bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Quartz Piezoelectric Weigh-in-Motion Sensors
Authors: White Ronald , Song Jongchul , Haas Carl , Middleton Dan
Published: May 2018

Quartz piezoelectric weigh-in-motion (WIM) sensors are potentially appealing because of their low sensitivity to temperature fluctuations, according to information gathered from previous installations in other states. These installations also called into question the durability of the quartz sensors. Some sensors stopped producing a signal even though the sensor installation did not exhibit physical distress. After design changes were made, it was necessary to reevaluate the quartz sensor before any major investment in this technology in Texas. This research was undertaken to evaluate the performance and durability of quartz piezoelectric WIM sensors. To perform this evaluation, researchers instrumented two sites with quartz sensors and collected truck weight and sensor condition data to analyze the accuracy and durability of these sensors. The results of this research show that the sensors meet or exceed the weight accuracy specified by the ASTM specification for Type 1 highway WIM systems. The data further show that the truck weights produced by the WIM system are stable over time with minimal variation due to temperature change. There have been no sensor failures or degradation of the installations to date.
Network-Level Evaluation of Specific Pavement Study–2 Experiment
Authors: Buch Neeraj , Chatti Karim , Haider Syed Waqar , Pulipaka Aswani S. , Lyles Richard W. , Gilliland Dennis
Published: May 2018

The research described here was conducted as a part of NCHRP Project 20–50 (10&16), LTPP (Long-Term Pavement Performance) Data Analysis: Influence of Design and Construction Features on the Response and Performance of New Flexible and Rigid Pavements. The relative effects of various design and site factors on the performance of jointed plain concrete (JPC) pavements are presented. The data used in this study were primarily drawn from Release 17 of DataPave. The Specific Pavement Study (SPS) 2 experiment was designed to investigate the effects of portland cement concrete (PCC) slab thickness, base type, drainage, PCC flexural strength, and slab width on the performance of JPC pavements. On the basis of the statistical analysis of 167 test sections, ranging in age from 5 to 12 years, it was concluded that base type was the most critical design factor affecting performance in terms of cracking and roughness as measured by the international roughness index. Pavement sections with a permeable asphalt-treated base and in-pavement drainage performed better than those with a dense-graded aggregate base or a lean concrete base. PCC slab thickness also played an important role in improving the cracking performance of the pavements. PCC flexural strength and slab width have only marginal effects on performance at this time.
Practical Probabilistic Design Format for Flexible Pavements
Authors: Kim Hyung Bae
Published: May 2018

Mechanistic–empirical (M-E) pavement design procedures such as the AASHTO 2002 design guide have been widely accepted and are being implemented by many highway agencies. However, several issues need to be resolved before this implementation is completed. One issue is that the design procedure should provide a consistent pavement performance level considering inherent variability associated with design input parameters. For a complete M-E pavement design procedure, the effects of the inherent variability of input design parameters on predicted pavement performance must be addressed and quantified. Some key principles for applying the reliability concept to M-E pavement design are presented to account for the inherent variability of design parameters. In particular, an appropriate reliability assessment technique and careful characterization of design input variability were considered because of their central role in calculating the reliability of pavement performance. Finally, a practical probabilistic design format for evaluating uncertainties in the M-E flexible pavement design procedure is introduced.
Motorist Comprehension of Traffic Control Devices for Mobile Operations
Authors: Finley Melisa D. , Ullman Brooke R. , Trout Nada D.
Published: May 2018

In 2004, researchers conducted surveys to evaluate motorist comprehension of various mobile traffic control devices used to inform drivers about the number of vehicles in a work convoy; speed differential between the work convoy and the normal traffic stream; and passing a work convoy on two-lane, two-way roadways with improved shoulders. Four static signs were investigated to ascertain whether they inform motorists that they are approaching multiple work vehicles. Three of the signs (including the sign “Work Convoy”) had comprehension levels less than 53%. Placing the number of work vehicles on the sign (i.e., “3 Vehicle Convey”) improved the comprehension level to 79%. Various mobile speed displays were evaluated to determine if they provide information to motorists about the speed differential between the work convoy and approaching traffic. Only the “Your Speed” display (indicating speed of approaching vehicles) was understood by more than 85% of participants. In Texas, when mobile operations are conducted on the centerline of a two-lane, two-way roadway with improved shoulders, motorists are directed via a right flashing arrow panel to pass the work convoy to the right on the improved shoulder. However, under the current setup, only 66% of participants understood that they were supposed to pass the work vehicles on the right. All alternative text messages improved the comprehension rate; however, the “Pass on Shoulder” message was understood by the highest percentage of participants, at 97%.
Automated Work Zone Information System on Urban Freeway Rehabilitation
Authors: Lee Eul-Bum , Kim Changmo
Published: May 2018

In October 2004, about 9 lane km of deteriorated truck lanes on Interstate 15 at Devore in Southern California was rebuilt during 18 days with extended one roadbed full-closures with the counterflow traffic system and 24-h construction operations. The project implemented the automated work zone information system (AWIS) to reduce peak hour delay during construction by changing road user's travel patterns and diverting traffic to detour routes. This paper describes the design, performance, and validation of AWIS with monitored traffic data before and during construction used. The AWIS was installed to provide road users with real-time travel information so that they could avoid traffic delays in the construction work zone (CWZ) corridor. Travel times through the CWZ were estimated from speed data and enhanced in two ways: ( a) portable and permanent changeable message signs on site and ( b) off-site (project website) implementation with travel time messages, traffic snapshots, and video streaming. AWIS travel time was estimated at 90% of actual travel times as measured by probe vehicles. The peak hour traffic demand through the CWZ was reduced by up to 18%, with significant volume increases to detour freeways. The AWIS operation contributed to a decrease in the maximum delay for weekday peak hours (from expected 90 min to measured 50 min on average during construction). The outcome of this study will help transportation agencies and practitioners efficiently design and operate AWIS for highway rehabilitation under high traffic volume.
Feasibility of Accelerated Pavement Testing to Evaluate Long-Term Performance of Raised Pavement Markers
Authors: Choubane Bouzid , Gokhale Salil , Fletcher Jim
Published: May 2018

Raised pavement markers (RPMs) are used to provide long-range nighttime guidance to drivers. The visibility of these markers lessens over time, and they must be replaced. Thus, many state departments of transportation test various markers to provide the most durable marker available. One of the most critical approaches is the field test whereby markers are subjected to a roadway environment for a specified time. Because of the durability of typical RPMs, several years of field testing may be required before a product is qualified for state roadways. To shorten the product evaluation period, the feasibility of using the heavy vehicle simulator (HVS) to perform accelerated wear and deterioration testing of raised pavement markers was investigated. The HVS allows for controlled application of realistic wheel loads to a pavement system, simulating long-term, in-service loading conditions. This paper summarizes the initial results of HVS testing on four types of RPMs with regard to degradation of both the physical structure of the element and its level of retroreflectivity. Preliminary accelerated testing indicated similar degradation patterns to field testing, thus showing the potential for HVS accelerated testing to simulate existing field tests. Further evaluation is required to understand better the correlation between accelerated testing and actual in-service degradation rates.
Regression Tree Models to Predict Winter Storm Costs
Authors: Adams Teresa M. , Juni Emil , Sproul Michael , Xu Lei
Published: May 2018

Winter maintenance can consume one-third or more of highway maintenance budgets. Tools for estimating winter maintenance costs can enhance allocation, accountability, and management of expenditures. Historical weather forecasts and associated maintenance resources are used to create statistical models to estimate county-level resources to fight a forecast snow or freezing rain event. County-level analysis allows for model refinement for slightly different business practices and areas small enough to assume uniform weather effects. The statistical models are organized as regression trees that accommodate variables for operation of winter maintenance, such as service level expectations, range of county size, and weekend and overtime events. The regression trees fit subsets of data to form families of multiple linear models. In this way, models can be refined for important categorical variables such as service level and county size. The models presented here estimate labor, equipment, and material resources required to fight a storm in counties having 87 to 1,460 lane mi to maintain. The models estimate resources, not cost. Accordingly, the models are independent of unit costs of labor, equipment, and material that change over time and vary from county to county. Unit costs for labor, material, and equipment at each county are needed to convert resource estimates to resource costs. Statewide or regional storm costs can be computed by summing county-level costs.
Whether Weather Matters to Traffic Demand, Traffic Safety, and Traffic Operations and Flow
Authors: Maze Thomas H. , Agarwal Manish , Burchett Garrett
Published: May 2018

Weather affects many aspects of transportation, but three dimensions of weather impact on highway traffic are predominant and measureable. Inclement weather affects traffic demand, traffic safety, and traffic flow relationships. Understanding these relationships will help highway agencies select better management strategies and create more efficient operating policies. For example, it was found that severe winter storms bring a higher risk of being involved in a crash by as much as 25 times–-much higher than the increased risk brought by behaviors that state governments already have placed sanctions against, such as speeding or drunk driving. Given the heightened risk of drivers’ involvement in a crash, highway agencies might wish to manage better and restrict use of highways during times of extreme weather, to reduce safety costs and costs associated with rescuing stranded and injured motorists in the worst weather conditions. However, the first step in managing the transportation systems to minimize the weather impact is to quantify its impact on traffic. This paper reviews the literature and recent research work conducted by the Center for Transportation Research and Education on the impact of weather on traffic demand, traffic safety, and traffic flow relationships. Included are new estimates of capacity and speed reduction due to rain, snow, fog, cold, and wind by weather intensity levels (e.g., snowfall rate per hour).
Backcalculation of Permanent Deformation Parameters Using Time Series Rut Data from In-Service Pavements
Authors: Salama Hassan K. , Chatti Karim , Haider Syed Waqar
Published: May 2018

Time series of rut data from 109 in-service pavement sections in the Long-Term Pavement Performance (LTPP) Special Pavement Study-1 (SPS-1) experiment were used to predict the permanent deformation parameters for the VESYS mechanistic–empirical rut model. This was accomplished by matching the rut performance curves versus time being matched for each section with a commercially available iterative solver. To ensure uniqueness of each section's permanent deformation parameters (PDPs), the transverse surface profiles were used to match the most likely contributions by layer according to the criteria proposed in the NCHRP Report 468. On average, the contribution to the total surface rutting from the various pavement layers was as follows: 57% from the asphalt concrete layer, 27% from the base layer, and 16% from the subgrade. These results confirmed that the contribution to the total rutting from asphalt concrete and base layers is important and needs to be included in any mechanistic–empirical design procedure.
Lifting Scheme Theory to Detect Road Surface Waveform Influencing Vehicle Vibration
Authors: Shirakawa Tatsuo , Kawamura Akira , Nakajima Shigenori , Kameyama Shuichi , Nakatsuji Takashi
Published: May 2018

Vehicle vibration is caused by road roughness. When wavelength and amplitude are at the same level and the road surface waveform is different, the vibration waveform can also be different. When vehicle–road interaction is strictly analyzed, it is necessary to divide the vehicle vibration data according to the type of road surface waveform. The lifting scheme theory, which is based on the wavelet transform, was used to consider the road surface waveform detection method, which is influenced by the unsprung mass vibration of a vehicle. The basis function used optimizes the shape corresponding to the analysis purpose, based on the spline function. This method can accurately monitor the unsprung mass vibration of a “convex” type waveform of high magnitude.
Comparison of Two Negative Binomial Regression Techniques in Developing Accident Prediction Models
Authors: El-Basyouny Karim , Sayed Tarek
Published: May 2018

There are several regression techniques to develop accident prediction models. Model development and subsequently the results are affected by the choice of regression technique. The objective of this paper is to compare two types of regression techniques: the traditional negative binomial (TNB) and the modified negative binomial (MNB). The TNB approach assumes that the shape parameter of the negative binomial distribution is fixed for all locations, while the MNB approach assumes that this shape parameter varies with the location's characteristics. The difference between the two approaches in terms of their goodness of fit and the identification and ranking of accident-prone locations is investigated. The study makes use of a sample of accident, volume, and geometric data corresponding to 392 arterial segments in British Columbia, Canada. Both models appear to fit the data well. However, the MNB approach provides a statistically significant improvement in model fit over the TNB approach. A total of 100 locations were identified as accident-prone by both approaches. A comparison between the ranks showed a close agreement in the general trend of ranking between the two models. While the MNB approach appears to fit the data better than the TNB approach, there was little difference in the results of the identification and ranking of accident-prone locations. This is likely due to the nature of the application and the data set used. The difference in results will depend on the extent to which deviant sites exist in the data set.
Modeling Demographic and Unobserved Heterogeneity in Air Passengers’ Sensitivity to Service Attributes in Itinerary Choice
Authors: Warburg Valdemar , Bhat Chandra , Adler Thomas
Published: May 2018

Modeling passengers’ flight choice behavior is valuable to understanding the increasingly competitive airline market and predicting air travel demand. Standard and mixed-multinomial logit models of itinerary choice for business travel are estimated on the basis of a stated preference survey conducted in 2001. The results suggest that observed demographic- and trip-related differences are incorrectly manifested as unobserved heterogeneity in a random-coefficient mixed logit model that ignores the demographic- and trip-related characteristics of travelers. Among demographics, gender and income level have the most noticeable effects on sensitivity to service attributes in itinerary choice behavior, but membership in a frequent flyer program, employment status, travel frequency, and group travel also emerge as important determinants. However, residual heterogeneity is significant because of unobserved factors, even after accommodating sensitivity variations due to demographic- and trip-related factors. Consequently, substitution rates for each service attribute show substantial variations in the willingness to pay among observationally identical business passengers.
Econometric Analysis of U.S. Airline Flight Delays with Time-of-Day Effects
Authors: Hsiao Chieh-Yu , Hansen Mark
Published: May 2018

An econometric model of average daily delay is formulated and estimated to analyze flight delay in the U.S. domestic system. The model considers the effects of arrival queuing, volume, terminal weather, en route weather, seasonal effects, and secular effects. In particular, the time-of-day effects of arrival queuing, the effects of scheduled arrivals, and the interaction between scheduled arrivals and weather conditions are investigated. The estimation results suggest that ( a) queuing has a greater delay impact in the morning than in the afternoon or evening (one unit of morning queuing delay causes about three times as much average daily delay as one unit of evening queuing delay), ( b) scheduled arrivals–-both alone and in interaction with weather conditions–-significantly affect average delay, and ( c) 31% of the total delay increase between early 2004 and early 2005 can be attributed to traffic growth.
Scenario-Based Management of Air Traffic Flow
Authors: Liu Pei-Chen Barry , Hansen Mark , Mukherjee Avijit
Published: May 2018

Recent studies of the single-airport ground-holding problem use static or dynamic optimization to manage uncertainty about future airport capacities. Scenario trees of airport capacity profiles provide the basis for formulating multistage recourse problems. In this paper, methodologies are presented for generating scenario trees from empirical data, and the performance of scenario-based models is examined with the scenario trees. Most U.S. airports have capacity profiles that can be classified into some nominal scenarios, and for many airports, these scenarios can be naturally combined into scenario trees. The delay costs yielded from using dynamic optimization are consistently and considerably lower than from static optimization. The results illustrate the benefit of the wait-and-see strategy in a real-world setting and suggest the need for further research on implementing scenario-based dynamic strategies.
Evaluation of Test Equipment for Determination of Fine Aggregate Specific Gravity and Absorption
Authors: Cross Stephen A. , Mgonella Msengi K. , Jakatimath Yatish
Published: May 2018

Concern has been expressed about the repeatability of the current AASHTO T 84 method for determination of fine aggregate specific gravity. Two new methods are available for determining bulk specific gravity and absorption of fine aggregates: the AggPlus system using the CoreLok device and the SSDetect system. In addition, a new automated Langley de-airing device is available for AASHTO T 84. The objectives of this study were (a) to evaluate the reproducibility of SSDetect, CoreLok, AASHTO T 84, and AASHTO T 84 with the Langley de-airing device and (b) to determine if either of the new systems would produce results statistically similar to those produced by the current AASHTO T 84 procedure. The AASHTO procedure, when used with the Langley de-airing device, gave similar results to AASHTO T 84 but with reduced variability. The SSDetect procedure produced the highest bulk specific gravity and lowest percent absorption followed by the CoreLok and AASHTO T 84 procedures. There was no significant difference in apparent specific gravity values. Increasing the cure time for the SSDetect procedure resulted in increased saturated surface dry mass.
Permanent Deformation in Flexible Pavements with Unbound Base Courses
Authors: Huurman Rien , Molenaar André A. A.
Published: May 2018

Permanent deformation of the unbound base and subbase layer of a flexible pavement is one of the damage types that can require extensive maintenance. To be able to predict the development of permanent deformation, two options can be considered. The first is the development of models that allow the prediction of permanent deformation as a function of the applied stresses, the number of load repetitions, and the material characteristics and moisture regime. The second is the determination of stress conditions at which no significant permanent deformations develop. Such a stress level is, of course, dependent on the material characteristics, the degree of compaction, and the moisture content. The development of such a “shake down limit” for unbound base materials made of mixtures of recycled concrete and masonry is the topic of this paper. It has been found that the allowable ratio of applied vertical stress at a given confining stress level and the vertical stress at failure at that same confinement level depend to some extent on the composition of the mixture of crushed concrete and crushed masonry but mainly on the degree of compaction; ratios between 0.45 and 0.61 were found. Furthermore, it was possible to estimate the parameters controlling the resilient, as well as the failure behavior from physical parameters such as gradation, mixture composition, angularity of the particles, and the degree of compaction. The relationships indicate that performance-related specifications for the materials as investigated still can be based on well-known parameters that can easily be assessed in a short period of time and at a low cost.
Selection of Optimum Gravel Aggregate Size to Resist Permanent Deformation in Hot-Mix Asphalt
Authors: Bhasin Amit , Button Joe W. , Chowdhury Arif , Masad Eyad
Published: May 2018

Siliceous river gravels form a significant fraction of the different types of aggregates used in the construction of hot-mix asphalt (HMA) pavements. Even after gravel particles are crushed into smaller-size fractions, a significant proportion of the larger-size fractions retain their original shape and surface texture. As a result, HMA with a larger nominal maximum aggregate size (NMAS) has a higher percentage of rounded and low-angularity particles, which might make it more susceptible to rutting. Using a smaller NMAS may decrease the percentage of rounded and angular aggregates in the mix, but potentially at the expense of loss in shear strength of the mix. This study evaluated the effect of increasing aggregate angularity by decreasing NMAS on the rutting potential of HMA mixes containing siliceous gravels. Nine mix designs composed of three different NMASs and siliceous aggregates from three different sources were included in this study. The percentage of rounded and angular aggregates in each mix was quantified using image analysis and crushed-face count. The rutting potential of HMA mixes was assessed on the basis of Hamburg, dynamic modulus, flow time, and flow number tests. Results verify that a decrease in NMAS results in a decrease in the percentage of rounded and angular aggregates. However, rutting performance improves initially with a decrease in NMAS but then decreases; this indicates an optimum size that maximizes the rut resistance of HMA with siliceous aggregates. Results from this study are especially useful in selecting an optimum aggregate size for HMA mixes in locations where river gravels are the main source of locally available aggregates.
Georgia's Use of Cement-Stabilized Reclaimed Base in Full-Depth Reclamation
Authors: Lewis Dwane E. , Jared David M. , Torres Helga , Mathews Monzy
Published: May 2018

The Georgia Department of Transportation (GDOT) has obtained favorable results from the initial use of cement-stabilized reclaimed base (CSRB) in a pilot full-depth reclamation (FDR) in rural southeast Georgia. CSRB is produced when portland cement is added to sand–clay base from an FDR, and it is used to underlie hot-mix asphalt. GDOT initiated its first FDR in 2004 on County Road (CR) 52 in Long County. A 4.8-km corridor of CR 52 was overlain with a 12.5-mm Superpave® mix, including a 1.8-km section reconstructed with FDR. Samples of the in situ sand–clay base and pavement were obtained for a mix design to determine if these materials would react satisfactorily with portland cement. With the same laboratory design strength requirement for a soil–cement base, the desired level of unconfined compressive strength was obtained at 6% cement. A provisional specification for CSRB was developed, and a 152-m trial section of 12.5-mm mix over CSRB was constructed in July 2004. Construction procedures were adjusted after the trial section was placed, and the remainder of the FDR and overlay was completed. Construction costs for the 1.8-km FDR section were reduced 42% using FDR. Falling weight deflectometer readings taken after construction indicated that deflections were significantly lower in the FDR section than in the overlay-only section. The road is performing well after nearly 1 year of use. GDOT is considering development of a permanent specification for CSRB on non–state routes.
Evaluating Safety Effects of Daylight Savings Time on Fatal and Nonfatal Injury Crashes in Texas
Authors: Stevens Charles R. , Lord Dominique
Published: May 2018

Daylight savings time (DST) takes place each year from 2:00 a.m. on the first Sunday in April to 2:00 a.m. on the last Sunday in October. It is expected that the changes to and from DST could positively or negatively affect safety. In fact, previous research has shown that these changes indeed affect safety, but many studies suffered from methodological limitations, including erroneously extrapolating short-term effects to long-term conditions. Given these limitations and contradictory results, there is a need to reexamine the effects of DST on the number of motor vehicle and pedestrian crashes. The primary objective of this study was to quantify the safety effects of DST through the use of statistical modeling for the morning and afternoon 5-h periods at the boundary delimiting dark and light conditions. The secondary objective consisted of conducting a before-and-after study to estimate the immediate effects following the change to and from DST. To quantify the potential safety effects of DST, model outputs were applied to different hypothetical time intervals during the year, including the newly proposed DST extension by the U.S. Congress. The results of the study showed that the statistical models performed as expected, with the exception of one model, with which the number of crashes decreased with an increasing proportion of daylight conditions in the 5-h period. The application of the models to different scenarios showed that the absolute difference in predicted crashes was relatively small between scenarios, a finding that supported previous work on this topic.
Value of Traffic Externalities from Attribute-Based Stated Choice
Authors: Parumog Michelle , Mizokami Shoshi , Kakimoto Ryuji
Published: May 2018

The increasing rate of motorization in major urban centers in Asia is having severe impacts on local social and physical environments. Sustainability principles call for consideration of these traffic impacts, which include congestion, air and noise pollution, road safety, and urban decay, in the evaluation of urban development programs and projects. This study aims to contribute to the scarce literature on valuing nonmonetary external costs of traffic in developing countries through the attribute-based stated choice method measuring willingness to pay for route environment improvements. A web-based stated preference route choice survey was conducted regarding private work trips in metro Manila, Philippines, to value the welfare derived from changes in the quality of road and roadside environments. The authors estimated and compared values from specifications of fixed and random parameter logit. This study shows that estimates are sensitive to model specification, particularly if the attributes have significant preference heterogeneity and covariance. The values of significant attributes affecting utility, which include the value of percentage improvement in air quality, the value of percentage reduction in noise, and the risk value from a traffic fatality, are presented and compared.
Developing Bus Transfer Facilities for Maximum Transit Agency and Community Benefit
Authors: Volinski Joel , Page Oliver
Published: May 2018

Bus transfer centers are often regarded as undesirable neighbors. They are difficult to site, and it is difficult to gain support for them because of noise, exhaust, traffic congestion, and the presence of unwanted passengers. Locations for proposed major bus transfer activities are not only unwelcome, but some are probably not in the best interests of the surrounding development. However, many transit agencies are increasing acceptance and relevance of transit in their service areas by making transfer centers true community assets rather than nuisances. This often means finding a location that is right for both surrounding community and passengers, replacing rundown development with facilities that have exciting and inspiring architecture and design, and improving the pedestrian amenities and safety and security of the immediate area. Some communities have expanded the concept of bus transfer centers by using them as locations for vital health and human services and other conveniences that improve the quality of life for the residents. Others have used federal grants that provide opportunities for joint developments. Such developments could generate revenues that can be used for public improvements in the immediate area and that help to attract additional private investment and development where there once was blight. This paper highlights how four transit agencies used bus transfer centers not only to improve their images and community relations, but also to serve as catalysts for positive development in the surrounding areas.
Service Quality Certification in Brussels, Belgium
Authors: Liekendael Jean-Claude , Furth Peter G. , Muller Theo H. J.
Published: May 2018

European public transport operators, first in Paris and then in Brussels, Belgium, have developed a framework, a standard, and certification procedures for the management of service quality. Based on Averous's service quality cycle, this framework incorporates both customer satisfaction and performance evaluation with service standards and service indicators that are customer oriented yet objectively measurable. The development of this quality movement is documented, and its implementation in Brussels is used as a case study. There, the management contract provides financial incentives based on the percentage of passengers served by lines whose service quality has been certified, and the organization chart includes several managers responsible for service quality. The process of defining service targets is described with a framework that emphasizes extreme values and specification of both a base level and a level of un-acceptability that demands immediate action. Special attention is given to two methods of performance measurement: automatic processing of archived automatic vehicle location data and “mystery shopper” surveys. Improvements, organizational changes, and new programs developed in response to the quality process are described.
Implementation of Web-Based Electronic Data Management System
Authors: Yuan Jie , Fu Chien Nan , Raba Gary W.
Published: May 2018

A case study of the implementation of a web-based electronic data management system (EDMS) for the construction material quality assurance program of the State Highway 130 Turnpike project, a 49-mi design–build highway megaproject in Texas, is presented. EDMS consists of a set of web-enabled data management and engineering analysis tools that support the independent construction quality assurance firm's (CQAF's) functions in managing, reporting, and analyzing materials test data. The system currently supports 43 field and laboratory test procedures and enables CQAF staff to process effectively a large volume of test reports. Substantial efforts were extended to develop online information delivery functions to disseminate consistent test information among a broad constituency of users, including engineers, managers, technicians and inspectors, construction superintendents, material vendors, and designers, in a virtual real-time fashion. The system automatically tracks and monitors material-related deficiencies and summarizes out-of-specification test results accepted by CQAF engineers on the basis of engineering judgment. To facilitate the oversight roles of federal and state transportation agencies, the system electronically transmits test data to the state transportation agency within hours of test completion. Using statistical analysis functions embedded in the system, engineers are able to monitor material quality trends and deficiencies effectively. Through EDMS, the quality and efficiency of the CQAF in making acceptance decisions, tracking deficiencies and corrective actions, and ensuring that the materials and workmanship incorporated into the project are in compliance with the requirements of the project specifications are greatly enhanced.
Parking Management and Modeling of Car Park Patron Behavior in Underground Facilities
Authors: Caicedo Felix , Robuste Francesc , Lopez-Pita Andres
Published: May 2018

Underground parking facilities in urban areas or central business districts have incorporated many information and communications technologies to provide better service, to achieve customer satisfaction, and to improve parking management. But the diversity of the off-street parking supply in terms of parking access and revenue control systems, the information offered, costs, and benefits suggests that the efficiencies of certain improvements in parking facility operations and the ultimate profitability obtained as a result of the corresponding investment made by the parking operator need to be compared. The present investigation focuses on the operations of and the behavior of parking patrons in underground parking facilities, a common type of facility in Barcelona, Spain. To model patron behavior, commonly known desegregated models based on the random utility theory were adapted to facilitate an understanding of how parking patrons decide to use a particular garage level and determine their preferences for a particular garage level. The decisions made depend on the accuracy and the convenience of the information offered. The study finds that an intelligent parking management system that tells a customer the exact locations of the available spaces is of great benefit to patrons and in the long run is a cost-effective alternative to operators because the operator can achieve financial profitability with small increases in the parking rate, and in competitive environments patrons will prefer facilities with these systems over others. The conclusions presented in this paper will be particularly useful to planners, developers, and managers.
Cost-Effectiveness of Access to Nonemergency Medical Transportation
Authors: Wallace Richard , Hughes-Cromwick Paul , Mull Hillary
Published: May 2018

Although a lack of access to nonemergency medical transportation (NEMT) is a barrier to health care, national transportation and health care surveys and data sets have not comprehensively addressed this link. The current study builds on earlier work that identified and described the population that lacks access to health care because of transportation barriers by examining the combined transportation and health care impacts of providing access to NEMT for those who currently lack such access. The goal of this study was to compare the costs and benefits, including the potentially large net health benefits, of providing NEMT to those who lack access to it. This analysis uses data from the Medical Expenditure Panel Survey, which is administered by the Agency for Healthcare Research and Quality; the National Transit Database; and data provided by selected NEMT providers, as well as the transportation and health care literature. By a focus on 12 prevalent and costly medical conditions experienced by those who lack access to NEMT, it was determined that the provision of NEMT to those who currently lack it results in a net cost savings across the transportation and health care domains for four of these conditions (prenatal care, asthma, heart disease, and diabetes) and is cost-effective for the remaining eight conditions (influenza vaccinations, breast cancer screening, colorectal cancer screening, dental care, chronic obstructive pulmonary disease, hypertension, depression, and end-stage renal disease). These cost-effectiveness analyses take into account increased life expectancy and improved quality of life and indicate that the provision of additional transportation is worth the investment for these eight conditions. On the basis of these findings, it was concluded that the provision of NEMT to those transportation-disadvantaged individuals who lack access to it would result in net societal benefits for all 12 conditions examined.
Negotiating “Tax Peace”
Authors: Bailey Linda , Khan Sakina , Prince Ryan
Published: May 2018

Tribal fuel sales to tribal members are exempt from state fuel taxes under the current interpretation of federal law; the exemption can make it difficult for states to track tribal fuel sales because they typically track fuel upon taxation. FHWA has an interest because state fuel sales reports serve as a baseline for federal apportionments, and incomplete reporting could introduce bias. In addition to reporting concerns, states are under public pressure to ensure that tribal fuel retailers do not gain competitive advantage by selling fuel without the tax applied. Tribes, for their part, carefully guard their sovereignty on this issue, although many tribes still lack statutes governing tribal fuel taxation. This study investigated agreements on reporting and taxation between states and tribes, including recent legal cases, and developed a typology of agreement types. Researchers obtained input from tribal and state representatives in 12 states, most of whom reported resolution of fuel tax issues through one of three types of agreements. Under the most common type of agreement, tribes purchase fuel within the state's taxation system and receive refunds of the estimated revenue from tribal member purchases. Under the second most common type of agreement, tribes assess a fuel tax directly on distributors and report sales to the state. In general, tribes and states were positive about the agreements, saying they had contributed to increased cooperation between states and tribes, supported economic development on tribal lands by providing a revenue source for tribes, and created an equal taxation environment for the state.
Voyage of the SS Minivan
Authors: Goddard Tara B. , Handy Susan L. , Cao Xinyu , Mokhtarian Patricia L.
Published: May 2018

Numerous studies have examined the interactions between travel behavior and neighborhood design. However, little thought is given specifically to gender differences. Although sex is considered a possible independent variable in most multivariate statistical analyses, few studies focus primarily on travel behavior by gender as it is influenced by neighborhood design. Even fewer studies have examined the differences in travel behavior among women by neighborhood type. Naturally, women are not a homogeneous group and are characterized by a variety of preferences, needs, perceptions, and behaviors. This study uses a survey of residents of eight neighborhoods in Northern California. The survey collected data on their travel behavior as well as both their preferences for and their perceptions of neighborhood characteristics. The main questions that this study addresses are as follows: Are there gender differences in travel behavior? If so, what are the causes and the effects? Are there differences among women by neighborhood type, life cycle stage, presence of children, and so forth? The findings point to some significant differences for and among women, particularly not only by both the social and the infrastructure aspects of safety but also by neighborhood type (suburban versus traditional neighborhood) and the presence of children.
Asset Service Index as Integration Mechanism for Civil Infrastructure
Authors: Falls Lynne Cowe , Haas Ralph , Tighe Susan
Published: May 2018

One of the challenges in asset management is the integration of asset categories in the decision-making process. Asset management frameworks provide a structure to manage separate categories, and integration is assumed through database design. “Silo” management systems such as pavement and bridge management systems have parallel components that include all major elements of the classic asset management system, yet there is no integration of the results of each component system at the decision-making or expert system stage of the process. Senior decision makers are presented with the outputs of each component system and can clearly see the top priorities for each asset category; however, there is no mechanism for producing a single program list that has been developed with cross-optimization techniques. Trying to establish a multiyear priority program is difficult because of the number of asset categories, the different performance models used by each asset, and the challenges of multilevel optimization. This paper explores the links between silo systems and proposes an integration mechanism for cross optimization that recognizes the unique characteristics of individual asset categories.
Development and Implementation of Highway Structures Information System for Wisconsin Department of Transportation
Authors: Becker Scot M. , McDaniel W. Travis , Baeverstad Eric
Published: May 2018

The philosophy on highway structure asset management has evolved over the past two decades at the Wisconsin Department of Transportation (DOT) and required a new system approach to data management and modeling. The Highway Structures Information (HSI) system was developed to meet such needs. HSI is a systematic approach to effectively managing all state and locally maintained structures through a responsive, efficient online system. When state and local program managers are equipped with real-time performance data, they can make better-informed decisions on resource allocation. In addition, HSI is a valuable resource to contractors, consultants, and DOT management teams as well as a response system for inquiries from legislators, public citizens, and the media. An extensive menu system provides an easy method for users to inquire about specific data and create their own customized reports. This provides instantaneous responses to requestors and eliminates their waiting in line for bridge personnel to generate answers to queries. HSI also incorporates the concept of the structural data life cycle; this allows management of the structure from the planning phase through design, construction, maintenance, and eventual replacement of the structure. This paper presents Wisconsin DOT's development of this system. It explores what work is needed to develop a more complete asset management system and some benefits encountered during the process.
Correlating Chip Seal Performance and Construction Methods
Authors: Gransberg Douglas D.
Published: May 2018

A survey of U.S. public highway and road agencies that use chip seals as a part of their roadway maintenance program was developed and conducted as a part of NCHRP Synthesis of Highway Practice 342. Ninety-two individual responses from across the United States, Canada, and overseas were received. This paper seeks to correlate individual chip seal performance ratings with the construction practices reported to achieve those ratings. It finds a number of strong correlations. The most important is that the ambient air temperature specification is generally higher [average of 60°F (15°C)] for those respondents reporting excellent or good chip seal performance. The same trend was observed with the average amount of time before full-speed traffic was allowed to traverse a newly sealed road, with the best performing seals having an average wait period 28 h. Finally, respondents reporting the best performing seals used more preseal preparation measures and more detailed traffic control measures. The same respondents validated the success of their construction procedures by not requiring a fog or scrub seal to be placed on a freshly chip sealed road.
Viscosity Determination of Hot-Poured Bituminous Sealants
Authors: Al-Qadi Imad L. , Fini Eli H. , Elseifi Mostafa A. , Masson J.-F. , McGhee Kevin M.
Published: May 2018

Hot-poured bituminous sealants are typically selected on the basis of empirical standard tests such as penetration, resilience, flow, and bond to cement concrete briquettes (ASTM D3405). Yet there is no indication of the pertinence of these standard tests to predict field performance. To bridge the gap between sealant fundamental properties and field performance, performance-based guidelines for selection of hot-poured crack sealants are currently being developed. A procedure to measure sealant viscosity is proposed as part of that effort. Using a sealant with an appropriate consistency at the recommended installation temperature would provide a better crack filling and would ensure appropriate bond strength. Therefore, to ensure that sealant–crack wall adhesion is achieved and that the sealant penetrates hot-mix asphalt during installation, a testing procedure for bituminous-based crack sealant viscosity at installation temperature is suggested. This paper proposes use of a rotational viscometer to measure viscosity of hot-poured crack sealant materials. From results of this study, the measured viscosity of hot-poured crack sealant using a SC4-27 spindle at 60 rpm at the recommended installation temperature is reasonably representative of sealant viscosity at shear rates resembling field application. To ensure measurement consistency and stability, a 20-min melting time and 30-s waiting time before data collection are recommended. Repeatability of measurements was acceptable, with an average coefficient of variation of less than 5%. Variability between operators and variability between sealant samples were acceptable.