bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison and Analysis Tool for Automatic Incident Detection
Authors: Browne Roger , Foo Simon , Huynh Shawn , Abdulhai Baher , Hall Fred
Published: May 2018

A new test bed for automatic incident detection (AID) systems uses real-time traffic video and data feeds from the Ontario, Canada, Ministry of Transportation COMPASS advanced traffic management system. This new test bed, called the AID comparison and analysis tool (AID CAAT), consists largely of a data warehouse storing a significant amount of traffic video, the corresponding traffic data, and an accurate log of incident start and end times. Also presented is a proof-of-concept field evaluation whereby the AID CAAT is used to calibrate and then analyze the performance of three AID algorithms: California Algorithm 8, the McMaster algorithm, and the genetic adaptive incident detection algorithm. In the calibration and testing process, nuisance rate and false normal rate are introduced as two new performance measures to supplement the three traditional measures (detection rate, false alarm rate, and mean time to detection). Further, the pilot evaluation shows the considerable advantages of AID CAAT in its ability to investigate the impact of freeway geometry, traffic flow rate, and traffic sensor spacing on the performance of the three AID algorithms. This work represents the first stage in a series of further tests to develop a set of AID algorithm deployment guidelines.
Reconsidering Freeway Bottlenecks
Authors: Walters Carol H. , Cooner Scott A. , Ranft Stephen E.
Published: May 2018

Implementing minor geometric and operational improvements on existing freeways to remove bottlenecks has the potential of achieving high benefits, yet it is not routinely done. Four case studies of bottleneck removal projects in Texas are presented in some detail with before-and-after evaluations of speeds, volumes, and crash histories. The case is made that many benefits may be realized for little cost. In addition, evaluations of nine other bottleneck removal projects are included in summary tables. Benefit–cost ratios as high as 400:1 have been found, with the lowest ratio being 9:1; costs ranged from $8,000 to $2.45 million. Injury crash rates were substantially lower after the bottleneck removal in almost all cases (average reduction of approximately 35%); however, an increase in crash rate was noted in one of the 13 cases.
Analysis of Transit Signal Priority Using Archived TriMet Bus Dispatch System Data
Authors: Kimpel Thomas J. , Strathman James , Bertini Robert L. , Callas Steve
Published: May 2018

Findings are presented on changes in bus running times, on-time performance, and excess passenger wait times following implementation of transit signal priority (TSP) in select bus corridors in the Portland metropolitan region. Analysis of the effectiveness of TSP is often undertaken by using simulation techniques or empirical studies that are limited in either scope or data availability, or both. The current research uses an abundance of trip-level data collected from TriMet's Bus Dispatch System, in Portland, Oregon. The study focuses on the most common performance measures of interest to both transit operators and passengers and shows that the expected benefits of TSP are not consistent across routes and time periods, nor are they consistent across the various performance measures. The authors believe that benefits of TSP will accrue only as the result of extensive evaluation and adjustment after initial deployment. In most cases, an ongoing performance monitoring and adjustment program should be implemented to maximize TSP benefits.
Performance of Advance Warning for End of Green System for High-Speed Signalized Intersections
Authors: Sunkari Srinivasa R. , Messer Carroll J. , Charara Hassan
Published: May 2018

A major difficulty with traffic signal operation on high-speed approaches is the dilemma faced by approaching motorists when the downstream signal turns yellow. Should the motorists stop or proceed through the intersection? Crashes that may occur at these intersections result in excessive property damage and personal injury because of the high speeds involved. The Texas Transportation Institute has developed a new system named the Advance Warning for End of Green System (AWEGS) for application at high-speed signalized intersections. Typically, dilemma zone detection strategy is based on a certain approach speed (typically the 85th percentile). AWEGS provides protection for the majority of motorists who are not covered by the dilemma zone treatment. AWEGS provides advance warning to motorists by using signs mounted on the roadside. These signs (Be Prepared To Stop When Flashing) would flash a beacon about 5 to 6 s before the onset of the yellow signal for high-speed approaches. Similar systems have been implemented in Canada and in a few U.S. states that use the trailing-green approach, which results in loss of dilemma zone protection every cycle. AWEGS, however, is almost completely independent of the traffic signal controller, and hence the signal controller would continue to provide the dilemma zone protection for which it was designed. The system was implemented at two sites in Waco and Brenham, Texas. Results of AWEGS implementation illustrated an improvement in traffic operations. AWEGS consistently enhanced the dilemma zone protection at intersections and reduced red light running by about 40%.
Investigation of the Development and Use of a Concept of Operations in Traffic Management Systems
Authors: Smith Brian L. , Evans Marc H. , Woodley Derek W.
Published: May 2018

The purpose of this research effort was to identify benefits provided by a concept of operations in the life-cycle of a transportation management system (TMS) and to identify best practices in the development and use of the concept of operations for TMSs. Experience has shown that the systems engineering process is well suited for the complex nature of the contemporary TMS. The foundation of the systems engineering process is the concept of operations, a high-level, nontechnical document focusing vision and goals for all aspects of a system that are necessary for operation in such a way that a diverse audience will fully understand what the system will do. The research surveyed current practice in TMS applications and compared this with concept-of-operations standards from the industry. Key findings of the research include the following recommendations and best practices for development and use of the concept of operations for TMSs: ( a) stakeholder communication and involvement in system development is the main benefit from the concept-of-operations development process; ( b) when the system development team is created, owners of the system should begin compiling the team of stakeholders immediately and focus on those who will be responsible for using the system; ( c) recommended practices for improving readability of the documents include minimizing technical jargon and frequent and effective use of graphics; and ( d) operational scenarios should be developed and extensively used in the concept-of-operations document. A concept of operations is dynamic and useful throughout the entire life-cycle of the system, providing guidance for all stages of system development.
Empirical Analysis of Factors Affecting the Resolution of Activity-Scheduling Conflicts
Authors: Ruiz Tomás , Polak John W. , Joh Chang-Hyeon
Published: May 2018

This paper describes an analysis undertaken to characterize how individuals resolve conflicts in activity scheduling. The focus is on the case in which a single new activity episode is inserted between two existing consecutively planned activities. The data used in the analysis were collected from students and staff members at a university, with the use of a web-based survey instrument. A range of characteristics, including demographic and socioeconomic variables of the individual, attributes of the observed activity-travel schedule, and attributes of the implied activities can be linked with resolution of the conflict. The results suggest that people tend to resolve schedule conflicts by simultaneously changing the starting time and the duration of the posterior planned activity. Several endogenous relationships have been found among the amount of modifications of these variables.
Relationship between Specific (Dis)Utility and the Frequency of Driving a Car
Authors: Diana Marco
Published: May 2018

An interesting issue in contemporary travel behavior research is whether the transportation demand has to be considered purely derived from underlying activity patterns or whether a utility is also associated with traveling per se. In the latter case, substantial amendments of current planning models would be needed to represent this phenomenon adequately. Earlier research consistently gave evidence of the existence of this specific utility, but its quantification is hindered by a specific measurement problem because survey respondents tend to mingle the utility of traveling and the utility of reaching a destination. The present work defines a methodology to quantify the decrement in the specific utility of driving a car due to the presence of difficulties and self-limiting behaviors. This is in turn responsible for an alteration of driving frequency. A structural equation modeling technique is used for the analysis. The structural submodel represents the complex relationships between socioeconomic variables, specific utility, and driving frequency. The measurement submodel defines the specific utility on the basis of reported self-evaluations concerning physical fitness and self-limiting behaviors while driving. An application of the method based on data collected in the 2002 National Transportation Availability and Use Survey is presented. The results show that the decrement of specific utility (which can be seen as a disutility) of driving a car has an important impact on the frequency of performing this activity compared with the derived utility that is customarily modeled through socioeconomic variables.
Value of Travel Information
Authors: Chorus Caspar , Arentze Theo , Molin Eric , Timmermans Harry J. P.
Published: May 2018

For models of the use of advanced travel information services (ATISs) and their effect on traveler behavior to be realistic from a behavioral point of view, conceptualizations of travelers’ perceptions of the value of information must be valid. This paper presents a formulation of perceived information value based on the idea that travelers face different types of uncertainty when choosing from and executing travel alternatives, such as routes, travel modes, and departure times. Notions of Bayesian updating are then applied to represent the effect of singular messages from an information service. Acquiring information is deemed valuable to the extent that travelers expect, on the basis of the information received, that their update in perception results in a decrease in the levels of uncertainty they face. Numerical examples that are presented aim to verify the derived measures for uncertainty and perceived information value. This is done by varying proven determinants of uncertainty and ATIS use and investigating the effects on the derived measures for uncertainty of choice and execution and on perceived information value. It appears that trends that occur in the measures developed correspond to common intuition and empirical evidence from the literature on ATIS use; this indicates a certain degree of behavioral validity of these measures. In future research, these measures will be used in simulation and model estimation and applied to study a variety of trends in travelers’ use of information services.
Spatial Attributes and Patterns of Use in Household-Related Information and Communications Technology Activity
Authors: Krizek Kevin J. , Li Yi , Handy Susan L.
Published: May 2018

Information and communications technologies (ICTs) are affecting an ever-increasing array of household activities. Although considerable research has documented patterns of ICT use and sociodemographic profiles of ICT users, surprisingly little research has examined the role of spatial attributes such as accessibility, ICT availability, and levels of congestion in ICT-related activities. This paper aims to answer questions related to the propensity of residents in metropolitan areas to use the Internet for e-commerce, e-banking, and other financial transactions and how such use is affected by spatial attributes of retail and bank accessibility and traffic congestion. First, a snapshot of aggregate patterns of ICT use in the United States is provided, and past theories are described. Next, the methodology is described for administering a mail-out and mail-back survey of households in the spring of 2003 (including Seattle, Washington; Kansas City, Kansas and Missouri; and Pittsburgh, Pennsylvania). The survey measured participation in ICT-based activities in the form of shopping on the Internet (referred to as e-shopping), electronic banking, and other financial transactions. Finally, analyses are presented that focus on the degree to which the use of such activities is shaped by factors of accessibility, ICT availability, and traffic congestion. Contrary to expectations, the results suggest that, for the most part, spatial attributes do not appear to play a significant or substantive role in affecting rates of ICT use.
Developing Standard Times for Repair Activities for Transit Vehicles
Authors: Centeno Grisselle , Chaudhary Rajesh , Lopez Paula
Published: May 2018

This paper presents a systematic method for determining repair time standards for transit vehicles. Most approaches typically used for time and motion study are designed mainly for manufacturing processes and thus find limited applications in transit environments. The methodology developed in this study is comprehensive and incorporates relevant factors such as maintenance procedures and work bay components and design, which are particular to the transit industry. This methodology has been employed on two systems: brake repair and preventive maintenance on buses. A major component of the methodology pertains to restructuring procedures, not only to improve work flow but also to normalize the operative assignments across transit shops. That focus facilitates productivity control and allows managers to assess training needs better. Outcomes reveal that the proposed methodology serves as a framework to develop valid standards that could have an impact on the efficiency of technicians while reducing total job completion time. Results are enhanced by the development of an information system that allows tracking of the time technicians take to complete the tasks and that represents, graphically, the performance rating based on the time standards developed. This tool assists supervisors during complex management decisions for resource allocation and scheduling. This project was initiated by the Florida Department of Transportation and the Center of Urban Transportation Research (CUTR). The research is part of the Florida Maintenance Training and Technical Assistance Program in CUTR and is guided by the committee of Transit Maintenance Consortium. The committee includes the managers and supervisors of the transit agencies throughout Florida.
Making Automatic Passenger Counts Mainstream
Authors: Furth Peter G. , Strathman James G. , Hemily Brendon
Published: May 2018

Although automatic passenger counters (APCs) have been used for many years, significant obstacles have hindered their becoming a mainstream source of data for monitoring ridership and peak load, estimating passenger miles, and other measures of passenger use important for transit management. The key to APC usefulness is the automatic, routine conversion of the APC data stream into a database of accurate counts. On the basis of case studies of transit agencies, five issues important to achieving this goal are analyzed: data structures, data accuracy, accuracy need and sampling requirements, controlling drift, and balancing algorithms. Balancing algorithms deal with routes with loop ends, negative loads, and rounding. Sampling and accuracy requirements related to passenger miles estimates for National Transit Database (NTD) reporting are also analyzed. The analysis shows that, for most agencies, NTD precision requirements can be met with a small level of fleet penetration, provided that measurement, screening, parsing, and balancing methods keep bias in load measurement below 8%.
Validation and Sampling of Automatic Rail Passenger Counters for National Transit Database and Internal Reporting at TriMet
Authors: Strathman James G. , Kimpel Thomas J. , Callas Steve
Published: May 2018

This paper presents findings from an evaluation of the accuracy of automatic passenger counters (APCs) on the Tri-County Metropolitan Transportation District of Oregon's (TriMet's) light rail vehicles. APC boarding and alighting counts were compared with manually recorded counts. Overall, the APCs tended to undercount boardings and overcount alightings. Thus, correction factors will be needed for use of APC-recovered data for National Transit Database (NTD) and internal reporting. The paper also describes the sampling procedures employed by TriMet for NTD and internal reporting, in which sampled trips are linked to archived APC data records.
Experimental Study on Ultimate Behavior at Negative Moment Regions of Composite Bridges
Authors: Ahn Il-Sang , Chiewanichakorn Methee , Nottis Aaron F. , Carpenter Jeffrey A. , Chen Stuart S. , Aref Amjad J.
Published: May 2018

This paper presents experimental results of the ultimate behavior of the negative moment region of a quarter-scale full model and a half-scale subassemblage model of a two-span continuous composite bridge of concrete deck slab on steel girder. The two specimens are based on a prototype bridge that has a large girder spacing [3,800 mm (13 ft)]. At the ultimate state, it is shown that a larger portion of the deck is activated to resist tensile stress compared with the effective width specified in the AASHTO load and resistance factor design bridge specifications. Also, a plastic hinge that forms at the internal support has enough rotational capacity (ductility) to enable development of a second plastic hinge within the span. Experimental results show a reasonably good match with accompanying finite element method analyses.
Dynamic Field Performance of Glued Laminated Timber Bridges
Authors: Bigelow Jake , Phares Brent , Wipf Terry , Ritter Mike , Wood Doug
Published: May 2018

To use and develop timber structures in transportation better, the U.S. government implemented several national programs starting in the early 1990s to address the needs of the timber industry. One need was to investigate the dynamic field performance of timber bridges in relation to vehicular loading. The AASHTO load and resistance factor design specifications recommend a dynamic load allowance of 0.165 for timber bridges. To investigate this codified value, research was needed to determine the dynamic characteristics of timber bridges and to study their dynamic performance. To obtain dynamic performance data, five glued laminated girder bridges and four longitudinal glued laminated panel bridges were selected for testing. The testing involved loading the nine structures to obtain dynamic performance data including deflection and acceleration, as well as to assess the overall condition state of the bridges. The nine bridges tested were found to have fundamental frequencies between 5 Hz and 11 Hz as well as a dynamic load allowance of less than 0.25. The bridges found to have dynamic amplifications above specified code values were also found to have physical characteristics (i.e., rough entrances) that likely caused the higher dynamic amplification values.
Evaluation of Circular Texture Meter for Measuring Surface Texture of Pavements
Authors: Prowell Brian D. , Hanson Douglas I.
Published: May 2018

The circular texture (CT) meter is a laser-based device for measuring the mean profile depth (MPD) of pavement at a static location. MPD measurements from the CT meter and mean texture depth measurements from the sand patch test were obtained in five random locations in each of 45 sections of the 2000 National Center for Asphalt Technology (NCAT) test track. The NCAT test track provides a wide range of surface types, including coarse and fine dense graded Superpave® mixes, Hveem mixes, stone mastic asphalt, and Novachip. Testing indicated that the CT meter produced results comparable with the ASTM E965 sand patch test. When open-graded mixtures were excluded, this study indicated that the offset was nonsignificant between CT meter and sand patch test results. Previously developed equations to predict macrotexture were found to be inadequate for the wide range of mix types and aggregate types found at the NCAT test track. An equation was developed to relate fineness modulus to macrotexture. This equation was validated with independent data collected by the Virginia Transportation Research Council. Testing conducted as part of a mini round robin indicated that two readings should be averaged to represent a single CT meter measurement. The within-lab coefficient of variation for the CT meter is estimated to be 2.3%. The between-lab coefficient of variation for the CT meter is estimated to be 4.2%. Both estimates are based on the average of two tests being reported as a single measurement.
Critical Evaluation of Use of the Procedure of Superpave Volumetric Mixture Design for Modified Binders
Authors: Cho Dong-Woo , Bahia Hussain U. , Kamel Nabil I.
Published: May 2018

This study examined the possible interference of modified binders with the standard procedure of Superpave® volumetric mixture design. Sensitivity of volumetric properties and moisture damage performance were evaluated with four binders modified with and without polymeric additives. The study focused on effects of compaction temperatures and vertical pressure on densification of mixtures and on effects of compaction temperatures on moisture damage. The zero shear viscosity concept was used to estimate acceptable mixing and compaction temperatures. The compaction energy index was used to study changes in compaction effort, and cohesion and adhesion of binders were measured to study moisture damage potential. Results indicated that temperature effects were somewhat marginal and that unless temperatures were reduced to below 80°C, effects on volumetric properties were rather small. It was also found that using a target zero shear viscosity of 1.5 Pa·s for mixing and 3.0 Pa·s for compaction could provide reasonable compaction temperatures for binders used in this study. Varying vertical stress used in the gyratory compactor showed significant effects on volumetric properties. Changing pressure from 600 kPa to 300 kPa resulted in 3.0% to 4.0% increase in air voids, more significant than changing viscosity by more than 10 times. It is postulated that the focus on keeping temperature high during compaction in the lab and in the field might be unfounded. Moisture damage does not appear to be affected significantly by the variation in binder viscosity profiles for the binders and aggregates used in this study. Because of the limited sample size, more work is needed in this area to study the effect of mixing and compaction temperatures on moisture damage.
Comparison of Superpave and Marshall Mix Performance in Alabama
Authors: Watson Donald E. , Brown E. Ray , Moore Jason
Published: May 2018

The Alabama Department of Transportation specifies the Superpave® design system for most of its dense-graded HMA mixes. However, there is concern that the number of design gyrations ( NDesign) may be too high for specified traffic levels. Mixes designed with an NDesign level that is too high would be rut resistant but may be difficult to compact in the field and may suffer from durability problems such as premature cracking and raveling. The objective of this project is to evaluate the performance of Alabama's mixes designed according to Superpave criteria and compare them to the performance of Alabama's Marshall-designed mixes to determine whether current NDesign levels should be adjusted. The following conclusions are based on an evaluation of 25 Marshall and Superpave projects placed about the same time and serving under approximately the same traffic conditions: ( a) Generally, both Marshall and Superpave mixtures are performing quite well with little rutting and cracking after a period of about 4 years. ( b) It is likely that most Marshall and Superpave mixtures will not reach the design air voids of 4.0% during the life of the pavement. After 4 years, the average air voids measured in the wheelpaths was 5.3% for Marshall mixes and 5.9% for Superpave mixtures. ( c) It appears that the durability of Superpave mixtures can be improved, without adversely affecting the rutting resistance, by increasing the asphalt content. Practitioners, however, are cautioned to monitor rutting indicators closely during mixture design, production, and construction.
Effect of Construction Quality, Temperature, and Rutting on Initiation of Top-Down Cracking
Authors: de Freitas Elisabete Fraga , Pereira Paulo , Picado–Santos Luis , Papagiannakis A. Thomas
Published: May 2018

Top-down cracking (TDC) is a flexible pavement distress caused by a number of factors, including high contact stresses from truck tires, mix design characteristics (e.g., binder type and aggregate gradation), and poor construction quality (e.g., segregation and compaction methods). This paper presents the findings of a study seeking to quantify the effect of those factors on TDC. The study consists of a laboratory component involving an accelerated wheel-tracking device and a modeling component involving a 3-D nonlinear viscoelastic finite element model. The laboratory component of the study involved 17 asphalt bituminous slabs constructed to simulate the variation in material properties observed in the field as part of an earlier forensic TDC study. The effect on TDC of air voids, bitumen content and type, aggregate gradation, and segregation were studied under three temperature conditions. Air voids, segregation, and binder content were found to have a significant effect on TDC for all temperatures tested. Modeling the TDC involved laboratory testing to establish the viscoelastic and tensile strength properties of the asphalt mixtures tested. It was found that the rutted surface contributes significantly to TDC initiation.
Evaluation of a Predicted Dynamic Modulus for Florida Mixtures
Authors: Birgisson Bjorn , Sholar Gregory , Roque Reynaldo
Published: May 2018

The new 2002 AASHTO guide for the design of pavement structures is based on mechanistic principles and requires the dynamic modulus as input to compute stress, strain, and rutting and cracking damage in flexible pavements. The 2002 AASHTO guide has three different levels of analysis; the level used depends on the importance of the pavement structure in question. Dynamic modulus testing is required for Level 1 pavement analysis, whereas no laboratory test data are required for Level 2 and Level 3 pavement analysis. Instead, a predictive dynamic modulus equation is used to generate input values. It is of significant importance to state agencies to understand how well the dynamic modulus for locally available materials compares with the predicted dynamic modulus. This paper presents the results of a study by the Florida Department of Transportation and the University of Florida that focused on the evaluation of the dynamic modulus predictive equation used in the new AASHTO 2002 guide for mixtures typical to Florida. The resulting research program consisted of dynamic modulus testing of 28 mixtures common to Florida. Results showed that on average the predictive modulus equation used in the new AASHTO 2002 flexible pavement design guide appeared to work well for Florida mixtures when used with a multiplier to account for the uniqueness of local mixtures. Results of the study also identified optimal viscosity–temperature relationships that result in the closest correspondence between measured and predicted dynamic modulus values.
Personal Rapid Transit for Airport Applications
Authors: Lowson Martin
Published: May 2018

Personal rapid transit (PRT) systems offer a series of new opportunities for effective solution of airport-related transport problems, both on the landside and airside of the airport. A comparative analysis is offered of the potential advantages and disadvantages of this form of transport for airport applications. The work is illustrated by a case study of the application of the ULTra PRT system to serve passenger and staff car parks at Heathrow. The small scale and flexibility of the ULTra infrastructure allow use of the tunnel side bores and provide unexpectedly simple integration with the complex central terminal area. Detailed comparisons show a benefit of 60% in trip time and 40% in operating cost over current buses. The study shows that such forms of transport are well matched to landside applications for airports. An outline evaluation of possible benefits for airside operations is also presented.
Strategies for Streamlined Participation by Native American Governments in Federal Transportation Projects
Authors: Granell Jessica , Grachen David
Published: May 2018

Creating an effective public involvement process in transportation planning and project development is a challenge for transportation agencies. A meaningful and timely consultation process is especially challenging in projects that affect the cultural resources of Native American tribes. An overview is presented of the major legislative requirements for Native American involvement in federal transportation projects. Three case studies–-from Georgia, Wisconsin, and New York–-examined how states have effectively streamlined involvement with Native American nations in the transportation decision-making process. Although every transportation program is different and each approach to public involvement should be tailored to project-specific needs, many issues of the consultation process with Native American governments are the same across state transportation agencies. This paper presents how the studied states addressed these issues to improve consultation with Native American governments. Challenges discussed include how overloading tribes with information results in less feedback, the difficulties in ratifying memorandums of understanding to streamline the process, overcoming the lack of trust, dealing with different ways of doing business, dealing with out-of-state tribes, and the difficulties in working agreements on the ownership of artifacts. Much information can be applied by other states to improve and streamline their consultation processes with Native American governments.
Identifying Freight Mobility Projects for Possible Inclusion in a Statewide Transportation Improvement Program
Authors: Kale Steven R.
Published: May 2018

In 2001, the Oregon state legislature formally authorized the Oregon Freight Advisory Committee (FAC), which had been established by the Oregon Department of Transportation (ODOT) in 1998. One of the FAC's responsibilities according to the 2001 legislation was to identify high-priority freight mobility projects for consideration and inclusion in the statewide transportation improvement program (STIP). In 2003, the legislature reaffirmed the FAC's charge to identify high-priority freight mobility projects for possible inclusion in the STIP and authorized $100 million in new funding for projects that would enhance freight mobility, improve access to industrial lands, and improve access to job creation sites. The FAC's role was to identify and recommend freight mobility projects to be considered for the new funding. This paper summarizes the FAC process for addressing legislative direction to identify and recommend high-priority freight mobility projects. The summary includes a discussion of how the FAC ( a) developed and approved eligibility criteria for screening projects along with prioritization factors for narrowing the list of screened projects; ( b) incorporated planning considerations in identifying and screening projects; ( c) involved ODOT, FAC members, and the public in identifying, screening, and ranking projects; ( d) developed a list of prioritized projects; and ( e) presented a list of recommended projects to the Oregon Transportation Commission for its consideration to include all or some of the projects in the 2006–2009 STIP.
New Approach to Transportation Planning for the 21st Century
Authors: Sussman Joseph M. , Sgouridis Sgouris P. , Ward John L.
Published: May 2018

The complex large-scale integrated open systems (CLIOS) process is an overarching mechanism for considering systems, especially those exhibiting nested complexity, in which both the physical and the institutional aspects are complex. A special case of the CLIOS process is regional strategic transportation planning. New technologies, such as intelligent transportation systems, allow consideration of the planning, management, operations, and maintenance of transportation systems at the regional scale. Although the technological issues in advancing to this scale have proved tractable, the institutional issues concerned with deploying these systems across political jurisdictions with different measures of performance and different cultural perspectives has proved quite difficult. This paper explores processes for studying these institutional questions and integrating a number of concepts into the process: technological change, sustainability, real options, supply chain management, the various transport modes, and social, political, and economic factors. The paper serves as a case study of tailoring the CLIOS process into a process specifically designed to systematically address particular issues, in this case, regional strategic transportation planning.
Effects of Rural Highway Median Treatments and Access
Authors: Gattis J. L. , Balakumar Ramasubramaniyan , Duncan Lynette K.
Published: May 2018

The safety records of rural and suburban four-lane highways in Arkansas as a function of median treatment and access density were examined. The study excluded roadways with posted speeds lower than 64 km/h (40 mph) and excluded fully controlled access roadways. When entering an urban area, the segments were normally terminated when the first traffic signal or stop sign was encountered. By using 3 years of crash data, the analyses revealed a number of relationships relating crash frequency to median, volume, and access frequency attributes. Crash severity and crash type were also examined. As median width increased, there was a weak but statistically significant decline in the crash rate. There was a weak but statistically significant increase in the crash rate as access density increased. The roadways with shoulders and depressed medians had the lowest crash rates, and the roadways with no median (i.e., painted centerline) and curbs had the worst safety record. An inspection of these data suggests that there may be a correlation between median type and land use type: certain types of median are more likely to be present in certain land use environments. This raises the possibility that in this and in other studies of the safety effects of median treatments, the findings may be influenced or skewed by correlations between median type and land use or surroundings or by other factors.
Estimating the Safety and Operational Impact of Raised Medians and Driveway Density
Authors: Eisele William L. , Frawley William E.
Published: May 2018

This paper describes research sponsored by the Texas Department of Transportation to investigate the operational and safety impact of raised medians and driveway consolidation. Operational effects (travel time, speed, and delay) were investigated through microsimulation on three field test corridors and three theoretical corridors. Safety effects were investigated along 11 test corridors to estimate relationships between crash rates and access point densities as well as the presence of raised medians or two-way left-turn lanes (TWLTLs). The research demonstrates that access management effects are case specific and that microsimulation can assess these unique operational effects. For the case studies investigated, replacing a TWLTL with a raised median resulted in an increase in travel time on two test corridors and a decrease on one test corridor. Small increases in travel time were found with the theoretical corridors as well. The travel time differences are based on the traffic level and location and number of the raised median openings. When present, the relatively small increases in travel time, and subsequent speed and delay, appear to be outweighed by the reduction in the number of conflict points and increased safety. Detailed crash analysis on 11 test corridors indicated that as access point density increases, crash rates increase. This trend holds regardless of the median type. For test corridors in which crash data were investigated before and after the raised median installation, a reduction in the crash rate was always found. Finally, future research needs are identified, including the need to investigate operational and safety impact over a broader range of geometric conditions and longer corridors than investigated here.
Access Management
Authors: Gluck Jerome , Michel Jean , Geiger Michael , Varughese Maya
Published: May 2018

This paper discusses issues encountered in developing a retrofit project for a roadway in a densely developed, commercialized area. The project was initiated, directed, and funded by the New York State Department of Transportation (NYSDOT). Numerous major shopping centers and a high volume of through traffic produce congestion and affect safety. NY-27, also known as Sunrise Highway, is a principal arterial in suburban Long Island. The conditions along NY-27 reflect what happens when development approvals are granted by local land use agencies without sufficient consideration of whether the transportation system can accommodate the associated traffic. NYSDOT, in this case, was put in the position of attempting to implement a retrofit project to mitigate the traffic and safety conditions. The proximity of shopping center driveways to each other and to nearby intersections results in weaving movements and heavy turning-movement volumes that block the through travel lanes and cause overlapping conflicts. The significant traffic congestion and high accident rate reflect the problems caused by inadequate access spacing and need for improved access management. The improvement options identified represented a wide range of access management strategies and configurations. The options were screened and modified to reflect community desires and business concerns. This paper reviews operational and safety problems, identifies a theoretical access configuration along the NY-27 corridor that could mitigate these problems, and reviews the alternative that was approved and is being progressed. The approved alternative reflects real-world considerations that affect a retrofit project.
Impacts of Transit in National Parks and Gateway Communities
Authors: Dunning Anne E.
Published: May 2018

The U.S. National Park Service has worked to reduce traffic congestion in parks through a transit service. Consistently, communities around parks that are planning for transit want to know what effects they will experience from introductions or changes in service. This research developed a comprehensive understanding of the encountered effects. Seven case study investigations revealed no clear patterns in visitation changes at parks with recent transit initiatives. Circulation and economic impacts depended on local situations and followed from transit planning decisions. The case study findings provide models that can inform planning for continued expansion of transit on public lands.
Risk Sharing in the New Public Works Concession Law in Spain
Authors: Vassallo José M. , Gallego Juan
Published: May 2018

Budgetary constraints are forcing transport infrastructure authorities to raise private funds to finance the construction of new projects and the maintenance of existing ones by using concession contracts. One of the key elements in correctly defining a concession scheme is to establish an adequate risk-sharing mechanism among the stakeholders that take part in the process. This paper describes and analyzes the effect of the new Spanish Concession Law on risk sharing, in particular, the effect of the so-called progress clause on the calculation of risk held by the concessionaire. This law was designed both to reinforce private financing of public facilities and to improve the legal framework by defining a new risk-sharing approach, particularly in relation to the risks involved in estimating traffic demand. The paper finishes with an analysis of a specific application of the traffic risk-sharing approach for highway concessions in Spain.
Development and Performance Evaluation of a Revenue Collection System Based on Vehicle Miles Traveled
Authors: Porter J. David , Kim David S. , Vergara Hector A. , Whitty Jim , Svadlenak Jack , Larsen Norman C. , Sexton Charles B. , Capps Darel F.
Published: May 2018

The State of Oregon is heavily dependent on fuel tax revenues to maintain roads. Several technological developments, including the introduction and use of more fuel-efficient vehicles, will have a dramatic effect on fuel tax revenues in the near future. In response to these trends, Oregon House Bill 3946 mandates that the Oregon Department of Transportation (ODOT) begin implementing pilot systems to test alternatives to the current system of taxing highway use through fuel taxes. The Road User Fee Task Force (RUFTF) was created as part of the bill with the mission of “developing a revenue collection design funded through user pay methods, acceptable and visible to the public, that ensures a flow of revenue sufficient to annually maintain, preserve and improve Oregon's state, county and city highway and road system.” One alternative being considered by the RUFTF employs a fee based on vehicle miles traveled (VMT). This paper describes the development of two working VMT-based prototype technology configurations. This development effort was necessary because commercial-off-the-shelf technology with the functionality required by RUFTF was not available. Multiple concepts for on-vehicle mileage collection devices (using both odometer and Global Positioning System technology) and systems for fee calculation and collection were developed, integrated, and tested as part of the two prototype technology configurations. Results indicate that a VMT-based fee collected via radio frequency communications at service stations is technologically feasible.
Private-Sector Participation in Infrastructure Projects and Value for Money
Authors: Miyamoto Kazuaki , Sato Yukiya , Kitazume Keiichi
Published: May 2018

Private-sector participation in infrastructure projects has gained worldwide acceptance as a way of ensuring more efficient and effective projects and of supplementing public financing. However, few studies have comprehensively focused on the possible impacts of private-sector participation, including changes in multiplier effects, economic benefits and costs, and the tax effects and transfer between local and central governments. The aim of the present study was to develop a comprehensive system of estimating the various impacts caused by changes in the scheme of public works or procurement of public services and evaluating the final impacts on stakeholders in the society. After establishment of a general flow system of money and benefits in the case of an infrastructure project by identification of the relationships between the stakeholders, tools were installed into the system to estimate the amount of financial flows, including tax and subsidy, under an alternative public finance institution and a project scheme. As a case study, a road project adhering to the design, build, finance, and operate scheme was compared with one adhering to the conventional scheme. The results of the case study indicate that value for money evaluation depends to a significant extent on the viewpoint and the scope of the analysis and that the difference between evaluations can be substantial. In addition, the results demonstrate the necessity of public finance transfer between central and local governments to ensure that the project is more efficient and effective with the participation of the private sector.
Environmental Justice Issues Related to Transponder Ownership and Road Pricing
Authors: Parkany Emily
Published: May 2018

Electronic transponders used on toll roads often reduce delays at toll facilities and sometimes offer customers a discount in the toll. Nonetheless, many people avoid using toll roads or acquiring electronic transponders. Their reasons include a dislike for toll roads based on a belief that roads should be a public good or on infrequent use of the roadway. Obtaining a transponder requires an application process and an initial prepayment of tolls as a minimum requirement. In worst cases, applications must be mailed (rather than obtained at a distribution center, online, or through a phone call), transponder deposits are demanded, and credit cards are required for automatic replenishment of tolls. In addition to the impediment of submitting an application, at least 20% of U.S. households do not have a credit card, and 10% do not have a bank account; such households would essentially be barred from obtaining transponders from most U.S. toll authorities. This paper analyzes these barriers by presenting the costs and benefits of the various toll transponder “tags” available in the United States in addition to models of toll road corridor users. Results show that higher-income households are more likely to have transponders and to use toll roads frequently. Other demographic and trip characteristic variables have less influence on toll road frequency choices but do influence transponder acquisition. Several agencies insist on large transponder deposits and initial prepayment amounts and require payment methods that are not available to a large percentage of the U.S. population.
Discussing High-Occupancy Toll Lanes with the Denver, Colorado, Public
Authors: Ungemah David , Swisher Myron , Tighe C. Daniel
Published: May 2018

As managed lanes and high-occupancy toll (HOT) lanes gain popularity as a potential mobility measure, the question of how the public views these relatively new concepts is of vital importance. Concerned that a potential conversion of the North I-25 high-occupancy vehicle (HOV) facility in Denver, Colorado, to HOT lanes could be perceived as too controversial, the Colorado Department of Transportation (CDOT) sponsored market research and public outreach and assessment for evaluating the level of controversy. The messaging, methodology, activities, and findings from this effort may provide valuable information for communities that are considering HOT lanes as a component to their mobility challenges. This paper outlines the efforts conducted by CDOT's project team, including focus groups with commuters and business owners, stakeholder outreach to vested public officials and interest groups, conversations with the public in varying open houses, and a stated preference telephone survey. The conclusions from this effort indicate that ( a) support for HOT lanes is greater than it was a few years earlier, ( b) issues related to income and equity are not as pronounced as anticipated, ( c) public opinion can be favorably affected when individuals are informed on means of avoiding tolls by carpooling or riding the bus, and ( d) HOT lanes are viewed as an interim solution that is only a component of a regional multimodal transportation system. For practitioners hoping to extend support for HOT lanes to their facilities, the principal finding indicates that comarketing the HOT lane option with a means of avoiding a toll (through carpooling or riding the bus) may favorably affect public acceptance.