropriate to the situation in
the area. The assessment consists of two parts:(1) The actual previous incident; based on actual situation which happened to the network, the score is 0.7%of the main factors.
(2) Risk assessment; based on an analysis of possible future flood risk areas for example, assessed by the risk
analysis and sensitivity analysis of the network. The score is 0.3% of the main factors, each of the following will
be considered:• The role of the network: considering the importance of applications in areas such as the route which has
immigration landmark and is parallel to the highway. This can be used as an escape route when the highway
has been affected by the floods• The previous record of flooding in the area: considering the previous flooding of the area that were affected
between the years of 2007 to 2011.
• Risk of flooding in the area: considering the possibility of flooding to the area from various causes.

8762• Current traffic volume: considering the amount of traffic traveling on those roads.
• Sensitivity: considering the changing traffic conditions in the event of future events which may use themodel to analyze traffic networking.
6.2 Scenario
The situation is predicted the impact that would occur on the road network, the detail of analysis can beapplied for modelling the road network based on transport engineering. However, if the network is not very
complex, the analysis could use statistical information, experiences of traffic analysis in the past, as appropriate.
For example, the following are the considered scenarios;• Under normal circumstances; considering the amount of traffic going in each direction during the flooding.
• Scenario F1; requiring the decrease in some of highway roads ability which were affected by flooding by
reducing the capacity of the road and reducing in speed. On the other hand roads under the Department of
Rural routes are still fully in service.
• Scenario F2; requiring the condition that ability of highways declined on some routes which were affectedby flooding by reducing the road capacity and speed. Also the roads of DRR are not available based on theroutes affected by the floods (2011).
6.3 Network analysis
The ratio of traffic volume to capacity (V / C Ratio) under various circumstances are shown in Figure 10 to
Figure 12.

PCU (vehicles/day)Figure 10 Under normal circumstances

9763

PCU (vehicles/day)Figure 11 Scenario F1

PCU (vehicles/day)Figure 12 Scenario F2

10764

7. HIGHWAY MANAGEMENT PREPARATION
7.1 Assessment of the flood impact.
Road network in Nakhon Sawan province had all been evaluated according to the guidelines and shown in
Figure 13 by considering various factors, including the role of the road, recorded of previous flooding, the risk offlooding, traffic volume, and the sensitivity of the network. These networks were analyzed by the road networkmodel which allows the model to group rural access roads in Nakhon Sawan respect to the impact of flooding into
3 groups, which were;• Group 1 severe impact: the road with a total of 18 roads which 16 roads from the assessment and additionalof two roads from surveying.
• Group 2 moderate impact on the 18 roads.
• Group 3 small effects on the 8 roads.
7.2 The forthcoming plan for severe impact roads.
From assessment of the road network above it was found that the road in Nakhon Sawan which were severely
affected by the floods are the main network serving as a secondary routes in the event of flooding, therefore, itneeds to be maintained at any time.
Important Rural Road

Figure 13 the forthcoming plan for severe impact roads

11765

8. CONCLUSION
This article presents an analysis applications integrated with transportation model planning in the
management of road network under the flood circumstances such an analysis is necessary to be prepared to cope withthe effects of quantitative analysis makes it possible to understand and verify the update. The case of Nakhon Sawan
province confirmed that the analysis gave tangible results that are essential for managing network services to facilitate
the traffic with fully safety and in the allocation of the budget is fairly consistent with the reality situation in the area.
9. REFERENCES[1] Department of Rural Roads; Final Report ‘Network Evaluation of Flood Impact for Rural Highways Management’(2013)[2] US Department of Defense. Guide to STRAHNET: Strategic Highway Network

12766

Investigation of engineering properties of bio-based binder derived from palm oil as areplacement for bituminous binder

Mohab Yaser Alamawi1, Faridah Hanim Khairuddin1, Nur Izzi Md. Yusoff1, Khairiah Badri2 and Halil Ceylan31

Dept. of Civil and Structural Engineering, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

2

School of Chemical Sciences and Food Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor, Malaysia

3

Dept. of Civil, Construction and Environmental Engineering, Iowa State University, Ames, IA 50011, USA

Corresponding author.
E-mail address: mohabyaser18@hotmail.com (Mohab Yaser Alamawi)This article introduces a new bio-binder containing palm kernel oil polyol (PKO-p) used asa partial replacement for bituminous binder. PKO-p was produced through esterificationand condensation for use in pavement mixtures. The proposed PKO-p was blended with abase binder (BB) to produce three variations of bio-binders (BIB), namely 100/0, 80/20,
60/40, and 40/60 bio-binders (weight of BB to BIB). The preliminary results for theconventional properties, high-temperature rheological properties (i.e., viscosity in terms of
mixing and compaction temperatures and non-dimensional viscosity analysis), attenuatedtotal reflection Fourier transform infrared (FTIR) spectrometer, and optical microscopy ofthe bio-binders are highlighted. Results showed that the bio-binder can be used as analternative for petroleum binder in the construction of road pavements.
Keywords: bio-binder, bitumen, palm oil, physical, rheology, chemical.

767

1 INTRODUCTION:
Asphalt binder, a sticky and highly viscous material, is produced through the refining of petroleum, and isderived from the bottom of the barrel cut through refinery stages. Asphalt is one of the basic materials used inconstruction, especially in the construction of pavements. Studies conducted by TOTAL bitumen, Oilibyaand MAS showed that 90% of the asphalt produced world-wide are used in the construction of roadpavements while the remaining of 10% is used for other purposes such as coating. The high demand for
petroleum products, including asphalt, has led to decreasing petroleum reserve and increasing energy cost;this in turn increase the cost of pavement construction. The quality of refined petroleum binder has been
declining steadily, and this has encouraged the exploration of new alternatives for asphalt. Researchindustries are currently investigating a new binder, namely bio-binder (bio-asphalt) extracted from biomass
or bio-waste products, which are ubiquitous and a bio-renewable resource.
According to Airey et al. (2008) there are three ways in which bio-binders can be used to decrease thedemand for fossil fuel based bituminous binders. They are used (1) as a direct alternative binder (100%replacement); (2) as bitumen extender (25 to 75% bitumen replacement); or (3) as bitumen modifier (<10%bitumen replacement). William et al. (2009) studied bio-oil fractions as an extender in original and polymer
modified asphalt binder. The results of this research showed that “the addition of bio-oil enhances theperformance grade of polymer binder by 6 oC and it’s shown by this research that the resource of biomass is asignificant factor affecting bio-oil properties”. A study conducted by Fini (2010) showed that asphalt
performance at low temperature could be improved by using swine-manure bio-binder as an asphalt modifier.
Raouf and Williams (2010) studied the rheology of bio-oils made from corn stover and found that therheological properties of corn stover bio-oil are similar and comparable to that of asphalt binders and hence
could be used as a renewable alternative for traditional asphalt binders. Raouf et al. (2010) took the research
further and investigated the properties of the bio-oil modified with polymers. Emmanuel et al. (2011)
conducted a research titled as an alternative binder from microalgae showed that The bio-asphalt, which
dripped, has rheological properties similar to fossil fuel asphalt.
Another study by Seidel and E. Haddock (2012) used soy fatty acids, which is chemically similar to asphalt,
to obtain a sustainable modifier. This bio-binder was used as an additive for the main binder and resulted inincreased viscosity and stiffness of the asphalt binders, thereby increasing its workability and lowering its
compaction and mixing temperature. Joana et al. (2011) conducted a study using varying percentages of biobinder combined with varying percentages of crumb rubber; they concluded that a bio-binder containing biooil reacted with crumb rubber could produce a binder which is comparable to asphalt binders derived fromcrude petroleum. Furthermore, the bio-oil could be successfully reacted with crumb rubber at 125 °C, which
is a substantially lower temperature than that used in normal asphalt binders, which is typically around 185°C. Zofka and Yut (2012) investigated the rheological and ageing properties of traditional asphalt binders
modified with waste coffee grounds and found that coffee beans could serve as a solvent in traditional asphalt
binders. Fini et al. (2010) and Mills-Beale et al. (2012) found that bio-oils generated from swine waste could
enhance the low temperature performance of asphalt binders and save costs. Asphalt binders modified or
partially replaced with bio-oil, together with other normal modifiers such as nano-material and crumb rubber,were also investigated.
Malaysia has the potential of leading the research in biotechnology considering that the country has a richsource of greenery, with massive amounts of timber, palm oil, rubber, cocoa, bamboo and rice. According to
the 2013 National Biomass Strategy Report published by Agensi Inovasi Malaysia (AIM), “A significant
amount of biomass is generated every year across a variety of crops, including but not limited to palm oil,rubber and rice. Within agriculture, by far the largest contributor to gross national income (GNI) is the palm
oil sector, contributing about 8 percent or over RM 80 billion. The palm oil sector correspondingly generates
the largest amount of biomass, estimated at 83 million dry tons in 2012. This is expected to increase to about
100 million dry tons by 2020, primarily driven by increases in yield”. Malaysia also has millions of tons ofbiomass from other sources.
Given this fact, it is worth the effort to explore the possibility of finding new technologies for producing
asphalt. The objective of this study is to evaluate a new bio-binder as a good extender for asphalt binders. In
achieving this aim several tests and analyses were conducted, such as tests on conventional properties, hightemperature rheological properties (i.e., viscosity in terms of mixing and compaction temperatures and non-768

dimensional viscosity analysis), attenuated total reflection Fourier transforms infrared (FTIR) spectrometer,and optical microscopy.
2 EXPERIMENTAL DESIGNPREPARATION OF MATERIAL
The materials used in this study include palm kernel oil polyol (PKO-p), 80/100 control asphalt binder, anddiphenyl methane diisocyanate (MDI). The proposed PKO-p was blended with the base binder (BB) to
produce three types of bio-binder (BIB), namely 100/0, 80/20,60/40, and 40/60 (weight of BB to BIB), and
MDI was added in the amount of 30% weight of PKO-p. Thus, a total of four asphalt binders were
investigated in this study. The bio-binders were prepared by heating both the bio-oil and control asphalt
binder to 110 °C. The bio-oil and control asphalt binder were then blended using a shear mixer at 120°C for
60 minutes at a mixing speed of 1000 revolutions per minute. MDI was then added and the mixing wascontinued for an additional five minutes. The names of the samples are given in Table 1.

Table 1 Sample compounds
Sample #Sample 1
Sample 2
Sample 3
Sample 4

Name(Abbreviation)
BB
BIB1
BIB2
BIB3

Samples Variations
Base Binder (%)
Bio-oil Compound (%)
100
0
80
20
60
40
40
60

LABORATORY TESTINGS

The tests for conventional properties, high-temperature rheological properties, attenuated totalreflection Fourier transform infrared (FTIR) spectrometer, and optical microscopy were conducted
to determine the characteristics of the new blends. The conventional test comprise of penetrationand softening point tests while the rotational viscometer (RV) test was conducted as a hightemperature rheological test. This allows for the determination of the mixing and compaction
temperatures of asphalt mixtures and for the non-dimensional viscosity analysis. While the FTIR
test was able to determine the functional group of the blends, optical microscopy was done todetermine the structural components of the new blends.
 Penetration Test
This test measures the hardness or softness of asphalt binder by measuring the depth in tenths of a millimetre
to which a standard loaded needle penetrate vertically in five seconds. The equipment and test procedure
have been standardized by the BIS. The penetrometer consists of a needle assembly with a total weight of
100g and a device for releasing and locking in any position. The asphalt binder was softened to pouringconsistency, stirred thoroughly, and poured into containers at least 15 mm thicker than the expected
penetration. The test was conducted at 25°C as specified by the ASTM D5.
 Softening Point Test
The softening point (ring and ball test) was carried out on all samples in accordance with the ASTM D36-76.
In this test, asphalt binder disks were cast in shouldered rings. The disks were then trimmed to remove excess
asphalt binder and heated at a constant rate of 5°C/min in a water bath using a special apparatus.
 Rotational Viscometer (RV) Test
The RV test was conducted to determine viscosity at high temperatures and the workability of asphalt
binders. The RV test for asphalt binder and blends could determine the optimal mixing and compaction
temperatures of asphalt mixtures during the construction. The RV test conducted in this study was inaccordance with the standard AASHTO T 316 and test temperatures were e 100, 120, 135 and 165°C.

769

 Optical Microscopy
Optical microscopy was used to the morphology of unmodified and polymer modified asphalt binders. A
drop of heated sample was placed between two microscope slides and the samples were observed at room
temperature using an optical microscope.
 Fourier Transform Infrared Spectroscopy (FTIR)
Fourier transform infrared spectroscopy (FTIR) is one of the two vibrational spectroscopy (Infrared andRaman) techniques widely used in industry. FTIR provides qualitative (through fingerprinting), semiquantitative, and quantitative information of chemical structures and physical characteristics. Solid, liquid, orgas samples can be analysed in the form of a bulk or thin film. In infrared spectroscopy, infrared radiation ispassed through a sample. Some of the infrared radiation is absorbed by the sample while others passed
through (transmitted) the sample. The resulting spectrum represents molecular absorption and transmission,
thus creating a molecular fingerprint of the sample. Just as a fingerprint, no two unique molecular structures
produce the same infrared spectrum, as shown in Table 2.

Table 2 FTIR spectra main bonds (Functional Groups)
Functional Group

Characteristic Absorption(s)1/cm

Alkyl C-H Stretch

2950-2850 (m or s)

Alkenyl C-H Stretch

3100-3010 (m)Alkenyl C=C Stretch

1680-1620 (v)Alkenyl C-H Stretch~3300 (s)Alkenyl C=C Stretch

2260-2100 (v)Aromatic C-H Stretch~3030 (s)Aromatic C-H bending

860-680 (s)Aromatic C=C bending

1700-1500 (m,m)

Alcohol/phenol O-H Stretch

3550-3200 (broad, s)

Carboxylic Acid O-H Stretch

3000-2500 (broad, v)

Amine N-H Stretch

3500-3300 (m)Nitrile C=N Stretch

2260-2220 (m)Aldehyde C=O stretch

1740-1690 (s)Ketone C=O stretch

1750-1680 (s)Ester C=O stretch

1750-1735 (s)Carboxylic Acid C=O Stretch

1780-1710 (s)Amide C=O Stretch

1690-1630 (s)Amide N-H Stretch

3700-3500 (m)3 RESULTS AND DISCUSSION PENETRATION TESTThe penetration test was conducted to determine the stiffness of the blends. Figure 1 shows that the values
for BB and BIB1 are within the standard of 80/100 penetration grade asphalt binder while the values for
BIB2 and BIB3 are higher than the value for 80/100 penetration grade asphalt binder, which indicate thatthese blends have higher stiffness, namely closer to the 60/70 penetration grade asphalt binder.

770

120
98.7

100

85.0

1/mm

80

70.5

60
59.22

40
20
0

Penetration at 25 C 1/mm
BB

BIB1

BIB2

BIB3

.

Figure 1 Results for Penetration Test

 SOFTENING POINT TESTThe ASTM D-36 and asphalt binder 80/100 softening point standard state that the values for this test should
be between 45 and 52 °C. The results for all samples is shown in Figure 2. The value for BB match thestandard value; the values for BIB2 and BIB3 are 46 and 45.5 °C respectively, while the value for BIB1 is 40°C. The values for the penetration and softening points showed the same trend, in that samples with higher
penetration value have lower softening point. However a general trend looks not applicable to be derived andviscosity analysis has to be conducted to better understanding.

48

46.5

46

46

45.5

44
42
40

40
38
36

Softening point C
BB

BIB1

BIB2

BIB3

Figure 2 Results for Softening Point Tests

771



ROTATIONAL VISCOMETER (RV) TEST

Figure 3 illustrates the rotational viscosities for control asphalt binder and bio-binder blends. The rotational
viscosities for BB, BIB2 and BIB3 have the same altitude of viscosity, while BIB1 has a slightly lower
viscosity value. This indicates that all BIB blends are similar to BB. The figure also show that the trends for
BB, BIB2 and BIB3 are close to one another. When the mixing and compaction temperatures were evaluated,
it was found that the temperatures of BIBs are 10-15% lower than that of the BB, which indicate that lessenergy was utilized. This is shown in Table 3.

Viscosity (cP)

10000

1000

100

10
80.00

90.00 100.00 110.00 120.00 130.00 140.00 150.00 160.00 170.00
Temp (oC)
BB

BIB1

BIB2

BIB3

Figure 3 Viscosity vs. Temperature

Table 3 Mixing and compaction temperatures
Construction Temp (oC)
MixingCompaction


BB
153
143

BIB1
136
129

BIB2
148
141

BIB3
147
139

NON DIMENSIONAL VISCOSITY

A non-dimensional viscosity index, expressed by Equations (1) and (2), was used to compare andcharacterize the rate of change in the rheological properties of BIBs with BB in terms of viscosity. .
𝜂=

𝜐
𝜐𝐶
𝛿𝜂𝑁

∇𝜂 = (

𝛿𝑁− − − − − −(1)

)= (

∆𝜂𝑁
Δ𝑁

)=

𝜂𝑁 − 𝜂𝐶𝑁− − − − − −(2)where ŋ is the relative viscosity of the blends;
υ is the viscosity of the binder blends,
υ𝐶 is the viscosity of the control binder; and∇ŋ is the non-dimensional viscosity index.

772

In addition, ∇ŋ was used to determine the effect of adding one-unit percent PKO-p material on the viscosityof the bituminous binder at each test temperature.
Figure 4 and Table 4 show the relationship between ∇ŋ and temperature for each bio-binder blend. The nondimensional viscosity index values for BB, BIB1, BIB2 and BIB3 are different from one another. For
instance, at 100 ºC, thevalues for BIB1, BIB2 and BIB3 blends are -2.74%, +0.516% and +0.179%,
respectively. These results showed that adding 1% PKO-p decreases the viscosity of BIB1 by -2.74%, whilethe viscosity for BIB2 and BIB3 were increased by +0.516% and +0.179% respectively. At 165°C thevalues for BIB1, BIB2 and BIB3 blends are -3.75%, -1.25% and -0.83% respectively. These results showedthat the addition of 1% PKO-p decreases the relative viscosity of the bitumen blends by -3.75%, -1.25% and 0.83% for BIB1, BIB2 and BIB3, respectively. This means that the change in performance caused by adding
one unit per cent of PKO-p vary for the same test temperature when measured in terms of.
The performance of asphalt binder mixed with bio-binder changed proportionately with test temperature andthe weight of the additive. However, no obvious trends was observed, as can be seen in Figure 4. For
example, thefor BIB2 is +1.688% at 120 oC, while at 135 oC the value decreased to -0.36%. The
evaluation of the relative change in viscosity caused by adding 1% PKO-p can be complicated.

Table 4 Computation of relative viscosity
TEMP C

Viscosity MPa.s

Relative Viscosity

Diff. in relative visc. BIB %

BB

BIB1

BIB2

BIB3

BB

BIB1

BIB2

BIB3

BIB1

BIB2

BIB3

100.00

3150

1425

3800

3488

1.00

0.45

1.21

1.11

-54.76

20.63

10.73

120.00

770

800

822

843

1.00

1.04

1.07

1.09

3.90

6.75

9.48

135.00

375

338

321

550

1.00

0.90

0.86

1.47

-9.87

-14.4046.67

165.00

100

25

50

50

1.00

0.25

0.50

0.50

-75.00-50.00-50.001.50001.00000.50000.0000-0.5000100.00°C Temp110.00120.00130.00140.00150.00160.00-1.0000-1.5000-2.0000-2.5000-3.0000-3.5000-4.0000

BIB1
BIB3
Linear (BIB2)

BIB2Linear (BIB1)
Linear (BIB3)

Figure 4 Temperature (ºC) versus non-dimensional viscosity index773

 OPTICAL MICROSCOPY
The morphology of the samples were developed to monitor separation. Figure 5 (a) and (b) show that thecomponents of the new blends have formed new materials and no separation was observed in the microscopy
images. Also, the morphology of the blends show the formation of homogeneous materials without any clots.
FTIR was done to evaluate the internal bonds.

Figure 5 Optical microscope images for (a) BB and (b) BIB2 FTIRFTIR is used to obtain the absorbance/transmittance spectrum of solid as well as liquid and gas materials.
The bonding of the samples investigated using the FTIR. So, Figure 7 shows the chemical structures which isuseful as a reference for bonding study. Investigation of the bonding of BB and BIB2 (Figure 6) show ahigher peak at 3350-3400, which is caused either by the N-H (amides), which is a part of the base binder, but
increased in the new BIB due to the reaction of PKO-p with MDI, or O-H (alcohols) which comes from theresidue of PKO-p which have not reacted with the MDI. However, the microscopy indicate that the peak was
not caused by residue. On the other hand, the peak at 1700-1740 for C=O was formed by hydrogen bonding
which is crucial for the stability of the material. Also the C=C aromatic ring at 1500-1540 was produced by
the MDI reaction. Generally, the other main bonds of the material has reformed well. To conclude that theinvestigated bio-binder may consider a significant development of a new material in asphalt technology.

774

Figure 6 FTIR spectrum indicating Functional groups in BB and BIB2

Figure 7 Chemical Structures of (a) BB and (b) PKO-p and MDI.

4 CONCLUSION
This article evaluated the performance of a new bio-binder made from palm kernel oil polyol (PKO-p) as apartial replacement for asphalt binder. The tests conducted revealed that: ,The values of RV for the BIBs are very compatible with the control binder, addition to that the
mixing and compaction temperatures are less than of control binder up to 10%.
The results for the softening point and penetration tests for BIB2 and BIB3 give a good indication of
the stiffness of the new blends.
The FTIR and microscope images showed that the new material formed its own bonds due to thephysical and chemical changes in the molecular bonds of the control binder and the absence ofseparation.

This study shows a successful development of new bio-binder from PKO-p as a replacement material.
Additional research need to be done and the behaviour of the new binder in the field need to be evaluated.

5 ACKNOWLEDGEMENT
The authors would like to express their gratitude to Universiti Kebangsaan Malaysia (UKM) and theMinistry of Education Malaysia for the financial support for this work (GPK012594 and
FRGS/2/2013/SG06/UKM/02/8).

775

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AASHTO T315 / ASTM D4402 –Standard Test Method for Viscosity Determination of Asphalt at ElevatedTemperatures Using a Rotational Viscometer (RV)
Airey, Gordon, D. and Musarrat Mohammed, H. (2008) Rheological properties of polyacrylates used as synthetic
road binders. Rheological Acta, V.47, pp. 751-763.
Alternative binders for sustainable asphalt pavement (transportation research circular number E-C165). (2012):
Washington D.C. USA
ASTM D2493/D2493M-09 Standard Viscosity-Temperature Chart for Asphalts
ASTM D36 - 76 Standard Test Method for Softening Point Of Bitumen (Ring-And-Ball Apparatus)
ASTM D5 / D5M-13, Standard Test Method for Penetration of Bituminous Materials, ASTM International, WestConshohocken, PA, 2013, www.astm.org
Badri, K. H. Ahmad, S. H. and Zakaria, S. (2000) “Production of a High-Functionality RBD Palm Kernel Oil-BasedPoly- ester Polyol,” Journal of Applied Polymer Science, Vol. 81, No. 2, pp. 384-389. doi:10.1002/app.1449
Badri, K. H. Ahmad, S. H. and Zakaria, S. (2000) Development of zero ODP rigid polyurethane from RBD palm
kernel oil, UKM, Malaysia.
Badri, K. H. and Wong, C. S. (2012) Chemical analyses of palm kernel oil based polyurethane prepolymer, UKM,
Malaysia.
Cuadri, A.A. García-Morales, M. Navarro, F. J. and Partal, P. (2014) Processing of bitumens modified by a bio-OilDerived polyurethane, spain , Fuel 118:83–90.
Emmanuel, C. Mariane, A. Bruno, B. Clemence, Q. Jack, L. Olivier, L. (2011). Alternative
binder from microalagae : Algoroute project.
Fini, E. H. Yang, S.H. and Xiu, S.(2010) Characterization and Application of Manure-Based Biobinder in Asphalt
Industry. Presented at the 89th Annual Meeting of the Transportation Research Board, Washington, D.C.
González, O. Mu˜noz, M.E. Santamar´ıa, A. Garc´ıa-Morales, M. Navarro, F.J. and Portal, b. (2004) Rheology andstability of bitumen/EVA blends, European Polymer Journal.
Jamshidi, A. Yao, H. You, Zh. and Hamzah, M. O. (2015) Characterization of the rate of change of rheologicalproperties of nano-modified asphalt, construction and building materials journal.
Jamshidi, A. Hamzah, M. Shahadan, Z. and Yahaya, A. (2014) "Evaluation of the Rheological Properties andActivation Energy of Virgin and Recovered Asphalt Binder Blends." J. Mater. Civ. Eng., 10.1061/(ASCE)MT.19435533.0001024, 04014135.
Joana, P. R, C.W. Marjorie, R. Hugo, M.R.S. (2011) Development of Rubber-Modified Fractionated Bio-Oil for Use
as Noncrude Petroleum Binder in Flexible Pavements. Iowa State University. University of Minho.
JOSEPH, C. S. JOHN, E. H. (2012). Soy Fatty Acids as Sustainable Modifier for Asphalt
Binders. Purdue University.
National Biomass Strategy 2020. (2013) New wealth creation for Malaysia’s biomass industry Version 2.0.
Nuha, S. M, Asim H. A. Mohamed, R. K. and Mahrez, A. (2013) A Review on Using Crumb Rubber in
Reinforcement of Asphalt Pavement, Center for Transportation Research, Faculty of Engineering, University of
Malaya, 50603 Kuala Lumpur, Malaysia
Raouf, M. A., M. Metwally, et al. (2010). Development of Non-Petroleum Based Binders for Use in Flexible
Pavements.
Shih, H.Y. Try, S. Ying, H.C. (2012) Investigation of rheological of Japan cedar based bio-binder
as partial replacement for bituminous binder. Washington D.C, USA: Transportation research board TRB 2013
annual meeting.
Williams, R. C. Satrio, J. Rover, M. Brown, R. C. and Teng, S. (2009) Utilization of Fractionated Bio-Oil inAsphalt. Presented at 88th Annual Meeting of the Transportation Research Board, Washington, D.C.
Yao, H. You, Z. Li, L. Goh, SW. Lee, CH. Yap, YK. And Shi, X. (2013) Rheological properties and chemical
analysis of nanoclay and carbon microfiber modified asphalt with Fourier transform infrared spectroscopy
Construction and Building Materials 38, 327-33.
Zofka, A. D. Behnia, B. Fini, EH. Buttlar, WG. Reis, H. (2013) Low-temperature performance characterization ofbio-modiﬁed asphalt mixtures containing reclaimed asphalt pavement. In: Transportation Research Board 92nd
Annual Meeting, Washington DC.
IR, UV/Vis, http://www.queensu.ca/asu/instrumentation/other .
Infrared spectroscopy, https://en.wikipedia.org/wiki/Infrared_spectroscopy
About Bitumen And Its Uses, http://www.total.co.za/pro/total-products/bitumen.html

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The natural frequency measurement of pedestrian bridge using smartphone
NGUYEN Ba Hoang1, NGUYEN Tien Thuy1, LE Quang Binh2
1

Ho Chi Minh City University of Transport, Vietnam

2

Department of Transportation of Dongnai Province, Vietnam

Abstract
Presented in this paper is the use of smartphone to measure the natural frequency of apedestrian bridge in Ho Chi Minh City. This measurement is compared with other threemethods including: theoretical equation, Midas/Civil modelling and vibration measurement
using Dynamic Strainmeter SDA-810C/SDA-803C. The Midas/Civil modelling andtheoretical equation provides 12-14% and 15-17%, respectively, lower results compare withthe other two measurements. These differences are due to the assumptions when producing
the theoretical prediction and the modelling of bridge can be different from the actual
structures. It is interesting to find that the difference between the measurement fromsmartphone and the SDA-810C/SDA 03C is only 2.3%, which can be neglected. From thesemeasurements and comparisons, the authors suggest that the smartphone can be used to give arough approximation of bridge vibration where official measurement methods using propermachines are not applicable.
Keywords: natural frequency, smartphone measurement, finite element, dynamic strainmeter777

1. Introduction
Pedestrian bridge is structure built for pedestrians and other way of light transportations suchas cyclist, animal traffic, etc. The design of pedestrian bridge follows the same principles asfor highway bridge with a different load type. Carrying only light load, the pedestrian bridge
is light-weight and thus is significantly vulnerable to vibration. In addition to stiffness,damping and mass are key factors in design for dynamic of pedestrian bridge. In design, thenatural frequency is of the most important factor. Generally, when then range of natural
frequencies lies between 1.25 Hz and 2.3 Hz [1], the vertical and longitudinal vibrations may
occur. For lateral vibration, this range is 0.5 Hz to 1.2 Hz. AASHTO standard [2] requires thatnatural frequencies lower than 3.0 Hz should be avoided in pedestrian bridges.

Figure 1 Simply supported beam method
The natural frequency can be approximated using a simplified method. For simply supported
beam (Figure 1), the natural frequencies for the 1st and 2nd mode for vertical vibration are,respectively:
f1 

f2 

1 9.869
2 L2

EI
m
1)

1 39.478 EI2 L2
m(Eq.1)(Eq. 2)in which m is mass per meter length of the structure (kg/m); EI is the vertical stiffness (kN.m2)
The use of finite element method in modern bridge design is widely spread with thedetermination not restricted only to stress and deformation, but also the natural frequencies.
By modelling the bridge using Midas/Civil software package [3] and using eigenvalue
analysis for natural periods, the frequencies can be obtained.
In reality, the most accurate way to measure the frequencies of a structure would be to use adynamic strainmeter. This equipment provides dynamic strain for a structure that change withtime. By using accelerometer, the acceleration of a structure can be measured from which
frequencies can be extracted.
With the development of technology, the smartphone nowadays provide way more functions
than general mobile phone. Most of the smartphone can sense the vibration of the structure778and the vibration data can be obtained using particular application. This is another way to
study the dynamic properties of the structures.
In this study, the authors adopt four methods stated above to investigate the natural
frequencies of a pedestrian bridge. By comparing the results of the four methods, theirreliabilities are shown and evaluated.
2. Fundamental frequencies approximation
A pedestrian bridge crossing over Pham Van Dong road at Ho Chi Minh City, Vietnam isinvestigated. The total length (including platform) of this bridge is 55.7 m, separated into two
simply supported spans. The calculated length for each span is 26.7 m. The general spanarrangement of the bridge is shown in Figure 2. The typical reinforced concrete box-section of
the bridge in presented in Figure 3.
Total length of pedestrian bridge, L=55700 mm

Figure 2 General arrangement of pedestrian bridge

Figure 3 Typical cross-section
By using Eq. 1, in which the mass of the structure is 5100 Kg/m; simply supported span L =26.7 m; the elastic modulus of the structure (assuming it is for concrete only) E = 30 GPa;
The second moment of area over the vertical axis is I x  2.91105 mm4 .

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The 1st mode of natural frequency is:

f1 

9.869
2  3.14  26.72

The 2nd mode of natural frequency is: f12 

3 1010  291000
 2.88( Hz )5100
39.4782  3.14  26.72

3 1010  291000
 11.52( Hz )5100

The modelling of pedestrian bride using Midas/ Civil starts with the input of material
properties and the definition of the cross-section. The nodes, elements were then created. The
boundary condition is defined as simply supported. The load on the structure for the natural
frequencies consideration include only uniformly distribution dead load for self-weight ofconcrete beam, deck and the wearing surface. There were defined accordingly.

Figure 4 First mode of vertical vibration

Figure 5 Second mode of vertical vibration
By adopting the eigenvalue analysis, the mode shapes and the periods are found. Figure 4 andFigure 5 show the eigenvalue mode shape for the 1st and 2nd vertical vibration. The periods of
1st mode calculated by Midas/Civil is 0.328 (s) and for 2nd mode, it is 0.083 (s). This isequivalent to the frequencies of 3.05 and 12.05, respectively.

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Comparing the approximation using theoretical equation and Finite element analysis, thedifferent is 5.9% for 1st mode and 4.6% for 2nd mode. This minor difference shows that for
simply structure (i.e. simply supported bridge), the theoretical equation can be quite reliable.
3. Fundamental frequencies measurement
The 1st measurement is by using the dynamic strainmeter (Figure 6 (a)). The ARF-20A-T type
acceleration transducer (Figure 6 (b)) is placed at mid-length of the span of the bridge. The
vibration is induced by a person walks from one end of the span to another. The strainmeter isconnected to a computer on which all the measurements for acceleration of structure will berecorded with time [4]. The data is used to obtain the natural frequencies of the structure using
the Fourier series transforms [5].

Figure 6 (a) Dynamic strainmeter;(b) Acceleration transducer

One period

One period

Figure 7 Acceleration with time domain

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Figure 7 presents the changes of acceleration with time. From this figure, one canapproximate the frequency of the structure by measuring the period T of vibration, fromwhich the frequency is calculated as f  1/ T . It is noted that several periods may be found in
the graph for different frequencies.

1st vertical mode, f = 3.4 Hz

Figure 8 Fourier amplitude spectrum with frequency domain
Figure 8 presents the Fourier amplitude spectrum with frequency domain. Each peak on thegraph shows a possible frequency for vertical vibration. For the mid-span measurement, thecritical mode would be the 1st vertical mode. From the figure, the 1st vertical vibration mode
happens at frequency of 3.4 Hz.
A similar measurement is adopted using application “vibsensor” on the iphone. This software,developed by Now Instrument and Software, Inc (UK), allows user to collect, analyse andexport accelerometer data of a vibrated object [6]. By placing the smartphone at the mid-spanof the bridge and recording the acceleration of the structure when a person walking from one
end of the span and to another, the similar data is obtained.

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Figure 9 Measurement of vibration using smartphone

Figure 10 Acceleration vs. time using smartphone783

Figure 11 Acceleration with frequency domain using smartphone
Adopting the same technique when analyse the raw data from measurement using smartphone,
it is found that the 1st vertical vibration occurs at frequency of 3.48 Hz as shown in Figure 11.
It is seen that two measurements provide similar results for 3.4 Hz and 3.48 Hz at the 1stvertical vibration mode, which is only 2.3 % difference. These measurements have differencesfrom 12-17% when comparing with the 1st two approximation methods. These differences canbe partly due to the assumption in theoretical approximations.
Concluding remark
Four different methods have been performed to study the natural frequencies of a pedestrian
bridge. It is found that the approximation using theoretical equations and finite element
analysis provide similar results for the same bridge. The theoretical equations give the natural
frequencies of 2.88 Hz for the 1st vertical mode and 11.52 for the 2nd vertical mode. The finite
element analysis with Midas/civil approximates the frequencies of 3.05 and 12.05, for the 1st
and 2nd mode, respectively. The differences between two methods are only for 5.9% and 4.6%,
which is fairly small.
By using the vibration measuring machine (dynamic strainmeter), the acceleration of thebridge can be obtained at mid-span. By transforming the data to frequency domain using
Fourier transformation, the 1st vertical mode of vibration is found at frequency of 3.4 Hz. The
same measuring technique is used with the smartphone as measuring machine. It is found thatthe frequency for the 1st vertical mode is 3.48 Hz. The difference between these two
measurements is only for 2.3% showing that the smartphone can be reliable when measuring
the vibration of structure. It is recommended that for the preliminary investigation of natural784

frequency of pedestrian bridge, the smartphone can be adopted to provide the first impressionof the dynamic behaviour of the structure. This method is simple without particular equipment
required. It can be convenient when measuring bridges at rural area.
Comparison between theoretical predictions and the measurement at the bridge shows thatthese differences are between 12 and 17% which is acceptable for the concept design.
Reference

1. MTC (1991). OHBDC-Ontaro Highway Bridge Design Code, 3rd ed, Ontario, Canada.
2. AASHTO (2015). LRFD Guide Specifications for the Design of pedestrian bridges, 2nd
Edition, with 2015 Interim Revisions
3. MIDAS(2011). Online Manual – Civil structure design system. MT co, ltd.
4. TSK (2000). SDA 810C/830C user guide. Tokyo Sokki Kenkyujo, Japan.
5. RL Pimentel (1997). Vibration Performance of Pedestrian Bridges due to Human-induced
loads. PhD Thesis, University of Sheffield.
6. NIS (2015). Vibsensor User guide. Now Instruments Software, UK.

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2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUTREQUIREMENTS OF AN EFFECTIVE ASSET INFORMATION MANAGEMENTSYSTEM (AIMS) FOR ROAD INFRASTRUCTURE
By TEH HING WAN
Head, Database and Management Systems
OPUS International (M) Berhad

Introduction
In the last decades we have witnessed the increasing adoption of Asset Management (AM) in
maintaining highway and road assets in road authorities and agencies around the world. There is aparadigm shift from the conventional reactive maintenance approach to the modern AM centric
processes and systems. Standards such as PAS55 and ISO55000 have been introduced to set
specifications and guidelines for its implementation, compliance and certification.
There is general consensus that AM will bring about numerous benefits to the stakeholders in roadassets, primarily the owner and the end road users. Understanding how an AM approach to roadmaintenance will realise the envisaged benefits is of primary importance to the practitioner.
The source of benefits which AM can derive stems from its strategic and whole lifecycle approach toplanning and maintaining assets. AM aims to “deliver the required levels of service at the minimum
Whole Life Cycle cost” of assets. The focus of AM is based on: A long term or whole life-cycle perspective.
 Balancing Levels of Service of Assets with the cost of maintenance and operations.
 Maximising the value or benefit of investments in maintenance.
A whole life-cycle approach to managing assets necessitates the extension of the planning horizon
from the short and medium terms to the long or strategic perspective. In AM terminology, the longor strategic periods denotes the expected useful lifespan of the road asset. This means the design or
required service life span of assets, which is often more than 10 years in road pavement assets.
To plan and sustain the required level of service of road assets over the whole life-cycle, thecapability to assess the condition, model the deteriorations and planning for the most beneficial
impact for each dollar investment spent sets AM apart from the ‘find and fix’ (reactive approach) ofconventional Maintenance Management.
AM aims to optimise maintenance strategies and maximise benefit-costs over time. Unlike
Maintenance Management, AM aims to sustain the required level of service, as defined underconsiderations of operational and budgetary constraints by prescribing when, where and what work
is to be carried out that would maximise benefit-cost. In contrast, Maintenance Management focus
on restoring serviceability of assets to its original design capacity or to the highest level possible,
without attempting to assess benefit-cost of alternatives or options.
An Asset Information Management System (AIMS) is the IT component of an enclosing AssetManagement System (AMS). It must be aligned with and support the objectives and the whole
lifecycle approach of AM. The adoption of work processes that focus on industry’s best practices in
AM and the institutionalisation of these practices among maintenance personnel would be the prerequisite of the successful implementation of an effective AIMS. AIMS must be more than just a
database of data and information, it shall support the assessment, analysis, forecasting and planningof maintenance works to achieve organisational Asset Management objectives by sustaining therequired levels of service over the asset’s life cycle.

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Components of an Asset Management System
An Asset Management System (AMS) should be distinguished from the Asset Information
Management System (AIMS), the former is a larger eco-sphere which is an integration of 3 subcomponents:a.

Framework
The Asset Management Framework (AMF) is a foundation of AMS. It is essentially a guiding
blueprint on the implementation of Asset Management, tailored to the environment of which
the implementing organisation operates in. It documents the objectives and policies of theAsset Management process, which may include an Asset Management Plan (AMP), which define
the long term plan in attaining the above objectives. It also defines the supportingorganisational structure and the roles and responsibilities of personnel in the AM supply chain.
It specifies the approach, methodology, data requirements, skills sets and functionalities of an
Asset Information Management System (AIMS).

b.

Data
AM is a data knowledge process and the availability and quality of data has a great impact on
the outcome of the whole AM process. Data can be classified into inventory, condition, work
related, traffic/loading demand, economic/cost, environmental and constraints. Data need tobe collected, analysed, modelled and reported in-lined with the AM process to produce therequired output. Data will need to be stored in a database that is structured to facilitate thedata access and usage. A robust data referencing system, such as a Location Referencing System(LRS) for linear assets needs to be developed for effective and efficient data retrieval andcorrelations.

c.

Tool
The AM tools include data collection, processing and analysis systems such as a computerised
Asset Information Management Systems (AIMS). The tools needs to able to make use of thedata contained in the database to support the AM process as defined in the AMF. The output
from AIMS will be an inventory register, condition and usage demand reports, trending andstatistical analysis, work effects and condition modelling, work and cost optimisation, AM
strategies and work programmes, budgeting and expenditure, performance and KPI reports.

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2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUTAll the above components of AMS are interrelated and needs to be aligned and integrated as aneffective overall system. Would be AMS implementers will need to focus on the requirements of all 3components and their relationships. A phased and structured approach should be adopted to evolve
iteratively the requirements of all three components and allow time for organisational assimilation.

Key Requirements of an AIMS
An Asset Information Management System is an embodiment of the organisational processes in
Asset Management. It needs to be provide functionalities beyond the simple storage and reportingof data in its database. It needs to support the AM process in line with the AMF. The following key
requirements should be on top of the list of would be AIMS developers and implementers:A.

Supporting the full Asset Management Process
The following diagram shows a generic AM process and the various tools that can be included in
an AIMS for each stage of the management process:Figure 1 AM Processes and Supporting AM Tools
The 6 AM processes as described above can be grouped into the generalised functional layers:a. Data Management – inventory “discovery” and condition assessment.
b. Analysis and Decision Support – deterioration/economic modelling, work requirements,
performance gap analysis, prioritisation of work, strategies formulation and selection.
c. Works Management – development of forward work programmes, budget allocation, work
implementation.
d. Performance Management – monitoring and controlling the performance of assets,
operations and management.
Each of the above functional groups of AM processes can be supported by the various softwaretools and applications as shown above. Depending the actual application requirements of theimplementing organisations, the examples given above may not be exhaustive or not essential.
Some of these tools can be obtained from commercially available software packages while788

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT
others needs to be developed to specific requirements. Whatever the case maybe, it should be
noted that all these sub-component systems will need to be integrated, if not at the systemlevel, at least at the data level. This is to facilitate data and information to flow the component
systems without much requirement for data transformation and reformatting.

Figure 2 Functional Layers of an Integrated AIMS

Data Management Level
The component systems at the Data Management layer manages the collection,compilation, referencing, storage and retrieval of data. In a corporate multi-user
environment, these data will be stored in a relational SQL database. As the AIMS database
will form the data and knowledge server to other functional layers, the robustness,availability, scalability and security features of the database software platform must be
carefully considered.
The design of the database structure (schema) has a large impact on the performance ofthe system. In designing the database structure, the following factors must be considered:a. Multi-referencing of assets and events – by unique asset ID (e.g. bridge), by KM
chainage referencing (e.g. work location from KM2.20 to KM2.53) and by coordinates
system (e.g. GPS coordinates), the database will be able to retrieve data based on any
one of the above methods.
b. Time series of datasets – database will need to be able to record current informationand the ability to relate to historic and future information for any asset inventory. Thisis crucial as data collected in different time continuum is used to develop trends andprojections in the Analysis and Decision Support level (described later).

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c. Logical Integrity of data – as the information of any particular inventory will beassessed and updated from multiple sources, the database will need to provide
automated data checks (e.g. there shall not be duplicate recording of same physicalasset inventory).
AM data to be stored in the database can be classified as textual or spatial data. Textual
data describes data that does not relate to location (e.g. IRI value). Spatial data describes
information that depicts locations (e.g. alignment of a road).
These two types of data, though can be stored into a common AIMS database, will
however need two different type of software systems to display and managed. While
textual data can be easily processed and managed by a database application modules,
spatial data is best managed by a GIS (e.g. ESRI’s ArcGIS) software. The challenge is tointegrate the two systems.

Figure 3 Integration of GIS and AIMSAt the database level both the GIS spatial database and the AIMS database resides as data
in tables of the same database platform (e.g. MS SQL Server or Oracle). At the system level,
these tables can be linked by unique key values in table fields. In linearly segmented data(such as rutting on pavement from KM5.2 to KM5.9 on Fifth Avenue), GIS provides afunctionality to link the textual information (e.g. rutting value of 5mm) to the right locationon the spatial data (e.g. alignment of the road).
This linking function requires the development of a Location Referencing System (LRS) in
the database. An LRS is a feature class that describes location of objects or events on alinearly measured line with linear measurements (Kilometer value) from a reference
station. A LRS for AIMS implementation should be a standard across the organisation torecord the location of linear assets.
At the application level, both GIS and the AIMS modules would be integrated by a common
web browser interface.
Data are collected from data acquisition systems such as laser-profiler, falling-weightdeflectometer, field GPS data collection devices, coring and lab testing, Lidar, GPS survey,
weigh-in-motion, traffic counting, aerial surveillance and remote sensing. These data, aretypically voluminous and tedious to enter manually into the system. AIMS will need to have790

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT
an automated data loading and logic checking facilities to import the data into the
database and setup the required location referencing for the data.
Analysis and Decision Support Level
The objective of application modules in this level is to turn data in the AIMS database into
useful information for operations support and management decisions. This is carried out
by the AM modules customised to manage the different classes of road asset including
pavement, bridge, drainage (including culverts), road furniture, road corridor, tunnels andeven facilities/building. The output from this level of application modules shall include:a. Gap analysis – current level of asset performance against required level of service.
b. Work requirement analysis – what are the repairs/rehabilitation required to close theperformance gap.
c. Developing maintenance options and strategies.
d. Model and predict the deterioration of assets under various projected traffic loading or
usage and maintenance options / strategies.
e. Applying constraints and carry out economic optimisation based on maximising
benefit-cost over whole lifecycle or analysis period.
f. Selection of AM strategy and development of funding requirements.
Processed data in the previous stage of the AM process is analysed for work/rehabilitation
requirements and treatment options are generated. The conditions and level of service ofassets over the whole lifecycle is analysed and predicted based on the various treatment
options and scenarios. Budgetary and maintenance policy constraints are subsequently
applied and the treatment option that offers the best benefit cost is selected andformulated in an optimised AM strategy, including the corresponding required funding. The
AM strategy forms the basis for the development of a Forward Work Program whichpackages work requirements into projects that can be implemented.
Pavement Management module
The common tools used in analysing pavement for deriving optimised maintenanceinvestment strategies are HDM4 and dTIMS. dTIMS is a full featured road asset
management system that is commonly used in Australia, New Zealand, Canada and otherdeveloped Western Countries. The cost and skills required in the implementation of dTIMS
are significantly higher than an all-in package solutions such as HDM4, which offers a lower
start-up barrier to dTIMS. HDM4 is a standalone analysis tool that is developed by
HDM4Global. sponsored by World Bank, it is used primarily in developing countries
including Malaysia. HDM4 should feature as an ‘analysis engine’ that is integrated to theoverall AIMS.
HDM4 is a very versatile and powerful analysis engine. However, the preparation of input
data and the extraction of information output from HDM4 is tedious and poses a challenge
to the less technically inclined asset manager. The process of preparing data input into
HDM4 for a large road network, if done manually, is labour intensive and error prone. A‘pre-processor’ is normally part of the pavement management module in AIMS toautomate/facilitate the processing of data from the AIMS database into HDM4 for analysis.
The primary function of the pre-processor it to reduce the intensity and volume of datathat is required to be analysed by carrying out a process termed ‘dynamic segmentation’.
This essentially turns raw data collected in small interval cells of the pavement into

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homogenous continuous sections of the pavement, termed ‘treatment lengths’ fordeterioration and works optimisation analysis in HDM4.
On completion of analysis in HDM4, the results of analysis is further processed to generate
the required AM reporting.

Figure 4 Schematic Data Processing Flow in AIMS Pavement Management Module
Bridge Management module

Figure 5 Schematic Data Processing Flow in AIMS Bridge Management Module
The primary objective of bridge management is to ensure safety of road users. In order toachieve the objective, earliest signs of deterioration or defects have to be captured
through scheduled inspections and special investigation/testing carried out for each of thecritical components of the bridge. The condition of all components of the bridge is assessed
for severity and extend of defect. Ranking for condition and urgency for repair for each of
the component is applied and an overall bridge index is calculated based on summation ofweighted scores of these components. The functionality of the Bridge Management
module of AIMS will have to be aligned with this data collection and condition assessment
technique.

792

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT
In a more advance application of Bridge Asset Management, a modelling or deterioration‘engine’ can be developed in the module to provide the forecasting functionality to themodule. This will enhance the long term preventive maintenance capability of the system.
The output from the Bridge Management module will be bridge repair/rehabilitation work
programmes with a prioritised work lists according to urgency to restore safety andfunctionality of the asset. The module will have the capability to schedule inspection basedon criticality of the component to the integrity and safety of the bridge.
Slope Management module

Figure 6 Schematic Data Processing Flow in AIMS Slope Management Module
The approach of Slope Management module for AMS can be based on a risk management
approach. Slope assets are ranked according to risk of failure happening and consequential
risk to road user. The risk of failure is dependent on the physical inventory attribute of theslope (inclination, height, type etc.) and environmental factors. These data will be part of
the AIMS database that is to be extracted for evaluation of risk ranking. To inculcate apreventive maintenance approach to slope management, the frequency of inspection ofslope assets is varied based on slope risk category as per the example below:

Figure 7 Assigning Slope Inspection Frequency based on Slope Risk Ranking
As there are numerous environmental factors specific to sites that will affect thedeterioration of slope stability, a generic slope failure model is not normally used in AIMS
to forecast future conditions and rehabilitation requirements.
Drainage and Road Furniture module
The approach to drainage assets and road furniture module is similar in that it is based on
visual (or instrumented) survey of condition of assets and evaluating the following indices:a. Structural integrity index – the degree to which the asset is structurally sound.
b. Serviceability index – the level of service of the assets compared to its design level.

793

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT
c. Urgency for work – the urgency to repair or maintain based on road user safetyconcerns or consequential damages due to unrepair.

Figure 8 Schematic Data Processing Flow in AIMS Drainage and Road FurnitureManagement Modules
An overall index is developed based on weightages being applied to each of the above
indices. Works are prioritised based on ranking of the overall index.
Work Management Level
Work Management process involves the development of Forward Work programmes fromthe asset management strategies. These are planned and scheduled works triggered as aresult of analysis carried out in the previous stage to conform to a selected asset
management strategy. In addition, this stage of process will include ad-hoc or unscheduledworks triggered from customer complaints, events happening such as damages caused by
accidents, emergency responses such as floods or work due to significant importance(protocol). The common application tools are work order / maintenance contract
management systems.

Figure 9 Schematic Data Processing Flow in AIMS Work Management module
The modules in the Work Management level of AIMS will support the following processes:

794

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT
Management processes:
a.
b.
c.
d.
e.

Compilation of prioritised candidate work lists from asset management modules.
Provides estimates on cost of works from Schedule of Rates or from tender/quotes.
Manage and control the authorisation of work flow.
Generation of work orders / specification of works / work documents.
Manage budget allocations and disbursement.

Monitoring processes:
a.
b.
c.

Project execution, status reporting, issues management.
Implementation of authorised work programmes.
Budget and expenditure.

Updating process:a.
b.
Provide feedback update to AIMS database on inventory changes.
Records work history.

Performance Management Level
Performance Management is an integral part of the AM process. Performance
Management provides the feedback required to the AMS for continual adjustment andimprovement of asset management strategies, work programmes, condition assessment
technique, work-triggering mechanism, analysis and modelling techniques, budgeting andfunding of works.
The objective of the AIMS module is to support the Performance Management process byproviding a tool to monitor the performance measures, or Key Performance Indices (KPI) as
defined in the AMF.

Figure 10 Categories of Performance Measure or KPIs

795

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT
KPIs are measured as dashboards on a computerised AIMS. An example of a KPI dashboard
is as shown in Figure 11.

Figure 11 Example of a AIMS Performance Management Dashboard
Dashboards displays are for management decisions support. It is used to monitor the
performance of physical assets and the operation efficiency and management
effectiveness of the Asset Manager. The KPIs are high levels summarised representationsof required levels of services as defined in the AMF. The definition of KPIs and themethodology to derive the achieved value should be defined and agreed upon between
stakeholders and documented in the AMF.
The Performance Management module in AIMS will need to be able to mine and extract
performance related data from the AIMS database, compute according to the specified KPI
computation methodology and display in the Performance Dashboard. In a more advanced
version of the dashboard, drill down from high level KPIs to derive at the root cause /issues that contributed to the achieved KPI level can be incorporated.
B.

System Architecture
AIMS should be a collaborative platform for all stakeholders in the AM delivery chain. The asset
owner (authorities, agencies) and/or its appointed asset manager should assume ownership of
the AIMS database and application system. They will be responsible for the operations andmaintenance of the system. Data collection contractors, who carry out annual or periodic
surveys of asset inventory and conditions will provide data in batches to the AIMS databasemanager and GIS staff to be input into the AIMS database. Data may also be updated directly
into the AIMS database by the asset owner/managers own staff, these are normally visualcondition assessment data (carried for the purpose of performance auditing) and works related
information. Maintenance contractors or concessionaires will need to provide input in terms ofwork requirements (notification of defects) and progress information into AIMS. The asset

796

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT
manager will carry out analysis on the data that is verified and uploaded by the database/GIS
manager and produce the required analysis and reporting deliverables.
AIMS will need to be established on an internet/cloud based platform to enable thecollaborative nature of AIMS among stakeholders as shown in Figure 12.
The system architecture of AIMS shall be a configuration that promotes:
a. Sharing of AM related data within the stakeholders sphereA networked or connected system architecture enables assessing and exchange of data andinformation among stakeholders. With the advancement in internet/web technology andprocessing capability of mobile devices, AIMS will be a common platform for sharing of vital
information for the effective management of infrastructure assets.
b. Collaborative work flow between owners, managers and works implementers
The process of AM needs to be conform to a defined and documented approach. This
process shall be part of the organisation’s standard operating procedure in AM. All staff
involved in the asset management process will have roles and responsibilities defined in
information and knowledge management using AIMS. The use of database and internet
technology enables more effective and efficient collaborative effort be made.

Figure 12 AIMS System Architecture to Enhance Accessibility and Usage797

2ND IRF ASIA REGIONAL CONGRESS & EXHIBITION OCT 16 – 20 2016 KUALA LUMPUT

Conclusion
The success of implementation of an AIMS hinges on the understanding that AIMS’ sole purpose
is to support the Asset Management process. An implementing organisation without an AssetManagement centric work processes will not be able to provide the framework for AIMS
development and implementation. In addition, AIMS depends on quality data to generate theknowledge for the most cost effective decision in maintenance investments or spending. For
AIMS implementation to be successful, funding for data collection should not only be required
for the initial development stage, but operations and maintenance of AIMS in the long run.
There are numerous cases of failed AIMS because there were insufficient funding for datacollection and updating of the AIMS.
Organisations implementing AIMS will need to have a top down approach to its implementation.
Senior management must understand and subscribe to the AM process and commit to
implementing not just a computerised AIMS but an AMS framework as a whole. Funding for thecontinued development, adjustments, enhancement to the overall AMS system underpins theeffectiveness and sustainability of the system. A champion from the senior management ranks
should be identified and provide the drive and change impetus required in its implementation.
The champion will be assisted by a knowledgeable industry implementer in providing advice inindustry’s best practices and pitfalls to avoid.
Organisation will need to adopt industry best practice in Asset Management and have all
stakeholders (including contractors) to understand and subscribe to an accepted AssetManagement Framework, which covers the following area:o

Objectives, KPIs, performance measures and required levels of service.

oAsset management process to be institutionalised.

oData collection, processing and reporting requirements.

oMethodology for forecasting, modelling and optimisation.

o

Establishment of a performance monitoring and management system.

Understanding that AIMS will be more than just an information system, it will need to assist theasset manager in all aspects of AM which includes:oCondition assessment and gap analysisoWorks Planningo

Condition and economic forecastingo

Costing, budgeting and valuationoPerformance MonitoringoRisk Management

All relevant stakeholders in the AM supply chain must be involved in the development,
operations and usage of AIMS. AIMS will need to be developed on a common collaborative
platform that all relevant stakeholders can participate in providing inputs and the knowledge
support in return from AIMS.

798

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Cost Analysis of Fiber-Reinforced Pavements

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Waleed A. ZEIADA

Assistant Professor

University of Sharjah

United Arab Emirates

CO-AUTHOR(S)(Capitalize Family NamePOSITIONORGANIZATIONCOUNTRY

B. Shane UNDERWOOD

Assistant Professor

Arizona State University

USA

Kamil E. KALOUSH

Associate Professor

Arizona State University

USA

E-MAIL(for correspondence)wzeiada@sharjah.ac.ae

KEYWORDS:
Synthetic Fibers, Asphalt Concrete, Pavement Performance, Cost Analysis

ABSTRACT:
Synthetic fibers have recognized as a cost effective strategy when added to paving materials around the world. Fiberbased asphalt pavement technologies generally require a larger initial investment than conventional asphalt concrete.
However, benefits in long-term performance reduce the overall cost of the project when examined over its entire life
cycle. The Mechanistic Empirical Pavement Design Guide (MEPDG) simulations showed that using the fiber-reinforced
asphalt concrete (FRAC) significantly reduces the rehabilitation activities especially to mitigate alligator cracking suchas crack sealing and patching when compared to conventional pavement. A Life Cycle Cost Analysis (LCCA) shows anominal present net worth savings of approximately 17% with the FORTA fiber product. The analysis described in thispaper shows that these savings can result in a dollar value difference of approximately $35,000 per mile/lane over a 50
year analysis cycle or $20,509 over a 40 year analysis cycle.

799

Dr. Waleed A. Zeiada1, Dr. B. Shane Underwood2, Dr. Kamil Kaloush2
1

University of Sharjah, Sharjah, UAE

2

Arizona State University, Arizona, USA

Email for correspondence: wzeiada@sharjah.ac.ae

1. INTRODUCTION
Fibers can be used to improve the properties of the Asphalt Concrete (AC) mixtures through spatial
networking, absorption and adhesion of asphalt. The first documented evidence of fiber reinforcement in asphalt
concrete (AC) occurred in the early 1950s as a strategy to prevent reflective cracking in an asphalt concrete overlay (1).
The current state of knowledge with respect to fiber-reinforcement in AC materials has made favorable conclusions
regarding the use of fiber reinforcement in AC. In dense graded and open graded asphalt concrete mixtures, fibers havebeen shown to: alter the viscoelasticity (2); increase dynamic modulus and decrease rutting (3-9); improve moisturesusceptibility (10); reduce reflective, thermal, and fatigue cracking (11-15); and enhance the overall mixture durability(16-18). To date, several fiber types have been used in AC mixtures and are categorized mainly as natural/non-synthetic
or synthetic. The use of natural and non-synthetic fibers has provided more inconsistent results due in large part to theirdegradation under environmental exposure and high temperatures (19-21). Due to the relatively small quantities needed,
the cost of using synthetic fibers in AC mixtures is normally low compared to the expected performance improvements
if properly distributed within the mix. The most commonly used synthetic fibers are polymer fibers which includes
polyester, nylon, polyethylene, polypropylene, aramid, and combinations thereof. Different polymers have different
melt points, which need to be considered when adding fibers to hot mix asphalt. Reportedly, aramid fibers contract at
high temperatures, which helps resist pavement deformation (3-5). The reinforcing capability of synthetic polymer
fibers has been proven in many laboratory and field studies as promising and safe reinforcing elements (3-5, 22-24).
Tapkin showed a positive effect for the Fiber-Reinforced Asphalt Concrete (FRAC) using polypropylene fiber
on Marshall Stability, flow values, prolonged fatigue life, resistance to rutting and reflective cracking (25). Wu et al.
examined the dynamic modulus of three fiber-modified asphalt mixtures: cellulose, polyester and mineral fibers at
dosages of 0.3%, 0.3%, and 0.4% respectively. The experimental results showed that fiber-modified asphalt mixtures
had higher dynamic modulus compared with the control mixture (6). Qadir investigated the rutting susceptibility of
FRAC mixture containing polypropylene fibers using the Wheel Tracking Device. The samples were tested at four
temperatures; 40°C, 50°C, 55°C and 60°C.The polypropylene fibers were found to increase the Marshall stability byalmost 25% and resist rutting more effectively at elevated temperatures (26). Tapkin reported that the addition ofpolypropylene fibers improves the behavior of the FRAC specimens by increasing the repeated creep loading lives by
5–12 times compared to control specimens (27). Research performed in Mexico and Texas has shown that the additionof polyester fibers in asphalt concrete pavements reduces reflective cracking (28, 29). Ma et al. 2006 compared thelaboratory behavior of polyester FRAC to no-fiber-reinforced asphalt mixture using laboratory performance tests
including high-temperature stabilization, low-temperature crack resistance, and fatigue resistance. The study indicatedthat polyester FRAC mixture has eminent pavement performance and economic benefits as expressway's surface layercompared to no-fiber asphalt mixture (30). However several studies have clearly showed the improved performance ofAC mixtures using synthetic fibers, only limited studies are available to show their cost effectiveness.
Since 2006, Arizona State University (ASU) has been engaged in a research program to evaluate theperformance benefits of synthetic polymer fibers. The fibers are a proprietary blend of collated fibrillated polypropylene
and aramid providing a three dimensional reinforcement to the Hot Mix Asphalt (HMA). The polypropylene fibers are
chemically inert, non-corrosive, and non-absorbent; whereas the aramid fibers have a high tensile strength, noncorrosive and have resistance to high temperatures. The physical characteristics of the fibers have been reported in otherpublications (3). The performance of the FRAC mixtures using the polypropylene-aramid fibers blend is assessed at
ASU and other pavement laboratories using advanced material characterization tests for mainly stiffness, permanent
deformation, and cracking evaluation. More details on the laboratory test results of the FRAC mixtures from several
field and laboratory projects can be found elsewhere (31).

2. OBJECTIVES
The main objective of this paper is to investigate the cost effectiveness of using the polypropylene-aramid fiber
blend with AC mixtures based on laboratory test results of 12 different mixtures tested mainly at ASU and othernational and international pavement laboratories.

800

3. SUMMARY OF FRAC PROJECTS, TEST METHODS, AND RESULTS
Polypropylene-aramid blend fibers are a performance enhancing technology that has been used to improve theresistance of AC mixtures to permanent deformation and cracking. The technological capabilities of these fibers havebeen demonstrated in multiple laboratory and field studies over the years. This study includes twelve different projects
from the United States and abroad where detailed performance assessment has been carried out. For many of theseprojects, AC mixtures were sampled during construction, transported to the laboratory, and evaluated using standard
and advanced experimentation. Only one study, ASU Fiber Dosage Study, used exclusively laboratory mixtures and it
was conducted to systematically evaluate parameters that could not be easily studied with field mixtures. The twelve
projects considered in this study are listed below:
1. FORTA Boeing Project, Arizona, USA
2. FORTA Evergreen Project, Arizona, USA
3. FORTA Jackson Hole Airport Project, Wyoming, USA
4. FORTA Cranberry Township Project, Pennsylvania, USA
5. FORTA Montreal Project 1, Canada
6. FORTA Montreal Project 2, Canada
7. FORTA South Dakota Project, USA
8. FORTA Middle East Study, Iran
9. FORTA New Jersey Study, USA
10. FORTA Czech Republic Project, Czech Republic
11. FORTA University of Illinois Study, Illinois, USA
12. ASU Fiber Dosage Study, Arizona, USA
The materials studied in these projects represent different aggregate and asphalt types, gradations, contents (airvoid, aggregate, and asphalt), climate region, and mixing plant type. Table 1 includes a summary of test methods
conducted mainly on AC mixtures from the 12 projects to assess stiffness, fatigue cracking, and rutting.
Table 1. Summary of Test Methods Performed on FORTA products

Mixture Test
Dynamic Modulus Test
Resilient Modulus Test
4-Point Bending Modulus Test
Hamburg Wheel Tracking Test
Asphalt Pavement Analyzer Test
Flow Number Test
Beam Fatigue Test
Uniaxial Fatigue Test
Indirect Tensile Fatigue
Semi-Circle Bending Test

PurposeStiffness/Material Response from Load

Rutting Evaluation

Fatigue Cracking (Initiation)

Project(s)1-7,9,11, 12
8
10
8,10,119
1-3,5,6, 8,9
1-3,9
4-6
8,10
10,11

In total these studies reveal many positive benefits using 1lb/ton fibers on mix stiffness, fatigue cracking, andrutting as summarized below:o Stiffness: The FRAC mixtures showed an overall average of 13% stiffness increase compared to theconventional mixtures.
o Rutting Resistance: The FRAC mixtures exhibited 4.7 times higher Flow Number and 1.9 times lower rutting
magnitude compared to those of the conventional mixtures.
o Fatigue cracking resistance: The cyclic fatigue tests results showed that FRAC mixtures exhibited 3 times
more fatigue life compared to the conventional mixture.

4. PREDICTION OF PAVEMENT PERFORMANCE USING MEPDG
The pavement performance of the conventional and the 1 lb/ton FRAC mixture was predicted using the
MEPDG. For this analysis MEPDG version 1.1 has been utilized. The total simulation period was 50 years for the
purpose of life cycle cost analysis (LCCA) divided into three individual simulation periods (10 to 20 years). Two main
distresses were considered in this analysis; total rutting and bottom-up fatigue cracking (alligator cracking). The
MEPDG simulations were conducted with respect to Arizona State calibration. For the fiber-reinforced pavement, thealligator cracking distress prediction model was calibrated to increase the fiber-reinforced pavement resistance against
alligator cracking by three times compared to the conventional pavement (concluded based on the average laboratory801performance of 12 fiber studies). The dynamic modulus |E*| values used for the fiber-reinforced pavement simulations
were also increased by 13% which is the average increase in the modulus due the use of fibers blend based on the
results obtained from 12 fiber studies. The total rutting distress prediction model for the fiber-reinforced pavement was
kept the same as the conventional pavement as there is not enough data to calibrate the model for fiber reinforced
mixture. However, it is anticipated that the fiber-reinforced pavement would exhibit better rutting performance due tothe increased stiffness of fiber-reinforced mixture. Table 2 shows the conventional and the FRAC |E*| values used in
the MEPDG simulations where the |E*| values of a typical 19-mm conventional dense graded mixture was used andthen was increased by 13% for the FRAC mixture. Table 3 shows the MEPDG inputs for both conventional and fiberreinforced pavements.

Table 2. |E*| Values for Conventional and Fiber-Reinforced Mixtures
Temp. oF
(oC)

14
(-10)

40
(4.4)

70
(21.1)

100(37.8)

130(54.4)

Freq. Hz
25
10
5
1
0.5
0.1
25
10
5
1
0.5
0.1
25
10
5
1
0.5
0.1
25
10
5
1
0.5
0.1
25
10
5
1
0.5
0.1

Dynamic Modulus, MPa - ksi(Test Values)
Fiber-Reinforced
Conventional
6,847
47,206
6,059
41,775
6,313
43,528
5,587
38,5206,215
42,8505,500
37,9205,631
38,822
4,983
34,356
5,397
37,206
4,776
32,9264,760
32,812
4,212
29,037
4,736
32,654
4,191
28,897
4,551
31,378
4,027
27,7684,286
29,548
3,793
26,1493,621
24,961
3,204
22,0893,322
22,905
2,940
20,2702,663
18,3592,357
16,247
2,552
17,5902,258
15,566
2,223
15,326
1,967
13,563
1,989
13,715
1,760
12,137
1,454
10,023
1,287
8,870
1,252
8,630
1,108
7,637
858
5,910
759
5,230
1,141
7,865
1,010
6,960
924
6,374
818
5,641
774
5,337
685
4,723
499
3,441
442
3,045
407
2,805
360
2,482
266
1,834
235
1,623
437
3,015
387
2,668
332
2,287
294
2,024
279
1,923
247
1,702
195
1,349
173
1,194
176
1,216
156
1,076
147
1,009
130
893

Modular
Ratio
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13
1.13

802

Table 3. Inputs of MEPDG Simulations
Traffic Data
Initial two-way Annual Average Daily Truck Traffic(AADTT)

2,500

Number of lanes in design direction

2

Percent of trucks in design direction (%)

50

Percent of trucks in design lane (%)

80

Operational speed, kph (mph)96.6 (60)Traffic Growth Factor

Comp. 4%
Climate Data

Weather Station

Phoenix Airport, PHX

Latitude (degrees.minutes)

33.26

Longitude (degrees.minutes)-111.59

Elevation, m (ft)337 (1106)

Depth of water table, m (ft)

6.1 (20)
22.92 (73.25)

Mean annual air temperature, ºC (ºF)
Pavement Section Data
Material type
Layer 1

Layer 2

Layer 3Asphalt concrete

Layer thickness, cm (in)10 (4)

Reference temperature, ºC (°F)

21.1 (70)

Unbound Material

Crushed Gravel

Thickness, cm (in)20 (8)

Modulus, kPa (psi)172,369 (25,000)

Plasticity Index, PI

1

Liquid Limit, LL

6

Unbound Material

A-6

Modulus, kPa (psi)99,974 (14,500)

Plasticity Index, PI

16

Liquid Limit, LL

33Preliminary MEPDG simulations were conducted on the conventional pavement section so that it would show
a balanced performance with respect to rutting and fatigue cracking and to be close as possible to the failure criteria ofrutting or alligator cracking after 20 years from the initial construction. The total rutting failure criteria was 0.75 inch
and the alligator failure criteria was 25% of the of the pavement area. The MEPDG simulations were then conducted on
the rehabilitated conventional pavement section for another 20 followed by maintenance activities and then 10 years
which is the end of the LCCA analysis period. The MEPDG simulations were conducted on the fiber-reinforced
pavement using the same conventional structure until failure criteria was reached. In this case, the total simulation
period was also 50 years divided into three stages where the stage period was determined when the fiber-reinforced
pavement performance (total rutting or alligator cracking) reached the same level the conventional pavement reached at
the end of each analysis period. The future traffic for each simulation period was predicted using 4.0% compound
traffic growth rate. Figure 1 and Figure 2 showed a comparison of predicted total rutting and alligator cracking
respectively for conventional and fiber-reinforced pavements. It is observed that the rutting performance of the fiberreinforced pavement is slightly better than the conventional pavement; however the alligator cracking performance ofthe fiber-reinforced pavement is substantially better than the conventional pavement. Table 4 includes a summary of the
MEPDG simulations for conventional and fiber-reinforced pavements.

803

1.00

Total Rutting, Inch

Conventional

Fiber-Reinfroced

0.75

0.50

0.25

0.00
0

10

20
30
40
Pavement Age, Year

50

60

Figure 1. |E*| Prediction of Total Rutting for Conventional and Fiber-Reinforced Pavements

30

Conventional

Fiber-Reinforced

Alligator Cracking, %

25
20
15
10
5

0
0

10

20

30
40
Pavement Age, Year

50

60

Figure 2. |E*| Prediction of Alligator Cracking for Conventional and Fiber-Reinforced Pavements

Table 4. Summary of MEPDG Simulations for Conventional and Fiber-Reinforced Pavement
Simulation
Stage

Parameter

Conventional

Fiber-Reinforced

First

Simulation Period
AADT at End of First Stage
Rutting at End of First Stage, inch
Alligator Cracking at End of First Stage, %

20
5,500
0.74
26.2

22
6,000
0.74
8.9

SecondSimulation Period
AADT at End of Second Stage
Rutting at End of Second Stage, inch
Alligator Cracking at End of Second Stage, %20
12,000
0.767
22.9

21
12,500
0.767
8.2

Third

Simulation Period
Rutting at End of Third Stage, inch
Alligator Cracking at End of Stage, %Extended Surface Life after 50 Years, year
(For salvage calculation)

10
0.66
9.7

7
0.58
2.0

4.75

8.25

804

5. REHABILITATION STRATEGY
The following decisions are made for the rehabilitation plan for both conventional and fiber-reinforced
pavements:






Crack seal is applied at 4% increment of alligator cracking
Patching of alligator cracks is applied at 8% increment of alligator cracking
Milling and asphalt concrete overlay are applied when total rutting is close to 0.75 inch
The milling of the conventional pavement is 2.0 inches deep and 1.0 inch deep for fiber-reinforced pavement due
to the higher alligator cracking for the conventional pavement
The AC overlay thickness is 3.0 inches for the conventional pavement and 2.0 inches for the fiber-reinforced
pavement as it has less amount of alligator cracking.

Based on the maintenance decisions, the rehabilitation activities for conventional and fiber-reinforced
pavements are shown in Figure 3 and Figure 4 respectively. The predicted performance of both pavements showed thatthe use of the FRAC mixtures significantly reduces the rehabilitation activities especially to mitigate alligator cracking
such as crack sealing and patching. Analysis was completed using 30, 40, and 50 year performance windows. Following
national convention user costs (costs of delays, increased vehicle maintenance, impacts from pavement roughness onfuel consumption, etc.) were omitted from this analysis. In light of the impact of increased maintenance activities onthese costs it is expected that this analysis results in a conservative assessment of the true life cycle cost benefits of
FRAC mixtures.
Milling &Overlay

InitialConstruction

Patching

Patching

Patching
Crack Seal

Crack Seal

Crack Seal

Milling &Overlay

Patching

Patching
Crack Seal

Crack Seal

50
0

4

8

12

16

20

24

28

32

36

40

44

48

Pavement Age, year
Figure 3. Rehabilitation Activities for Conventional Pavement
Milling &Overlay

Milling &Overlay

InitialConstruction

Crack Seal

Salvage

Crack Seal

50
0

11

22

33

43

Pavement Age, year
Figure 4. Rehabilitation Activities for Fiber-Reinforced Pavement

Salvage

6. LCCA ANALYSIS
Updated costs for the applied rehabilitation activities were obtained according to the state of Arizona. The
costs of the different construction and rehabilitation items are summarized in Table 5. The LCCA is conductedconsidering only one lane/mile for both conventional and fiber-reinforced pavement. The salvage value was determinedbased on the extended pavement service life after the LCCA period. The patching area was calculated by taking 33% of
the cracked area and assuming one third of the alligator cracking area has severe cracks. The crack sealing length wasestimated assuming there is one main fatigue crack under each wheel path and one transverse crack repeated every 15
ft. Table 6 and Table 7 include a summary of LCCA results of conventional and fiber-reinforced pavements
respectively for the 50 year analysis period. Costs are assessed using both the net present worth, Equation (1), and theequivalent annualized cost, Equation (2). The net present worth converts all costs during the life cycle to current year
dollars whereas the equivalent annualized method distributes the costs over the life time (accounting for the time-value805

of money). Discount rates of 3-5% were used, which represent the conventionally suggested rates for LCCA. Resultsfrom all of the analysis cases are summarized in Table 8, as the difference in the PWC or EAC between theconventional and FRAC mixtures. In all cases the benefits of fibers are clear.
N
 1 
 1 
(1)
NPW  InitialCost   R j   SalvageValue 

n
n
j 1
 1  i    1  i   

 i  1  i  n 
EAC  PWC n 1  i    1

(2)

Where,
i'
n
Rj

=
=
=

discount rate
year of expenditure
rehabilitation expenditure (single cost expenditure)

Based on the 50 year analysis period and the 4% discount rate, the following conclusions can be made:1. The addition of the fibers at 1 lb/ton dosage reduces the net present worth by $36,268 per mile/lane.
2. Increasing the cost of the fiber-reinforced mixture tonnage to $72, the estimate reduction in the net present worth
is $33,462.
3. The savings in the net present worth due to the fiber usage is anticipated to increase if the user cost is considered
due to the lower rehabilitation activities rate of the fiber-reinforced pavement compared to the control pavement.
That means the user delays in case of the fiber-reinforced pavement is much less compared to the conventional
pavement.
LCCA summarized in Table 8 showed that the cost differences change depending on the exact discount rate
and analysis period considered, but in all cases the fiber-reinforced pavement was found to yield a reduced cost whencompared to the conventional pavement.
Table 5. Costs of Construction and Rehabilitation Items
Item

Unit

Cost/Unit, $Conventional Asphalt Mix
Fiber-Reinforced Asphalt Mix
Crack Sealing
Patching
Milling
Asphalt Concrete Overlaytontonlinear footsquare foottonsquare foot/ inch

60.0
70.0
0.35
2.6
5.0
0.715

Table 6. Summary of LCCA for Conventional Pavement, 4% discount rate, (Lane/ Mile)
Activity
Initial Construction of 4 inches
Conventional Mixture
Crack Sealing
Patching
Crack Sealing
Patching
Milling of 2 inches
Overlay of 3 inches
Crack Sealing
Patching
Crack Sealing
Patching
Milling of 2 inches
Overlay of 3 inches
Crack Sealing
Patching
SalvageTime, year

Unit

Unit
Cost, $

Quantity

Total
Cost, $

Present
Worth, $

0

ton

60.00

1,584

95,04095,0404ft
0.35
8square ft
2.60
12
feet
0.35
16
square ft
2.60
20
ton
5.00
20
square ft
2.15
24
ft
0.35
28
square ft
2.60
32
ft
0.35
36
square ft
2.60
40
ton
5.00
40
square ft
2.15
44
ft
0.35
48
square ft
2.60
50
ton
60.00
Net Present Worth, $Equivalent Annual Cost, $/yr

580
1,670
580
1,670
792
63,360
580
1,670
580
1,670
792
63,360
580
1,670
765

203
4,342
203
4,342
3,960
136,224
203
4,342
203
4,342
3,960
136,224
203
4,342(45,900)

174
3,173
127
2,318
1,807
62,171
79
1,448
58
1,058
825
28,37436
661(6,459)190,8898,886

806

Table 7. Summary of LCCA for Fiber-Reinforced Pavement, 4% Discount Rate (Lane/ Mile)
Time,
year

Unit

Unit
Cost, $

Quantity

Total
Cost, $

Present
Worth, $

0

ton

70.00

1,584

110,880

110,880

11
ft
0.35
22
ton
5.00
22
square ft
1.43
33
ft
0.35
43
ton
5.00
43
square ft
1.43
50
ton
70.00
Net Present Worth, $Equivalent Annual Cost, $/yr

580
396
63,360580
396
63,360
1285

203
1,980
90,605203
1,980
90,605(89,950)132
835
38,23156
367
16,777(12,657)
157,624
7,198

Activity
Initial Construction of 4 inches
Conventional Mixture
Crack Sealing
Milling of 1 inches
Overlay of 2 inches
Crack Sealing
Milling of 1 inches
Overlay of 2 inches
Salvage

Table 8. Summary of LCCA Results for NPW and EAC Methods for Analysis Periods and Discount Rates
Discount Rate (%)
Analysis Period(years)3
4
Difference in NPW ($/Lane/Mile)30
27,92320,05740
28,43820,50950
51,41936,268Difference in EAC ($/Lane/Mile/Yr)
30
1,085
934
40
1,105
955
50
1,998
1,688

5
13,95814,33325,190
765
785
1,380

7. CONCLUSIONSIn this study, the laboratory test results of 12 projects on FRAC and conventional mixtures were reported. The
testing plan tended mainly to evaluate the materials stiffness, fatigue cracking, and rutting of conventional and FRAC
mixtures. Based on the average results from 12 projects, the FRAC mixtures showed 13% stiffness increase, 4.7 times
higher Flow Number, 1.9 times lower rutting magnitude, 3 times more fatigue life compared to the conventional
mixture. Predicted pavement performance using MEPDG showed a better performance of the fiber-reinforced pavement
especially against fatigue cracking which required less rehabilitation activities compared to the conventional pavements.
Using discount rate ranges from 3-5% and analysis period ranges from 30 to 50 years, the LCCA detailed in this paper
showed that using fibers can result in a saving in the net present worth dollar value ranges from $14,000 to $50,000 per
mile/lane or a reduction in the equivalent annual cost ranges from 750 to 2,000 mile/lane/year. The estimated savingsare expected to increase by calibrating the rutting model for the FRAC mixture in the MEPDG simulations and byconsidering user cost in the LCCA.

8. REFERENCES
1.
2.
3.
4.

Zube, E. (1956) Wire mesh reinforcement in bituminous resurfacing, Highway Research Record, vol. 131, pp.
1-18.
Huang, H, White, TD. (1996). Dynamic properties of fiber–modified overlay mixture, Transportation researchrecord: Journal of transportation research board, vol. 1545, pp. 98-104.
Kalloush, K.E., Biligiri, K.P., Zeiada, W.A., Cary, C., Dwivedi, S., Reed, J., Rodezno, C. (2008). Evaluationof FORTA Fiber-Reinforced Asphalt Mixtures Using Advanced Material Characterization Tests – Evergreen
Drive. Tempe, Arizona, Final Report Submitted to FORTA Corporation, Grove City, Pennsylvania.
Kaloush, K.E., Biligiri, K.P., Zeiada, W.A., Rodezno, M., and Reed, J. (2010). Evaluation of Fiber-Reinforced
Asphalt Mixtures Using Advanced Material Characterization Tests. Journal of Testing and Evaluation, ASTM
International, Volume 38, Number 4, pp. 400-411.

807

5.

Kaloush, K.E., Underwood, B.S., Zeiada, W.A., and Stempihar, J. (2015). Fiber reinforced asphalt concrete:
Performance tests and pavement design consideration. In Bituminous Mixtures and Pavements VI, Proceedingsof the 6th International Conference on Bituminous Mixtures and Pavements, ICONFBMP 2015. (pp. 313-318).
CRC Press/Balkema.
6. Wu, S., Ye, Q., Li, N., and Yue, H. (2007). Effects of fibers on the dynamic properties of asphalt mixtures.
Journal of Wuhan University of Technology- Materials Science Edition, vol. 22(4), pp. 733-736.
7. Behbahani, H., Nowbakht, S., Fazaeli, H., and Rahmani, J. (2009). Effects of fiber type and content on therutting performance of stone matrix asphalt. Journal of Applied Sciences, vol. 9(10), pp. 1980-1984.
8. Mahrez, A., Karim, M.R., and Katman, H.Y. B. (2005). Fatigue and deformation properties of glass fiber
reinforced bituminous mixes. Journal of the Eastern Asia Society for Transportation Studies, vol. 6, pp. 9971007.
9. McDaniel, R.S. (2001). Asphalt additives to control rutting and cracking. PhD Dissertation, Purdue University,
West Lafayette, Indiana. USA.
10. Putman, B.J., and Amirkhanian, S. N. (2004). Utilization of waste fibers in stone matrix asphalt mixtures.
Resources, conservation and recycling, vol. 42(3), pp. 265-274.
11. Tapkın, S. (2008). The effect of polypropylene fibers on asphalt performance. Building and Environment, vol.
43(6), pp. 1065-1071.
12. Maurer, D.A., and Malasheskie, G. J. (1989). Field performance of fabrics and fibers to retard reflective
cracking. Geotextiles and Geomembranes, vol. 8(3), pp. 239-267.
13. Peltonen, P.V. (1991). Characterization and testing of fibre-modified bitumen composites. Journal of materials
science, vol. 26(20), pp. 5618-5622.
14. Wu, S., Ye, Q., and Li, N. (2008). Investigation of rheological and fatigue properties of asphalt mixturescontaining polyester fibers. Construction and Building Materials, vol. 22(10), pp. 2111-2115.
15. Ye, Q, Wu, S, and Li, N. (2009). Investigation of the dynamic and fatigue properties of fiber-modified asphalt
mixtures, Intl. J. of Fat. 31: 1598–1602.
16. King, G., King, H., Pavlovich, R.D., Epps, A.L., and Kandhal, P. (1999). Additives in asphalt. Journal of the
Association of Asphalt Paving Technologists, vol. 68, pp. 32-69.
17. Bruce R.W. (20030. The pavement performance and life-cycle cost impacts of carbon fiber modified hot mix
asphalt,” MS Thesis, Michigan Technological University, Houghton, Michigan, USA.
18. Reed, BF, James, L, and Burati, J.R. (1996). Polyester fibers asphalt paving mixtures, Journal of the
Association of Asphalt Paving Technologists, vol. 65: pp. 387-407.
19. Bushing, H.W, and Antrim, J.D. (1968). Fiber reinforcement of bituminous mixtures, Journal of the
Association of Asphalt Paving Technologists, vol. 37, pp. 629-659.
20. Tons, E., Krokosky, E.M. (1960). A study of welded wire fabric strip reinforcement in bituminous concrete
resurfacing, Journal of the Association of Asphalt Paving Technologists, vol. 29, pp. 43-80.
21. Marais, C.P. (1979). The use of asbestos in trial sections of gap-graded asphalt and slurry seals, Proceedings of
the Third Conference on Asphalt Pavements for South Africa. Durban, pp. 172-175.
22. Maurer, D.A., and Malasheskie, G.J. (1989). Field performance of fabrics and fibers to retard reflective
cracking. Geotextiles and Geomembranes, vol. 8(3), pp. 239-267.
23. Stempihar, J., Souliman, M., and Kaloush, K. (2012). Fiber-Reinforced Asphalt Concrete as Sustainable
Paving Material for Airfields. Transportation Research Record: Journal of the Transportation Research Board,
vol. 2266, pp. 60-68.
24. Prowell, B.D. (2000). Design construction, and early performance of hot-mix asphalt stabilizer and modifier
test sections interim report. Virginia Transportation Research Council, Interim Report VTRC 00-IR2,
Charlottesville, VA, USA.
25. Tapkın, S. (2008). The effect of polypropylene fibers on asphalt performance. Building and Environment, vol.
43(6), pp. 1065-1071.
26. Qadir, A. (2014). Rutting performance of polypropylene modified asphalt concrete. International Journal of
Civil Engineering, vol. 12(3), pp. 304-312.
27. Tapkın, S., Uşar, Ü., Tuncan, A., and Tuncan, M. (2009). Repeated creep behavior of polypropylene fiberreinforced bituminous mixtures. Journal of Transportation Engineering, vol. 135(4), pp. 240-249.
28. Button, J.W., and Hunter, T.G. (1984). Synthetic fibers in asphalt paving mixtures. Texas State Department ofHighways and Public Transportation, Research Report 319-IF.
29. Maurer DA. (1985). Comparison of methods to retard reflective cracking in bituminous concrete pavements
using fabrics and fibers: construction and early performance report. Pennsylvania Department ofTransportation, Research Project No. 83-8.
30. MA, X., NI, F.J., GU, X.Y., and SHEN, H. (2006). Study and Analysis on Pavement Performance of the
Polyester Fiber-reinforced Asphalt Mixture. Journal of Highway and Transportation Research andDevelopment, vol. 1, 006.
31. Zeiada, W.A., Underwood, B.S., and Kaloush, K.E. (2014). ASU Results Summary of FORTA Projects.
Tempe, Arizona, Final Report Submitted to FORTA Corporation, Grove City, Pennsylvania.

808

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Automated detection of sealed cracks using 2D and 3D road surface dataTRACK
AUTHOR(Capitalize Family Name)John LAURENT
CO-AUTHOR(S)(Capitalize Family Name
Jean-François HÉBERT
CO-AUTHOR(S)(Capitalize Family Name
Mario TALBOTE-MAIL(for correspondence)

POSITION
Co-Founder and CTO

ORGANIZATION
Pavemetrics Systems Inc.

POSITIONORGANIZATION

Co-Founder and Director
of products

Pavemetrics Systems Inc.

POSITIONORGANIZATION

Member of Scientific Staff

Pavemetrics Systems Inc.

COUNTRY
CanadaCOUNTRY
CanadaCOUNTRY
Canadajlaurent@pavemetrics.com

KEYWORDS:
3D analysis; sealed cracks detection; pavement distress analysis; Laser Crack Measurement System; LCMS

ABSTRACT:
Reliable cracking data has proven difficult and expensive to obtain using cameras and video systems because of the lackof good automated 2D image processing crack detection algorithms. To solve this problem, 3D technology such as the
LCMS (Laser Crack Measurement System) has been used to obtain automated reliable and repeatable cracking data.
The LCMS system has been widely used for automated crack detection on a variety of road surfaces (DGA, porous,
chipseal, concrete) in over 35 different countries. While 3D techniques [1] [2] [3] [4] [5] have proven reliable atdetecting open cracks these systems have not been used for detecting sealed cracks. These sensors however also often
produce intensity (2D) images that are used to detect lane markings. Using this intensity (2D) data for the automateddetection of sealed cracks has also proven unreliable because sealed cracks can sometimes be darker or brighter than thesurrounding pavement in the images and tire marks and other features can also cause false detections.
This article will demonstrate that the accuracy of sealed crack detection can be improved by using both 2D intensity dataand 3D texture information evaluated from the 3D data. To do this 3D texture evaluation algorithms are described andimplemented in order to generate a complete texture map of the road surface. The intensity images are also processed inorder to extract dark and light areas of the appropriate geometry (size and shape of sealed cracks). The combination of
the results from both sets of processed data is then used to detect and validate the presence of sealed cracks.

809

Automated detection of sealed cracks using 2D and 3D roadsurface data
John Laurent, Jean-François Hébert and Mario Talbot1
1

Pavemetrics Systems Inc., Québec, Canada
jlaurent@pavemetrics.com

1 INTRODUCTION
In order to optimize road maintenance funds and improve the condition of road networks, asset managers needdetailed and reliable data on the status of the road network. 3D technology such as the LCMS (Laser Crack
Measurement System) has been used to obtain automated reliable and repeatable cracking data on a variety of roadsurfaces (DGA, porous, chipseal, concrete). The LCMS is composed of two high performance 3D laser profilers that areable to measure complete transverse road profiles with 1mm resolution at highway speeds. The high resolution 2D and
3D data acquired by the LCMS is then processed using algorithms that were developed to automatically extract crack
maps and severity. Also detected automatically are ruts (depth, type), macro-texture (digital sand patch) and raveling(loss of aggregates). This paper describes results obtained recently regarding road tests and validation of this technology
for the detection of both sealed and unsealed cracks.

2 HARDWARE CONFIGURATIONThe sensors used with the LCMS system are 3D laser profilers that use high power laser line projectors,
custom filters and a camera as the detector. The light strip is projected onto the pavement and its image is captured by
the camera. The shape of the pavement is acquired as the inspection vehicle travels along the road using a signal froman odometer to synchronize the sensor acquisition (see figure 1). All the images coming from the cameras are sent to
the frame grabber to be digitized and then processed by the CPU. Saving the raw images would imply storing nearly
30Gb per kilometer at 100 km/h but using lossless data compression algorithms on the 3D data and fast JPEG
compression on the intensity data brings the data rate down to a very manageable 20Mb/s or 720Mb/km. The criticalspecifications for the LCMS system can be found on table I. It is important to note that in addition to the 3D profiles the
LCMS acquires the intensity of the reflection of the laser at each 3D point thus creating an intensity 2D image of thepavement while simultaneously measuring the shape. Figure 2 shows range (distance) image and intensity (2D) dataacquired from the LCMS. A 3D image can be generated from the range and intensity data as shown.

Figure 1. LCMS on an inspection vehicle.

810

Table 1. LCMS Specifications
Nbr. of laser profilers
Sampling rate (max.)
Vehicle speed
Profile spacing
3D points per profile
Transverse field-of-view
Depth range of operation
Z-axis (depth) accuracy
X-axis (transverse) resolution

2
11,200 profiles/s
100 km/h (max)Adjustable
4096 points
4m
250 mm
0.5 mm1 mm

Figure 2. LCMS data type - Range (left) - Intensity (center) - 3D merged (right).

3 RANGE DATA
The 3D data acquired by the LCMS system measures the distance from the sensor to the surface for every
sampled point on the road. The previous image (above left) shows a range data image acquired by the sensors. In thisimage, elevation has been converted to a gray level. The darker the point, the lower is the surface. In a range image theheight can vary along the cross section of the road. The areas in the wheel path can be deeper than the sides and thus
appear darker this would correspond to the presence of ruts. Height variations can also be observed in the longitudinal
direction due to variations in longitudinal profiles of the road causing movements in the suspension of the vehicle
holding the sensors. These large-scale height variations correspond to the low-spatial frequency content of the range.
The first step in range analysis is to separate the high frequency content from the low one. This is performed using a
specially designed filter. Figure 3b shows the result of this process. The low frequency part is what can be referred to as
the mean surface. The high-frequency part clearly shows the presence of surface defects (cracks) and texture. Once
separated, both frequency parts are then used as an input to the various feature detection algorithms the high frequency
component is called the rectified range image as shown below.

Figure 3. (a) Range (raw) and (b) Range (rectified) images811

4 MACROTEXTURE
Macrotexture is important for several reasons, for example it can help estimate the tire/road friction level,water runoff and aquaplaning conditions and tire/road noise levels produced just to name a few. Macrotexture can beevaluated by applying the ASTM 1845-01 norm [6]. This standard requires the calculation of the mean profile depth(MPD). To calculate the MPD, the profile is divided into small (10cm) segments and for each segment a linear
regression is performed on the data. The MPD is then computed as the difference between the highest point on the
profile and the average fitted line for the considered portion. MPD is the only way possible to evaluate texture using
standard single point (64 kHz) laser sensors. The LCMS however acquires sufficiently dense 3D data to not only
measure standard MPD but also to evaluate MTD texture (mean texture depth) using a digital model of the sand patch
method (ASTM E965) [7] as shown on figure 4.

Figure 4. MPD vs sand patch.
The digital sand patch model MTD calculates the volume of the voids in the road surface that would beoccupied by the sand (from the sand patch method) divided by a surface area. The digital sand patch method
implemented allows texture to be evaluated continuously over the complete road surface instead of measuring only asingle point inside a wheel path. The MTD results can be mapped into road surface texture image where the color
corresponds to texture levels. In this example bleeding or flushing on the road surface corresponds to areas of very low
MTD (0.2mm) shown in blue (figure 5).

Figure 5. Bleeding812

5 CRACKING
Although the basis of 3D crack detection is finding the crack points that are below the road surface, detecting
cracks reliably is far more complex than applying a threshold on a range image. As mentioned previously the 3D dataneeds to be rectified to remove the effects of rutting and vehicle movements. Macrotexture is also a problem; roadsurfaces have very variable macrotexture from one section to the next and even from one side of the lane to the other. In
general to detect a crack using 3D techniques the majority of the crack points must be below the average depth of themacro-texture of the road surface. For example, on roads with weak macrotexture we can hope to detect very small
cracks which will be harder to detect on more highly textured surfaces. It is thus necessary to evaluate and to adapt theprocessing operations based on the texture and type of road surface. Once the detection operation is performed, a binary
image is obtained where the remaining active pixels are potential cracks. This binary image is then filtered to remove
many of the false detections which are caused by asperities and other features in the road surface which are not cracks
on the pavement. At this point in the processing, most of the remaining pixels can correctly be identified to existing
cracks, however many of these crack segments need to be joined together to avoid multiple detections of the same
crack. After the detection process, the next step consists in the characterization of the cracks. The severity level of acrack is determined by evaluating its average width (opening) typically cracks will be separated in low, medium andhigh severity levels.
The LCMS system has been used to survey millions of lane kilometers over the past 6 years and has
demonstrated its ability to automatically detect cracks [3]. Independent 3rd party users and DOTs have also evaluatedthe system [8] [9]. Typical results include repeatability tests that usually attain 95%+ in many different conditions.

Figure 6. Example of crack detection results (severity = color code).

Figure 7. Repeatability results (3 passes) on two MTQ road sections.

6 SEALED CRACKSThe images (Figure 8) below demonstrate what the majority of sealed cracks look like, i.e. the sealed cracks
are very dark in the images due to the black color of the sealant. This makes these cracks very visible in the intensity
images (high contrast) and the fact that they are sealed makes them virtually ‘invisible’ in the range images compared tothe unsealed cracks that appear as dark lines in the rectified range images.

813

Figure 8. Example sealed cracks: Intensity image (left) Rectified range (right).
However, the next images (Figure 9a) shown below demonstrates that in some cases the sealed cracks do notappear dark, in fact their color can vary greatly ranging from black to shiny white. Thus intensity alone cannot be used
as a reliable indicator of their presence.

Figure 9 Example sealed cracks: a) Intensity image b) Texture map
Not being able to rely on color and since sealed cracks do not have a 3D depth associated with them as do
unsealed open cracks we attempted to detect them using texture measurements as the surface of a sealed crack is verysmooth (low MPD values) as the sealant used not only fills the crack but also the air voids of the asphalt texture. Figure
9b shows the texture color map of the roadsection with sealed cracks it is clear that these areas show very low texture
MTD values (blue).

Figure 10. Main steps in the detection of sealed cracks814

Figure 10 describes the main steps in the algorithm implemented. This algorithm uses in fact both intensity andrange (texture) data to detect sealed cracks. The intensity image analysis algorithm looks for dark or light areas that areof different color then the surrounding background (road surface) and flags these areas as possible sealed cracks. As
mentioned above the range data 3D texture is evaluated (MTD) and areas of low texture are detected as possible sealed
cracks. All candidate areas are then evaluated as to their shape conformity to make sure they are crack shaped i.e. much
longer than wide and with a width ranging up to a few centimeters. A final validation is done to make sure all remaining
sealed crack candidate areas have both appropriate texture and color characteristics before being accepted.

Figure 11. Three examples of sealed cracks detection on road surfaces (results in red)815

7 CONCLUSIONS
Initial road tests on sealed crack detection were conducted with algorithms identifying only black sealed cracks
based on intensity images only. These tests allowed us to acquire a set of 100+ road sections where the use of an
intensity based algorithm alone for the detection of sealed cracks did not work. These examples were taken fromdifferent surveys covering several hundreds of kilometers of roads. With the algorithm described above using both 3D
texture and intensity combined, over 90% of the sealed cracks missed by the initial algorithm were correctly detectedwith less than 5% false positives (visually it is never 100% certain in the images if a sealed crack is or isn’t present, no
on-site validation type ground truth was attempted).
Currently network level testing has been going on over the last six months with two different vehicles inoperation in both New Zealand and the USA. No obvious or systematic cases of false or missing detections of sealed
cracks have been noted. However, it has been noted that as the sealed crack ages and the sealant wears away andchipping starts. The chipping of the sealant and the texture of the road thus begin to appear increasing MTD (texture)values that can over time cause the sealed crack to be missed by this algorithm.

8 REFERENCES[1] Laurent, J., Lefebvre, D., Samson E. (2008). Development of a New 3D Transverse Profiling System for theAutomatic Measurement of Road Cracks. Proceedings of the 6th Symposium on Pavement Surface Caracteristics,
Portoroz, Slovenia.
[2] Laurent, J., Hébert JF. (2002). High Performance 3D Sensors for the Characterization of Road Surface Defects.
Proceedings of the IAPR Workshop on Machine Vision Applications, Nara, Japan.
[3] Laurent, J., D. Lefebvre, and E. Samson. Development of a New 3D Transverse Laser Profiling System for theAutomatic Measurement of Road Cracks. Proc., 6th International Symposium on Pavement Surface ,2008.
Bursanescu, L., M. Bursanescu, M. Hamdi, A. Lardigue, and D. Paiement. Three-Dimensional Infrared Laser Vision
System for Road Surface Features Analysis. Proceedings of SPIE, Vol. 4430, 2001, pp. 801–808.
[4] Wang, K. C. P. Automated Survey of Pavement Distress Based on 2D and 3D Laser Images. Mack–Blackwell
Transportation Center, University of Arkansas, Fayetteville, 2011.
[5] Li, Q., Y. Ming, Y. Xun, and B. Xu. A Real-Time 3D Scanning System for Pavement Distortion Inspection.
Measurement Science and Technology, Vol. 21, No. 1, 2010, p. 015702.
[6] ASTM E1845 - 09 Standard Practice for Calculating Pavement Macrotexture Mean Profile Depth, Active Standard
ASTM E1845 Developed by Subcommittee: E17.23.
[7] ASTM E965 - 96 (2006) Standard Test Method for Measuring Pavement Macrotexture Depth Using a VolumetricTechnique, Active Standard ASTM E965 Developed by Subcommittee : E17.23[8] Wix, R & Leschinski, R 2012, ‘Cracking a tale of four systems’, ARRB conference, 25th, 2012, Perth, Western
Australia, ARRB Group, Vermont South, Vic, 20 pp.
[9] Wix, R & Leschinski, August 2013, ‘3D TECHNOLOGY FOR MANAGING PAVEMENTS’, Institute of Public
Works Engineering Australia conference , Darwin, Australia.

816

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
Ryoji OKAMOTO
CO-AUTHOR(S)(Capitalize Family Name
Koichi SUGIOKA
E-MAIL(for correspondence)

Weight impact tests of light-weighted barriers on expressways

Road Safety
POSITION
engineer

ORGANIZATION
Hanshin Expressway

POSITION
engineer

COUNTRYJapan

ORGANIZATION
Hanshin Expressway

COUNTRYJapan

ryoji-okamoto@hanshin-exp.co.jp

KEYWORDS:
barriers, light-weighted, weight impact tests

ABSTRACT:
Three light-weighted barriers, namely, the ultra-high-strength fiber reinforced concrete barrier (UFC barrier), the hollow
reinforced concrete barrier (hollow RC barrier), and the base concrete barrier (BC barrier) were developed .
For the practical use of three types of barriers developed, it was necessary to carry out evaluation tests to confirm therequired performances according to the safety standards. Therefore, weight impact tests were implemented to simulate
vehicle collision.
In the present paper, the results and discussions of the weight impact tests that were carried out for the three concrete
barriers developed are reported.

817

Weight impact tests of light-weighted barriers on expressways
Ryoji Okamoto1 and Koichi Sugioka2
1

Hanshin Expressway, Japan
Email : ryoji-okamoto@hanshin-exp.co.jp
2

Hanshin Expressway, Japan
Email : koichi-sugioka@hanshin-exp.co.jp

1 INTRODUCTION
Steel barriers are often used to reduce the dead load of bridges. These steel barriers are hollow structures andare designed under the concept of being a sealed structure. However, corrosion due to infiltration of water was found in
the interior of steel barriers.
As a result, steel barriers posts and base fixing bolts were corroded, reducing considerably their cross-sectional
areas and load carrying capacity. This problem indicates that steel barriers cannot perform their function as protective
fences. In addition, traffic regulation on the highway when repairing the steel barriers are also considered to be a
problem and thus, steel barriers maintenance is considered to be a difficult work.
From the above, it was decided to replace these barriers by corrosion resistant light-weighted concrete barriers.
However, such bridge barriers did not exist in the market. Therefore, three types of lightweight barrier, namely, Ultra
High Strength Fiber Reinforced Concrete barrier (UFC barrier), hollow Reinforced-Concrete barrier (hollow RC
barrier) and the Base Concrete barrier (BC barrier) were proposed and their development have started. In addition,weight impact tests were carried out as a performance verification for the developed bridge barriers.

Figure 1.Reduction of Cross-sectional Area due to Internal Corrosion of Steel Barrier Posts

2 CHARACTERISTICS OF THE PROPOSED BARRIERSAs there was no concrete barrier having unit weight close to that of steel barriers, new barrier structures having
better maintenance properties, such as light-weight and improved corrosion resistance were necessary.
When steel barrier problems were re-evaluated it was found that one problem to be overcome was water. The
condition inside the barriers was highly humid, because water drainage was not secured. Further, repeated dry-wet
cycles occurred inside the barrier, contributing to the significant advances of corrosion.
So, with basic idea of a barrier structure having a concrete base, the following three types of barriers were
proposed as replacement structures, and their standardization was carried out.

818

(a) BC Barrier(b) Hollow RC Barrier(c) UFC Barrier

Figure 2.Proposed barriers(1) BC BARRIERSteel barriers are very good protection fences, but problems were found in their posts and post bases, which aretheir main elements of the steel barriers. Therefore, we considered solving these problems by taking advantage of thegood characteristics of steel barriers.
To reduce corrosion progression in post base members, the elements were protected against corrosion by
galvanization. Further, drainage of the structure was provided by making a space between the side plate and the barrierat the curb part. In addition, by installing the steel wall at the base concrete block above the pavement surface,
infiltration of water from the road surface, which may contain anti-freezing agent, was prevented. As a result, corrosion
factors could be reduced considerably.
By arranging transverse beams between posts, the resistance to the impact resistance is enhanced. Although
there are corrosion risks, as there are steel parts remaining, the structure had improved corrosion resistance.

(a) BC Barrier wall provisional assembly(b) BC Barrier wheel guard concrete part(c) BC Barrier installation
Figure 3.BC Barrier819

(2) HOLLOW RC BARRIER
To ensure corrosion resistance, light-weight concrete barrier was considered. To lighten the RC barriers, fillingthe structure with styrene foam was considered.
Hollow RC Barrier was a successful design in lightening the structure where styrene foam worked as internal
formwork. In addition, ribs were also provided inside the barrier. Having reduced its weight, it is a fairly thin structure.
Since the required covering depth cannot be secured, rebar rust protection is secured by using the epoxy resin rebar.

(a) Styrene foam(b) Hollow RC Barrier inside of Styrene foam(c) Completed Hollow RC Barrier
Figure 4.Hollow RC Barrier(3) UFC BARRIER
For UFC barriers, as in the case of hollow RC barriers, to ensure corrosion resistance, light-weight concrete
was considered. Barrier concrete material was changed and UFC was used.
Due to UFC material properties, rebars were unnecessary in UFC barriers and structure lightness could beobtained successfully. Since the UFC barrier does not use rebars, it is necessary to consider the barrier shape.
In order to obtain light-weight and high-strength, ribs were provided at the rear part of the barrier to ensure therequired weight and strength.

(a) UFC Barrier front surface(b) UFC Barrier back surface
Figure 5.UFC Barrier

820

(4) COMPARISON OF THE THREE BARRIER WEIGHTS
Table 1 shows the weight ratio of the three structures compared to that of a steel barrier of a certain section.
The results of the calculations considering the weight ratio in a certain section confirmed the reduction of weight, oncethe calculated weight is close to that of the steel barriers.
However, it is necessary to confirm the girder strength against the increase of the barrier load, because many ofthe bridges were designed for live loads of old specifications.

Table 1. Comparison of the barrier weight

Steel Barrier

BC Barrier

Hollow RC Barrier

UFC Barrier

weight3.73kN/m

4.74kN/m

5.49kN/m

4.59kN/mweight ratio

1

1.27

1.47

1.23

3 TEST METHOD
The purpose of weight impact tests is to confirm the condition that "the barrier collapses when the vehicle
collides and the vehicle does not jump over the barrier" has been fulfilled or not.
In order to confirm it, weight impact tests were planned for the developed barriers. The advantage of thistesting method is that it can be carried out at prices lower than that of impact tests using vehicle. In addition, thedifferences with the tests carried out with vehicles is that the weight does not break, and experiments can be carried out
repeatedly until the specimen is destroyed, and failure shape of the specimen can be verified. In this test, the free fallhanging the weight collides with the barrier. The behavior and failure shape of the barrier is checked for the time of
impact.
If the drop height of the weight of impact tests is 650mm, it is confirmed that the barriers is able to ensure theperformance. Therefore, in the present paper it was decided to evaluate the behavior of the barriers for drop height of
400mm for small impact, and drop height of 650mm for standard impact.

Figure 6.Schematic diagram of barrier impact tests821

4 TEST RESULTS
The results of the tests are presented in the figure below, presenting the failure shape after the weight collision
for each case.
Drop height of 400mm for RC hollow barrier•A maximum of 20mm level difference at the impact surface has occurred with the cracks•Cracks of about 2mm have occurred around the box vent for the barrier for joints
Drop height of 400mm for UFC barrier•Cracks of about 0.1mm have occurred at the impact surface and its back surface
Drop height of 650mm for BC barrier•The impact surface of the side plate deformed to a maximum of approximately 20mm.
•The concrete at the curb back and the top surface presented cracks of about 0.1mm and a level difference ofabout 1mm have occurred with the cracks.

Table 2 Shape after the weight collision

BC Barrier

Hollow RC Barrier

UFC Barrier

Drop height of 650mm

Drop height of 400mm

Drop height of 400mm

front
surfacetop
surfacebacksurfaceAftertheimpacttests

822

5 CONCLUSIONS
To summarize,·Three types of light-weighted and high-corrosion-resistance barriers were proposed•The three barriers were successful in lightening the structures•Impact tests were performed on the three types of the developed the barrier·None of the barriers did not collapse through weight impact tests. However, experiments on RC hollow barrierand UFC barrier were not completed.
·In Drop height of 400mm for RC hollow barrier, cracks occurred with a maximum of 20mm of level difference.
•In Drop height of 400mm for RC hollow barrier, cracks of about 2mm around the barrier joint box vent haveoccurred.
·In Drop height of 400mm for UFC barrier, cracks of about 0.1mm occurred at the impact surface and its backsurface.
·In Drop height of 650mm for BC barrier, impact surface of side plate deformed to a maximum of
approximately 20mm. Cracks of about 0.1mm with a level difference occurred at concrete barrier curb back surface andthe top surface.
It was confirmed that UFC barriers did not collapse at the time of vehicle collision and did not jump over the
Barrier.
However, hollow RC barrier and BC barrier are schedule to proceed the impact tests.
When performance verification of the developed barriers are completed, improvements can be made by applying
the experimental results to the developed barriers. We expect to complete the replacement works using the modified
barriers with improved quality.

REFERENCESJapan Road Association : Design specifications for road barriers, 2008
Japan Society of Civil Engineers：Recommendations for Design and Construction of Ultra High Strength
Fiber Reinforced Concrete Structures, -Draft, September 2004823

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Layout Design of Korean-Type Road Debris Remover Instrument

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Jinguk KIM

Researcher

Korea Institute of Civil
Engineering and Building
Technology

Korea

CO-AUTHOR(S)(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

Choongheon YANG

Researcher Fellow

Korea Institute of Civil
Engineering and Building
Technology

Korea

E-MAIL(for correspondence)chyang@kict.re.kr

KEYWORDS:
Road debris, Road kill, road worker, layout design, Safety

ABSTRACT:
Despite the government’s efforts to control overloaded vehicles on the roads in South Korea, the number of road debrisinduced accidents is increasing every year. Such accidents being an extremely likely cause of massive accidents,
preventive measures should be established to protect the drivers as well as the road maintenance crews against safety
hazards.
This study conducted surveys that targeted field professionals working for the road maintenance agencies. The results
were incorporated into the layout design of road debris remover instrument which is customized to the road condition.
The design involved examination and incorporation of instrument construct, road debris remover quantity, target andscope of removal, and other relevant information as identified through the surveys.
The proposed layout design is capable of maximally securing the safety of drivers and road workers through swift
removal and handling of road debris. The advantages will likely ensure improvement of road service and traffic safety.

824

Layout Design of Korean-Type Road Debris
Remover Instrument
Jinguk KIM1, Choongheon YANG2
1,2

Korea Institute of Civil Engineering and Building Technology, KOREA
Email for correspondence, chyang@kict.re.kr

1. INTRODUCTION
Each year the Republic of Korea’s Ministry of Land, Infrastructure and Transport (MOLIT) carries out its
control and citing of overloaded vehicles that drive on the roads. The monitoring produces the citation of average some
30,000 to 40,000 cases including violation of load limits imposed by the relevant legislation. Despite the activities, roadaccidents involving debris are showing an increasing trend every year. Analysis of debris-related accidents over the past
few years show the average annual accident rate of 41. Table 1 shows statistics on road debris on highways in South
Korea.
Table 1. Statistics of road debris on Korean highways

Year

Number ofroad debris
collected

Number ofaccidents related toroad debris (death)

Number of reports on bad loading

2010

312,82920(0)50,964

2011

314,08033(0)65,8002012

313,60544(0)87,0702013

273,02664(0)83,527

2014

290,76443(1)60,789Source: Data from Parliamentary Land, Infrastructure and Transport Committee’s regular audit of Korean Expressway Corporation

Currently, the type of road debris that pose the greatest danger to driver safety is estimated to be road kills suchas roe deer. Similarly, rocks and stones, automobile components from accidents (shredded tires, bumpers, metals, etc.),
beverage cans, glass bottles, boxes, and wood panels were found to threaten the road travel safety. Removal of roaddebris has been done mostly by manual cleanup of road workers upon receiving complaints. Additionally, sweeping
machines are used to clean up after road traffic accidents. With the sweeping machines, the problem is their inadequacyin picking up larger debris such as bulky waste, cargo and dead animals. No particular device or equipment has beendevised to remove such items. Any debris-related incident on highways is a potential hazard that can cause massive
traffic accidents, including chain-reaction crashes. As such, debris-induced accidents should be subject to appropriate
preventive measures. The purpose of this study was to create a layout design for debris remover equipment that aims toaccomplish cleanup in swift and safe manners. Road maintenance agencies were contacted for surveys to be carried out.
Results were incorporated into the layout design following reviews on the instrument’s construct and on the capacity,
targets and scope of removal.

2. LITERATURE REVIEW AND TECHNOLOGY TRENDS
Patent applications regarding road debris removal technology revealed a total of 13 such applications of which
7 cases were available for citation in South Korea. The corresponding number overseas was 354 in total. Four of themwere found to be citable. Investigation of the applications’ details showed that very few technology solutions existed
which specifically addressed road debris removal, and that the majority of the applications simply utilized conventional
cleaning equipment or machines to collect the road debris (Table 2).

825

Table 2. Patents related the road debris remover instrument
Patent nameApplication year

The road surface rubbish collect equipment

2013

Patent drawings

Applicant

KISUNG Engineering, South
Korea

ROAD DEBRIS REMOVAL EQUIPMENT

2009

Korean Expressway Corporation,
South Korea

ROAD WORK REFUSE COLLECTION
2011
APPARTUSYOUNGSIK KIM, South Korea

RETECH Technology & Seoul
Multi-functional street cleaning vehicle

2008

Metropolitan Facilities
Management Corporation, South
Korea

Road surface removing machine

1979

Allied Steel & Tractor Products,
Inc. Solon, US

Vehicle for collecting debris from a road

1995

David Tolmachoff, US

The AAA Foundation for Traffic Safety (2004) investigated danger associated with debris on North American
roads (2004). The Colorado Department of Transportation (CDOT) carried out field tests on the Gator Getter™, a highspeed debris remover instrument developed by CDOT. Valdes-Vasquez et al. (2014) conducted evaluation of theperformance of the instrument. C.H. Yang et al. (2016) proposed directions of design concept in the development ofroad debris remover instrument customized to Korean roads.

3. SURVEYS
In developing a debris remover instrument that is customized to the condition of Korean roads, it is crucial tohave feedback from personnel involved in actual road maintenance work. Keeping that in mind, the present author
conducted surveys with some of the local highway agencies so as to identify the actual demand for debris remover
instrument (Fig. 1).

826

Fig. 1 Employers of survey respondents
Fig. 2 summarizes the frequency of debris removal work as performed by the highway maintenance agencies.
As shown, the majority of these agencies (89%) responded that they handle at least one incident per day.

Fig. 2 Prevalence of debris removal duties across agencies
The types of debris items getting removed are presented in Fig. 3, where tire pieces (89%) and waste paper(89%) were found to be the major contributors. Dead animals, plastics, and auto accident debris followed in said order.
The respondents also reported that most of the debris items are collected manually, with the remaining ones being
picked up by sweeper machines.

Fig. 3 Major types of debris items removed
As to the necessity of nighttime removal of debris, 67% of the respondents said ‘No’ (Fig. 4). The result
indicates that the majority of debris removals are carried out during the day unless in an emergency. The survey
participants advised night shifts, if any, would require related equipment/tooling and support to indicate such work isunder way, e.g., safety signage, speed reduction, fluorescent markers for temporary lane changing, and surveillancecameras. Their input is considered to aim at preventing road blocking, rear-end crashes, etc. during removal operations.

Fig. 4 Necessity for nighttime removal work
On removing debris using the instrument, 56% of the respondents answered yes to whether speed limits need827

to be considered (Fig. 5). The most preferred maximum speed during removal work was indicated as ‘below 30 km/h’ followed consecutively by ‘30-40 km/h’ and ‘80 km/h and above.’ The rating suggests debris removal is necessary for
driving at not only low speeds but high speeds as well.

Fig. 5 Necessity for maximum speed limit while removal under way
The intensity of demand for debris removal was examined for road type. Fig. 6 shows the highest demand was
identified with highways and expressways. In descending order, national highways in cities and non-urban areas, androads in municipalities, counties and provinces followed.

Fig. 6 Intensity of demand for removal equipment (by road type)Fig. 7 summarizes highway agency-specific needs for purchasing the debris remover instrument. Across theagencies, the most prevalent answer in terms of purchase quantity was ‘2’ (44%) while 11% of the responding agencies
answered ‘4 or more.’ Of note, some agencies said they were not considering the purchase because, as investigatedfurther, of insufficient instrument drivers and the currently available instrument other than the one being proposed inthis study.

Fig. 7 Purchase intentions
The quantity of debris per removal most preferred by the respondents was ‘Less than 1 ton’ (78%) (Fig. 8).
The second most preferred answers were ‘1 ton or more’ (11%) and ‘More than 3 tons’ (11%). Further, given the828responses on the quantity, the most favored answer for the removal tool capacity was 2.5 tons.

Fig. 8 Quantity of debris to be removed (per removal)

4. LAYOUT DESIGN
Based on the results of the surveys, Table 3 lists considerations to be made while designing and developing the
instrument for removing road debris. A truck capable of carrying a 2.5 ton load was selected for the design development
taking into account the preferred appropriate amount of debris per removal around 1 ton. Additionally, the vehicle’s
construct and the types of debris items to be picked up were examined and then incorporated into the layout. The latterstages of the development will also incorporate travel speed of the vehicle, the total weight of debris per removal plus
other factors.
Table 3. Considerations for tool development
Factors

Considerations

Vehicle type

Truck with large freight capacity (2.5 t)

Truck travel speed

Driving at 10 km/h or above while picking up debris

Per-pickup total debris
weight (by type)· Ordinary waste: max. 5 kg (approx.)· Carcass: 11 kg (approx.)

Debris amount
per removal dispatch

Approx. 1 ton

Vehicle construct

Must be able to:· Collect both carcass and ordinary waste· Separate carcass from non-carcass debris· Satisfy relevant vehicle safety standards

Debris item

· Sand and pebble· Carcass, and debris remaining after auto accidents· Any and all debris obstructing traffic flow (plastics, wood chips, boxes)

For the purpose of the study, CATIA (Computer Aided Three-Dimensional Interactive Application) was used.
The software program allows the implementation, modification and control of the entire design and manufacturing
process of industrial product models. It is adopted widely in the aerospace engineering and automobile industries aswell as in related disciplines.
Fig. 9 (plan view) and Fig. 10 (elevation view) illustrate the layout of the truck to pick up debris. In
consideration of the diversity of debris, the vehicle’s frame height was raised by approx. 300mm so as to allow themounting of the removing equipment underneath the frame. This design reflects difficulties securing vehicle safety
certification which can often be encountered with front-mount applications. Also, difficulties picking up debris wereconsidered with rear-mount apparatuses. Further, front-mount designs would limit the types of debris due to the set
amount thereof to be removed. Significantly poorer vehicle safety during removal operation carried out at higher travel
speeds was another disadvantage associated with front-mount designs. The rotating brushes at the front (Fig. 9) draw
the debris in and push it underneath the frame. Once underneath, the debris will be transported onto the conveyor belt
via underside collection tool and then to the freight space. For hygiene purposes, the design provides separate cargo829

space for animal carcasses and ordinary debris items.

Fig. 9 Road Debris Remover Instrument (Plan View)

Fig. 10 Road Debris Remover Instrument (Elevation View)

5. CONCLUSION
Despite the government’s efforts to control overloaded vehicles on the road in South Korea, the number ofroad debris-induced accidents is increasing every year. Such accidents being an extremely likely cause of massive
accidents, preventive measures should be established to protect the drivers as well as the highway maintenance crews
against safety hazards.
The purpose of the study was to propose a layout design for a debris removal tool that is suitable for the roadcondition in South Korea. To this end, surveys were conducted targeting the field professionals working for the roadmaintenance agencies. The results were incorporated into the instrument layout design. Although some local agencies
are already using debris collection instrument, its safety performance is yet to be validated. For that reason, such
instrument is being used only in a limited capacity, maintenance of specific roads or uninterrupted flow. The
conventional instrument also poses possible hygienic problems in the latter stage of debris disposal due to the nonsegregating approach being adopted whereby ordinary debris items are removed and stored along with wildlife animal
carcasses. The current sweeping machines can only pick up relatively smaller objects such as metal scraps, glass, anddebris remaining on the shoulder after automobile accidents. Contrastingly, the study proposed a design of the road830

debris remover instrument that is capable of cleaning up even bulky animal carcasses, tire pieces, boxes, and wood
panels. Such capability will likely enhance the work of the road maintenance. Further, the proposed instrument canaccurately identify the type of debris present on pavements and can collect them swiftly. The speed and accuracy will
likely offer greater efficiency in the secure of the road management and traffic safety.

ACKNOWLEDGEMENT
This research was supported by a grant from “Development of Accident Risk Mitigating Technology for
Vertical Structure Collision on Road and Road Workers” in the Transportation and Logistics Research Program fundedby the Ministry of Land, Infrastructure and Transport of Korea.

REFERENCES
1.
2.
3.
4.
5.
6.
7.

AAA Foundation for Traffic Safety. (2004), The safety impact of vehicle related road debris
Colorado Department of Transportation. (2014), CDOT rapid debris removal research project, DReport No.
CDOT-2014-9
Korea Expressway Corporation. (2012), Standard for Wildlife Carcass Disposal
Korea Expressway Corporation. (2012), Status of Animal Road Kills Submitted for Parliamentary Audits
Korea Institute of Civil Engineering and Building Technology. (2016), Technology to Mitigate Crashes Involving
Wayside Vertical Structures and the Hazards for Highway Workers: First Year Outcomes Report
Valdes-Vasquez, Rodolfo Lewis, Anderson M Strong, Kelly C. (2014), Assessment of a System for Debris
Removal at High Speeds ; Implications for Roadway Operations and Maintenance
Yang, C.H., Kim, J.K.(2016), Design of Korean-Type Road Debris Remover Instrument, Journal of Emerging
Trends in Computing and Information Sciences, Vol. 7, No. 4, pp.200~203

831

2nd IRF Asia Regional Conference
Kualalumpur, Malaysia 16 – 20 October 2016

Slope Maintenance Program is the key factor on choosing the Retrofitting Technology
comply with the standard requirement laws for road user safety and comfortability.
Eddie Sunaryo Munarto and Djoko Purnomo, Institute of Road Engineering, Agency of
Research and Development, Ministry of Public Works and Housing

Abstract
Slope maintenance program is usually come up with the chosen solution of slope protection
against landslides, including debris avalanche falls. This is probably an importance activity to
be setup in advance in order to manage the stability of slope against failures occurrences toachieve the traffic safety and road user comfortability. Dealing with the evidence ofavalanched debris material falls which is one of slope failure evidence, a number of chosen
solutions have to be implemented either as the temporary solution and the permanent
solution for maintaining functionally roads. An importance task is usually by implementing
such kind of the retrofitting technology using the reinforced structures to support theincreasing slope stability. Due to the limitation of the retrofitting budged cost and the other
hand, the road network functionally have to be always maintained, hence the temporary
retrofitting solution have to be priority chosen. The protecting avalanched debris falls isavailable and have been studied working well in order to perform road safety and road user
conformability. Hence, Fence Defense and Catchment Area were effectively well
implemented for temporary solution, especially to protect the occurrences of debris
avalanche falls in the national Road in East Nusa Tenggara Island of Indonesia.
Key word: slope maintenance, road user, importance task of implementing technology,
traffic safety and road user conformability, avalanched debris falls, road network functionallyand retrofitting technologies

Introduction
The slope maintenance programme is likely a good practice to be implemented on carryingout the traffic safety and road user comfortability against landslide evidences due to thetraffic will be blocked. The performance of the slope stability either natural and man-madeslopes is usually implementing the retrofitting technology such as retaining walls and otherreinforced strength structures to support the stability of slopes.
Basically, the maintenance activity is the programme for inspections and maintenance works
to keep the slopes are in good condition with well-designed to achieve the traffic safety androad user comforatable. Hence, the inspections and maintenance works are recommended
within road networks, and in the mountainous region the instability of slopes will beconcerned due to can impact to the landslide evidence and come up with the blocked traffic
occurrences. However, the slope have been designed comply with the currently geotechnicalstandards, the occurrences of landslide is still happened due to the number of many factor
that influenced instability of slopes. As previously mentioned in this paper that thefunctionality road network was the main concern to be solved, therefore, one of the area
have been studied which is as the national road networks of the link road connected
between Ende City and Kelimutu village, exactly in Nuamuri Village, Kabupaten Ende at KM

832

46+000 have been experienced with the debris avalanched falls. The material falls havebeen recognized from the exposed rock on the outcrop slope and and reported by Tribun
News Kupang magazine on Thursday (3/3/2016). Based upon the record during study in2008 can be also noted that the currently landslide was not the first evidence due to thesimilary landslide is commonly occurred at KM 13+000 and KM 76+000. Hence, along theroad networks were identified a number of potential landslide can be occurs which is in Km
13+000 and KM 76+000 are critical due to the traffic can be blocked within uncertainty
period of time. Regarding to this evidence, in 2008, the research by IRE have been
implemented in those 2 (two) locations, using the temporary solution which is stressing tomaintain the functionally road with performing the traffic safety and road user comfortable.
This site location of road networks between Ende city to Maumere city have been noted
there are many high slope with the outcrop rocks are un-well jointed and hanging on theslope outcrop, therefore potential to occurrences of debris avalanched falls into the roads will
be impacted to the dangerous of road users. The occurrences of debris avalanched falls
have been reported by Tribun News Kupang (2014) at KM 17 on Sunday (23/2/2014) and
Pos Kupang magazine KM 46+000 on Thursday (3/3/2016). Hence, to come up with thesolution, the principle retrofitting technologies were applied is by implementing a temporary
solution to perform the traffic safety and road user comfortable besides the maintaining
functionally roads.
Dependant upon the size of landslide evidence can be small or big scales, obtaining theretrofitting technologies were recommended by Institute of Road Engineering (IRE), Agency
for Research and Development, Ministry of Public Works and Housing based upon theregulation laws on implementing the minimum standard of level services that to be adopted.
The idealism on problem solving of slope failures, there are 2 (two) options can besuggested, which is no 1 (one) bay protecting the slope failure evidence it self and number 2(two) by implementing technology on suffering the road user from the debris avalanche falls.
The first one is indeed as the structural retrofitting countermeasures which might be costly
while 2 (second) is indeed less costly which is on supporting the functionality of the road
networks against blocking current traffic flows.

National Road Situation in Trans Ende – Maumere, at East “Nusa
Tenggara” Province
The occurrences of debris avalanched falls have been reported by local news paper either
from Tribun News Kupang magazine (2015) and Pos Kupang magazine (2016) which havebeen previously noted by IRE (2008), in East “Nusa Tenggara” Province of Indonesia withthe typical of the material slides contain with the avalanched debris combined with thefractured rocks, boulders mixed with sands and soils developed by volcanic breccias andmetamorphic rocks were caused by un-jointed rock fragments.
During study on the implementation of the Slope Maintenance Programme by IRE in thisNational Link Road between Ende to Maumere in 2008, such as showed in Figure 1 arenoted there are 2 (two) critical conditions with the occurrence huge avalanched debris falls
which is each location are shown in Figure 2 for KM 13+000 and Figure 3 for KM 76+000.
Hence, Its can be stated refers from IRE research in 2008, the location of landslide at KM
17+000 and KM 46+000 have been identified as small potential avalanched debris falls.
Within the following years such as showed on Figure 4 for KM 17 was reported by the
Tribun News Kupang (2014) and Figure 5 for KM 46 was reported by the Pos Kupang(2016), those locations have been developed to become the huge landslide evidences due
to changes on its material character manners as an impact of the environmentally changes.
On Figure 5 also showed the heavy equipment are ready for clearing up the Debris Flows
which were always blocked the existing road and can be dangerous for road users against
the safety and decreasing their conformability.

833

location

KM 13+000

KM 76+000

Figure 1. the Trans national Road between Ende – Maumere, East Nusa Tenggara Provinces,Indonesia (IRE, 2008)

Figure 2. Avalanched Debris Falls at KM 13+000 Ende, trans road Ende – Maumere, East Nusa
Tenggara Provinced (IRE, 2008)

3834

Figure 3. Avalanched Debris Falls at KM 76+000 Ende, Trans Ende – Maumere East Nusa
Tenggara Province, Indonesia (IRE, 2008)

Figure 4. Landslide Evidence at KM 46+000 Ende, East Nusa Tenggara Island, Indonesia (Pos
Kupang, 2016)

835

Figure 5. The Evidence of landslide at other side of KM 17+000 Ende during road widening
progress, East Nusa Tenggara Province, Indonesia (Tribun News Kupang, 2013)

Main Principle of the Implementation of the Retrofitting Technology
against the Debris Avalanched Falls.
There were previously noted that the implementation of the Retrofitting Technology with lesscostly even might be temporarily solutions which is mainly based upon the concerning on full
filled the regulation laws to the requirement to obtain the standard minimum of road levelservice which is meant on managing the potential of blocking road traffic flows. The
regulation laws are stated as The Indonesian Government Regulation Law no 22, 2009 andthe Ministry of Public Works no. 11, 2009.
Refer to the research results regarding to the retrofitting technology against those regulation
laws (IRE, 2008), there are a number of retrofitting technologies can be adapted which isprincipally concerned to the trafic safety and road user conformability, such as:1) Technology on protecting the avalanched debris falls using shotcrete technology which issuitable for potential debris avalanched falls by filling the gaps between the crack roackfragment joint and changes on material character manners due environmental changes
which are usually intended to the increasing degree of weathering2) Technology on managing the avalanched debris falls, which are containing Fence
Defense Technology and Catchment Area Technology which are intended suitable forsmall to medium dimension of debris avalance material sizes.
3) Technology on protecting the avalanched debris falls using Rock Netting techniques
which is intended for the small dimension of debris material sizes
The techniques before starting on choosing the suitable retrofitting technologies, based upon
the IRE research (2008) are by measuring the outcrop rocks, such as by measuring thejointed patterns by determining the value of RQD (Rock Quality Designation). The measuring
RQD is stated the ability of slope on performing stand up time alone during period of time
without any doubt. The other method on measuring the rock quality designation (RQD) can

836be done using the Scaling System as they have closed relationship correlations, as showed
bellow on Figure. 6. If the measuring scaling is between thos values then can beinterpotated.

.
Measurement of Joint Cracks

20 / meter
11 / meter
5 / meter
2 / meter
1 / meter

Measurement of RQD Value (%)< 25
25 - 50
50 - 75
75 - 90> 90

Figure 6. Measurement of RQD values using the Scaling System Approach on the Outcrop
Rock Slopes in meter length (IRE Research, 2008)

The result from measuring the RQD (Rock Quality Designation) on the outcrop rock slope
Surface in each location in 2008 by IRE showed in Table 1 for 4 (four) locations werecategorized as the dangerous risk for safety and un-comfortable for road user due tooccurrences of the Scaled value from2018 to 2016, which is road traffic flows can be blockedwithin the mater of time, especially in raining season and can be also impacting to the roadsafety and the user road conformability.
Table 1. Measurement of the Scaling and RQD on the Outcorp Roack Slopes

Location Outcorp Condition
KM 13
Jointed Cracks/m length
RQD values
KM 17
Jointed Cracks
RQD values
KM 46
Jointed Cracks
RQD values
KM 76
Jointed Cracks
RQD values

20081125 - 502
75 - 902
75 - 901125 - 50

2010
20
< 25
5
50 - 755
50 - 75
20
< 25

2014
20
< 25
11
25 - 50
11
25 - 50
20
< 25

2016
20
< 25
20
< 25
20
< 25
20
< 25

Hence, referring to the result on measuring the RQD value based on the Scaling Method
Approach are shown that the location at KM 13 and 76 have been decided to be immediately
retrofitted in advance if compared to the location at KM 17 and KM 46. Further, referring to
the period of time in relation with the RQD value of KM 17+000 and Km 46+000 are dropped
significantly as a result of its change in character manners due to environmental changes.
6837

The implementation of the retrofitting technology types against theoccurrences of Avalanched Debris Falls at KM 13+000 and KM 76+000
Referring to the regulation law by Indonesia Government and the implementation ofregulation law on road building refers to the standard minimum road services, hence thepriority on the adapting retrofitting technology using “Fence Barrier and Catchment Area” or“Buffer Zones” were concerned in order for improving against the traffic safety and road user
conformability.
Based on the research results by IRE, there were 3 (three) typical technologies have been
implemented in Full Scale Study, (IRE, 2008) and showed on the following figures as a
Buffer Zone Techniques on bellow using Fence Defense and Catchment Area Technologies
as showed on Figure 7.

Fence Barrier

Catchment Area

Figure 7. Buffer Zone Techniques (IRE, 2008)

The types of those retrofitting technology on above are believed will be not costly andeffective if compares to the typical countermeasure technologies based upon the aims on
increasing strength to improve the slope stability against the avalanched debris falls, such as
anchoring and grouting techniques and as well as “shotcrete”..
Based upon the monitoring program in 2013 in order to recognizing the performance of theretrofitting technology using either Fence barrier and Catchment Area, have been known thatthe local Government thorugh the EINRIP (Eastern Indonesia National Roads Improvement
Project) programme in 2013, has adopted one of those technologies at KM 17+000 using
Fence Barrier by modifying with “Earth Retaining Wall Structure”, showed on Figure 8.
However the type of Fence Barrier is differ but on principle is still similar for protecting theavalanched debris falls and the following concerned should be noted:
1) The material debris can be dumped on the specific area between the buffer zone
construction and the slope surface and might be can develop the New Slope with gently
surfaces. The dumped material can be regularly thrown away if necessary or can be left
to develop the gently slope.
2) The water might be trapped behind the buffer zone construction should be able to drainout thereforea) The buffer zone or buffer zone constructions should have the facility to drain of thetrapped water or having the enough permeabilityb) The function as the Earth Retaining Structures, the facility such as the weep holes
have to be included to drain out the trapped water.

7838

Weep HolesSpace forCollecting
the Debris
falls

Figure 8. Implementation of Fence Defense as Earth Retaining Structure ate KM 17+000 by
local Government Authority (IRE, 2013)

Further Action to Defining the Performance of Retrofitting Technology
on carried out the Avalanched Debris Falls
Regarding to the retrofitting technologies using Fence Barrier and Catchment Area havebeen implemented by IRE in 208, to fullfil and comply with the regulation laws on achieving
the minimum standard level of servicing therefore, should have also fulfilled to the roadsafety and road user comfortability. Hence, the maintenance and repairing works then canbe set up as part of inspection programme within the passage of time.
Regarding to the slope stability on these location which have been distinguished 4 (four)
locations with the high potentially rock slope failures, hence, the maintenance activity should
be prepared along the road for each site location, KM 13+000, KM 17+000, KM 42+000 and
KM 76+000, within the inspection programmes (Layman’s, 2006):(a) Routine Maintenance Inspections, which can be carried out by any responsible personwith professional geotechnical knowledge. This is(b) Engineer Inspectors for Maintenance programmes should be carried out by aprofessionally-qualified geotechnical engineer,(c) Regular Check of Buried Water-Carrying Services should be carried out by a specialist
leakage detectiocontractor for the fence barrier structure which night be performed as
earth retaining structure walls.
(d) Regular Monitoring of Special Measurement should be carried out either by a firmcompany, or individually with a special expertise in particularlu to detecting theperformance. Hence, the monitoring programmes to be set-up for determining either
short-term or long term stability of the slope. If the retaining wall structure has becoming
implementd, to be noted that the rating values have to be relies in specific measurement
due to the liable on detecting the retrofitting technology performance that might be lesseffective within the passage of time.

8839

Conclusion and Recommendation
1) The requirement on building and managing the Road Networks comply on urging thestatement of standard minimum level of services against road safety and road user
conformability, the investigation of the avalanched debris fall can be rates and grouped if
necessary in order on choosing the suitability retrofitting technologies.
2) The measuring the Rock Quality Designation (RQD) is necessary by the measurement of
Jointed Cracks of Rock Pattern using Scaling System then can be useful to define theSuitability Retrofitting Technology comply to accommodate the evidence of Avalanched
Debris Falls occurrences.
3) The types of retrofitting technologies using the buffer zone techniques are as a suitable
technology in order to effectively maintain the road network to be safety and conformablefor road user and otherwise un-costly compare with the reinforced technologies.

References
1. IRE (Institute of Road Engineering, 2008), study on the implementation of buffer zone
and catchment area as technology of buffer zones
2. Institute of Road Engineering (IRE) – Agency for Research and Development,
Ministry of Public Works and Housing, Republic of Indonesia (2008), Impementationof Retrofitting Technologies against the Avalanced Debris Falls, Full Scale Studied at
National Road between Ende and Maumere ate KM 17 and KM 76, Bandung
3. Layman’s (2006), Guide for Slope maintenance, Geotechnical Engineering Office –Civil Engineering and Development Department, The Government of the Hong Kong
Special Administrative Region, 101 Princess Margaret Road, Homantin, Kowloon,
Hong Kong.
4. Ministry of Public Works no. 11 (2009), Implementation of Road Network with therequirement capability on adapting the minimum standard servicing forRoad Users.
5. Pos Kupang.com, Ende (2016); http://kupang.tribunnews.com/2016/03/04/jalur-km46-arah-kota-ende-rawan-longsor.
6. The Indonesian Government Law no 22 (2009) the regulation of Road Network
Building comply with safety and comfortability requirements for Road User, jakarta
Indonesia.
7. Tribun News, Kupang (2014) http://kupang.tribunnews.com/2014/02/24/longsor-dikm-17-ende-sudah-belangsung-dua-tahun.

840

2nd IRF Asia Regional Congress Abstract Submission
October 16-20 2016
Kuala Lumpur, Malaysia

PAPER TITLE(90 Characters Max)

Performance Based Key Performance Indicators for Expressway
Concessions in Malaysia

TRACK
AUTHOR(Capitalize Family Name)POSITIONORGANIZATIONCOUNTRY

General Manager

Opus International (M) Sdn
Bhd

Malaysia

POSITIONORGANIZATIONCOUNTRY

Zainuddin ABDULLAH

Senior Assistant Director,
Regulatory Maintenance

Malaysian Highway
Authority

Malaysia

Ir Abdullah HASHIM

Director, Regulatory
Maintenance

Malaysian Highway
Authority

Malaysia

Ir Suhaimi ABD AZIZ
CO-AUTHOR(S)(Capitalize Family Name

E-MAIL(for correspondence)suhaimi.aziz@opusbhd.uemnet.com

KEYWORDS: Key Performance Indicator, Performance Based

ABSTRACT:The paper outlines the study undertaken for the introduction of performance based KPIs for monitoring whichemphasizes the Malaysian Highway Authority’s governance role while at the same time will encourage
expressway Concessionaires to adopt a preventative approach to the maintenance of their assets. Efficiencies
in terms of maintenance and upkeep of the expressway assets can be gained if all Concessionaires aremonitored under appropriately similar KPIs and employ compatible asset management systems andprocedures in line with their respective Concession Agreements.
.

841

1

Background

The Malaysian Highway Authority (MHA) was incorporated by the Malaysian Act 231 (Highway Authorityof Malaysia (Incorporation) Act 1980). The Authority was initially established for the supervision andexecution of the design, construction, regulation, operation and maintenance of inter-urban highways with theobjectives of:i.

Providing a fast, safe and efficient transportation system on a national scale;ii.

Connecting all major towns and their surrounds for economic, cultural, social development andnational unity; andiii.

Enabling an effective inter-urban public road transport system throughout the country.

All Malaysian tolled expressways are managed through the Design Build Operate and Transfer (DBOT)
model where concessions were given to private companies to finance, build, operate and collect tolls for a
stipulated duration ranging from 30 to 50 years. The Concessionaires are obliged to operate and maintaintheir expressway facility based on the agreed Concession Agreements.
In 2013, Concessionaires under MHA each employ their own maintenance management systems andprocedures. Key Performance Indicators (KPIs) are not fully established in their Concession Agreements
resulting in dissimilar performance targets being adopted by concessions in the course of maintaining theirassets.
In general, MHA recognizes that efficiencies in the governance role and upkeep of the expressway assets canbe gained if all Concessionaires are under appropriately similar KPIs and employ compatible asset
management systems and procedures in line with their respective Concession Agreement obligations. These
objectives will be achieved by a move to a performance based process that:-

1.1



Minimises auditing and inspecting tasks undertaken by MHA of the expressway networks andmoves it to a monitoring / governance role;

Obligates expressway Concessionaires to maintain their networks including identification,
recording, programming and reporting of works to meet agreed minimum service levels; and

Encourages expressway Concessionaires to:oadopt a preventative approach in the maintenance of their assets to minimize larger failures
which may result in longer operational distress or interruptions; andoadopt contemporary asset management principles in optimizing maintenance activities in a
KPI achievement based framework.

Introduction

Opus International (M) Bhd and Ace Vector Sdn Bhd (Opus-AVSB) was appointed by MHA to provide theconsultancy services for the development of Key Performance Indicators (KPIs) required to support the
governance role of MHA within the framework of the Concession Agreements signed with the Highway /Expressway Concessions. The constituents of the highways/expressways covered under this scope of services
comprise pavement, slopes, bridges, drainage culverts and tunnels (inclusive of related mechanical andelectrical) assets. The SMART Tunnels are not part of the scope of this study.
The scope of services is broken into distinct phases to enable MHA to meet its objectives. The total durationof the project was 24 months comprising of Stage 1 (Phase 1 to 4) and Stage 2 (Phase 5). The distinct phases
are shown below and further description is provided in the following sections.
Table 1.1:
Stage
1

2

Summary of Project Stages
Phase & Description
Phase 1 – Project Scope
Phase 2 – Monitoring Framework
Phase 3 – Performance Measures
Phase 4 – Supplementary Documentation
Phase 5 – Roll Out (Pilot Program)842

Phase 1 - Project Scope
This phase focused on discussions for mutual understanding of the objectives between MHA and theConsultant’s team. In this phase, the scope of services was defined by the Consultant in terms of objectives,
methodology and work programme taking into account the kick-off discussion with the Client.
Phase 2 - Monitoring Framework
The objective of Phase 2 was to derive a monitoring framework for the Client to adopt. The monitoring
framework allows the Client to enhance its governance role in managing the concession agreements andreduce the amount of on-site activities such as the detailed inspection and identification of defects they are
currently required to undertake.
Phase 3 - Setting of Minimum Service Level
The objective of Phase 3 will be to assess and recommend minimum performance levels or service levelvalues for each of the previously identified measures.
The derivation of the level of services will be based upon the following aspects.
Best practice elsewhere;
Current requirements of the Concessionaires;
MHA’s current requirements (e.g. MHA Manual M1, Expressway Maintenance System,
Maintenance Manual and Guidelines (Civil Works), September 1996); andOther factors (in discussion with MHA).

Consideration will also be given to the situation where an expressway network has fallen below the derived
or agreed performance values, the manner that the network could be brought up to the required standard,
including the time frame to do this. These aspects will take into account the terms of the prevailing
Concession Agreements.
Phase 4 - Supplement to Existing Guidelines and Documentations
Appropriate supplementary documentation to the MHA’s Expressway Maintenance System Civil Works
Guideline and Manual (M1) and the Expressway Maintenance System Civil Works, Guideline and Manual(Response Time) will be identified upon the performance measures and service level values being determined
and agreed.
Phase 5 - Roll Out
A pilot program to be undertaken on appropriate stretches of expressway to assess the most appropriatemanner for implementation of the Key Performance Indicators.

2

Current Highway/Expressway Network

There were 29 expressway concessions under the scope of the study as shown in Table 2.1 and Figure 2.1.
The network comprises of the expressways traversing from north to south of Peninsular Malaysia, i.e. theNorth-South Expressway and from east to west, i.e. the East Coast Expressway. The majority of theexpressways (20 nos.) are situated within or around the capital city of Kuala Lumpur as shown in Figure 2.2.
The length of the expressways ranges from 5km to 823km.
The characteristics of these 29 expressways vary from large numbers of steep high slopes to no slopes andsome with high proportions of structural elements. The pavements of these expressways are a mix of flexible
and rigid.

843

Table 2.1: Highway/Expressway Concessions
No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29

Route No
E1&E2
E3
E5
E6
E7
E8
E8
E9
E10
E11
E12
E13
E14
E15
E17
E18
E20
E21
E22
E23
E25
E26
E29
E30
E33
E35
E36
E37
E38

Expressway
North South Expressway
Malaysia Singapore Second Crossing
Shah Alam Expressway
North South Expressway Central Link
Cheras Kajang Expressway
Kuala Lumpur - Karak Expressway
East Coast Expressway
Sungai Besi Expressway
New Pantai Expressway
Damansara - Puchong Expressway
Ampang Kuala Lumpur Elevated Highway
Kemuning - Shah Alam Highway
Johor Bahru Eastern Dispersal Link
Butterworth - Kulim Expressway
Butterworth Outer Ring Road
Kajang SILK Highway
KL - Putrajaya Expressway
Kajang Seremban Expressway
Senai-Desaru Expressway
Western KL Traffic Dispersal System
Kuala Lumpur - Kuala Selangor Expressway
Southern Klang Valley Expressway
Seremban - Port Dickson Highway
North Klang Straits Bypass
Duta Ulu Kelang Expressway
Guthrie Corridor Expressway
Penang Bridge
East West Link Expressway
SMART Tunnel

Length (Km)
823.0
44.7
34.5
48.0
11.7
60.0
169.0
16.7
19.6
40.0
7.9
14.7
8.1
17.0
12.1
37.0
26.0
44.3
77.0
26.0
31.0
51.7
22.7
17.5
18.0
25.0
13.5
17.0
5.0

Abbreviation
NSE
LINKEDUA
KESAS
ELITE
CKE
KLK
ECE
SBE
NPE
LDP
AKLEH
LKSA
EDL
BKE
BORR
SILK
MEX
LEKAS
SDE
SPRINT
LATAR
SKVE
SPDH
NKSB
DUKE
GCE
PNB
METRAMAC
SMART

Note: Tunnel in SMART is not in the scope of the study

Figure 2.1:

The Highway/Expressway Network844

Figure 1.2:
2.1

The Highway/Expressway Network within /around Kuala Lumpur

Concession Agreements

The Concession Agreements were reviewed in terms of the following subject matters.










Asset management
Asset condition (Data Collection)
Level of service/Performance measures
Key performance indicators
Routine maintenanceMonitoring
Non-conformance
Reporting
Systems and processes

In general, while there were differences between the CAs with regard to funding, financing and toll rates, theobserved differences in terms of maintenance requirements between the earlier concession agreements are interms of the preparation of maintenance manuals. After 1991, all CAs were referred to the MHA’s M1Maintenance Manual and its subsequent publications.

3International Best Practices

The objective of researching and reporting current international best practice in the field of performancemonitoring of road networks is to give MHA an insight into what might be achieved through the introductionof a performance monitoring regime.
Performance based specifications were introduced to manage road assets approximately 20 years ago.
Australia, The United States and then New Zealand and a number of other countries recognized the benefits
in terms of the management of their road assets and started moving from traditional forms of contracting toperformance contracting. This review and the lessons learnt and will give MHA a sound basis upon which to
make decisions about moving the management of tolled expressways in Malaysia to a performance based
monitoring system.
The countries and projects reviewed were:845

Table 3.1: Countries Reviewed in International Best Practice Study
Item
1
2
3
4
5
6

Country
New ZealandAustralia
CanadaUnited Kingdom
India
Turkey3.1

Projects
NZ Performance Specified Maintenance Contracts (PSMC), Western Bay of Plenty,
Auckland Motorway Alliance, Lyttleton Tunnel
Hybrid PSMC New South Wales, Queensland Motorway Road Franchise
Ontario, British Columbia, New Brunswick Public Private Partnership (PPP)Highways Agency’s Asset Support Contracts (ASC)World Bank Output Performance Road Contracts (OPRC)
Trans European Road Network (Tunnel)

Lessons Learnt from International Best PracticeOver the years various countries have put in place performance based contracts many lessons have beenlearnt. Often the lesson has been drawn from trial and error as road controlling authorities strive to achieve
value for money while keeping road users safe and comfortable. Key lessons learnt are described in thefollowing sections.
3.1.1

Roles

Worldwide the maintenance and asset management of road works is split between two or three key parties.
Usually they are:
1.
2.
3.

Road Controlling Authority (client)
Consultant (asset manager)
Contractor

Each brings different expertise to the team. In order to recognize this expertise and provide clear
responsibilities it is important that separation is achieved between each of the roles.
In general the contractor is best at and suited to implementation, that is carrying out the physical works on the
network. It is important that they do things right by using the correct standards of workmanship. The
consultant brings asset management skills into the mix as well as long term understanding of asset
characteristics and performance over time. They need to ensure the right treatment has been selected in theright location. The road controlling authority, or client organization, has valuable connections to politicians
and the community. They are in a good position to translate the preferences and demands of political andcommunity bodies into desirable contract outcomes.
This separation of roles can be illustrated against an asset management continuum as shown in the following
illustration.
Doing things right Contractor

Doing the right thing Consultant

Implementation

Management

Setting the rightoutcomes – Road
Controlling
Authority
Governance

Figure 3.1: Asset Management Continuum
Inefficiencies will occur when a clear separation between the roles is not achieved. From experience
duplication of effort results and the true value from each party’s expertise is marginalized.

846

3.1.2

Culture ShiftIn each of the countries that have moved from traditional method specified maintenance to performancebased management a significant culture shift, across the whole industry has been necessary.
Just as the road controlling authority struggles to keep out of the detail the contractor has often struggled tothink and act proactively. They have been used to being told what to do, where and when. Their challenge is
to take responsibility for short term programming of works, selecting cost efficient work techniques andorganizing resources as effectively as possible.
Often the change to performance management comes with a change to the procurement or contractual
arrangements between parties. Relationship based contracts are favoured worldwide to extract maximum
value from the parties involved. In this arrangement working cooperatively, with risk sharing and best for
network decisions being made, people involved need to cast aside old relationship roles and embrace a more
open working environment.
3.1.3

Service Levels

In the early days of performance based management it was thought a road network should and could bemaintained in perfect condition at all times. Through experience this has proven to be an extremely difficult
aspiration that has also been expensive to achieve. It is now fairly well acknowledged that a network cannever be 100% perfect all the time. This is particularly so since many defects have to be evident before they
can be fixed. For example – a missing or damaged sign, a damaged length of guardrails.
A level of service is set to recognize the varying needs of a particular part of a road network. Factors varying
a level of service often relate to traffic volumes, location (urban/ rural), and geotechnical conditions. It is
important that three areas are addressed when setting a service level.
1.
2.

3.

Road user safety and comfort – those using the road need to feel safe and to enjoy a comfortableride – particularly if they have a choice of routes to use
Durability (or resilience) – the road has to last with minimal intervention in its life time to keep it
usable. The asset has to be maintained in an optimal condition and managed to minimize whole oflife costs
Information flows – a successful performance managed road network relies on good flow of
information between all parties. However, a poorly chosen level of service that requires excessive
reporting will draw effort way for the core functions of the management team. Ensure the level ofservices reflects a desired outcome and is realistically measurable

Another big challenge in setting service levels is to avoid setting a level that is greater than actually required.
Experience has proven that capturing ‘what usually happens’ on a network into ‘what must happen’ incurs acost increase. Good practice has proven to be to define key objectives or Customer Service Levels, and thenset performance measures to achieve these.
3.1.4

Monitoring

A number of international best practice examples include response times for rectification of identified
defects. While the concept of response times is not hard to comprehend, monitoring of response times has
proven to be time consuming and complex. Response times generate what can be considered a ‘two pass’monitoring and auditing regime. The first pass identifies the defect. The second pass is made at the end of thespecific response time to ensure compliance with the given time period for rectification.
The two pass system is made complicated by the varying response times on each defect. This can beillustrated by considering two separate defects within say 50 m of each other. The first a pothole with a 24
hours response time while the second a missing sign with a 7 day response time. In order to assess truecompliance with the response time the auditor would be required to return to the defect site after 24 hours forthe pothole and again after 7 days for the sign replacement. Monitoring of response times becomes a full time
occupation.
The solution to address both issues was to change the monitoring regime to a ‘one pass’ system and a level ofallowable defects. A move to defects per unit of length was adopted. Returning to the example of the potholeand missing sign within 50m of each other the one pass regime would require the auditor to record thelocation and nature of each defect and then continue to the next similar defect and record that until the audit
was completed. The audit data would then be assessed against the performance measures which would state847

the allowable number of potholes over a certain length, or the allowable number of missing signs over agiven length of network. No further requirement to go back out onto the network until the next audit. An
assessment of compliance is achieved in ‘one pass’ thus reducing the contractors self-auditing, or monitoringtime and similarly reducing the road controlling authorities auditing time.
Compliance results are generally repeatable if the site inspections are undertaken within similar time periods.
3.1.5

Measuring

Human nature appears to compel us to take action if we know we are going to be assessed or monitored.
Similarly in a performance based environment what get measured gets done. Or more importantly ‘what does
not get measured does not get done’. Knowing this human tendency it is important to set performancemeasures that actually reflect what the road controlling authority wants.
Ultimately these performance measures need to relate to the levels of service which have been derived froman understanding of what the customer (road user) wants. The challenge is to set performance measures thatencompass or drive desirable behaviour and results without having to specify excessive numbers ofmeasures.
It is also ideal to have a mechanism to change or modify performance measures throughout the contract
period. In the New Zealand performance models this mechanism is achieved through the Management Board.
Successful performance measures are ones that are agreed by all parties. It is therefore important that eachparty bring to the table their concerns relating to the way performance measures have been set in order tomake improvements.
3.1.6

Conformance

Three strikes and you are out has been a typical instrument for ensuring conformance with performancemeasures in a number of performance based contracts. This simply means that when the contractor fails tocomply three times with performance measures the contract is terminated. It sounds harsh and in reality it issuch a huge step to take to terminate that the ‘three strikes and you are out’ has rarely been used.
Despite the difficulties in implementing this conformance framework it remains critical to the success of aperformance based contract to have some form of conformance, or non-conformance framework.
Consequences of not meeting performance measures remain influential drivers in contractors taking
responsibility and undertaking what they are being paid to do.
The solution developed to date has been called ‘the non-conformance bucket’. Essentially this assigns aweighting to each type of non-conformance and allows the contractor to build up to a number of nonconformances before a financial penalty is triggered.
Network conformance is measured each month via the following methodology.
1.
2.
3.
4.

The contractor audits 10% of his network
Each non-conformance identified, on any asset, has a predetermined value. Each defect is weighted
to reflect significanceThe identified non-conformances are ‘placed’ in the bucket containing the at risk money
In the month if the volume of liquid fails to reach the top of the bucket and overspill then the
network conforms. Too many individual non-conformances and the liquid overspills and thecontractor loses some at risk money

If the road controlling authority identifies a non-conformance not previously identified by the contractor theweighting is greater than for the same non-conformance has the contractor identified it.
This bucket system recognizes that a network cannot realistically be 100% compliant at all times and gives
the contractor flexibility to manage resources, plant and materials efficiently.

4

Monitoring Framework

The Monitoring Framework sits within a wider set of inspection regimes. A three tier inspection regime ismost commonly adopted in performance based contracting. They are:-848

Patrolling – the Contractor’s day to day inspection of the network. Patrolling aims to identify defects that arethen programmed for rectification. Frequency and inspection methodology are usually at the discretion of theContractor but he must ensure his patrolling regime enables him to meet the target levels of service.
Monitoring – undertaken by the Contractor to assess compliance against target levels of service. Assetinspections are undertaken in accordance with the details of individual performance measures but commonlycompliance is reported on a monthly basis.
Auditing – this activity is undertaken as part of the governance role. It seeks to confirm that the level ofcompliance reported through the Contractors monitoring process is accurate. It usually involves the selectionof a random audit length in the network and an independent assessment of compliance in the audit lengths.
Levels of service are set to define minimum values to which the Concessionaire must manage their asset
condition to. However, he is able to make decisions about when and where to invest in his maintenanceworks. His investment decisions will be based on his understanding of asset condition through condition datacollection and his calculation of whole of life costs for various treatment solutions and the consequences ofnot meeting the targets.
Evidence from New Zealand, India and Canada is that the ‘non-conformance bucket’ is driving desirable
behaviours and that assets are being maintained at the ‘correct’ level of service which had been set. Successof the bucket system will be assisted by the ability of the Principal to place an ‘at-risk’ payment in the bucket
initially.
While a financial penalty system has been introduced on a small number of the Expressway Concessions, it isunderstood there is very little, if any, attempts to make similar changes to all of the existing Concession
Agreements (CA) for Expressways in operation. The amendments made to the several CAs mentioned were
mostly due to a revision in scope mostly in terms of additions to the lengths of individual Concession
network. Without financial consequences, the ‘non-conformance bucket’ would rely on ‘name and shame’ todrive Concessionaires to comply with performance measures. While ‘name and shame’ may not be as
powerful as a financial penalty it is highly likely that Concessionaires would be motivated to be reported as
operating as a compliant network.
4.1

Recommendations for MHA Monitoring Framework

The following recommendations were made based on the findings as follows:4.1.1

Concession Maintenance Patrolling

The Concessionaire is responsible for identifying defects, programming repairs to meet performancemeasures (and response times where applicable) and for carrying out the repairs. In order to identify defects
for rectification they need to patrol their network. The form the patrolling takes will vary from asset to asset
and will be dictated by the nature of the performance measures. Whatever form patrolling takes, thefrequency is the responsibility of the Concessionaire.
Pavement OPMs, some Street Lighting and Tunnel performance measures may require patrolling on a daily
basis. This is likely to take the form of a vehicular drive over identifying and locating defects. These records
are then used to program rectification works.
Where constant evaluation of compliance is required, for example air quality within a tunnel, theConcessionaire may opt to mount permanent equipment from which adjustments to ventilation can be madefrom real time data.
For assets such as culverts, bridges, street lighting, tunnels and slopes periodic site inspections will be
required, at times under temporary traffic management. Again inspection records are compiled and defects
requiring rectification are fed into the works program.
Pavement Durability Performance Measures require the Concessionaire to patrol the network using special
equipment (usually high speed data collection). This will be undertaken on a less frequent basis and mostConcessionaires will opt to collect such data to meet condition monitoring and reporting requirements(typical - annually). However, where a Concessionaire feels they need to build their forward works programwith more frequent collection of pavement data they may opt to undertake high speed data collection at afrequency greater than that required for their own condition monitoring purposes.

849

Management Performance Measures do not in themselves require any form of patrolling but theConcessionaire will need to put in place a comprehensive program of reporting requirements in order toensure compliance.
4.1.2

Concession Monitoring

The objective of Concession Monitoring is for the Concessionaire to determine compliance against the target
levels of service. Compliance is then reported to MHA on a regular basis. As each concession is already inplace MHA do not have a great deal of flexibility to introduce financial penalties through the Non
Conformance Bucket. However, the principles of the Non Conformance Bucket do not vary a great deal fromthe concept of the current MHA performance assessment system. Therefore the proposed methodology draws
on both the current system and the Non Conformance Bucket specifically for MHA to introduce into all
Concessions.
4.1.3

Non Conformances

The proposed Monitoring Framework is not built on the identification of defects but the identification of nonconformances. A non-conformance is when the number of defects exceeds the target level of service.
Drawing away from the identification and recording of individual defects allows the Monitoring Framework
to cover all the asset groups and include the network wide performance measures, such as the Pavement
Durability Performance Measures (PDPM) and the Management Performance Measures (MPMs).
Non Conformance by Asset GroupThe effect on an expressway and the impact on a road user of non-conformances from the different asset
groups can vary significantly. Comparison of non-conformances from different asset groups is therefore
difficult. To overcome this and avoid comparisons being made it is proposed that non-conformance isassessed and reported by asset groups.
The relevant performance metrics are initially developed from the review of existing information andinternational best practice. Further insight was gained from the major stakeholders i.e. MHA and theConcessionaires via the workshop sessions carried out. Preliminary performance measures arrived at were
evaluated via site sampling data collection to obtain a snapshot of the current Level of Service and toascertain the practicality of the measures proposed during the implementation phase. Discussions were also
held with MHA to streamline the study with MHA’s objectives and aspirations. Further refinements weremade based on the results obtained during Stage 2 (Pilot Program) of the project where the proposed
performance measures were tested against the rigours and demands of tolled expressways in operations.
4.1.4

Recommended Performance Measures

A total of 47 performance measures are recommended comprising as follows:Table 4.1: Recommended Performance Measures
Description
Management Performance Measures
Pavement Durability Measures
Pavement Operational Measures
Culvert Operational Measures
Slope Performance Measures
Bridge Performance Measures
Tunnel Performance Measures
Street Lighting Performance Measures

Total

Notation

Number

MPM
DPM
OPM
CPM
SPM
BPM
TPM
LPM

6
6
10
3
5
5
9
4

47

Recommended Performance Measures and their relevant Levels of Service were derived after taking into
account of the current and international practices, MHA Standards, manuals and guidelines, site sampling
data collection, Pilot Program findings and discussions and suggestions by MHA. Further refinements
undertaken were incorporated into the Supplemental Document.

850

4.2

Monitoring

Various methods will be engaged to identify non-conformances. The following monitoring methodologies
were proposed:

Table 4.2:

Compliance Monitoring Methodologies

Asset Group

Monitoring

Pavement - Durability
Pavement – Operational
Street Lighting

Automated data collection
Visual inspection
Structural – visual
Functionality – visual
Functionality - light meter
Functionality - visual inspection
Structural integrity - record of inspection

Culverts

Bridges (Inspections)
Tunnels

Slopes4.2.1

Record of inspection
Air quality – automated
Structural – record of inspections
Lighting – light meter
Risk assessment
Condition assessment

Frequency of Monitoring
AnnualMonthly
Annual (or as specified)Monthly
Annual or as specified
Functionality – Monthly
Structural integrity – annual (or as
specified)
Annual (or as specified)
Air quality – continual
Structural – annual (or as specified)
Annual (or as specified)
As required
Annual (or as specified)

Weightings

Within each asset group weightings will be applied to each different non-conformance. The weightings will
be assigned to reflect important factors such as road safety. As in the bucket non-conformance systemdescribed, it is proposed that the new MHA system also increase non-conformance weighting for nonconformances occurring in multiple consecutive months. In each consecutive month a repeat nonconformance attracts higher and higher weighting. A non-conformance identified by MHA but not previously
identified by the Concessionaire will also attract a higher weighting.
4.2.2

Compliance Achievement Level

Currently MHA set compliance achievement for Periodic Maintenance defects at 88% and Routine
Maintenance defects at 100%. This recognises that for periodic type maintenance the expressways are notgoing to be in ‘as constructed’ states 100% of the time. However, it is likely that stakeholders do expect a
perfect network and equally likely those Concessionaires will not be in a position to physically provide sucha perfect network given the dynamic nature of the asset. There are two ways to balance stakeholder
expectations against what a Concessionaire can realistically achieve:
1.

2.

Set achievable target levels of service – setting the target level of service at perfection is costly,
to the point where some concessions may not be viable. In addition to this many asset defects
cannot be treated until they are visible. There are always going to be periods of time where theasset is not perfect.
Set compliance against target levels of service to < 100% - a high target level of service is set
but a certain level of non-compliance is allowed to enable the Concessionaire to manage costand effort effectively

It was recommended that recognition is maintained of the concept that the expressways cannot be maintainedin a perfect condition; that dynamic factors such as asset age, traffic loading and climatic conditions willcontinue to influence the condition of each asset.
4.2.3

Proposed Compliance Monitoring & Methodology

The Supplemental Documentation describes the monitoring methodology to be employed, the relevant nonconformance weightings, measurement of compliance and reporting based on the performance measures andlevels of service recommended for each asset class.

851

Since the Malaysian expressway networks have different lengths, normalization is introduced to some of therecommended performance measures so that the compliance performance can be compared. This is usually inthe form of a %, based on length. Without the normalisation, if the total numbers of non-conformances arereported instead, longer networks will be at a disadvantage since they will have the higher likelihood of being
more ‘non-conforming’. Normalisation however, is not always required i.e. tunnel air quality – it is either
compliant or not, irrespective of length (and if reported by tunnels it would be irrespective of the number oftunnels in the same network).
4.2.3.1

MHA Auditing

One of the key objectives of the project is to draw MHA away from an operational role (identifying defects
and assessing compliance) to a governance role. Once the Concessionaire takes responsibility for assessmentof compliance MHA can transfer effort to an auditing role. Essentially they will be checking that each
Concessionaire is reporting compliance accurately.
4.2.3.2

Current MHA Practice

MHA currently undertake a comprehensive defects inspection each month and compiles a performanceachievement report for each Concession on a six monthly basis. In brief the following process is undertaken:Month 1 – drive over inspection of 100% of network undertaken jointly by MHA and Concession.
All routine and periodic defects recorded.
Months 2, 3, 4, 5, 6 – drive over inspection of 100% of network undertaken jointly by MHA andConcessions. All new routine and periodic defects recorded. All defects from the previous month(s)that have been fixed recorded as ‘rectified’. Any defects from the previous month(s) that have notbeen fixed are recorded as ‘not rectified’.

Of particular note in relation to this performance assessment is that it is undertaken by MHA and not theConcessionaire. It is also restricted to the assets and maintenance activities defined as either routine or
periodic maintenance. In order to move MHA toward a governance role three significant changes to thecurrent monitoring framework need to be considered:


4.2.4

The Concessionaire must be responsible for the assessment of conformance against the performancemeasures;
MHA moves from detailed monitoring of defects to auditing on non-conformances; andThe performance assessment should cover all performance measures.
Non Compliance Penalty (Rewards & Consequences)

Once implemented the non-conformance system will provide MHA with a clear understanding of complianceacross each concession. However, in itself it will not necessarily drive desired behaviours from theConcessionaire. An incentive to comply or a penalty for noncompliance should be considered. As eachconcession is signed, incentives need to be identified within the bounds of the concession agreements.
4.2.4.1

Concession Extensions

Extension of a concession period could be sufficient incentive for a concession to maintain compliance withlevels of services. Concessions invest significant amounts in terms of resources and equipment. Being able toextract further value from equipment and keep resources employed for maximum time frames may beattractive to Concessionaires.
Consideration of extending the years of a concession in proportion to the consistency of compliance against
levels of services can be considered. With this, the greater the consistency of compliance, the longer theextension can be considered.
4.2.4.2

Name and shame

A powerful non-financial incentive for a Concessionaire to comply is comparison of performance against
competitors. It is not in a contractor’s interest to be known as a supplier who fails to meet a client’s
objectives, or who is not performing as well as competitors. The consequences of being ‘shamed’ aresignificant in the long run as the reputation of the contractor is affected. Contractors may then struggle to852

secure further work with the client, or if the performance data is available to the wider industry they may
jeopardise opportunities with other clients.
‘Name and Shame’ can be used in conjunction with an incentive scheme, such as the contract extensions
described previously, or a penalty scheme, such as the calling of the Maintenance Bond for non-complianceas described in the next section.
4.2.4.3

Maintenance Bond

Consideration could be given to linking the calling of the maintenance bond (common to all the concessionagreements) when non-conformance reaches a predefined level. The maintenance bond is currently called
when a concession fails to rectify defects identified by MHA. It is rarely invoked and somewhat
discretionary.
If an objective framework were developed to provide both Concessionaire and MHA with a mechanism forcalling the bond when the level of non-conformance reached a maximum allowable level (perhaps with atime factor) it may well act as a sufficient consequence to minimise cases of non-compliance against levels ofservice.
4.2.5

Pavement Management and Performance Monitoring Systems

Information Communication Technology (ICT) plays a vital an important role in the management of highway
assets. MHA has long realised the importance of road asset management systems with the implementation of
Total Expressway Asset Management System (TEAMS) for pavement management and Highway Audit
Quality System (HAQS) for Concession performance monitoring system. A system study and review for both
systems were undertaken and areas for improvement for the integration of the KPI Compliance wereidentified.

5

Summary

The development of the KPIs for the Malaysian Expressway Concessions was undertaken in two stages asfollows:Stage 1 Stage 2 -Development of the KPIs and KPI Monitoring Framework; andPilot Program

The various components essential for the success of the full implementation of the KPIs to all Concessions
under MHA purview are illustrated as follows:-

Figure 5.1: Essential Components for Implementation of KPIs to All Concessions

853

5.1

Essential Components for KPI Implementation

5.1.1

Performance Measures

Performance measures and their respective Levels of Service (LOS) need to be established based on thecurrent practice and compared to internationally accepted practices. They need to be ‘tested’ forappropriateness and practicality in terms of data collection and reporting which will facilitate the buy – infrom both MHA and Concessions.
5.1.2

Monitoring Framework

The Monitoring Framework need to be properly documented outlining all of the processes involved that are
to be employed. This includes the auditing process, the parties involved and the reporting aspects.
5.1.3

Supplemental Document

This technical document provides the necessary details of the performance measures involved and theirrespective Levels of Service required. The means of how the data is collected, the frequency of measurement,
the equipment to be used (if required) and evaluation of compliance are to be defined in the document.
5.1.4

Data Collection Applications

Depending on the frequency of data to be collected, vast amount of data are to be collected and reported
every month. The usage of data collection applications especially in the field would be very useful when thecollected data is to be used for further processing and reporting. Usage of data collection applications (using
Smart phones and computer tablets) will simplify the process of data recording compared to the manual paper
forms. The data can be automatically updated to a database.
5.1.5

Database Systems

It is crucial that database systems are to be in place when huge amount of data would be expectedconsidering the number of Expressway Concessions operating and soon to be operating in Malaysia. The typeof data includes the inventory and type of assets, raw monthly audit data, asset condition reports, compliancereporting etc. The use of computerized database systems will facilitate the management and monitoring ofdata to ensure ease of reporting due to standardization and in real time, if web based systems were to be used.
Since MHA is currently using HAQS as a reporting database, it is of utmost importance that the existing
HAQS to be enhanced to include KPI Monitoring where all maintenance related data and reporting can be
updated into the system and the extraction of documented data could be possible from the existing HAQS
database.
5.1.6

Data Sets

With larger data sets and longer data cycle, further data mining processes can be employed to derive trending
and predict the Concessionaire’s maintenance and asset performance. Further refinements of related
processes can then be undertaken accordingly to ensure that the expected levels of service would be met.
5.2

Recommendations

Based on the findings of the study, it was recommended as follows:






the KPI Monitoring Framework and reporting is to be implemented to all Concessionaires under
MHA purview;
more training sessions would be warranted for Concessionaires who were not involved in the Pilot
Program for data and compliance reporting;sufficient time need to be allowed for Concessionaires to become fully conversant with theCompliance Reporting procedures and requirements;
to undertake data collection, analysis and trending for all Concessions for between 12 – 24 months
to ensure consistency;
the Supplemental Document is a ‘live’ document and it can be refined as necessary;to consider further improvement in data collection using data collection applications (Smartphones
or computer tablets); and

854



to consider enhancing the current MHA HAQS for integration of the KPI Monitoring Framework.

The asset management approach of implementing KPI for the Malaysian Expressway Concessions would
ensure the standardization of maintenance criteria of expressway assets where reporting of performance
would be streamlined. To ascertain success, collaborative effort between MHA and Concessions would be
warranted.
The management of the Concessions via performance reporting would set the asset management ofExpressways in Malaysia by MHA on a new threshold with benefits as follows:5.2.1


5.2.2




6

MHA
Reinforces and enhances the governance role for the maintenance and upkeep of the expressways
and Concessions.
Concessions
Encourages innovation in maintenance approach
Provides flexibility of how assets and funds are to be maintained and managed based on a set KPIs
Promotes a sense of responsibility of Concessions for the maintenance of their respective assets.

Conclusions

Performance based specifications were introduced to manage road assets approximately 20 years ago.
Government and road controlling authorities internationally recognized the benefits in terms of the
management of their road assets and started moving from traditional forms of contracting to performance
contracting.
The relevant performance metrics were initially developed from the review of existing information andinternational best practice. Further insight was gained from the major stakeholders i.e. MHA and theConcessionaires via the workshop sessions carried out. Preliminary performance measures arrived at were
evaluated via site sampling data collection to obtain a snapshot of the current Level of Service and toascertain the practicality of the measures proposed during the implementation phase. Discussions were also
held with MHA to streamline the study with MHA’s objectives and aspirations. Further refinements weremade based on the results obtained during Stage 2 (Pilot Program) of the project where the proposed
performance measures were tested against the rigours and demands of tolled expressways in operations. A
total of 47 performance measures and their related levels of service were recommended, and these
performance measures are deemed critical to the governance role of MHA and become the Key Performance
Indicators (KPI) for the monitoring of the Malaysian Expressway Concessions.
In conclusion, the study to date had achieved its objective in terms of developing a performance based
monitoring framework which will emphasize MHA’s governance role while at the same time will encourage
expressway Concessionaires to adopt a preventative approach to the maintenance of their assets. Efficiencies
in terms of maintenance and upkeep of the expressway assets can be gained if all Concessionaires were to bemonitored under appropriately similar KPIs and employ compatible asset management systems andprocedures in line with their respective Concession Agreements. The overriding objective is to have a safe,
well maintained and appropriately preserved expressway networks which road users use by choice.
Currently, MHA is undertaking all of the recommendations made for the implementation of the KPIs for theConcessionaires since 2015. It is envisaged that with the advent of 2 years data to be obtained in 2015 –2016, further refinements would be made in terms of the assets involved, the means of data to be collected
and reported and also the KPIs themselves for further improvement.

855

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Experiences of improving road safety in Brazil

TRACK
AUTHOR(Capitalize Family Name)
Paolo Franchetti

CO-AUTHOR(S)(Capitalize Family NamePOSITIONCEOORGANIZATIONFranchetti
Engenharia

POSITION&

BrazilORGANIZATION

Michele Frizzarin

R&D Manager

Franchetti
Engenharia

Alceu Ferreira

Engineering Manager

MGO Rodovias

E-MAIL(for correspondence)

MerolaCOUNTRY&

MerolaCOUNTRY
BrazilBrazilpaolo.franchetti@studiofranchetti.com

KEYWORDS:
Road safety, Road enlargement, existing structure refurbishment

ABSTRACT:The theme of Road Safety is often related to other engineering issues, both of transportation and structural nature.
Ensuring or increasing a suitable level of safety would bring the Road Network Manager to deal with several levels ofproblems.
In Brazil, in the States of Minas Gerais and Goiás, the Road Network Manager MGO is planning to strongly increase
the safety of the BR-050 highway, by enlarging the road platform and bringing the number of lanes to 4 in every
kilometer of its total length of 437 km. This project would double, in half of the length of the highway, the number oflanes.
The paper will present the main transportation and structural issues faced by MGO, with a huge effort of conservation,
refurbishment, reinforcement and enlargement of the existing structures and infrastructures, in order to deliver a costeffective intervention of the whole road network branch.

856

Experiences of improving road safety in Brazil
Paolo Franchetti1, Michele Frizzarin2, Alceu Ferreira3
1

Franchetti & Merola Engenharia Ltda, Rio de Janeiro (RJ), Brazil
paolo.franchetti@studiofranchetti.com

2

Franchetti & Merola Engenharia Ltda, Rio de Janeiro (RJ), Brazil
michele.frizzarin@studiofranchetti.com
3

MGO Rodovias, Uberlândia (MG), Brazil
aferreira@mgorodovias.com.br

1 INTRODUCTION
The theme of Road Safety is not only related to vehicles and road regulation, but it is often also related to
specific engineering issues, both of transportation and structural nature.
In fact, Road Safety depends on the condition of the infrastructure, on its geometrical characteristics, on its
conservation state and level of safety. This not only helps to increase comfort and safety of road users, but decreases
also the risk of damage and loss of operability in case of disaster events like earthquake, floods and others (Franchetti etal., 2008).
Therefore, increasing and ensuring a suitable level of safety is a challenge that every Road Network Manager
has to face, dealing with several levels of problems of technical, functional and economical nature.
In this paper it is presented a real case of application of Road Safety Improvement Planning in Brazil. In
particular, in the States of Minas Gerais and Goiás, the Road Network Manager MGO Rodovias is planning to strongly
increase the safety of the BR-050 highway.
This will be achieved by enlarging the road platform along all the highway and bringing the number of lanes to
4 in every kilometer of its total length of 437 km. This project would double, in half of the length of the highway, thenumber of lanes.
In this paper the main transportation and structural issues faced by MGO Rodovias are presented anddiscussed.

2 FRAMEWORKStarting from 2014, MGO Rodovias is the Road Network Manager of BR-050 (GO / MG), a 436.6 km
Brazilian highway that runs from the intersection with BR-040, in Cristalina (GO), until the border between Minas
Gerais and São Paulo states, in the municipality of Delta (MG).
Currently, the segment under concession has:






191.85 km of two-lane road in Goiás;
26.65 km of four-lane road already duplicated by the concessionaire, still in Goiás;
218.1 km of four-lane road with central separation in Minas Gerais;
22.8 km of side roads,
1.3 km unpaved.

In its extension it covers 9 municipalities, 5 in Goiás (Cristalina, Ipameri, Campo Alegre de Goiás, Catalão andCumari) and 4 in Minas Gerais (Araguari, Uberlandia, Uberaba and Delta).
The highway is one of the main lines connecting the Federal District (with the Capital City of Brazil, Brasilia)
and São Paulo, cutting important municipalities of agro-industrial activity and wholesale trade.

857

Figure 1. Map of BR-050 Highway.

Figure 2. BR-050 Highway.

2 PLANNED WORKS OF ROAD SAFETY IMPROVEMENT
The works of structural and operational improvements to be made by MGO Rodovias during the contract will
have a direct impact on the quality of road transportation in Goiás and Minas Gerais, with the improvement of the BR050 on security aspects, fluidity, economy and comfort. They are considered essential for the modernization of thisregional infrastructure.
In 30 years of concession, MGO Rodovias will invest $ 3 billion in BR-050, and 1.5 billion in the first five
years of the concession. Of this total, R $ 2.0 billion will be for structural interventions in the pavement and functionaland operational improvements, and R $ 650 million specifically for enlargements / duplication of the highway.
Franchetti is an engineering company that operates in the fields of civil, transportation and environmental
engineering. The structural engineering work undertaken by Franchetti mainly involves existent strategic and importantworks that require a rapid assessment of safety and degradation.

858

Figure 3. Bridges to be refurbished and enlarged along BR-050

Figure 4. Some examples of the bridges to be upgraded
Franchetti is in charge for the verification and design of the refurbishment and enlargement of 27 bridges along
the BR-050. The activities included in-depth initial inspections of the bridges, assessment of their condition state,859

analysis of the actual safety condition of the structure, design of refurbishment, reinforcement and enlargement of thebridges.
The bridges were all in reinforced concrete, with only two of them in pre-stressed concrete. The lengths of thebridges span from 20 m to 170 m. 14 of them were bridges on water stream, usually of small width, with the exceptionof the bridge Wagner Estelita Campos, between the states of Minas Gerais and Goiás, across the river Paranaíba with awidth of over 150 m. The other bridges are crossing over other roads and railroads.

2 PRELIMINARY ACTIVITIES: INSPECTIONS AND TESTS ON MATERIALSAs a preliminary activity, a campaign of in-depth inspections was carried out, focused on the assessment ofconservation state of the bridges.
The activities provided:
 Visual inspection with damage assessment, degradation assessment and condition state definition;
 Campaign of destructive and non-destructive tests on materials, included concrete core boring, carbonationand chemical tests, steel corrosion and tensile stress test, Schmidt hammer tests, pull-out tests.
A total amount of 570 tests was performed.
The tests helped the designer to identify the structural characteristics and conservation state of the bridges inorder to define their residual capacity and therefore design the interventions.

Figure 5. Some examples of test on materials

3 STRUCTURAL AND ROAD REQUIREMENTS
The main structural and road geometry requirements related to the planned works were the following:
1.
2.

Structural refurbishment and reinforcement to increase the load classification of the bridges (from TB-36 to
TB-45);
Structural and road enlargement to increase the road capacity.

3.1 STRUCTURAL REFURBISHMENT AND REINFORCEMENT
The bridges along the BR-050 highway, like many bridges in Brazil, were designed with the code NB6/60, thatprescribed a truck load on bridges of 360 kN of weight (TB-36).
Starting from the code NBR-7188/84, and then with other revision in the following years until the last one in2013, the vehicle load on regular bridges passed from 360 kN to 450 kN (TB-45). This brought the bridge to have an
increment on nominal load of 25%, plus some correction coefficients that take into account dynamic effects, number oflanes and defects on the road surface.

860

Figure 6. Comparison between TB-36 and TB-45 load characteristics
Given the need for Road Manager to enlarge the bridge, it was also the necessary to upgrade them to the newcode.

3.2 STRUCTURAL AND ROAD ENLARGEMENT
The principal goal of MGO Rodovias, following the indication and the planning of ANTT (National Agency ofLand Transportation), was to enlarge the road platform in every kilometre of the concession, in order to achieve thefollowing: At least four lanes (two lane in north direction and two lanes in south direction); Total width of 13,66 m (13,16 m in Minas Gerais); Lane width of 3,60 m;
 Emergency lane of 3,00 m (2,50 m in Minas Gerais); Presence of 1,50 m wide crosswalk; Internal shoulder of 1,00 m.
The initial width of the existing bridges was from 10 to 14 m, needing in some cases an enlargement of morethan 3,5 m.

Figure 7. Road enlargement characteristics861

4 DESIGN OF INTERVENTIONS
The interventions were guided by the following principles:They had to be cost-effective;
They had to preserve the main structure of the bridge, without any deep modification on the structural
behaviour;
They had to be as simple as possible to apply, without complex procedures that involve skilled figures notalways present in the territory;
They had to leave the road always open during the works, at least in alternating directions. This isimportant mostly in the segments of the road with only two lanes, since BR-050 is the only connection
between north and south regions in this area, without any alternative road.

4.1 REINFORCEMENT INTERVENTIONS
The reinforcement interventions were designed, starting from the previous guidelines, in 4 typologies:To increase the negative moment resistance of the deck, the thickness of the slab was increased, withadditional reinforcement;
To increase the positive moment resistance of the deck, concrete beam section were widened, withadditional reinforcement and grouting;
When additional reinforcement was needed, or when geometrical condition didn’t allow the application of
concrete widening (slab deck), FRP reinforcement strips were used;
When strong additional reinforcement was needed, post-tension was added to the beam.

In the case of bridge Wagner Estelita, a specific solution had to be designed to substitute the existing concrete
piers on the water with new piers, always without interrupting the traffic on the road. This was necessary because theexisting piers had lost the bearing of the ground at foundation level, due to scour of the water under the piers.
Together with the principal interventions described above, other procedures were applied in order to have thebridges fully upgraded.
For example, on most of the bridges, the old bearing, constituted by steel or lead plates, were substituted withnew modern bearings, like confined elastomeric bearings with controlled degree of restraint.
In order not to change the original static scheme of the bridge and create unexpected solicitation states, the new
bearing scheme had to be as similar as possible to the old one, assuming the columns with only metallic plate on the top
as fixed bearings and the short columns (usually at the extreme sides of the bridges) as mono-directional bearings, sincea “freyssinet” type hinge was originally built at the bottom of them.
The new bearing system provides a couple of fixed columns (usually the ones at the centre of the bridge) andtwo or more mono-directional bearings at the sides.
The substitution of the bearings is provided through the use of metallic cantilevers fixed at the top of thecolumns, and with hydraulic jacks to lift the bridge. For every column a variable number between 2 and 4 jacks isprovided. All the jacks are connected to a central control device, in order to lift the bridge homogeneously.
After the bearing substitution, the metallic cantilever are disassembled and used on another bridge.

862

Figure 8. Wagner Estelita Campos bridge: substitution of existing piers with new piers

Figure 9. Bearing substitution863

4.2 ENLARGEMENT INTERVENTIONSThe enlargement interventions were designed, starting from the previous guidelines, in the first attempt by
avoiding additional foundation and piers. Where possible, this allows quicker interventions and reduced costs:

Where the four road lanes were separated in the middle, usually there was enough space to allow
symmetrical enlargement of the bridges, suitable for structural needs. In these situations, a system of
cantilever transversal beams, made on steel or concrete, were designed, connected to the longitudinalbeams; the existing columns and foundations were verified with the new loads;
Where the four road lanes were not separated in the middle, another type of intervention was designed,
usually with an additional beam and column by one side, or additional deck slab.

Figure 10. Symmetrical bridge enlargement: solutions with steel frame and concrete cantilevers

Figure 11. Asymmetrical bridge enlargement: solutions with slab deck864

Figure 12. Asymmetrical bridge enlargement: solutions with beam deck

4.3 ROADWAY SAFETY
Together with structural interventions, also roadway safety issues were taken into account.
The width of the lanes was not increased with respect to the previous situation, but additional safety measures
were introduced, like: Emergency lane, not present before the intervention;
 Internal shoulder, not present before the intervention;
 Physical separation between road platform and crosswalk through concrete barrier (new jersey).
The choice of concrete new jersey is related mostly to the construction practice of the area, and to the lack ofsteel barriers suppliers.
The bridges object of the analysis are not crossed often by pedestrians during the day, since most of thestructures are far from inhabited areas. However there are some people that stop on the bridges for long periods of time
(mostly fishers).
The previous crosswalk configuration was not sufficient to ensure the minimum level of safety for pedestrians,
since the crosswalks were constituted by narrow bands (from 50 to 80 cm wide) not physically separated from the road
platform but only elevated of 10-15 cm with respect to the road.

865

The countermeasures that were provided, even if not fully completed, started to give the first outcome, as seenfrom the following graph. The monthly number of events in the BR-050 roadway is showing a decrease in the recent
periods.

Figure 13. Number of monthly events in the past months
The safety barriers of the bridge were built in concrete, due mostly to the construction practice of the area, andto the lack of steel barriers suppliers. Also the barriers along the roads, when present, were mostly in concrete. In thisway the transition between bridge and road is not affected by the change in barrier typology.
4.3 LIFE CYCLE ANALYSIS
Given an estimation of the cost of intervention for the reinforcement and enlargement of the bridges, a reallyrough and preliminary analysis was performed in order to have a rough order of magnitude (ROM) of the Return ofInvestment (ROI) of the rehabilitation intervention.
The estimation was made by comparing the cost of intervention for some bridges to the cost of construction ofa bridge with the same length at the side of the first one. This happens when the existing road has a width of only 2lanes, and the design road has a width of 4 lanes. In this situation, the existing bridge is reinforced and enlarged to fit
the emergency lane and the crosswalk, while a new bridge is built next to the old one for the others 2 lanes.
For example, for Wagner Estelita Bridge, we have: Cost of rehabilitation of existing bridge: 4’500’000 US$
 Cost of construction of the new bridge: 7’500’000 US$
 Cost of demolition of the existing bridge: 500’000 US$
With these values we have a ROI of 0,78, index of good investment.

5 CONCLUSIONSThe paper presented the main issues faced by MGO with the goal of refurbishment and enlargement of BR-050
bridges, in the general planning of road safety improvement.
A huge effort of conservation, refurbishment, reinforcement and enlargement of the existing structures andinfrastructures was made, in order to deliver a cost-effective intervention of the whole road network branch. The final
result was a series of structural solutions that allowed minimum cost of intervention and time-effective actions.

866

6 ACKNOWLEDGEMENTS
The authors would like to acknowledge the staff of MGO Rodovias for the valuable help and availability.

REFERENCES
Franchetti P., Da Lozzo E., Shinozuka M., Modena C (2008). Optimal Resource Allocation for Seismic
Rehabilitation of Highway Networks. International Conference on Bridge Maintenance, Safety and Management(IABMAS’08), Seoul, Korea, 13 – 17 Luglio 2008.
MGO Rodovias – Internet site (www.mgorodovias.com.br).

867

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)
Yu-Min SU

CO-AUTHOR(S)(Capitalize Family Name

Pilot study of permeability of pervious concrete in conjunction with ultrasonic pulse
velocity and X-ray computed tomography
Innovations in Pavements & Materials
POSITION
Assistant Professor

POSITIONORGANIZATION
Department of Civil
Engineering,
National Kaohsiung
University of Applied
Sciences

COUNTRY
TaiwanORGANIZATIONCOUNTRY

Ping-Ni HOU

Graduate Research
Assistant

Department of Civil
Engineering,
National Kaohsiung
University of Applied
Sciences

TaiwanKrishna Prapoorna BILIGIRI

Assistant Professor

Department of Civil
Engineering, Indian Instituteof Technology Kharagpur

India

Anush K. CHANDRAPPA

Graduate Research
Assistant

Department of Civil
Engineering, Indian Instituteof Technology Kharagpur

India

Jui-An Wu

Ph.D. candidate

Department of Civil
Engineering,
National Kaohsiung
University of Applied
Sciences

TaiwanE-MAIL(for correspondence)

yuminsu@kuas.edu.tw

KEYWORDS:
Permeability, Pervious Concrete, Ultrasonic Pulse Velocity, X-ray Computed Tomography

ABSTRACT:The research objective of the pilot study was to study the permeability of pervious concrete in conjunction withultrasonic pulse velocity and X-ray computed tomography. The research scopes cover to batch three different pervious
concrete, to cast concrete cylinders, to assess the mechanical properties of 28-day moist-cured compressive, to evaluate
dynamic modulus of elasticity conducted by ultrasonic pulse velocity, and permeability virtually determined by X-ray
computed tomography. The potential research outcomes explore preliminary results in mechanical properties ofhardened pervious concrete and predictive correlations between dynamic modulus of elasticity and permeability
nondestructively evaluated. The pilot study is still an ongoing project and more outcomes will be unveiled in in the near
future.

868

Pilot study of permeability of pervious concrete in conjunction
with ultrasonic pulse velocity and X-ray computed tomography
Dr. Yu-Min Su1, Ping-Ni Hou1, Dr. Krishna Prapoorna Biligiri2, and Anush K. Chandrappa2
1Department of Civil Engineering, Kaohsiung University of Applied Sciences, Kaohsiung 80778, Taiwan
2Department of Civil Engineering, Indian Institute of Technology Kharagpur, West Bengal 721 302, India

Email for correspondence, yuminsu@kuas.edu.tw

1 INTRODUCTION
Pervious concrete pavement (Tennis et al., 2004) has been found a well-designed tool in recharging groundwater,
reducing stormwater runoff, and meeting U.S. Environmental Protection Agency (EPA) stormwater regulations.
Typically, the porosity or the interconnected porous structures are designed to meet between 15% to 25% in hardened
pervious concrete and the flow rates for water running through are 0.34 cm/s or 200 L/ m2/min (480 in/hr or 5 gal/ft2/min).
The benefit of use of previous concrete may help on getting credit point in the U.S. Green Building Council’s Leadershipin Energy & Environmental Design (LEED) Green Building Rating System (Sustainable Sites Credit 6.1) which
eventually possible winning the LEED project certification. In general, the density of pervious concrete is about 1600 to2000 kg/m3 (100-125 lb/ft3); typical compressive strength can develop from 3.5 to 28 MPa (500 to 4000 psi).
The research objective was to develop a pilot study and assess pervious concrete cylinders with three different
mix proportioning in conjunction with ultrasonic pulse velocity and X-ray computed tomography. The research scope
was to utilize the local siliceous aggregates obtained in southern Taiwan to mix and proportion previous concrete mixtures.
Fresh and hardened concrete properties, permeability, and voids were of the major research interests in this pilot study.
2 EXPERIMENTAL PROGRAM
Details of materials and mixing proportioning used, fresh and hardened concrete tests performed, and ultrasonicpulse velocity and X-ray computed tomography tests executed are as follows:
2.1 Materials and mixing proportioning
ASTM Type I cement (ASTM C150-16e1) was purchased by a local contractor and mixing water was the tap
water provided on campus. Coarse aggregates identified as the siliceous aggregate were supplied by a local contractor
and it was a blended type with the 12.5mm of Nominal Maximum Aggregate Size (NMAS), 2.64 of bulk specific gravity(ASTM C127-15), and 1.35% of absorption (ASTM C127-15), respectively.
Table 1 shows the mix proportioning of three different pervious concrete mixtures, namely P1, P2, and P3
mixtures. P1 mixture contains one fractionated coarse aggregate that was retaining on the 4.75mm (#4) sieve and passing
through 9.5mm (3/8 inch) sieve; P2 mixture also comprises another fractionated coarse aggregate that was retaining on
the 9.5mm sieve and passing through 12.5mm (1/2 inch) sieve; P3 includes the aforementioned blended type of 12.5mm
coarse aggregates without fractionation process. It has to be noted that three pervious concrete mixtures were carefully
designed and identically proportioned by weight. The water to cementitious ratio (w/c) was selected to 0.30. Concrete
cylinders were cast and later brought to cure in the limewater tank for 28 days curing process, shown in Figure 1. It has
to be noted that only a very few amount of superplasticizer was added to improve the workability of pervious concrete
mixtures.
Table 1. Mixing proportioning of pervious concrete mixtures (by weight)
Mixtures

W/C

P1
P2
P3

0.30
0.30
0.30

Coarse aggregates(kg/m3)
1530
1530
1530

Cement(kg/m3)
340
340
340

Water
(kg/m3)
100
100
100

Superplasticizer(kg/m3)222869

(A) P1(B) P2(C) P3Figure 1 (A)(B)(C) Three pervious concrete cylinders (Photos taken by Ping-Ni Hou).
2.2 Fresh and harden concrete tests
Unit weight test (ASTM C138-16) of fresh concrete and compressive strength (ASTM C39-16b) test for
hardened pervious concrete cylinders were performed. Figure 2 (A) and (B) show the scheme of the unit weight andcompressive strength test in the materials testing laboratory located the Department of Civil Engineering of National
Kaohsiung University of Applied Sciences.
The percentage of interconnected air voids inside of three pervious concrete cylinders were also assessed. The
hardened concrete cylinder was measured the volume (V) and weighted in water tank (W1); the cylinder later brought outof water tank, placed to drain, and weight in ambient and surface dry condition (W2). Equation (1) indicates the percentage
of interconnected voids or porosity (Pa_interconnected) as follows:

𝑃𝑎_𝑖𝑛𝑡𝑒𝑟𝑐𝑜𝑛𝑛𝑒𝑐𝑡𝑒𝑑 = [1 −(𝑊1 −𝑊2 )/𝜌𝑤
𝑉

]

(1)

Where the density of water generally assumed 1.0 (g/cm3).
2.3 Ultrasonic Pulse Velocity test
Ultrasonic Pulse Velocity (ASTM C597-16) test was utilized to evaluate the velocity of ultrasonic pulse running
through three hardened pervious concrete cylinders nondestructively, shown in Figure 3. The pulse velocity (V) was alongitudinal stress ultrasonic waves propagating through a pervious concrete cylinder to relate with its dynamic modulus
of elasticity (Ed), dynamic Poisson’s ratio (μ), and density (ρ). Equation (2) shows the aforementioned parameters andrelationship as follows:
𝐸 (1−𝜇)𝑑
𝑉 = √𝜌(1+𝜇)(1−2𝜇)

(2)

870

(A)

(B)

Figure 2. Scheme of unit weight and compressive strength test (Photos taken by Ping-Ni Hou).

(A)

(B)

Figure 3. Scheme of Ultrasonic Pulse Velocity test (Photos taken by Ping-Ni Hou).
2.4 X-ray computed tomography
The nondestructive evaluation through the medical X-ray CT was conducted at the E-Da/I-Shou University
Hospital. The Somatom® Emotion manufactured by the Siemens Healthcare is a 16-channel X-ray CT facility andprovides maximum 0.75 mm in resolution in Z-axis. Figures 4 presents the scheme of performing the X-ray CT scan andthe orientation of the segments. While performing the X-ray CT scan, the concrete cylinder was placed on the patient’stable. The operator positioned the table properly and started the scan. The concrete cylinder was going back and forththrough the ring of the facility along with the Z-axis and the embedded sixteen X-ray channels/sources acquired multiple
X-ray digital images to construct the three-dimensional reconstruction momentarily. The setting of acquiring the concrete
cylinder CT images was to use 110kV with automatic current (mA or μA). Previously research work (Su et al 2014;2016)
conducted have identified and adopted setting with the same voltage and automatic current during to scan PCC or asphalt
concrete without any problem. After the segments acquired from the facility, series of segments in the medical
formatting—DICOM were brought back to KUAS to proceed the image processing and analysis. It has to be noted thatthe image processing and analysis were conducted by Mathworks MATLAB R2015b and the ImageJ provided by
National Institutes of Health. The goal was to quantitatively evaluate the voids area and ratio of each segments and thenconduct a topdown and in-depth voids distribution along the Z-axis.
2.5 Constant-head permeability test
The indoor constant-head permeability testing device was assembled in-house to measure the permeability ofpervious concrete with 150mm (6 inches) in diameter, shown in Figure 5. The constant head was set to 300mm and theoutflow water was collected for fifteen seconds. The permeability KT (cm/s) is computed as follows in Equation (3):

871

𝐿

𝑄

𝐾𝑇 = ℎ × 𝐴(𝑡 −𝑡 )
2

(3)

1

Where: KT: permeability (cm/s); L: sample height (cm); h: head difference; (t2-t1): 15 seconds adopted; Q: volume ofoutflow water collected (cm3); A: area of concrete cylinder (cm2).

Y-axis0.75mmFigure 4. Scheme of performing the X-ray CT scan and the orientation of the segments (Photos taken by Dr. Yu-Min
Su).

Figure 5. Scheme of constant-head permeability test (Photos taken by Ping-Ni Hou).

3 TESTING RESULTS IN COMPRESSIVE STRENGTH, UNIT WEIGHT, AND UPVTable 2 shows experimental results in average compressive strength (MPa/psi), unit weight (kg/cm3), and 3, 12,
21, 28-day of pulse velocity (m/s). In terms of compressive strength, the larger the nominal aggregate size was, thestronger the strength exhibited. The tendency of unit wright followed the same trend as that of the compressive strength.
As posed to the ultrasonic pulse velocity, Chandrappa and Biligiri,(2016) adopted 0.25 of the Poisson’s ratio and so wasthis pilot study. The 3, 12, 21, 28-day of dynamic elastic modulus (GPa) were able to be converted by adopting equation
2 and the outcomes were shown also in Table 2. Both UPV and dynamic elastic modulus increased as the hydration timeincreased. More investigations are needed to comprehend the concrete consensus as well as UPV or dynamic modulus.

872

Table 2. Compressive strength, unit weight, and UPV of previous concreteCompressive strength (MPa/psi), 28-day
Unit weight (kg/cm3)
UPV (m/s), 3-day
UPV (m/s), 12-day
UPV (m/s), 21-day
UPV (m/s), 28-day
Ed (GPa), 3-day
Ed (GPa), 12-day
Ed (GPa), 21-day
Ed (GPa), 28-day

P1
8.52/1235.42
1731
3792.834018.00
22.47
25.21

P2
9.99/1449.15
1874
3928.57
4271.144327.29
24.10
28.49
29.24

P3
11.26/1632.66)
1907
4251.594320.374387.56
28.23
29.15
30.06

4 ANALYSIS OF X-RAY COMPUTED TOMOGRAPHY
Table 3 indicated results in terms of air voids: the measured interconnected voids, the estimated by X-ray CT,
and permeability. It is worthy to note again that the percentage of interconnected voids was measured and calculated byequation 1 and the percentage of air voids was an average of what estimated by X-ray CT. Figure 6 showed the top-down
voids analysis along with the Z-axis of the pervious concrete cylinder. In-depth voids on each level of a cylinder can beextracted to be analyzed. Both voids presented that P2 appeared much porous than P1, followed by P3, which wereconsistent with results in permeability. Both measured and estimated voids are seemingly correlated and more specimens
are needed to scan and relate in the future.
Table 3. Measured interconnected voids and air voids estimated by X-ray CT

Percentage of interconnected voids (%)
Percentage of air voids (%), by X-ray CT
Permeability (cm/s), constant-head

P1
26.6
22.2
1.53

P2
26.5
24.0
1.61

P3
19.9
19.0
1.28

Top-down Voids Analysis
0%

10%

Voids estimated
20%
30%

40%

0

Topdown depth of the concrete cylinder (mm)

50

100

150

200

250
P1: 4.75mm

P2: 9.5mm

P3: 12.5mm Blended

Figure 6. Top-down voids analysis (Photos taken by Ping-Ni Hou).

873

5 CONCLUSIONS
Three previous concrete cylinder proportioned with different fractionated coarse aggregates were cast andassessed by pulse velocity and X-ray CT. Several preliminary results are concluded as follows:
In terms of fresh and harden concrete properties, the unit weight and compressive strength of P3 mixture containing
blended 12.5mm coarse aggregates were higher than those of P1 and P2 composed of single fractionated aggregates.
However, it was not a surprise to find that the percentage of interconnected voids of P3 was the lowest in comparison
with these of P1 and P2.
In terms of UPV or computed dynamic modulus, both increased with the hydration time of 3, 12, 21, 28-days aswell as the fresh and hardened concrete properties, namely unit weight and compressive strength. More evaluations
are required to perform.

The top-down voids analysis on each pervious concrete cylinder performed by the X-ray CT can be extracted toevaluate the internal voids nondestructively. The average voids of P1, P2, and P3 estimated by X-ray CT werealigned with the measured interconnected voids, as well as permeability. However, more studies on the correlation
are needed in the future.
6 ACKNOWLEDGEMENTS
The authors like to extend appreciations to both the National Kaohsiung University of Applied Sciences andIndia Institute of Technology at Kharagpur to provide the equipment and laboratories to support this pilot study. It also
has to be noted to specially thank for staff of Cancer Hospital of E-Da Cancer hospital to operate the medical X-ray CT
facility and scanned pervious concrete specimens.

REFERENCES
ASTM C39-16b (2016). Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens, WestConshohocken, PA, United States.
ASTM C127-15 (2015). Standard Test Method for Relative Density (Specific Gravity) and Absorption of Coarse
Aggregate, West Conshohocken, PA, United States.
ASTM C138-16 (2016). Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of
Concrete, West Conshohocken, PA, United States.
ASTM C150-16e1 (2016). Standard Specification for Portland Cement, West Conshohocken, PA, United States.
ASTM C597-16 (2016). Standard Test Method for Pulse Velocity Through Concrete, West Conshohocken, PA,
United States.
Chandrappa, A. K., & Biligiri, K. P. (2016). Influence of mix parameters on pore properties and modulus ofpervious concrete: an application of ultrasonic pulse velocity. Materials and Structures, 49(12), pp.5255-5271.
Su, Y-M., Hsu, C-Y., Lin, J-D. (2014). Clogging evaluation of porous asphalt concrete cores in conjunction withmedical x-ray computed tomography, SPIE Smart Structures and Materials+ Nondestructive Evaluation and Health
Monitoring, pp. 90630O-90630O-11.
Su, Y-M., Lee, M-G., Chen, G-Y. (2015). The exploration study of fire damage to concrete specimen using x-ray
computed tomography, SPIE Smart Structures and Materials+ Nondestructive Evaluation and Health Monitoring,pp. 94370A-94370A-8.
Tennis, P., Leming, M., and Akers D. (2004). Pervious Concrete Pavements, Portland Cement Association, Skokie,
IL, United States.

874

Enhancing Road Safety in Nepal: a systematic approach
Background
Nepal like many other developing countries, could not give due priority for Road safety in the last few decades.
There was lack of Lead agency to plan, design, implement, coordinate and monitor activities related to roadsafety which caused Road safety as nobody’s business. Although there were some individual efforts put by
various stakeholders from some petty budgets available to them there was neither coordination nor continuity ofsuch programs. There was absence of dedicated budgets and hence dedicated staff to carry the road safety
agenda ahead. Road safety was given priority only when there were some donor funded projects. It was also
talked and highlighted by everybody for a while when there were some major accidents causing huge fatality.
Some good works done by a British funded project in the nineties on a major highway linking Kathmandu, thecapital city has also lost continuity and a Unit created then known as Traffic Engineering and Safety Unit, TESU
got function less in course of time. Road Safety Audit practice initiated at this stage was also not continued.
While, the Road traffic was growing annually at double digit, the road conditions were not up to the mark androad accidents were alarmingly increasing. Precious lives which could be saved were getting lost every day andits cost on society was huge. There were commitments from Nepal to curb down the rate of accidents
significantly by 2020 in line with UN Decade of Action for Road safety and UNESCAP targets. The UN Global
Action mandates member countries to develop their individual national plans for the decade (2011 to 2020)
incorporating interventions under the following five pillars to road-safety.

-crash response
It was urgently required to bring all the stakeholders under one umbrella, coordinate with them and put them into
integrated action in a planned and systematic manner. The Government therefore decided Ministry of PhysicalInfrastructure and Transport, MoPIT as the Lead Agency and approved National Road Safety Strategy andAction Plan 2013- 2020. Road Safety Council is about to be formed. The plan is now put to implementation andpositive improvements are now seen in the field of Road Safety.
The Status of Roads and Road safety in Nepal
The rate of accident in Nepal is quite high compared with neighbouring Asian countries. There are about six
deaths every day on average. The total number of vehicle is 1.7 Millions. Based on this figure rate of fatal
accident per 10000 vehicles per year are 12. If we exclude one million two wheelers from the total, the rateworks out to be 33. This figure is still too high. Awareness campaigns are weak and there is even question about
under reporting of the rate of accidents. The post accident care and presence of trauma hospitals are insignificant.
The following are the findings of RTAs in Nepal based on past research and monitoring.

country’s fleet ply.
everity of the RTA injuries in the Kathmandu Valley is less pronounced compared to the rural areas and
RTA fatalities amongst the vehicle fleet are higher in the regions outside the Kathmandu Valley.
-safety has not been duly considered andPeople between 15 to 40 years of age are most affected in road-accident followed by those above 50 years.

875

rban areas suffer from significant number of motor-cycle accidents. In the rural areas, there are significant
number of trucks and bus accidents.
ong the long-distance routes are of serious concern accounting for 13% and 31%of all thefatalities and serious injuries, respectively. Single bus accidents where the vehicle runs over the hill-roads
represent the fatal RTAs of catastrophic proportions.
30 to 40% of the accidents happen after sunset when traffic is low. Accidents tend to cluster at Urban
intersections, bridge approaches, and roadside built-up areas.
overtaking, over speed , random roadside parking, reckless pedestriancrossing, poor road conditions, etc., were identified as the major causes of accidents.
The economic loss from RTAs in Nepal was at least NRs.22.7 billion(US$ 41.2 million) annually or 0.4 % of
the GNP at 2007 price. When the accident under-reporting are adjusted, the loss was 0.8% of the GNP annually.
There are numerous safety issues on the Nepalese hill roads (which form a substantial portion of the road
network) such as poor visibility at blind corners; poor shoulders; unforgiving side-drains, inadequate safetybarriers at steep vertical drops; unscientific location of passing bays in single lane roads; lack of climbing lanes;
very steep gradients at numerous sections, narrow sections at built-up areas, etc..
Table 1: Traffic Growth in Nepal

S.N.

Year

VehicleGrowth %1

2004/05

482464

9.2

Motor

2

2005/06

537439

11.4

bikes

3

2006/07625174

16.3

included4

2007/08

71091413.7

5

2008/0981348414.4

6

2009/10101527124.8

7

2010/11117891116.1

8

2011/121348995

14.4

9

2012/13155747815.5

10

2013/14175582112.7

11

2014/15

1995404

13.6

12

2015/162339169

17.2

Average growth over last
12 years =Remarks

14.90%

876

Table 2 : Traffic Composition in Kathmandu Valley
Bus
/mini

truck

Car/ vanmotorcycle

others

Total

20214

18929

14926472272211971

923100

2.2

2.0

16.2

78.3

1.3

100

A Total of 43 % of Nepalese vehicles ply in Kathmandu valley out of which the share of Motorcycle isabout 78%.
Figure 1 : Road Networks of Nepal

Road Network of Nepal,
2015
Highways
Feeder Roads, km

Local Road Network, km

Total, km

Highways

Feeder Roads District Roads

Urban Roads

5031

6604

3835

47108

11636
Type of Road

62579

50943

Blacktop

GravelEarthen

62579
Total

Km/100
sq km

SRN

5574

1888

4173

11636

7.9

Local

1575

14601

34766

50943

34.61

Total

7149

16489

38939

62579

42.52

11.4%

26.3%

62.3%

100%

Network in %Source: DoR and DoLIDAR, 2015

2877

Table 3 : Trends in Road AccidentYear

Accidents Fatalities Serious

SlightInjury/Total

Fatality per

injuryinjuryfatal ratio vehicle

10000 veh

2001/02

3823

879

458

4138

5.23

36282824.2

2002/03

3864

682

785

4442

7.66

40043817.0

2003/04

5430

802

1659

3925

6.96

44013718.2

2004/05

5532

808

1795

4039

7.22

48066816.8

2005/06

3894

825

1866

3655

6.69

536443

15.4

2006/07

4546

953

2583

5331

8.30

62517915.2

2007/08

6821

1131

2663

5245

6.99

710917

15.9

2008/09
2009/10

8353
11747

1356
1734

3609
4130

6457
7383

7.42
6.64

8134871015271

16.7
17.1

2010/11

14013

1689

4018

8503

7.41

117891114.3

2011/12

14297

1837

4018

7811

6.44

1348995

13.6

2012/13

13582

1816

3986

8000

6.60

1557478

11.7

2013/141839

1660250

11.1

2014/15

2004

1995404

10.0

2339169

8.6

2015/16

10013

2006

4882

8166

6.50

25000

Vehicles/100
20000

15000

No of Accidents
Series1
Series2

10000
N
u5000
m
b
e
0
r

1

2

3

4

5

6

7

8

9

10 11 12 13 14
15
Years

878

Table 3

Analysis of causes of accidents 2015/16

S.No

CausesDrivers
negligence
speed up
Drink and drive
Passangers fault
Mech breakdown
overtaking
OverloadRoad Condition
Stray animal
Bad weather
Others
Total

1
2
3
4
5
6
7
8
9
10
11

Number

Percentage
7433
1273
321
321
245
226
53
34
34
16
57
10013

74.2
12.7
3.2
3.2
2.4
2.3
0.5
0.3
0.3
0.2
0.7
100

Figure 3 :Causes of
Accidents
OthersBad weather
Stray animal
Road Condition
Overload
overtaking

Series2

Mech breakdown

Series1

Passangers fault

Drink and drive
speed up
Drivers negligence
0

2000

4000

6000

8000

879

The Strategy on Road safety
Government of Nepal has given top priority to road safety issue in its policy documents andannual budgets. It states about the strategy in Nepal Transport Policy 2001 as•“to develop a reliable, cost effective, safe facility oriented and sustainable transportsystem that promotes and sustains the economic, social, cultural and tourism developmentof Nepal as a whole”•

Likewise the Vision and Mission are well defined in National Road safety Strategy 2013 as
Vision: Safe road-infrastructures and services backed with effective post-crash response andconducive environment resulting in little or no casualties from the RTAs.
Mission:(i) To mitigate the loss of life, properties and economic loss from RTAs.

(ii) To complement the broader mission of the National Strategy on thePrevention and Control of Violence, Injuries and Disabilities(iii) To meet the targets of the UN Decade of Action.
(iv) To provide a common framework for stakeholder agencies to implement
the various interventions required to mitigate RTAs outcomes.
In order to implement the strategy Nepal Road Safety Council headed by the Transport Minister isenvisaged. There is a steering committee led by Transport Secretary to implement the decisions of theCouncil. Ministry of Infrastructure and Transport is appointed as the Lead Agency for Road safety
policy and actions. The steering committee would also fill the gap till the council is in function backed
by appropriate legal mandates.
The Action Plan
The action plan is prepared so as to achieve the target of reducing the road accidents by 50% by the year 2020.
The actions are time bound, detailed and supported by resources. A glimpse of the action plan is presented
below:
Pillar 1 : Road safety management
The objective of this pillar is to set up mechanism to improve capacity to manage road safety through:
1.
2.
3.
4.
5.

Adopt UN Legal instrument
Encourage adoption of road safety instruments
Increase horizontal coordination among stakeholders
Develop sustainable road strategy and accident reduction targets
Improve accident data collection and research

880

Pillar 2 : Safer Roads and Mobility
The objective of this pillar is to improve the inherent safety of road networks for all road users especially thevulnerable groups ( eg pedestrians, bicyclists and motorcyclists). This will be achieved through:
Adoption of UN and international standards for the design of safe roads.

Incorporating safe design practice during design, construction and operation of roads.

Pillar 3: Safer Vehicles
The objective of this pillar is to promote the universal adoption of both the active and passive technologies thatare available for safe vehicles through the harmonization with the global standards, publicity and incentives forthe consumers in their adoption.

Pillar 4 : Safer Road Users
The objective of this pillar is to develop comprehensive programmes to improve road-user behavior through thefollowing activities:-safety awareness campaigns.
-belts and helmets.
-driving and other risky behaviours-users including pedestrians.
Pillar 5 : Post crash Response:
The objectives of this pillar are to improve the post-crashesresponse, improve capacity of the health-care systems
to provide emergency treatments and long-term rehabilitation for crash victims.

The Action plan is quite detailed with responsibility assignment, time frame and resource allocation.

Ongoing initiatives
Nepal is one of the signatories of Busan declaration 2006. The declaration aims to save 600,000 lives on theroads of Asia and the Pacific by a reduction of 20 per cent in the fatality rates and in the rates of serious injuries
over the period 2007 to 2015 with following strategies:

881

Strategies:


Making road safety a policy priority;

Making roads safer for vulnerable road users, including children, pedestrians and motorcyclists;

Making roads safer and reducing the severity of accidents (building “forgiving roads”);

Making vehicles safer;

Improving road safety systems, management and enforcement;

Improving cooperation and fostering partnerships;

Developing the Asian Highway as a model of road safety;

Steering Committee has been formed led by Secretary and including major stakeholders. This steering committee
has started its work for budgeting and programming.
A separate budget head is assigned so as to support the Road safety program in a sustained manner. Donors haveshown their interest on road safety and supports are being materialized.
Kathmandu Sustainable Urban Transport Project, KSUTP has started working towards improving the Footpaths,
junctions and some key roads in the valley. It is constructing couple of bridges for pedestrians crossings and is
improving the traffic lights in 3 junctions. It plans to establish a central traffic control room.
Government of Nepal has done substantial amount of Road widening/ Junction improvement works in the
Kathmandu valley as well as major cities. The program is ongoing.
Recently Road rating Survey was carried out for 700 km of Highways with the help of iRAP . A Regional TA
from ADB on Road safety enhancement in Nepal and Bhutan has completed in 2014.
Road safety audit for major highways have begun. Based on the survey results, Road safety barriers are being
installed on 70 km of sample road such as Kathmandu Mugling road, Araniko highway and Karnali Highway.
Awareness programs are being organized by the stakeholders. Recently there was a traffic safety exhibition
organized by Traffic Police in Kathmandu. This exhibition was visited by large number of people of different
age group and was well appreciated.
Stakeholders are now collaborating to reduce Road Traffic Accident. Road safety society, a NGO is formed so as
to enhance the Road safety activities
The traffic police have come up with a successful program of checking and penalizing drink and drive. The datashows this initiative has helped reducing the RTA in Kathmandu valley substantially.
Rewards and prizes are being distributed for best works on road safety.
Traffic Road safety week is organized regularly by Traffic Police. Media attention and coverage on Road safety
is appreciable and increasing and the Civil Society gets active when there is a major accident on Nepal roads.
Nepal Automobiles sports Association, NASA has joined hand to promote Road safety activities.

882

The Government has decided to remove old public vehicles (older than 20 years) from Kathmandu.
Road upgrading projects have the mandatory provision of road safety elements and Road safety Audit.
Fine for Traffic rule violation has been doubled despite some resistance from drivers.
A regulation have been passed in 2014 which provisions for specific qualifications including age limits andseparate license exams for obtaining driving license as Public vehicle driver.
Government has begun investigation of RTAs. There is a National Accident Investigation Committee formed incase of Major accidents on case basis and other accidents are investigated through a permanent committee
chaired by the Regional Roads Director.
ADB, DFID and World Bank are supporting Road Safety Initiatives in Nepal and the new MCC project isplanning Road safety as one of its project component.
Future Plans
The Ministry of Physical Infrastructure and Transport, MoPIT plans to amend prevailing Acts and regulations so
as to specify clearly the role and responsibilities of major stake holders. This will also enable to establish a
National Road safety Council headed by Transport minister. The Department of Transport Management, DoTM
has delegated some of its power to Nepal Traffic Police. This has enabled the traffic police to take action against
those who violate traffic rules. Driving License tests are being made more practical and scientific. There is a planfor separate and more rigorous license tests for public vehicle drivers. Necessary legislation is now available forthis. The Driving Training Institutes which are envisioned by existing laws as an integral part of the licensing
process will be better managed and assisted to perform their crucial roles. More works will be done under theupcoming phase of Kathmandu Sustainable Urban Transport Project. Likewise mass transport andEnvironmentally Sustainable Transport, EST will be promoted in the near future. The old vehicles will be
replaced gradually. The nation will have a federal structure completed in two years and the Traffic and Road
Safety activities will be performed from provincial governments as well in line with the program of the National
Road Safety Council.
Conclusion and Recommendations
There were sincere and serious efforts in Nepal for last couple of years towards enhancing Road safety. The
National Road Safety Strategy is now in place. The Road safety action plan 2013- 2020 is prepared, approved
and put to implementation. This plan is well backed by necessary resources: internal as well as external. The
stakeholders are gradually getting integrated and collaborating for the common cause of enhancing road safety.
Donor communities are also keen to support the positive initiatives taken by the government. New roads
construction including upgrading works is now subject to proper safety audit. Works are in the final phase todraft a separate Road Safety Act. The works performed so far has started producing results. The rate of accidentsof last three years has stabilized. Considering the large growth rate of vehicles it can be seen that number ofaccidents and the fatalities per 10000 vehicles are reducing during last five years. There is now expectation andconfidence among stakeholders that we can deliver if we are united. This initiatives needs to be continued withadditional backings of resource and legal mandates. Since things are now positively moving good results are
expected to come by 2020. The political commitment, the budgetary provisions and stakeholder supports
exhibited in last couple of years has laid a very good foundation for road safety enhancement in a systematicmanner.

883

References:
Annual Accident data 2016 , Nepal Traffic Police
Annual Road Data 2015, Department of Roads, Nepal
Annual Road Data 2015, DoLIDAR, Nepal
Annual Vehicle data 2016, Department of Transport Management, Nepal
Nepal Transport Policy 2001, Government of Nepal
Road Safety Strategy and Action Plan, 2013, Government of Nepal
Regulation for Public vehicle driver License 2014, Government of Nepal
Nepal Government Budget 2016
Interim Plan 2013- 2016, National Planning Commission, Nepal

884

Investigating the Contributing Factors Affecting Traffic Crash Caused by Young
Drivers

Corresponding Author:
Nuha M. Albusaeedi
Traffic Engineer
Traffic and Patrols Directorate
Abu Dhabi Police, Abu Dhabi, UAE
E-mail: nuha.albusaeedi@gmail.com, Tel: +971 502201028

Mohammed Kishta, M.SC.
Road and Traffic Engineer
Traffic and Patrols Directorate
Abu Dhabi Police, Abu Dhabi, UAE
E-mail: eng.m.kishta@gmail.com, Tel: +971 503220883
Mohamed Shawky Ahmed, PhD
Assistant Professor
Department of Public Works
Ain Shams University, Cairo, Egypt
E-mail: m_shawky132@hotmail.com , Tel: + 971 561236607

Paper submitted for presentation at the 2nd IRF Asia Regional Congress & Exhibition,
Kuala Lumpur, Malaysia, October 16-20, 2016.

June 15th, 2016885

ABSTRACT
Young drivers are considering as most risky in driving compared to other age groupsof drivers. Understanding the contributing factors affecting traffic crashes caused byyoung drivers leads to more effective actions for improving road safety. This paper aims
to examine the contributing factor affecting the occurrence of young drivers’ crashes.
Crash data from 2010 to 2015 has been collected from Abu Dhabi Traffic Police
database. At-fault drivers’ aged between 18 to 24 years is defined as the young drivers in
the analysis process. Descriptive statistics show that 23% of severe crashes are caused byyoung drivers. These crashes resulted 26% of the total fatalities of traffic crashes.
Logistic regression model was developed to identify and quantify the variables that affectthe occurrence of crashes related to young drivers. The model findings indicated thatspeeding, sudden lane changing and tailgating are the most caused of young drivers
crashes. Young drivers are probably to be involved in multi-vehicle crashes andpedestrian-related crashes. Regarding the environmental factors, young drivers havehigher risk at night and at intersections compared to older drivers.

886

INTRODUCTION
Each year, about 1.2 million people are killed, and up to 50 million are injured in roadbecause of traffic crashes (1). In 2008, HAAD (Health Authority – Abu Dhabi) report (1)documented that for each 3 fatal in Emirate of Abu Dhabi (the capital of United ArabEmirates), 2 of them related to traffic crashes. Known the human factors are consider as
the major cause of traffic crashes, driver’s age is one of these main factors that havesignificant contribution in crash occurrence.
Recently, many researchers giving attention to the young drivers because of the
combination of youth and low inexperience puts them at high risk level. Their
inexperience means they have less ability to spot hazards, and their youth means they areparticularly likely to take risks but they can’t act correctly during critical situations. In
Abu Dhabi (AD), statistics show that 23% of sever crashes and 29% of overturned
crashes were related to young driver. In addition, 26% of the fatality and 23% of theserious injuries were resulted in crashes caused by young drivers during the last 6 years(from 2010 till 2015) as shown in table 1. Despite the increasing on the percentage ofyoung driver’s overturned crashes from 26% in 2010 up to 35% in 2015, the number ofthese type of crashes occurred by young driver has been decreased in the same period.
Table 1: Statistics related to young drivers in Abu Dhabi
Abu Dhabi Emirate
Total number of crashes related to at-fault
driverSevere crashes (*)

2010

2011

2012 2013 2014 2015 Average

2648

2382

2115 2115 1905 1857

2170

598

552

489

462

418

428

491

% of crashes (*)

23%

23%

23%

22%

22%

23%

23%

Total number of overturned crashes

468

431

354

305

254

270

347

Number of overturned crashes (*)

120

120

99

90

80

95

101

% of overturned crashes (*)

26%

28%

28%

30%

31%

35%

29%

Total number fatalities

376

334

271

289

267

245

297

Number of fatalities (*)

96

98

74

53

61

74

76

% of fatalities (*)

26%

29%

27%

18%

23%

30%

26%

Total number of serious injuries

400

390

364

366

240

293

342

Number serious injuries (*)

78

109

84

74

51

68

77

% of serious injuries (*)

20%

28%

23%

20%

21%

23%

23%

(*) related to young driver crashes
In general, there is no much information in regard of young driver behavior in the Gulf
Corporation Council (GCC) countries. Hence, the interaction between young drivers’
behavior in terms of their involvements in traffic crashes has not been much investigatedor published in prior studies. In (AD), a tangible effort has recently been done to improve
the road safety through the three main strategic approaches: Engineering, Education and887

Enforcement. Accordingly, road crash fatalities have reduced from 376 in year 2010 to
245 in year 2015 (about 35% reductions).
Understanding the young driver behavior is the key factor to maintain a proper
reduction rate of fatalities and improving the road safety strategies. Especially in the caseof UAE where more than two hundred different nationalities are living along withdifferent education levels, culture, language, and driving skills background which createsa considerable challenge for different AD agencies that are responsible for road safety.
Accordingly, the main objective of this study is to investigate the contributing factors
affecting young driver risk potential to be involved in a traffic crash. Relationships
between at-fault young drivers involved in traffic crashes and their demographic
characteristics were investigated.
LIRETUTRE REVIEW
Who are the young drivers? In the United States drivers classified as young when
they fall within the age group between 15 and 20 years old (2). UK drivers know the
young drivers as those drivers aged between 17 and 24 years (3). In Australia young
drivers are all drivers who hold driving licenses and under the age of 25 years (4). OECD
countries, which include 41 countries, including Germany, Sweden, the Netherlands,
Switzerland, Japan and South Korea know young drivers as drivers aged between 18 and24 years (5).
Based on World Health Organization (WHO) (6), more than 1,000 people under theage of 25 years are killed in road traffic crashes around the world every day. Road traffic
injuries are the leading cause of death globally among 15–19-year-olds, while for those in
the 10–14-years and 20–24-years age brackets they are the second leading cause of death.
Even in countries that have high level of road safety indicators such as OECD
countries more than 8,500 young drivers die in every year and death rates for young
drivers are about double those of older drivers. In these countries, young drivers represent
about 27% of all drivers’ fatalities, despite the fact that they represented only about 10%of the population. In particular, the young drivers’ fatalities included nearly 4,000
fatalities in the United States, more than 750 in Germany, 645 in France, and more than
300 in Japan and Spain (5). As a share of all driver fatalities within the EU counties, theproportion of fatalities for young drivers ranges from 18 % in Denmark to 32% in
Germany. In contrast, the share of this age group in the total population ranges from 8%
in Denmark to 13% in Ireland. In New Zealand (2013) young drivers aged 15–24 wereinvolved in 71 fatal traffic crashes, 485 serious injury crashes and 2,581 minor injury
crashes. Of these crashes, the 15–24 year-old drivers had the primary responsibility in 55of the fatal crashes, 394 of the serious injury crashes and 1,932 of the minor injury
crashes. These crashes resulted in 64 deaths, 512 serious injuries and 2,659 minor
injuries. The total social cost of the crashes in which 15–24 year-old drivers had theprimary responsibility was $737 million. This is 24 percent of the social cost associatedwith all injury crashes (7).
On the other hand, many studies have been conducted to examine the severity ofyoung driver related crashes and their contributing factors. Curry, et al. (2015) (8)investigated the factors affecting the young driver related crashes. The data has been
selected from all drivers who have an intermediate license and aged between 17-20 years

888old. The outcomes indicated that the crash rates were highest in the first month ofobtaining the license. These rates started to decrease and once the driver transition his
intermediate license to full license the rates increased again. Amarasingha, et al. (2014) (9)tried to find the deference in crash involvement between young female driver and young
male driver. Drivers from 15 to 24 years were considered as young drivers. A logistic
regression model was developed to identify the Factors which increase young female
drivers' injury severity and young male drivers' injury severity. The outcomes showedthat the rear-end collision & collision with vehicle are the factors affected the severity of
male driver. For the female driver the overturn and run over crashes are the two factorsthat affect the crash’s severity.
Alver, et al. (2014) (10) evaluated traffic violation getting by young driver and theeffect of this behavior on the traffic crashes. The data has been collected from face-toface questionnaire and the target driver is the young driver aged 18-29 years old. Ordered
probit model & binary logit model has been used. The results revealed that the trafficcrash rate was 38.3% for those who stated that they received at least one violation during
the past 3 years. Dissanayake, S. (2004) (11) investigated the effect of the single vehicle
crashes by young driver on crash severity. The young driver considered as 16-25 years
old. A logistic regression model was used to develop a model to predict the crashseverity. The results suggested that the speeding and not using a seat belt were the twomost factors affect the crash severity. Dissanayake, S. (2004) (12) developed a model toidentify the factor affecting the severity of young driver related crash. The single vehicle
crashes data has been used in the model. The outcome showed that the speeding and notusing a restraint device (for example the seat belt) were the most two factors increase thecrash severity. Also, the young driver crash severity determined high when the crashes
occurring in the curve or on the bridge.
Chliaoutakis, et al. (2002) (13) examined the influence of aggressive behavior for the
young driver on the traffic crashes. The data has been collected from 356 participants
who aged between 18-24 years using self-reported questionnaire. The result showed thatthe young drivers who drive without any predefined their trip destination are more likely
to involve in car crashes. In other words, the young drivers who use their car just for fun
and not as a transportation mean are causing many crashes. Also, it found that the age is asignificant factor in traffic crashes. McGwin, G. & Brown, D, (1999) (14) conducted astudy to identify the characteristics of young driver related crashes. The data has beencollected from police –reported crashes which occurring during year 1996. The results
explained that the young driver cause a traffic crash because of skill shortage and run therisk.
According to the previous statistics and the literature review the objective of thispaper is to investigate which factors are affecting to the crashes caused by young driverin Abu Dhabi Emirate.
DATA SOURCE & DESCRIPTION
The employed data in this study was extracted from the traffic crashes database of Abu
Dhabi Traffic Police for six years from 2010 to 2015. Severe crash (i.e. any crash
involving at least one injury) data are used in this analysis due to the limitation of theavailable property damage only crash data. The database includes different sets of data889

groups; basic crash information, at-fault drivers and vehicle’s characteristics, casualties’
information, environmental and surrounds condition, traffic violations, etc. Full data of
about 12,611 crashes has been extracted and utilized in this study. It is worth mentioningthat the driver’s community in AD consists of more than one hundred different
nationalities. Male drivers represent 85% of total number of licensed drivers and 92% has
age less than 45 years. Approximately, 2947 crash report related to young driver has beenused in the analysis. Young driver is defined as the driver aged between 18 to 24 years
old.
To achieve the objectives of this study, detailed descriptive statistical analysis will befirstly provided. After that an investigation of the contributing factor that affects young
drivers’ related crashes will be conduct by applying logistic regression modelingapproach.
STATISTICAL DESCRIPTIVE ANALYSIS
Comparisons between at fault young drivers and others was conducted in terms of thefrequency of traffic crashes, crash severity, crash types, crash causes and traffic
violations during the period 2010 till 2015 which occurred in Abu Dhabi Emirate. Figure
1 illustrates the distribution numbers of crashes and fatalities resulted from the young
driver during 2010 till 2015 in Abu Dhabi Emirate. It’s observed that in spite of crashes
number decreased by 28% during study period, the percentage of these crashes out of
total crashes has almost the same trend. On the other hand, although their fatality has
been declining significantly during the study period by 23%, the percentage of thesefatalities out of total crashes fatalities have significantly increased.

(a) Traffic crash frequency(b) Fatality frequency

Figure 1 Young drivers traffic crashes and resulted fatalities
Figure (2) presents the severe crash rate per 10,000 drivers for both young drivers andother drivers. In general, a significant increase (about 54.5%) in the young drivers fatality
crashes rate was observed in the last six years. Which improve the theory of classify
young drivers as a critical driver with regards to traffic safety.

890

Figure 2 Crashes severity during 2010-2015
Table 2 shows the characteristic of at- fault driver involved in sever crashes. The tableshows that the majority (about 60%) of at fault young drivers were local. In addition, it
was observed that the most age of those at fault young drivers was 23 years old, which
seems that young drivers gain more confidence at this age and they tend to commit many
mistakes. These findings prove the necessary of conducting educational campaigns at
Universities, Colleges and high schools where young at this age found.
In addition, table 2 indicates that 74% of at fault young driver were obtained theirdriving license from Abu Dhabi Emirate and 13% from the other Emirates. Regarding thegender, the male young drivers were more likely to causes a severe crash than the female
for both age group (young driver & old driver).
Table 2: The characteristic of at fault drivers who involved in sever crashes in Abu
Dhabi during 2010-2015
18 -24 year
Variable

categories

Gendermale
femaleUAE
GCC
Arab countries
Asian countries
Other countries
Abu Dhabi
Dubai
Other emirates
GCC
othersNationality

Source of driving
licenseFrequency(average)
454
38
293
22
69
105
3
366
27
35
21
35

Percentage
92.4%
7.6%
59.6%
4.4%
14.1%
21.4%
0.6%
74.5%
5.4%
7.2%
4.2%
7.2%

> 24 year
Frequency(average)
1417
173
362
52
358
767
52
1106
228
126
41
91

percentage
89.1%
10.9%
22.7%
3.3%
22.5%
48.2%
3.2%
69.5%
14.3%
7.9%
2.6%
5.6%

891

Figure 3 shows that the crash percentage decreases with increasing the experienceyears of driving up to 20 years. After 20 years of experience the crash percentage
increases that can be explained due to the elder age of the drivers.

Figure 3 Traffic crashes depend on driver experience
Table 3 illustrates the characteristic of young driver related crashes. For both young
drivers and others, it can be clearly observed that 82% of the injuries and fatality resulted
from young driver crashes were classified as slight to middle injuries and 18% wereclassified as severe & fatal injuries. In addition, table 3 shows the percentage of thehighest seven causes of traffic crashes related to young drivers and others. Sudden lanechange (19%), driving too fast (15%) were the main causes of young driver crashes. In
general, non-significant differences exist between young drivers and others in terms ofthe causes of traffic crashes except a slight increment for those due to speeding. Table 3
also presents the percentage of the highest five types of traffic crashes related to young
drivers and others. It was found that the highest percentage of the crash type wasoverturned (21%), followed by pedestrian crashes (17%), rear-end (16%), sideswipe
crashes (14%) and angle crashes (13%). It shows non-significant differences in thepercentage share values of the crash types over the six years for most crash types except asignificant increment in overturned crashes related to young drivers.
With respect to the land use where the crash occurred the analysis shows that (26%) of
young drivers crashes occurred on the rural area, (25%) occurred on residential area and(16%) occurred on commercial area. Regarding to the crash location, the majority ofyoung driver related crashes occurred at non- intersection (74%), while about (15%)
occurred at intersection.

892

Table 3: The characteristic of young driver related crashes
Variable

Injuryseverity

Crash causes

Crash TypeArea type

Crash
Locationcategories
Slight Injury
Medium Injury
Severe Injury
Fatalities
Sudden lane change
Careless driving
Tailgating
driving too fast for conditions
Not following road directions
un respecting of road user
running the red light
OthersOverturned
Rear-end
Sideswipe
Pedestrian
Angle
othersRural area
Commercial area
Residential area
OthersAt Non-intersections locations
At intersections
roundabout
Others18 - 24 years> 24 years
frequency percentage frequency percentage
1893
37.5%
6312
39.6%
2232
44.2%
6824
42.8%
464
9.2%
1509
9.5%
456
9.0%
1295
8.1%
562
19.1%
1575
17.0%
258
8.8%
804
8.7%
313
10.6%
1044
11.3%
442
15.0%
985
10.6%
225
7.6%
679
7.3%
194
6.6%
742
8.0%
201
6.8%
997
10.8%
730
24.8%
2445
26.4%
604
20.5%
1317
14.2%
471
16.0%
1515
16.3%
403
13.7%
1327
14.3%
506
17.2%
1777
19.2%
379
12.9%
1524
16.4%
562
19.1%
1809
19.5%
764
25.9%
2496
26.9%
473
16.1%
1932
20.8%
747
25.3%
1939
20.9%
941
31.9%
2904
31.3%
2186
74.2%
6238
67.3%
432
14.7%
1918
20.7%
220
7.5%
641
6.9%
87
3.0%
474
5.1%

Number of traffic violations can be used as an indicator of drivers’ behavior changes.
The database includes two types of violations; in presence (by Face-to-Face tickets) andin absent (by automated enforcement devices). On this study we depended on (Face-toFace tickets) data to be sure that the violator driver was belongs young drivers’ category.
Table 5 shows that the total number of Face-to-Face traffic violations increased during
the years 2010 to 2015 by 37%, while the total number of young drivers’ Face-to-Facetraffic violations increased by about 45%.

893

TABLE 4: Face-to-Face Traffic Rule Violations Records

Face-to-Face
Violation
Total
Young Drivers
Percentage

2010
504,599
26,9595%

2011
615,90735,329
6%

Years
2012
2013
641,314745,159
34,616
39,411
5%
5%

2014719,156
38,4295%

2015691,220
38,987
6%Face-to-Face (over-Speeding traffic violations) represented about 11.31% of the total
number of Face-to-Face traffic violations over study period, while (young drivers’ Faceto-Face over-Speeding traffic violations) represented about 11.01% of the total number ofyoung drivers’ Face-to-Face traffic violations. Moreover, data shows that in spite ofslight reduction (17%) of Face-to-Face (over-Speeding traffic violations) over study
period, (young drivers’ Face-to-Face over-Speeding traffic violations) significantly
reduced by (35%).

a) face to face violationsb) serious violations
Figure 4 young driver face to face violations
With respect to Face-to-Face violations figure (4-a) presents the number of Face-toFace violation for every 1000 young drivers and the percentage of these violations during
the period from 2010 till 2015.in general there is no significant deferent in number ofFace-to-Face violation during the study period. The highest rate of these violations was in2011 about 142 violations per 1000 young drivers and the lowest rate was in 2015 around
119 violations per 100 young drivers. Although the rate was decreased during the study
period the percentage of those violations was increased. As for serious violations figure(4-b) illustrate the rate of serious Face-to-Face violations and the percentage of these
violations out of total Face-to-Face violations. It can be clearly observed that both therate and the percentage of this type of violations were decreased during the study period.
LOGISTIC REGRESSION MODEL
In order to define the factors affecting the occurrence of young drivers’ crashes combined
to other drivers’ crashes, logistic regression analysis applied. Binary logistic model is agood approach to deal with binary outcomes (1= young drivers’ related crashes, 0= otherdrivers’ crashes). Also, as one of the aims of the study was to develop models to predict894

young drivers’ related crashes, logistic regression was identified as the most suitableapproach to identify the important factors.
In case of binary logistic regression model, the response variable, y takes the form ofeither of the two binary values (0 or 1). For k explanatory variables and i=1, 2, 3, …, n
individuals, the model takes the form as follows
𝑃

𝑙𝑜𝑔 [1−𝑃𝑖 ] = 𝛼 + 𝛽1 𝑥𝑖1 + 𝛽2 𝑥𝑖2 + ⋯ + 𝛽𝑘 𝑥𝑖𝑘. . . . . . . . . . . . . . . . . . . . . . . . . . . . . (1)𝑖𝑃𝑖 = Prob. ( 𝑦𝑖 = 𝑦1 |𝑋𝑖 ) is the response probability to be modeled, and 𝑦1 is the firstordered level of y,𝛼 = Intercept parameter,𝛽 = Vector of slope parameters,
𝑋𝑖 = Vector of explanatory variables.
The odds ratio for dichotomous explanatory variable, x, which takes value 1 or 0 (with1 meaning that the event will certainly occur and 0 meaning that the event will definitely
not occur) can be represented as the ratio of the expected number of times that an event
will occur (x = 1) to the expected number of times it will not occur (x = 0). This can beillustrated by the following formula:𝜋 (1)/[1−𝜋(1)]OR = 𝜋 (0)/[1−𝜋(0)]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (2)Where,OR = Odd Ratio
𝜋 (1)/[1 − 𝜋(1)] = Probability that the event will occur when x=1
𝜋 (0)/[1 − 𝜋(0)] = Probability that the event will occur when x=0
The model was estimated by using SPSS software package. The total number of trafficcrashes involved in the model estimation is about 12,611 crashes.
Explanatory Variables
Many variables were tested includes vehicle, at-fault driver, roadway, and environment
characteristics. At that stage it considered the fact that the quality of the modeling could
be expected to increase to a certain level once the number of variables increases.
Secondly, selection of the variables was carried out depending on the assumption that a
particular variable would affect the young drivers’ crashes. The descriptions of 13
explanatory variables that are considered for the modeling are provided along with theirstatistics in Table 5. All the explanatory variables are binary. Binary variables take theform of either 0 or 1; for example, if a crash occurs on WEEKEND, the variable
WEEKEND has been assigned “1” as its value; otherwise “0” is assigned to this variable.
One binary logistic regression model was developed by considering crash been related toyoung driver as the response variable and the description of the model which is binary innature (YOUNG DRIVER_RELATED = 1 if at fault driver is young driver (18-24 years
old), =0 otherwise). The model has been development using SPSS software.

895

Table 5: Explanatory variable considered in the modelling process
Variable
SUDDEN_LANE_CHANGE
SPEEDING
TAILGATINGLAND_USE
LOCATIONNIGHT
OVERTURNED_CRASHPEDESTRAIN_CRASHREAR_END_CRASHOBJECT_COLLISIONWEEKDAY
MULTI_VEHICLE_CRASH
UAE_NATIONALITY

Description= 1 if crashes occurred because of improper lane change,= 0 otherwise= 1 if crashes occurred because of speeding,= 0 otherwise= 1 if crashes occurred because of not keeping enoughspace, = 0 otherwise= 1 if crashes occurred on commercial & residentialarea, = 0 otherwise= 1 if crashes occurred at signalized intersection orroundabout, = 0 otherwise= 1 if the crash occurred after sun set, = 0 during daylight= 1 If Vehicle upside down, = 0 otherwise= 1 if vehicle hit the pedestrian, = 0 otherwise= 1 if crash type is rear -end, = 0 otherwise= 1 if vehicle hit an object (tee, sidewalk, street light), =0
otherwise=1 if the crash occur during weekdays,= 0 crash occur during weekend (Friday & Saturday)=1 if vehicle hit another vehicle, = 0 otherwise= 1 if driver is UAE Nationals, =0 otherwise

MODEL RESULTS AND DISCUSSIONS
Table (6) shows the results of the estimated parameters of the logistic regression model.
The results indicate that eight variables are significantly changed for young drivers
compared to others at significant of 95%. These variables are sudden lane change, driving
too fast, location, when the crash occurred at night, crash type overturned & pedestrian,
multi vehicle crashes and UAE nationality.
The significance of sudden lane change and overturned crashes variable can bejustified due to driving too fast (which is significant variable) and the desire for speed
and competition cars to satisfy the desire of superiority felt by young drivers. Amongthese variables, young drivers’ crashes have higher probability to be occurred during
night time on commercial and residential areas due to the passion of young to spend thenight with friends in shopping centers and cafes. In addition, pedestrian crashes of young
drivers increased by 1.73 times compared to other drivers. This finding reflects theInability of young drivers to take the right decision and right proper appreciation of the
distances. Also, young drivers have more probability to be involved in multi-vehicle
crashes than other drivers by about 1.57 times over. Moreover, it is remarkably that local
young drivers’ crashes increased by 4.44 times compared to other nationalities young
drivers (Although few in number compared to other nationalities young drivers). Thisvariable can be justified due to local’s high income and their ability to ownership
luxurious high speed vehicles and UAE society is characterized as a small community
Age.

896

The results also show that three variables are significant affect young drivers’ crashes
at a significant level of 90%. These variables are tailgating (not keep a safe distance),
rear-end crashes, and object collision. These findings improve the reality of Inability ofyoung drivers to take the right decision and right proper appreciation of the distances
because of limited experience.
Table 6: The results of the regression model
Variables

B

S.E.

Wald

Sig.

Odds ratio

SUDDEN_LANE_CHANGE

.176

.065

7.396

.007*

1.192

SPEEDING

.374

.066

32.483

.000*

1.453

TAILGATING

.179

.096

3.501

.061**

1.196

LAND_USE

-.015

.047

.107

.744

.985

LOCATION

.117

.047

6.255

.012*

1.124

NIGHT

.227

.045

25.195

.000*

1.255

OVERTUTRNED_CRASH

.682

.221

9.498

.002*

1.977

PEDESTRAIN_CRASH

.547

.222

6.083

.014*

1.728

REAR_END_CRASH

.390

.226

2.969

.085**

1.477

OBJECT_COLLISION

.409

.225

3.306

.069**

1.505

WEEKDAY

-.040

.050

.640

.424

.961

MUTI _VEHICLE CRASH

.451

.218

4.272

.039*

1.570

UAE_NATIONALITY

1.491

.045

1105.827

.000*

4.439

CONSTANT-2.540.221

131.955

.000

.079

* Significant at α = 0.95 level** Significant at α = 0.90 level
CONCLUSION
The main objective of this paper is to investigate the contributing factors affecting young
driver risk potential to be involved in a traffic crash. Relationships between the at-fault
young drivers involved in traffic crashes and their demographic characteristics were
investigated. Traffic crashes and violations data from AD Traffic Police database during
six years (2010-2015) were employed in this study. The main findings of the data
analysis and modelling results can be summarized as follows:- About quarter of sever crashes were related to young driver. In addition, 26% of thefatality and 23% of the serious injuries were resulted because of young driver related
crashes during the last 6 years (from 2010 till 2015).
- A significant increase (about 54.5%) in the young drivers fatality crashes rate wasobserved in the last six years. Which improve the theory of classify young drivers asa critical driver with regards to traffic safety.

897

-

-

-

-

-

The total number of Face-to-Face traffic violations increased during the years 2010
to 2015 by 37%, while the total number of young drivers’ Face-to-Face traffic
violations increased by about 45%..
Sudden lane change (19%), driving too fast (15%) were the main causes of young
driver crashes. In general, non-significant differences exist between young drivers
and others in terms of the causes of traffic crashes except a slight increment for thosedue to speeding.
No significant differences in the percentage share values of the crash types overstudy period for most crash types except a significant increment in overturned
crashes related to young drivers
Pedestrian crashes of young drivers increased by 1.73 times compared to otherdrivers. This finding reflects the Inability of young drivers to take the right decisionand right proper appreciation of the distances.
Young drivers have 1.57 times more than other drivers in case of multi-vehicle
crashes.
It is remarkably that local young drivers’ crashes increased by 4.44 times comparedto other nationalities.

ACKNOWLEDGEMENTS
The authors thank Traffic and Patrols Directorate of Abu Dhabi Police for theirsupport and helping us to fund this research. The authors are also thankful the statistical
department for their great efforts and we do not forget to thank the CRISP Consultancy
for their helpful guidance & advice.
REFERENCES
1. Youth and road safety, 2007, World Health Organization, ISBN 92 4 159511 6,

2.
3.

4.

5.
6.

7.

(NLM
classification:
WA
275),
ISBN
978
92
4
159511
7,
www.who.int/violence_injury_prevention/publications.
http://www.haad.ae/haad/tabid/58/Mid/417/ItemID/86/ctl/Details/Default.aspx.
TRAFFIC SAFETY FACTS_ 2012 Data _Young Drivers, April 2014, NHTSA’s
National Center for Statistics and Analysis, DOT HS 812 019, 1200 New Jersey
Avenue SE., Washington, DC 20590.
Facts on Young Drivers, April 2014, Department for Transport, Press enquiries: 020
7944 2813, https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/306500/young-car-drivers-2012.pdf.
Road safety and young Australians, March 2007, Australian Automobile Association,
http://www.aaa.asn.au/storage/Road%20Safety%20and%20Young%20Australians.
Young Drivers: The Road to Safety, OCTOBER 2006, ORGANISATION FORECONOMIC CO-OPERATION AND DEVELOPMENT, Policy Brief based on thework of the Joint Transport Research Centre of the Organization for Economic Cooperation and Development (OECD) and the European Conference of Ministers ofTransport (ECMT).
Youth and road safety, 2007, 1.Accidents, Traffic – prevention and control. 2.
Wounds and injuries – prevention and control. 3. Safety. 4. Adolescent. 5. Child.
I.World Health Organization, ISBN 92 4 159511 6 (NLM classification: WA 275),

898

ISBN 978 92 4 159511 7, This document is downloadable from:www.who.int/violence_injury_prevention/publications.
8. Young Drivers, 2014, The Ministry of Transport, New Zealand Government,
http://www.transport.govt.nz/assets/Uploads/Research/Documents/Young-drivers2014.pdf
9. Curry,A. , Pfeiffer,M. , Durbin,D. , Elliott,M. , Young driver crash rates by licensing
age, driving experience, and license phase , Accident Analysis and Prevention 80(243–250), 2015.
10. Amarasingha,N. & Dissanayake,S. , Gender differences of young drivers on injury
severity outcome of highway crashes, Journal of Safety Research 49 (113–120) ,2014.
11. Alver,D. , Demirel,M. , Mutlu,M. , Interaction between socio-demographic
characteristics: Traffic ruleviolations and traffic crash history for young drivers,Accident Analysis and Prevention 72 (95–104), 2014.
12. Dissanayake,S. , comparison of severity affecting factors between young and older
drivers involved in single vehicle crashes, Department of Civil Engineering, Kansas
State University, Kansas, USA, 2004.
13. Dissanyake, S., Comparison of severity affecting factors between young and older
drivers involved in single vehicle crashes, IATSS Research vol.28 No.2, 2004.
14. Chliaoutakis,J. , Demakakos,P. , Tzamalouka,G. , Bakou,V. , Koumaki,M. ,Darviri,C. ,2002, Aggressive behavior while driving as predictor of self-reported car
crashes , Journal of Safety Research , 33 (2002) 431– 443.
15. McGwin, G. & Brown, D. characteristic of traffic crashes among young, middleaged, and older driver, Accident Analysis and prevention 31 (181-198), 1999.

899

Organosilane ‘Warm Compaction’ Technology for Green Roads
Dr Ajay Ranka1 and Vivek Kane2
Zydex Industries, Vadodara, Gujarat, India
Email for correspondence: ashitpathak@zydexindustries.com
Abstract:
New Organo-Silane ‘Warm Compaction’ technology, apart from other green benefits, enables dropping of
mixing and compaction temperatures of Hot Mixes. Although, the concept of Warm Mix Asphalt (WMA) has
been around for a while, the available WMA technologies only talk of drop in mixing temperature and not thecompaction temperature, which the new Organo-Silane technology does. It is therefore prudent to call thistechnology, a ‘Warm Compaction’ technology.
In addition, this ‘Warm Compaction’ technology improves strength, fatigue resistance and water resistance,
leading to potential extension of pavement life, contributing to sustainability.
This paper presents the summary of laboratory studies made at the IMT (Instituto Mexicano del Transporte),
Mexico, and Braunschweig University, Germany to assess stiffness modulus, fatigue-resistance and waterresistance of this ‘Warm Compaction’ technology at different mixing and compaction temperatures for
optimization.
1 GREEN ROADS
We have taken this earth on lease from our future generations. It is our duty to return it to them in liveablecondition if not better. Striving for sustainability through prudent use of limiting natural resources and restraint
in emissions is the call of the day.
As it is said, ‘Nations don’t build roads. Roads build a nation’. It is very important to develop road infrastructure
at a brisk pace, if we want to attain / sustain high economic growth. At the same time, it is equally important toensure that such infrastructure development is sustainable. Prudent use of limiting natural resources therefore,
becomes our responsibility now, more than ever before.
There may be many ways of bringing in sustainability in building roads. Here are some of the ways in which
Zydex Nanotechnology contributes to sustainability in road construction :•••Reducing the usage of limiting resources like bitumen, aggregates etc.
Extending the life cycles of the roads, so as to defer the demand for such resources
Reducing fuel consumption and low temperature operation leading to reduction in emission

This paper discusses the ‘Low Temperature Operation’ aspect of the Zydex Nanotechnology in particular.

2 CONVENTIONAL WARM MIX ASPHALT AND ITS LIMITATIONS
The concept of Warm Mix Asphalt (WMA) has been around since the 90’s. It was developed in Europe in
response to EEC countries signing the 1997 Kyoto Treaty to reduce greenhouse gases.
A warm asphalt mix process (WAM) has been developed in Europe and was reported by Harrison andChristodulaki at the First International Conference of Asphalt Pavements in Sydney, 2000. A more complete
report was given by Koenders et al. at the Eurobitume congress in 2000. [1] Their paper describes an innovative
warm mixture 3 process that was tested in the laboratory and evaluated in large-scale field trials (in Norway, theUK and the Netherlands) with particular reference to the production and laying of dense graded wearing courses.
[2] Their work resulted in the development of WAM Foam, Warm Asphalt Mix with foamed bitumen. [3] At the
Eurobitume congress in 2004, Barthel et al. introduced the use of a synthetic zeolite additive to produce warmmix asphalt. The zeolite creates a foaming effect that results in a higher workability of the mix. [4] Warm mixes
have received some attention in Europe and Australia since around 2000. The pavement industry in North
America started to give warm mixes some interest a few years later and in June 2005 the National Center for

900

Asphalt Technology (NCAT) published two reports about the use of Sasobit, a synthetic wax, and Aspha-min, a
synthetic zeolite, in warm mix asphalt. [5,6].
Lower mixing temperature in case of WMA, is certainly a huge advantage, but the technology does have certain
challenges as follows.


Lower temperatures used for WMA can result in incomplete drying of the aggregates and the resulting
trapped water in the coated aggregates may cause moisture damage.
Finding the right balance between lowering the production temperatures, applying anti-stripping agentsand achieving a sufficiently moisture resistant asphalt mixture might be a challenge when using WMA

This is probably the reason behind WMA technology not catching up all over the world at the pace initiallyanticipated.
3 ORGANOSILANE ‘WARM COMPACTION’ TECHNOLOGY
The available WMA technologies only talk of drop in mixing temperature and not the compaction temperature.
The new Organosilane technology now allows reduction in both, mixing as well as compaction temperature.
In addition the new Organosilane technology also improves coating efficiency, leading to faster and complete
coating of even the fines. This is because the Organosilane chemistry reduces the surface tension of bitumen forfaster and better wetting.
The workability of the Organosilane mixes is also observed to be better and the compaction easier.
The low temperature mixing, low temperature compaction and the other benefits mentioned above are verified
by laboratory studies.
4 CASE STUDY - TRANSFER CENTRE FOR THE ROAD SECTOR (TSW),BRAUNSCHWEIG UNIVERSITY, GERMANY
Table 1 : Compositions of the type of asphalt applied

901

Graph 1
Coating Efficiency of ZycoTherm at different mixing temperatures

Graph 2
Effect of ZycoTherm on Power / Energy Consumption while mixing

902

Table 2
Effect of ZycoTherm on Compaction Resistance and Voids

SummaryGoal of the examinations carried out here was to document the influence of the binding agent
ZycoTherm® on the mixing process and to document the compression properties of asphalt.



For this purpose, two types of asphalt that are common in Germany, an asphalt binding agent AC 16 B
S with 50/70 and an asphalt concrete for asphalt surface layers AC 11 D S with 25/55-55 A, weremixed with and without ZycoTherm® and compressed at different temperatures. An overview of thevariants produced is specified in table 5-1.

During the mixing processes, the power consumption of the laboratory mixer was recorded and the timethat the degrees of coating of 50 %, 75 %, 90 % and 100 % were reached was noted. The times forreaching the degree of coating of 50 % are specified in table 5-1. Therefore, the mixed material iscoated quicker when ZycoTherm® is added. On average, 20 % less time is required. With regard to themixing performance, for AC 16 B S a tendency was recognised that less performance was required
when adding ZycoTherm®.



The compression resistance does not show any difference for both asphalt types when adding
ZycoTherm®, as documented in table 5-1.



The raw density of the asphalt mixture produced can be considered as equal for both types of asphalt.



The densities by volume of the roller compressed asphalt test plates only indicate small differences. The
void content is specified as outcoming result in table 5-1.

903

Table 3

Overview for producing the asphalt variants
Variant

Mix type

Binder type

Addition of
ZycoTherm®

Compaction Temp.

50% Coating
achieved

Compaction
resistanceVoidcontent

1a
1b
1c
1d
2a
2b
2c
2d

-

-

O

AC 16 B S

50/70

AC 11 D S

25/55-55 A

No
Yes
Yes
Yes
No
Yes
Yes
Yes

s
25 s
15 s
19 s
19 s
37 s
22 s
30 s
30 s

21 Nm
41.6
43.5
42.8
41.3
37.3
34.2
36.5
36.5

Vol.-%
7.0
7.1
7.2
6.9
4.3
4.6
5.0
5.3

C
135
135
115
95
145
145
125
105



For AC 16 B S, no tendency could be specified with regard to the void content. The void contents arewithin a narrow range so that this can be considered as equal.



The void contents for AC 11 D S increase with reducing compression temperature. This increase
however, is not within the testing accuracy so that here, only one tendency can be specified, there is no
statistical security. Deviations within these ranges can still be considered as close to practice.



As a summary, it can be stated that when adding ZycoTherm® you can reduce the time for coating thestones and with a significantly reduced compression temperature, you can achieve an almost consistentvoid content.

5 CASE STUDY – INSTITUTO MEXICANO DEL TRANSPORTE (IMT)
Parameters for testing
Asphalt binder : AC 20 (PEMEX, Mexico) with ZycoTherm: 0.075%; reference OBC 5.5% and with
ZycoTherm OBC 5.8%; Aggregates: La Canada Quarry
Sample size:50mm H X 63 mm W X 380 mm L
Air voids : 6%
Test temperature : 20 0C
Deformation Frequency : 10 Hz for four levels - 300, 400, 500 & 600 µԑ (represents pavement deformation
under normal transit condition)
Asphalt mix fatigue life failure criteria: Number of cycles in which the beam stiffness modulus decreases 50%
compared to its initial value904

Graph – 3Higher Number of Cycles means Higher Fatigue Life

Graph - 4
Wohler curve (fatigue law)For all levels of(.075%) presented extended life for fatigue, so the incorporation of Zycotherm significantly favors theasphalt mix.
The amount of load repetitions recorded for the Zycotherm samples were increased by 37 to 180%
depending on the level of deformation.
It was also observed that Zycotherm addition to the asphalt mix modifies the slope of the fatigue law,which means that Zycotherm samples are less susceptible to deformation levels, compared with thereference samples.

905

Graph – 5
Effect of ZycoTherm on TSR






It was observed that with the addition of Zycotherm in the highest dosage (0,125%) the TSR
specification was achieved (≥80%), even when mixing and compaction temperatures were reduced to135° and 110°.
Asphalt mixes with 0,075% and 0,1% presented slightly inferior to 80% TSR values. The conditioned
specimens with additive presented 2 to 3 saturation cycles to achieve saturation levels between (7080%).
For all missing dosages, it can be estimated that TSR results will be acceptable for temperature
reduction.
It was observed that for mixing 135°C and compaction 110°C temperatures, TSR increased when the
Zycotherm dosage was increased as well.

Graph – 6
Effect of ZycoTherm (@0.075%) on compaction density906Graph – 7
Effect of ZycoTherm (@0.1%) on compaction density

Graph – 8
Effect of ZycoTherm (@0.125%) on compaction densityWhen Zycotherm is used a greater compaction can be achieved for the same and lower temperatures
than the reference mix.
If mixing and compaction temperatures are reduced benefits in time can be obtained; more time forhauling and waiting before compaction is possible with the Zycotherm addition.
Fuel savings during the mixing process and less carbon footprint benefits can be obtained as well.

907

Graph – 9
Wheel Tracking performance for ZT @ 0.075%

When the 0,075% additive dosage is incorporated into the asphalt mix, it is observed that deformation
is maintained with acceptable tolerance, for similar temperatures as the reference mix.
When mixing and compaction temperatures are reduced, deformation is still within high transit levels,
according to AMAAC specifications.
There is not affectation in rutting behavior when lowering mixing and compaction temperatures.

Graph – 10
Wheel Tracking performance at ZT @ 0.1 %The asphalt mix with Zycotherm present a superior behavior when produced and compacted at the same
temperatures as the reference mix.
When adding 0,1% of Zycotherm to the mix the mixing temperature can be lowered in 20°C andcompaction temperature to 35°C, deformation is slightly affected, but it is still whitin the high transit
levels and this results may be between the test dispersion.
If mixing and compaction temperatures are reduced benefits in time can be obtained; more time forhauling and waiting before compaction is possible with the Zycotherm addition.

908

6 CONCLUSION
In summary, addition of ZycoTherm, the Organosilane additive to bitumen
1.
2.
3.
4.
5.
6.

Allows the mixing temperature to be lower
Gives equivalent or better compaction at lower compaction temperatures.
Improves coating efficiency, leading to faster and complete coating.
Reduces mixing effort and saves energy.
Results in acceptable levels of TSR at lower mixing temperatures.
Gives excellent rut resistance at lower mixing and compaction temperatures.

Overall, the Organosilane technology, in addition to lower mixing temperatures, allows lower compaction
temperature and gives all the benefits stated above.

LIST OF REFERENCES
1. Advisory note 17 – Warm Mix Asphalt – a-state-of-the-art review. Australian Asphalt
Pavement Association (AAPA). http://www.aapa.asn.au/docs/no17.pdf
2. Koenders, B.G., D.A. Stoker, C. Bowen, P. de Groot, O. Larsen, D. Hardy & K.P.
Wilms. Innovative processes in asphalt production and application to obtain lower
operating temperatures. 2nd Eurasphalt & Eurobitume Congress, Barcelona, Spain
September 2000.
3. Webpage of Shell Global Solutions. http://www.shell.com. Accessed November 2005.
4. Barthel, W., J.P. Marchand, M. Von Devivere. Warm asphalt mixes by adding a
synthetic zeolite. Eurovia. www.asphamin.com. Accessed November 2005.
5. Hurley, G.C. and B.D. Prowell. Evaluation of Aspha-min® zeolite for use in warm mix
asphalt. NCAT Report 05-04. National Center for Asphalt Technology, Auburn
University, USA, June 2005.
6. Hurley, G.C. and B.D. Prowell. Evaluation of Sasobit® for use in warm mix asphalt.
NCAT Report 05-06. National Center for Asphalt Technology, Auburn University, USA,
June 2005.

909

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

Pragmatic Road Hazard Assessment with the aid of new technology

TRACK
AUTHOR(Capitalize Family Name)POSITION

Brodie VON BERG

Head of Sales & Marketing

CO-AUTHOR(S)(Capitalize Family Name

ORGANIZATIONCOUNTRY

MiX Telematics

UAE

POSITIONORGANIZATIONCOUNTRY

Qasim SHAH

Regional Marketing
Manager

MiX Telematics

UAE

E-MAIL(for correspondence)

Qasim.shah@mixtelematics.com

KEYWORDS:
Road Hazard Assessments, Road Safety, Journey Management

ABSTRACT:
Many Oil and Gas producers and service companies have already achieved substantial and sustained improvements inroad safety performance over the last decade, evident in the typical lagging indicator: Motor vehicle crash frequency
rate, often published in Corporate Sustainability reports. The single highest risk factor in commercial land transportremains: the Environment in which operations exist where 1.25 million people continue to die on the world’s roads eachyear (World Health Organisation Global Status Report on Road Safety, 2013).
The traditional method of assessing the environmental risk is by performing a Road Hazard Assessment (RHA) to
determine the hazards and risk rating by individual route, this approach is cumbersome and dated. Every time a newroute is established in the operation, the current best practice methodology would require a specialist to travel the newroute and populate a hazard register with all of the recognizable hazards and the associated risk rating. This method isimpractical and therefore rarely achieved in a timely manner.
In the search for a pragmatic solution, an alternative methodology to fixed route Road Hazard Assessment is explored inlight of new Journey Management technologies available to industry. The technology enables crowdsourcing of hazard
information, desktop validation, and real-time analysis of route risk. The benefits and challenges in adopting thistechnology in the Oil & Gas community will be assessed in both isolation and in conjunction with Journey Management.

910

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
Introduction
Many Oil & Gas producers and service companies have already achieved substantial and sustained
improvements in road safety performance over the last decade, evident in the typical lagging indicator: Motorvehicle crash frequency rate, published in public Corporate Sustainability reports. Different measures areused by different organisations in terms of classification (e.g. kms/miles, serious/all incidents,
work/private/all), however, despite the inconsistency in measurement, a trend of improvement appears acrossthe board as show in Figure 1 below.

Figure 1: Motor Vehicle Crash Frequency Rate trends 2006-2015.
The single highest risk factor in commercial land transport remains: the environment in which operations
exist where 1.25 million people continue to die on the world’s roads each year (World Health Organisation
Global Status Report on Road Safety, 2015).
Oil & gas operators and service companies attempt to quantify the risk from the road environment byperforming Road Hazard Assessments (RHA) to determine the hazards and produce a risk rating by
individual route, this approach is cumbersome and dated. Every time a new route is established in theoperation, the current best practice methodology would require a specialist to travel the new route andpopulate a hazard register with all of the recognizable hazards and the associated risk rating. This method isimpractical and therefore rarely achieved in a timely manner.
Journey Management (JM) is the holistic management of vehicle movements through a process ofcompliance audit, risk rating of hazards, and route planning. This process provides more holistic planningand risk assessment of vehicle movements and greater assurance of journeys completed successfully
otherwise offering early intervention to reduce loss. With advances in technology, JM has evolved andopened up opportunities to evolve the traditional RHA methodology.
The technology enables crowdsourcing of hazard information, desktop validation by an independent party,
and real-time analysis of route risk. The benefits and challenges in adopting this technology in the Oil & Gas
community will be assessed both in isolation and in conjunction with Journey Management.

911

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
Traditional Road Hazard Assessment
RHA seeks to quantify the risk exposure from road hazards on the routes used by the organisation. There aredifferent views on the process and method of risk quantification however a commonly used reference is the
OGP365-1 Land Transport Safety Recommended Practice - Road Hazard Assessment Guidance Note 1(OGP, 2003). The guidance includes hazard classification, risk ranking classification, and escalating factors(Figure 2); Essentially the framework for risk assessment, similar to the Job Safety Analysis (JSA), a tool for
qualitative analysis of a job procedure or practice (Rausand, 2005). The process requires subjective analysisof hazards to determine the risk presented to the operation based on the existing road safety controls adopted.

Figure 2 Summary of OGP365-1 Land transportation safety recommended practice guidance note 1.

912

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
Road Hazard Assessment in Isolation
During the RHA process, a Hazard Register is populated for a given route containing all of the identified
road hazards, location, risk rating, cell phone signal strength, and comments. In isolation, this document
forms the basis for driver briefing before they travel the route to inform the driver of the expected hazards.
This document is normally contained within the company intranet and/or in hard copy within the transport
department.
In practice, maintaining a current and comprehensive depositary of RHA Hazard Registers for all common
routes travelled by staff and/or contractors is resource intensive requiring specialists to complete andconsequently does not occur consistently. Additionally, variances in the number of identified hazards and risk
rating vary greatly from organisation to organisation. This results in inconsistency and can even occur inmultiple organisations even when they operate within the same geographical area.
Road Hazard Assessment Integration with Journey Management
The OGP365-2 Land transportation safety recommended practice – Guidance note 2 – Journey Management
provides a recommended example for journey assessment and approval. This method categorises the journey
in to low, medium, or high risk according to a points system assessing the risk factors, as seen in Figure 3
below.

Figure 3: Summary of OGP365-1 Land transportation safety recommended practice guidance note 1.
The road conditions contribute to the risk score for the total journey risk but only account for the road type in
4 categories; Paved, Mixed, Unpaved, and Mountain. The work carried out in the Road Hazard Assessment islargely ignored and the known risk does not convey across to the total journey risk score.

913

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
The evolution of commercially available journey management systems are now catering for the known riskpresented from road hazards and factoring in to the total journey risk score. This is achieved by categorising
journey risk in to 3 distinct categories; Environment, Asset and People (Figure 4).

Figure 4: Risk categories
This enables journey stakeholders to rapidly identify where the risk is highest. A further example is taking
the high risk environment rating and expanding the details to reveal the causes (Figure 5).

Figure 5: Environment rating details
The method of risk categorisation enables simple adjustments to the journey plan to be made during theplanning process (e.g. changing the route slightly to avoid high risk road hazards), reducing the risk profile ofthe overall journey.
Risk Assessment per Route
Adopting the current recommended practice for RHA provides a hazard register per pre-determined route.
The process requires for all common routes to be routinely surveyed to update the hazard register.
Inefficiencies can and do exist where routes crossover each other or new routes are assessed completely. The
concept of Road Hazard Assessment and the evaluation of environmental risk within the JM technology
significantly enhances this process. Road Hazards no longer need to be tied to a fixed route, instead they arerecorded as a geographical location with the required information. Commercially available JM solutions
enable the journey route to be created in real-time utilising a routing engine to increase efficiency of routeselection. When the route is created, the JM plan is able to ‘collect’ all the road hazards on the roads which
the route passes through and form the environmental risk assessment based on the collected hazards. This
enables a multitude of routes to be used and the known hazards to immediately impact the risk rating.
The next challenge with adopting the OGP365-1 framework or similar for the RHA process is the risk
ranking classification is provided per road hazard and there is no guidance on overall route road hazard risk
classification.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
Oil & Gas operators/service companies that adopt the OGP365 Land Transport Safety Recommended
Practice or a derivative of the same, should have sufficient procedures or practices that enable the driver tocontrol the vehicle and navigate road hazards without resulting in a motor vehicle crash. This assumption isbased on:

Driver capabilityo Driving license issued from relative government authority
o Defensive Driver Training certificate
o Fit-for-work
Vehicle reliability
o Fit-for purposeo Inspected prior to journey

Therefore, the assumption is that as long as there are no physical constraints (e.g. Bridges/tunnels) that would
prevent the vehicle from reaching the destination without interference, and no escalating factors present (e.g.
Fog/Snow), then the resulting risk ranking for all the identified hazards will be Low.
In absence of a documented industry best practice, there are different perspectives used across the Oil & Gas
industry for calculating overall route hazard risk, examples are:1.
2.

The highest risk rating for all road hazards in the route will determine the overall risk rating for the‘environmental’ risk for the route
Same as above, plus the combination of many low or medium risk road hazards compound to resultin a higher risk rating for the route

The first example appears rational on the basis that where a high risk road hazard is identified then the risk
for the journey will be high due to the high risk road hazard encounter being imminent. What the perspective
ignores is the potential for existing policies, procedures or practices to break down and expose higher risk.
The second example also appears rational, allowing for multiple road hazards with low or medium risk tocompound in to a higher risk rating given that a series of road hazards introduces more exposure than just asingle road hazard. This perspective relies on a repeatable formula for risk assessment typically using acalculation of the number and risk rating of each road hazard. The reliance on the number of identified roadhazards alone introduces potential for error where many low risk road hazards may be the result of a much
more comprehensive RHA exercise as opposed to a less comprehensive effort. The ability to create
repeatable RHA’s with the same volume of hazards identified is influenced by the hazard perception abilitiesof the individual or team conducting the assessment. For this reason, there is an increased reliance on theassessor/s that conduct the RHA.
In both the methods the robustness of the controls adopted according to policies, procedures or practices are
not duly tested. This could lead to individual process failures compounding the risk of the road hazard. An
example may be if Defensive Driver Training (DDT) is a mandatory requirement during which the driver istrained specifically on navigating crests, the risk presented by a driver not being trained on approach to a
crest will make the risk of a crest (An identified hazard) potentially higher than Low. The risk rating of Low
is therefore reliant on the DDT control being robust in terms of content, delivery, and controls aroundensuring drivers actually successfully completed DDT.
When a new route is going to be used by the organisation, a suitably qualified individual or team is required
to travel the route and conduct the RHA. The resource/s required to be able to adequately identify hazards is
not always readily available and it is not uncommon for organisations to deem the unknown as highest risk,
therefore a route without a completed RHA is deemed as high risk. When Journey Management is required,
the risk for the journey will in this case increase to High requiring a senior stakeholder to accept the risk foreach journey to start using the new route.
Road Hazard Assessor Profile915

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
There appears to be no documented industry best practice for determining the skills and experience required
for an individual to conduct a RHA. This leads organisations to use different criteria for selecting candidates
and typically the resource performs the RHA’s as a part time role, if not the task is outsourced. The hazard
identification process requires observation and assessment of the road area to identify hazards although thecurrent OGP365-1 risk classification process ignores the complexity of roadside furniture. An example may
be that frangible light poles may line the street and considered low risk due to the design of the poles,
however due to the installation method used locally, the frangible poles may not deform correctly in the eventof a collision and act more like a tree. The risk may be considered low initially, however a trained eye may
identify the higher risk due to the incorrect installation.
So how do we define the skills and experience required to sufficiently perform the RHA process? A
pragmatic approach is required to provide feasible solution that will ensure that sufficient knowledge andexperience is available to identify potentially high risk hazards without burdening operations withrequirements that are not practical to implement. Borowsky et al. (2010) find that older experienced drivers
were able to better detect cues and detect more potentially hazardous situations than novice drivers.
Additionally, there are several road safety engineering qualifications that focus on the safety aspect of roadinfrastructure and furniture design and placement. The challenge is the feasibility of having older
experienced drivers with road safety engineering qualifications available to assess the routes used byoperations on a frequent basis.
The ‘crowdsourcing’ concept offers an opportunity to innovate. Surrogate Road Hazard Assessors may besourced from driver trainers, HSE professionals, and other company resources that frequently travel theroutes. The concept of enabling other internal resources to capture potential road hazards supported byphotographic evidence provides an opportunity to gain more frequent updates. The potential issue is that due
to the subjectivity of hazard perception, each hazard reported would require validation from a suitably
qualified Road Hazard Assessor. The technology available today allows surrogate Road Hazard Assessors to
capture the detail of perceived hazards using just a smart phone and uploading to a central database, ready forreview by a Road Hazard Professional. Once the hazard has been vetted, it can be added to a live Road
Hazard Register.
When there are multiple organisations operating in the same geographical area, there is now an opportunity
to share Road Hazard Registers online between organisations to ensure that each other organisation benefits
from each other’s contributions. This enables contractor A to record a new road hazard and the operator andcontractor’s B, C, and D to all benefit from the information.
In order to share the Road Hazard Registers between organisations, there must be a common language andcommon risk classification system. While a unified global standard may not be possible, certainly a common
standard for the organisations operating within the same geographical location would be of benefit.
In the context of Journey Management, with the available technology commercially available today, the useof crowdsourced road hazard information updates will enable planned and even departed journeys to bereassessed in terms of risk based upon new hazard information received regarding road hazards on the routeselected. This can transform the risk assessment from an environmental risk perspective.
Summary
The safety performance of Oil & Gas land transport operations has improved on average and this is supportedby the trends from the abovementioned operators and service companies. The improvements are diminishingand performance stagnating. Now is the time to identify improvements through advances in technology since
the original recommended practices were produced.
The recommended practice for Road Hazard Assessment is based on assessing the fixed routes andclassifying each road hazard with a risk rating to produce a hazard register per route. The recommended
practice ignores the risk profile of the hazards per route, instead utilising different criterion in journeymanagement planning to risk profile the environmental risk.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia
There are no specific recommendations regarding the skills and experience of the person who should conduct
a road hazard assessment and in practice, the frequency at which road hazard assessments are performed
and/or the consistency of the information captured varies. Care needs to be taken to ensure sufficient quality
without the impracticalities of deploying road safety engineers on a full time basis in to sites to constantly
monitor for road hazards. With parallel works on hazard perception being driven by computer-based hazard
perception technology, we can learn that with experience, drivers become more attuned to cues that suggest ahazard.
Advances in technology can now enable any person with a smart phone to capture new road hazards andreport to a central remote database. Suitably qualified resources may then validate the road hazard and reportin to a live common road hazard database that may be shared across organisations within a geographicallocation. This creates a crowdsourcing model of road hazard data collection with quality control from acentralised resource validating road hazard data for many different geographical locations.
More up-to-date road hazard register databases enable a step change in the journey management process, nolonger utilising just distance and terrain inputs to quantify environmental risk. There is still a requirement toutilise escalating factors in the JM plan as the presence will escalate the risk of the route.
Recommendations
Organisations should assess the current processes used for evaluating environmental risk from a journeymanagement perspective. Commercially available technology can enable crowdsourcing of road hazard databy less qualified but more readily available resources. The quality control mechanism can be centralised andwhen implemented will provide more up to date and accurate hazard register database.
Organisations overlapping in geographical area should work together to define a localised standard forassessing risk profiling logic per road hazard, per route, and per journey. This logic should account for therobustness of the controls adopted to mitigate risk by using go/no-go compliances, all of which can beapplied in commercially available systems to enable crowdsourcing of road hazards and use of the same
information in the journey management plans, resulting in a uniform language of journey risk.
If adopted, there are efficiencies to be created.

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2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

REFERENCES
1.

Rausand, M., 2005. Job Safety Analysis. Dep. Product. Quality Eng. Norweg. Univ. Sci. Technol.

2.

Borowsky, A., Shinar, D. and Oron-Gilad, T., 2010. Age, skill, and hazard perception in driving.
Accident Analysis & Prevention, 42(4), pp.1240-1249.

3.

http://www.halliburton.com/public/about_us/pubsdata/hse/pdf/Glbl_Mon_Rpt_YTD_Public.pdf

4.

http://assets.cmp.bh.mxmcloud.com/system/96599d804d94403e9215de5516d322ef/pdfs/pdf/2013HSE-Annual-Report_web-FINAL.pdf

5.

http://www.bakerhughes.com/news-and-media/resources/brochures/2015-hse-annual-report6.

https://www.chevron.com/-/media/chevron/shared/documents/Chevron_CR_Report_2010.pdf

7.

https://www.chevron.com/-/media/chevron/shared/documents/2015-corporate-responsibilityreport.pdf

8.

http://tools.bp.com/hse-charting-tool.aspx#health-and-safety/Vehicle-accident-rates/Total-VehicleAccident-Rate9.

http://www.who.int/violence_injury_prevention/road_safety_status/2015/en/918

Application of appropriate repair materials
for asphalt pavement in JapanMai KOBAYASHI, Toshiaki HIRATO, Masato MURAYAMATOA ROAD CORPORATION, Tsukuba, Ibaraki, Japan
Email for correspondence, e.g. mai_kobayashi@toadoro.co.jp

1. INTRODUCTION
The transportation infrastructure in Japan was developed in a large part during the high economic growth
period from 1950s to 1970s, and has contributed greatly to the growth of Japan’s economy. The
transportation infrastructure constructed at that time has passed more than about fifty years, and decrepit
roads need to be renovated. Therefore, there is growing interest in appropriate, efficient and budgetconscious maintenance and repair methods. For road pavement, demand for new construction has been on the
decline since the 1980s, opening an era of maintenance of existing pavements.
The maintenance repair methods of pavement involve a technique to construct new pavement or to achieve
life prolongation of existing pavements. The latter approach can lead to substantial cost savings compared torebuilding, if implemented at the correct time using appropriate repair materials.
We have developed a number of pavement repair materials for different types of distress, which are easy to
use and highly durable, with the aim of efficient maintenance of paved roads. These materials are already inwidespread use and have accumulated a track record. This paper describes the features of these materials andprovides examples of their application.

2. CLASSIFICATION OF THE DISTRESS IN ASPHALT PAVEMENT
Distress to asphalt pavements mainly consists of cracking, rutting, and loss of flatness. Other forms of
distress are level differences, potholes, and road surface roughness caused by raveling. The causes of such
distress include repeated loading by traffic, the durability of the materials involved, design issues,
construction work, and the effect of environmental conditions such as rain, UV, and so on. It is thought thatthese factors influence each other (Japan Road Association 2006a, b and 2013).
Distress to pavements can be broadly divided into structural distress and road surface distress. Structural
distress is addressed by all replaceable or other large-scale projects undertaken from a long-term perspective,
with consideration given to future traffic volume. Road surface distress, on the other hand, is typicallyaddressed by emergency repairs to ensure the safety of traffic. Figure 1 describes the evolution of distress topavements.
Road surfaces in service are subjected to forms of distress such as the raveling, aggregate scattering, andcracking. Under the influence of continual traffic loads, these distress proceed deeper into the pavement andescalate to structural distress. Therefore, repairing a pavement at an early stage before road surface distressbecomes structural distress can be an effective means of extending the life of existing pavement. It should be
noted, however, that because there are so many different types of distress, this approach may not be
successful unless an appropriate material is chosen and put in place at the correct time.

919

Figure 1. Shift from road surface distress to structural distress(Japan Road Association 2006a, b and 2013)

3. REPAIR MATERIALSThe repair material and method need to be appropriately selected based on the type and degree of distress.
Table 1 lists several repair materials which has developed in recent years to deal with the most common
forms of distress. All of these materials can be used at ambient temperature, so there is no need for heating or
temperature control. They also have highly portability and workability for making quick repairs. The
following subsections provide an outline of these materials, and describe their composition, properties andapplication method.
Table 1. Major repair materials
Distress
Cracking
PotholesFaulting

Repair material
Cold-mix crack injection material
Slurry-type material
Repair material for pothole
Resin-type road surface repair material

3.1 Repair materials for cracks
If the pavement suffers cracking or has furrows due to poor connections at joints, rainwater will infiltrate
the pavement, regardless of the size of the occurring distress. If it is not repaired, thus accelerating the change
to structural distress. Figure 2 shows different pavement cracking patterns. The conventional way of repairingcracks is to pour a hot injection material such as blown asphalt into them, but this method requires adissolving pot and other equipment since the hot injection materials have to make a high temperature to melt.
Furthermore, it is difficult to completely fill very thin cracks with widths of 10 mm or less, or deep cracks.
Rainwater can enter the pavement through such half-filled cracks, and in the end, no substantial life extension
benefit may be gained. Additionally, cracking can occur not only in linear patterns but also in complicatedshapes, as in the case of alligator cracks. In such a situation, the repair work needs to be performed over a920

planar area. We therefore developed both an injection-type and a paste-type material suitable for different
types of cracks. (Japan Road Association 2013)

(a)

(b)

(c)

Figure 2. Schematic diagrams of cracking patterns: (a) thin linear crack, (b) thick linear crack, and (c)alligator cracks
3.1.1 Cold-mix crack injection material(1) Appearance and application
The cold-mix crack injection material which we developed is a low-viscosity liquid at ambient temperatureand hence has excellent penetrability characteristics. Figure 3 shows the appearance of the material andapplication method. The product is composed of the main material contained in a plastic bottle, and a curing
agent in a separate small glass bottle. The curing agent is added to the main material bottle and shaken for
approximately ten seconds. The contents are then poured into the crack to be filled, as shown in Fig. 3(b).
Traffic can be opened within an hour after the injection. Cracks of any width can be filled because the widthof the injection nozzle can be adjusted by cutting it at the appropriate point. This newly-developed crack
injection material is applicable not only to cracks in asphalt pavements, but also to cracks and furrows in
concrete pavements.

(a)

(b)
Figure 3. Crack injection material: (a) appearance (b) application method(2) Composition and properties
Table 2 shows the composition of the cold-mix crack injection material.
Table 2. Composition of cold-mix crack injection material
Component
Rubber modified asphalt emulsion
Curing agent

Content
95%
5%(3) Improved workability
In addition to the bottled crack injection material shown in Fig. 3, we also provide a road crack
maintenance injection (RCMI) method that uses the equipment. This method involves filling cracks with theinjection material using an injector that simultaneously discharges the main material and the curing agent at a
fixed ratio. Figure 4 shows an example of such an injector and the RCMI method in action. The use of this921

equipment allows the material to be poured continuously, thereby minimizing material loss and the timerequired for repair work; this is expected to contribute to work efficiency.

(b)

(a)

Figure 4. (a) Example of injector and (b) product application method
3.1.2 Slurry-type material
The cold-mix crack injection material introduced in the preceding subsection is poured into one crack after
another, thus ensuring that each crack is completely filled and repaired. For alligator cracking, however, thisprocess need a long time. In this case, a planar approach is more time-efficient than filling individual cracks.
Accordingly, we developed a slurry-type material that can be applied to alligator cracks by injecting it over aplanar area.
(1) Application method
Figure 5 shows the application method. It does not require a special, dedicated tool, and can be easily
applied using only a hand mixer and a rubber rake. With this method, a wide area can be repaired within ashort period of time. Figure 6 shows the appearance of a road surface after applying this method. This slurrytype material can also be applied to linear cracks using a rubber rake.

Figure 5. Application method

922

(a)

(b)

(c)

(d)

Figure 6. Application of the slurry-type material to linear and alligator cracks: (a) Linear cracks–before
application, (b) Linear cracks–after application, (c) Alligator cracks–before application, and (d) Alligatorcracks–after application(2) Composition and properties
Table 3 shows the composition of the slurry-type repair material. The aggregate and the SBR modified
asphalt emulsion are mixed immediately before using it. The material has high anti-abrasion performanceafter hardening.
Table 3. Composition of slurry-type material
Component
Graded aggregate and curing agent
SBR modified asphalt emulsion

Content
75%
25%

To evaluate the degree of penetrability of the material into cracks, we conducted a penetrability test incompliance with Handbook of Pavement Investigation and Examination Method (Japan Road Association
2007). A slit was formed using two glass sheets and was filled with the repair material. The slit was 100-mm
long, 200-mm deep, and 3-mm wide. Figure 7 shows the penetrability test results. The slurry-type repair
material is seen to have significantly better penetration than a typical hot injection material, allowing theentire length and width of a crack to be filled.

(a)

(b)

Figure 7. Penetration test results: (a) Typical hot injection material and (b) Slurry-type material(3) Application to small-scale repair projects
We also developed a packaged version of the slurry-type material for small-scale repair projects. The
uniqueness of this product lies in the vinyl package that contains an aggregate combined with a curing agent
and SBS modified asphalt emulsion that acts as the binder. The contents weigh two kilograms. The

923

appearance of the product is shown in Fig. 8. The aggregate and the modified asphalt emulsion are packaged
together in one bag, but separated by an internal partition.

Figure 8. The packaged slurry-type material
Figure 9 shows the work procedure for the packaged slurry-type material. The bag is held with theaggregate section up, and downward pressure is applied so that the partition breaks and the aggregate andcuring agent enter the emulsion side. The components are mixed by kneading the bag well for approximately
thirty seconds. The mixture is then ready for use; it should be spread immediately using a trowel, and allowed
to cure for one to two hours before traffic opening. By having the two different materials in one package, thisproduct saves the time and labor involved in asphalt mixture preparation, and allows uniform production andapplication without soiling the surroundings.

(a)

(b)

(c)

(d)

Figure 9. Work procedure for packaged slurry-type material: (a) Breaking the partition, (b) Mixing, (c)Spreading, and (d) Final appearance
3.2 Repair material for potholes
Potholes cause not only discomfort for drivers but also lead to traffic accidents. Thus, they need to be
repaired immediately once created. This subsection discusses a pothole repair material that we developed,
which has high portability and durability. (Japan Road Association 2013)(1) Appearance and application
Figure 10 shows the appearance of the pothole repair material. This product is a cold-mix asphalt mixture.
The solvent uses oil derived from a plant. One bag contains twenty kilograms of the mixture. Since themaximum size is five millimeters, it can be applied to potholes with various shapes. For this reason, the924

product is also suitable for repairing narrow or complex areas, such as the vicinity of structures, in addition tolevel differences and potholes.
Figure 11 shows the work procedure for the pothole repair material. Before starting the application
procedure, dust and gravel should be removed from the surface to ensure that the material adheres well to thebase. When the package is opened, the material immediately begins to harden; therefore, it should be used assoon as possible. After opening the package, the pothole repair material for patching is spread over theaffected area to a thickness of one to five centimeters, and the surface is leveled using a shovel or the like. A
tamper or a plate compactor is then used to complete the project. Although traffic can be immediately
released, the durability of the product gradually increases as the solvent vaporizes, and reaches a sufficiently
high level in about 24 hours. This product requires only simple compaction, so the road can be used
immediately following the completion of the repair work. The mixture is compacted by a traffic vehicle, andthe strength of the mixture increases.

Figure 10. Appearance of repair material for pothole

(a)

(b)

(d)

(c)

(e)

Figure 11. Work procedure for pothole repair material: (a) Cleaning, (b) Unpacking andspreading/leveling, (c) Compacting, (d) Completion, and (e) Traffic opening(2) Composition and properties
Table 4 shows the composition of the pothole repair material. This is a cutback asphalt mixture using
plant-derived oil. It is significantly more durable than conventional repair materials because the speciallymodified material is contained.
Table 4. Composition of pothole repair material
Component
Aggregate
Modified asphalt, and cutback material

Content
95%
5%

925

We conducted a Marshall stability test at ambient temperature in order to evaluate the change in thestrength of the material during the curing period. The material was cured at 20C, and the Marshall stability
was measured immediately after the production and one day, three days and seven days later. The results arecompared in Fig. 12 to those for conventional mixture. The stability of our pothole repair material increases
over time, particularly during the first day. In addition, this highly durable, pothole repair material develops
its strength more quickly and exhibits a higher strength than conventional mixture.
We also conducted a Cantabro test in order to evaluate the resistance to aggregate scattering (Japan
Road Association 2007). The test was carried out after curing the product at 5C for 24 hours, and the results
are shown in Fig. 13, together with those for conventional mixture. The Cantabro loss for our pothole repair
material is seen to be much smaller than that for conventional mixture, indicating that it exhibits excellent
resistance to aggregate scattering soon after curing.

Figure 12. Change in Marshall Stability at ambient temperature with time

Figure 13. Cantabro test results
3.3 Resin-type road surface repair material
Figure 14 shows examples of level differences; these can be caused by differential settlement withdifferent pavement structure or construction defect at a joint between an existing pavement and a newly-built
pavement. Level differences also cause discomfort for drivers, as well as vibration, noise, and even damage
to cargo carried by vehicles. Thus, any level difference occurring on the road surface requires immediately
repairing.

926

Materials for repairing level differences must have high adhesiveness to existing pavement so as not to beeasily raveled due to the passing of vehicles. This subsection discusses a resin-type road surface repair
material that we developed for repairing of level differences. (Japan Road Association 2013)

(b)

(a)

Figure 14. Occurrence of level differences: (a) concrete structure and (b) Utility hole
(1) Appearance and application
The resin-type road surface repair material shown in Fig. 15 is a mixture of an aggregate and a special
acrylic resin, and can be applied using a trowel. It consists of a resin, a curing agent, an aggregate and antislip sand, all of which come in a single cardboard box. Figure 16 shows the application method for thisproduct, and Fig. 17 shows working appearance. First, the curing agent is added to the aggregate bag and thetwo are well mixed. The resin is then added, and the resulting mixture is well blended. The material is poured
over the affected area and the surface is leveled using a trowel. The process is finished by spreading the antislip sand.
Because this resin-type road surface repair material uses sand as an aggregate, it is applicable not only torehabilitation for level differences at bridge joints or around utility holes but other kinds of small-scale repair
projects, including patching very small potholes.

Figure 15. Appearance of resin-type road surface repair material

927

(a)

(b)

(c)

(d)

(e)

(f)

Figure 16. Application method for resin-type road surface repair material: (a) Adding the curing agent to theaggregate, (b) Mixing, (c) Adding the resin, (d) Mixing, (e) Spreading and leveling, and (f) Spreading antislip sand

(a)

(b)

Figure 17. Application appearance: (a) level difference at a constructed joint and (b) around a utility hole(2) Composition and properties
Tables 5 and 6 show the composition and properties of the resin-type road surface repair material,
respectively. The figures in the properties table represent the results of tests conducted in compliance with
Handbook of Pavement Investigation and Examination Method (Japan Road Association 2007). The resintype road surface repair material has significantly higher marshall stability and dynamic stability than asphalt
mixtures, because it uses a special acrylic resin as the binder, instead of asphalt. Moreover, it exhibits
excellent adhesiveness to the base and follows the expansion and contraction of the pavement. It also quickly
hardens so that traffic can be released about twenty minutes after the repair work.
Table 5. Composition of resin-type road surface repair material
Component
Aggregate
Resin and curing agent
Anti-slip sandContent
60%
30%
10%

928

Table 6. Properties of resin-type road surface repair material
Items
Curing time (25°C)
Density
Stability (60°C)
Residual stability (60°C)
Dynamic stability (60°C)
Bending strain (-10°C)
Raveling test (-10°C)

Properties
5-10 min1.866 g/cm3
17.9 kN88.8%
31,500 times/mm
6.14×10-3
1.09 cm2

4. APPLICATION
Table 7 summarizes all the products described in this paper. For each of the repair materials, ○ means“recommended”, × means “difficult”, and ― means “not applicable”.
Table 7. Recommended applications

Percentage of cracking

Height of level
difference
Less
5-50
than
mm
5 mm

Repair material

Less
than
10%

1020%

More
than
20%

Cold-mix crack
injection material

○
○
-

○
○
-

×
○
-

○
×

○

○

○

○

Slurry-typematerial

Size of pothole
25-50
mm

More
than
50 mm

Curing time

○

○

○

10 min○○×

Repair material
for pothole
Resin-type roadsurface repair
material○ means “recommended”, × means “difficult”, and ― means “not applicable”.

30 minImmediately
30 min5 CONCLUSIONSThis section summarizes the characteristics of each repair materials.
- The cold-mix crack injection material is a repair material to be injected into cracks or furrows. Due toits excellent penetrability characteristics, it can fill the entire length and width of any crack regardlessof outside air temperature. It can also be applied using the equipment-based RCMI method, whichallows continuous crack repair.
- The slurry-type material has high penetrability characteristics and completely covers pavement cracks,
providing an excellent water cut-off effect. It is a cold repair mixture that is applicable not only tolinear cracks but also to alligator cracks. It is particularly effective for road surface refreshing and for
repairing areas with high cracking rates. As the binder and aggregate are packaged in one bag, it
allows easy and efficient small-scale repairs.
- The repair material for pothole is a cutback cold-mix asphalt. It is applied in simple steps: opening thebag, spreading and leveling, and simple compaction. Traffic can be released immediately after its
application. Compared with other typical materials, this product exhibits high durability, plastic
deformation resistance, and waterproofness. It can be applied regardless of weather conditions or theseason of the year. It is used mainly for repairing potholes and smoothing level differences but canalso be applied to narrow areas around structures.

929

-

The resin-type road surface repair material is a cold-mix repair material with a special acrylic resin
acting as the binder. This composition exhibits excellent resistance to weather, raveling, andchemicals, and strong adhesiveness to the existing base. It hardens extremely quickly so that traffic
can be released about twenty minutes after curing.

CITATIONS AND REFERENCES
Japan Road Association, (2006a), Guideline of Pavement Design and Construction.
Japan Road Association, (2006b), Handbook of Pavement Construction.
Japan Road Association, (2007), Handbook of Pavement Investigation and Examination Method.
Japan Road Association, (2013), Guidebook for pavement rehabilitation and maintenance 2013.

930

2nd IRF Asia Regional Congress & Exhibition
October 16-20, 2016 – Kuala Lumpur, Malaysia

PAPER TITLE

TRACK
AUTHOR(Capitalize Family Name)Peter HARTZELL

CO-AUTHOR(S)(Capitalize Family Name

E-MAIL(for correspondence)

ISO 39001:2012 – Road traffic safety (RTS) management systems – Requirementswith guidance for use
Road Safety
POSITIONORGANIZATION

Secretary/Project Manager

ISO/TC 241 secretariat at
SIS – Swedish Standards
Institute

POSITIONORGANIZATIONCOUNTRY
SwedenCOUNTRY

peter.hartzell@sis.se

KEYWORDS:
Include up to 5 keywords






Road safety
Management system standard
International Organization for Standardization (ISO)Integration (with other management system standards)
Safety Performance Factors (SPF)

ABSTRACT:ISO committee TC 241 – Road traffic safety (RTS) management systems has developed the new management systemstandard for road traffic safety – ISO 39001:2012. ISO 39001 is an important and integral part of the work of the United
Nations Road Safety Collaboration/UNRSC and Decade of Action for Road Safety 2011-2020. ISO/TC 241 currently
has over 45 member countries and 20 international liaison organizations, including the World Bank and the World
Health Organization. Reference will be made to parts of ISO 39001 – for information, clarification, purpose andapplication. Examples of good practice of ISO 39001 will be presented. ISO 39001 is designed to work on its own,
parallel or integrated with other ISO MSS, management system standards, in any size or type of private or publicorganization, to build a structured and effective Road Traffic Safety/RTS system to save lives.

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ISO 39001:2012 specifies requirements for a road traffic safety (RTS) management system to enable an organizationthat interacts with the road traffic system to reduce death and serious injuries related to road traffic crashes which it can
influence. The requirements in ISO 39001:2012 include development and implementation of an appropriate RTS
policy, development of RTS objectives and action plans, which take into account legal and other requirements to which
the organization subscribes, and information about elements and criteria related to RTS that the organization identifies
as those which it can control and those which it can influence.
Road traffic safety (RTS) is a global concern. It is estimated that around 1,3 million people are killed and 20 million to
50 million are injured on roads around the world each year, and that this level is rising[10]. The socio-economic andhealth impacts are substantial.
The international standard ISO 39001 provides a tool to help organizations reduce, and ultimately eliminate, theincidence and risk of death and serious injury related to road traffic crashes. This focus can result in a more costeffective use of the road traffic system.
ISO 39001 identifies elements of good RTS management practice that will enable the organization to achieve its desired
RTS results.
ISO 39001 is applicable to public and private organizations that interact with the road traffic system. It can be used byinternal and external parties, including certification bodies, to assess the organization's ability to meet the requirements.
Experience from around the world has shown that large reductions in death and serious injury can be achieved throughthe adoption of a holistic Safe System approach to RTS. This involves a clear and unequivocal focus on RTS results andevidence-based actions, supported by appropriate organizational management capacity.
Government cannot achieve these reductions alone. Organizations of all types and sizes, as well as individual road
users, have a role to play. By adopting this International Standard, organizations should be able to achieve RTS results
at levels that exceed what can be achieved through compliance with laws and standards, and their own objectives, and,at the same time, contribute to the achievement of societal goals.
The management system specified in this International Standard focuses the organization on its RTS objectives and
RTS targets and guides the planning of activities that will realize these goals by using a Safe System approach to RTS.
Annex B describes categories of RTS results, the Safe System approach and a framework for good practice RTS
management, and shows how they can be aligned with this International Standard.
Annex A provides some guidance on the implementation of this International Standard.
The RTS management system can be integrated into, or made compatible with, other management systems (see also
Annex C) and processes within the organization.
ISO 39001 promotes the use of an iterative (plan, do, check, act) process approach that will guide the organization
towards delivery of the RTS results.

The international standard ISO 39001 specifies requirements for a road traffic safety (RTS) management system toenable an organization that interacts with the road traffic system to reduce death and serious injuries related to roadtraffic crashes which it can influence. The requirements in ISO 39001 include development and implementation of an
appropriate RTS policy, development of RTS objectives and action plans, which take into account legal and otherrequirements to which the organization subscribes, and information about elements and criteria related to RTS that theorganization identifies as those which it can control and those which it can influence.
The international standard ISO 39001 is applicable to any organization, regardless of type, size and product or service
provided, that wishes to

improve RTS performance,
establish, implement, maintain and improve an RTS management system,
assure itself of conformity with its stated RTS policy, anddemonstrate conformity with this International Standard.

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ISO 39001 is intended to address RTS management. It is not intended to specify the technical and quality requirementsof transportation products and services (e.g. roads, traffic signs/lights, automobiles, trams, cargo and passenger
transportation services, rescue and emergency services).
It is not the intent of ISO 39001 to imply uniformity in the structure of RTS management systems or uniformity of
documentation.
RTS is a shared responsibility. This International Standard is not intended to exclude road users from their obligations
to comply with the law and behave responsibly. It can support the organization in its efforts to encourage road users tocomply with the law.
All requirements of this International Standard are generic.
Where any requirement of this International Standard cannot be applied due to the nature of an organization and its
products or services, that requirement can be considered for exclusion, provided the exclusion and the reason for
exclusion are documented.
Where exclusions are made, claims of conformity to this International Standard are only acceptable where theseexclusions do not affect the organization’s ability to establish, implement, maintain and improve an RTS management
system successfully.
Introduction
Nearly 1.3 million people in the world die each year of road crashes – more than 3000 deaths each day. Another twenty
to fifty million people suffer non-fatal injuries, which are also an important cause of disability.
Ninety per cent of road traffic deaths occur in low- and middle-income countries, which claim less than half the world’s
registered vehicle fleet. Road traffic injuries are also the leading cause of death for people from 10 to 24 years of age.
Significant numbers of road traffic fatalities and injuries can be prevented by addressing the leading causes, which
include excess speed, lack of seat-belt and child restraint use, drinking and driving , lack of helmet use by riders on
two-wheel and three-wheel motorized vehicles, poorly designed and inadequately maintained roads, unsafe
infrastructure and vehicles, and inadequate trauma care.
Unless immediate and effective action is taken, road deaths are predicted to become the fifth leading cause of death in
the world by 2030, resulting in an estimated 2.4 million fatalities per year. This is, in part, a result of rapid increases inmotorization without sufficient improvement in road safety strategies and land use planning. The economic
consequences of motor vehicle crashes have been estimated between 1% and 3% of the respective GNP of the world
countries, reaching a total of over USD 500 billion. Reducing road casualties and serious injuries will reduce suffering,
unlock growth and free resources for more productive use.
These are facts provided by the United Nations and the World Health Organization.
Decade of Action for Road Safety and United Nations Road Safety Collaboration
The UN General Assembly resolution 64/255(http://www.who.int/violence_injury_prevention/publications/road_traffic/UN_GA_resolution-54-255-en.pdf) of March2010 proclaimed 2011-2020 the Decade of Action for Road Safety, with a global goal of stabilizing and then reducing
the forecasted level of global road fatalities by increasing activities conducted at national, regional and global levels.
Resolution 64/255, requested the World Health Organization and the United Nations regional commissions, incooperation with the United Nations Road Safety Collaboration (UNRSC) and other stakeholders, to prepare a Plan of
Action for the Decade as a guiding document to support the implementation of its objectives.
UN Secretary-General, Mr Ban Ki-moon, has said: “I call on Member States, international agencies, civil society
organizations, businesses and community leaders to ensure that the Decade leads to real improvements. As a step in thisdirection, governments should release their national plans for the Decade when it is launched globally on 11 May
2011.”The UNRSC was established in 2004 to support efforts to address the global road safety crises. The Collaboration ischaired by the World Health Organization and has brought together more than 50 international organizations,
governments, nongovernmental organizations, foundations and private sector entities to coordinate effective responses
to road safety issues.
The Decade of Action for Road Safety offers a common road map for reaching the ambitious goal of reducing roadtraffic fatalities globally by 50 per cent. The success will only be measured by its achievements. The target is to save 5
million lives by 2020.
The implementation plan is guided by the following five pillars:933

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1)
2)
3)
4)
5)

Road-safety management;
Safer roads and mobility;
Safer vehicles;
Safer road users;
Post-crash response.

Visit the official WHO, UNRSC and Decade websites:
All WHO data is online, see http://apps.who.int/ghodata/ and go to Injuries and violence on the left hand column.
These data are also published in the first Global Status report; see http://apps.who.int/ghodata/.
All resolutions can be found on the UNRSC website http://www.who.int/roadsafety/en/index.html check thesubcategory Resolutions on this homepage.
www.who.int/roadsafety/decade_of_action and www.decadeofaction.org
Sign up for email updates on the Decade:www.who.int/violence_injury_prevention/email_signup/en/index.html
Join the Decade on Facebook: www.facebook.com/roadsafetydecade
Follow the United Nations Road Safety Collaboration (UNRSC) on Twitter @UNRSC
Share Decade and other road safety photos on Flickr: www.flickr.com/groups/roadsafetydecade

ISO technical committee TC 241, Road Traffic Safety (RTS) and ISO 39001
One of the important stakeholders in the United Nations Road Safety Collaboration/UNRSC is ISO, International
Organization for Standardization, represented by Mr. Peter Hartzell, Secretary of the technical committee TC 241 –Road traffic safety management systems. This is the technical committee responsible for developing the new
management system standard for road traffic safety – ISO 39001 – Road traffic safety (RTS) management systems –Requirements with guidance for use. The standardization work, with the secretariat at SIS, Swedish Standards Institute(the Swedish ISO member NSB/National Standardization Body), was initiated in 2008 and ISO 39001 was published in
October 2012. ISO 39001 is an important and integral part of the work of UNRSC.
ISO/TC 241 has 45 member countries (both developed and developing countries) and 20 international liaisonorganizations, including the World Bank and the World Health Organization.
Read more about ISO work, technical committees and international standards on www.iso.org
The initial idea of an international standard for RTS came from Sweden’s work with the Vision Zero programme, where
the goal is zero deaths and zero serious injuries due to road traffic crashes. This new ISO management system standard
can provide a tool for systematic work and commitment among organizations that affect the safety of the road system.
Dr. Claes Tingvall, Director of Traffic Safety at the Swedish Transport Administration, who is the founding father of
Sweden’s Vision Zero programme, and also the previous (and first) Chair of ISO/TC 241, has said: “I believe that the
new standard (ISO 39001) could become as important to road traffic safety as for example the seatbelt or ESP(Electronic Stability Program).”
ISO 39001 is a management system standard, including both requirements and guidance for use. The status as arequirement management system standard puts ISO 39001 in the same distinguished category and family as world-wide
established and recognized ISO 9001 (Quality management) and ISO 14001 (Environment management).
ISO technical management board, TMB, has decided on a new common high level structure for all ISO management
system standards and ISO/TC 241 has been part of this process.
The new high level structure is now a part of ISO/IEC Directives, part 1, annex SL, chapter 8 – Guidance on thedevelopment process and structure of an MSS (management system standard). It includes the common structure, terms
and definitions and common text for management system standards.
ISO/TC 241 has been an early adopter in this process and the new structure is included in ISO 39001. This is a clear
advantage as it enables aligning, working parallel or integrating ISO 39001 with other management systems in an
organization where the organization is already working according to e.g. ISO 9001 or ISO 14001. There are alreadymore than one million organizations worldwide that are certified to ISO 9001 and about a quarter of a million to ISO
14001.
ISO management system standards High Level Structure
The new structure for all management system standards, according to which ISO 39001 is developed, has a high levelstructure of ten clauses which address the following:
1) Scope;
2) Normative references;
3) Terms and references;934

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4) Context of the organization;5) Leadership (including commitment and policy);
6) Planning;7) Support (including coordination, resources, competence, communication and information);8) Operation;9) Performance evaluation (including monitoring, measurement, analysis and evaluation, internal audit andmanagement review);10) Improvement (including nonconformity and corrective action and continual improvement).
These ten clauses will be common to all management system standards.
ISO 39001 embraces all these parts and also includes its unique content, especially in the planning clause, where RTS
performance factors and RTS objectives are addressed. There is also a section within the clause of performance
evaluation that addresses road traffic crash and other road traffic incident investigation.
Annexes in ISO 39001- Annex A (informative) provides guidance on the use of the international standard.
- Annex B (informative) addresses international work relating to road traffic safety management frameworks.
- Annex C (informative) shows the correspondence between ISO 39001:2012 (RTS), ISO 9001:2008 (Quality) and ISO
14001:2004 (Environment).
The Bibliography consists of relevant references including e.g. abovementioned ISO standards, as well as a World
Report on Road Traffic Injury Prevention(www.who.int/violence_injury_prevention/publications/road_traffic/world_report/en) and a Global status report on roadsafety by WHO (www.who/global_status_report_on_road_safety_2009).
The following sections address some of the unique core elements of ISO 39001.
RTS performance factors
The definition of this term is “a measurable factor, element and criterion contributing to RTS that the organization can
influence and that allows the organization to determine impacts on RTS.”
Clause 6.3 RTS performance factors states the following:
The organization shall identify for use RTS performance factors from the following list of risk exposure factors, final
safety outcome factors and intermediate safety outcome factors, depending on the context (see Clause 4) of theorganization and on the risks and opportunities it has identified.
a) Risk exposure factors:- distance travelled and road traffic volume, including vehicle and road user type, whether influenced or not
influenced by the organization;- volume of product and/or service provided by the organization.
b) Final safety outcome factors, e.g. the number of deaths and serious injuriesc) Intermediate safety outcome factors:
these safety outcome factors are related to the safe planning, design and use of the road network and of the
products and services within it, the conditions for entry and exit of those products, services and users, as wellas the recovery and rehabilitation of road traffic crash victims.
Additional RTS performance factors shall be developed by investigating relevant road traffic incidents and identifying
RTS deficiencies.
Based on the RTS performance factors, the organization shall specify elements and criteria in appropriate detail todetermine, monitor and measure RTS objectives and RTS targets. The organization shall document this information andkeep it up to date.
The definition for the term RTS targets is “detailed performance to be achieved, consistent with the policy and RTS
objectives that an organization applies to itself or together with interested parties.”
For example, seat belt use represents both the element and the criterion in relation to the RTS performance factor “useof personal safety equipment”. For the RTS performance factor “vehicle safety”, a consumer safety rating represents theelement and the rating level the criterion. Further guidance on the use of the RTS performance factors by different typesof organizations is given in annex A.11.
RTS objectives and planning
Furthermore, Clause 6.4 RTS objectives and planning to achieve them address the following:
The organization shall establish RTS objectives at relevant functions and levels.
The RTS objectives shall:- be consistent with the RTS policy;- be measurable (if practicable);935

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The organization shall retain documented information on the RTS objectives and the RTS targets.
When establishing and reviewing its RTS objectives and RTS targets, an organization shall take into account its risks
and opportunities (in Clause 6.2), its RTS performance factors (in Clause 6.3) and element and criteria (in Clause 6.3)
as well as give consideration to its management capacity. It shall also consider its technological options, its financial,
operational and business requirements, and the views of interested parties.
When planning how to achieve its RTS objectives and RTS targets, the organization shall determine- what will be done;- what resources will be required;- who will be responsible;- when it will be complete; and- how the results will be evaluated.
The action plans shall be documented and reviewed as necessary.
Competence
Clause 7.3 addresses Competence where it states that the organization shall:- determine the necessary competence of person(s) doing work under its control that affects its RTS performance;- ensure these persons are competent on the basis of appropriate education, training, or experience;- where applicable, take actions to acquire the necessary competence, and evaluate the effectiveness of the actions
taken;- retain appropriate documented information as evidence of competence.
Applicable actions can include, for example the provision of training to, the mentoring of, or the re-assignment of
current employed persons, or the hiring or contracting of competent persons.
Incident investigation
Clause 9.2 address Road traffic crash and other road traffic incident investigation.
The organization shall establish, implement and maintain a procedure(s) to record, investigate and analyse those roadtraffic crashes and other incidents in which they are involved that lead, or have the potential to lead, to death andserious injuries of road users, in order to:a) determine the underlying factors that it can control and/or influence and that can be causing or contributing to theoccurrence of those incidents;b) identify the need for RTS corrective action;c) identify opportunities for RTS preventive action.
Continual improvement
Similar to other ISO management system standards, ISO 39001 also addresses continual improvement (in Clause 10.2).
The organization shall continually improve the suitability, adequacy or effectiveness of the RTS management system.
This can be achieved through the use of the RTS policy, RTS objectives and RTS targets, audit results, analysis ofmonitored events, corrective and preventive actions and management review.
The above-mentioned unique parts of ISO 39001 make this international standard an effective and efficient tool to work
for improving RTS in a structured manner. Being a management system standard, similar to that of ISO 9001 and ISO
14001, makes ISO 39001 even stronger in application in any type or size of organization, both in developed and indeveloping countries.
Challenge – leadership, competence and resources
The relevance of any project, including those involved with RTS, is often a function of its leadership, competence andavailable resources. These factors are major challenges and necessary to address, particularly for developing countries,
to progress and succeed in the goal of reducing road crash fatalities and suffering, to unlock growth and to freeresources for more productive use.
In the work of ISO technical committees, funding is as important as in any other organization. The challenge is often
finding, coordinating and supporting the right competence, i.e. relevant subject matter experts participating in the work,
both at and in between meetings. It is important to involve standardization experts (i.e. from ISO and from
NSB/National Standardization Bodies) to support the administration and the process of developing the standard.
However, it is crucial to identify and gather the subject matter experts from respective country member. This isespecially important for developing countries that need to make the very best of the networking and sharing of goodpractices and bring experience learnt back with them to their public and private organizations – to make a difference in936

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the RTS work. Standards are created by those that participate and it is important that those that do participate are therelevant subject matter experts.
For those that want to find out more about this important work, and to ensure that your country is represented in
ISO/TC 241, contact your country’s NSB/National Standardization Body, through www.iso.org/isomembers
Update on the standardization work
Below are a couple of examples of pilot cases of application of ISO 39001, which can be similarly applied in bothdeveloped and developing countries.
Pilot cases of ISO 39001
Japan
The type of organizations involved in the pilots included transport, insurance, consultancy and car leasing companies.
The purpose was to:- construct a management system and control system in regards to road traffic safety;- improve awareness of road traffic safety for drivers in the company; to decrease accidents;- announce the policy of road traffic safety to its clients.
The challenge consisted mainly in identifying relevant RTS performance factors for each company/industry.
SwedenThe type of organizations involved included the Swedish road transport industry:- 8 000 companies;- 80% of road transport companies in Sweden;- 50 000 employees;- 30 000 motor vehicles.
The purpose of the pilot was to:- include ISO 39001 in the organization’s management system (QMS/ISO 9001, EMS/ISO 14001, ISO 45001/
Occupational Health and Safety management system);- establish a formula for risk assessment (R=SC).
Where
RTS Risk (R) = the probability (S) in percent for a consequence (factor C = 8 to10) to occur within 10 to 20 years
multiplied by the factor for the consequence.
Where
R= 0 to 1000; S= 0 to 100; and C= 0 to 10
WhereC=
1 incident with injury risk
2 minor injury
3
4 injury
5
6 major injury
7
8 serious injury
9 very serious injury
10 fatality
The challenges of the pilot included the following factors affecting risk:- Speed;- Use of safety belt;- Alcohol and drugs;- Fitness of driver (incl. considering fatigue);- Hands free (mobile phone);- Separation; oncoming traffic;- Surface texture and friction;- Load securing.
The Swedish pilot concluded that “All stakeholders should take measures and take responsibility for their own part of
RTS and collaborate with other stakeholders. ISO 39001 will be a good standard and guidance in this process.”937

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For discussion
 Core arguments
Humane and economic benefits to save lives (especially for developing countries that are over-represented inroad related deaths).
Objections vs. Arguments
1. Expensive cost vs. Effective investment for the future, especially for developing countries (aspects: humane,economic, environmental, occupational health and safety, etc.).
2. Close to impossible to achieve (Vision Zero) vs. There is no alternative, we all want to and need to continue
the good work that is already being done and spread the activities and positive outcomes.
Paradigm shift of attitude.
3. Who will be in charge vs. Everyone needs to take responsibility and action to make a difference, at various
levels (personal, local, regional, national and international). Various approaches, e.g. collaborations (UNRSC),
ISO (standards), public sector (governments and agencies) and private sector (corporations and NGOs, etc.).

Current and future challenges and action
The following are examples of what we all can do to contribute to improve RTS, both on a personal level aswell as on an organizational level:- Challenge your surroundings to get involved and to be part of the solution, e.g. local public/private sectors,
employer, customers, staff, local community, etc;
- Follow and get involved in the activities of UNRSC and Decade of Action for Road Safety 2011-2020;- Embrace ISO 39001: be prepared for publication and certification (e.g. through a pilot application), plug-in
and integrate with other ISO MSS (e.g. ISO 9001/Quality, ISO 14001/Environment, ISO 45001/Occupational
Health and Safety management system);- Upgrade your organization’s internal/external audit process including certification;- Be aware of local and national information drives, legislation, include RTS in recruitment and staff training
process, RTS training in schools (life-long learning);- Link RTS to the corporate (or public agencies) culture, structure and strategic process;- Link RTS with (corporate) branding and include RTS elements in recruitment and procurement;- Stay open minded for good/best practices (local, national and international), share (give and take);- Continue sharing between developed and developing countries;- Stay in a constructive and an innovative mode.

Conclusion
Road traffic safety, RTS, is a world-wide challenge, concern and focus. There are a lot of activities and tools
supporting RTS. E.g. the United Nations Road Safety Collaboration/UNRSC, Decade of Action for Road Safety
2011-2020 and the publication of the new international management system standard ISO 39001. Additionally tothese international efforts, there are many local, national and regional activities and projects linked to RTS.
It is important to keep focus on the subject of RTS being high up on the agenda of decision makers.
We need to keep the sense of urgency related to RTS.

Stockholm, Sweden 2016-06-10
Peter Hartzell
Secretary of ISO/TC 241 secretariat
SIS – Swedish Standards Institutepeter.hartzell@sis.se
Phone: +46-8-555 520 29
Mobile phone: +46-707-64 56 99
www.sis.se

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