bluuebunny/crossref_metadata_2025 huggingface dataset:
Designing Today's Urban Arterials
Authors: Dock Frederick C. , Zimmer Charleen , Becker Stacy , Abadi Fred
Published: May 2018

The recent design for the reconstruction of Lake Street in Minneapolis, Minnesota, provides the canvas for an illustration of the challenges in delivering a context-sensitive project within the center of a city where a dense built environment already exists. Lake Street's reconstruction involves a county-initiated design, the city's and the community's response, and the participation of a foundation in achieving a design linked to how the community can grow and prosper and how people interact with one another. A street is an integral part of community life. Its design can hinder or support a community. The Lake Street design process shows that this understanding, along with best intentions, is not always enough. Strong institutional biases and conventions drive street design processes toward traffic-moving outcomes and away from community-building outcomes. These biases can be countered only with deliberate forethought and persistent attention and action. This paper attempts to provide insights into how community goals and street design processes become misaligned. Through a case study approach reviewing a current design, it also offers strategies showing how future street design processes must be more than an act of engineering. Good street design is an act of community planning, with engineering expertise helping to execute those plans. Once those involved in street design processes begin to recognize this, the approach will be different, the discussions will be different, and above all, the outcomes will be different.
Context-Sensitive Urban Transportation Design in West Philadelphia, Pennsylvania
Authors: Casello Jeffrey M. , Wright Robert M. , Vuchic Vukan R.
Published: May 2018

The University of Pennsylvania is located in Philadelphia, Pennsylvania. Activities within the campus are supported by a host of transportation modes: private automobile, commercial vehicles, public transportation (including bus, light rail, heavy rail, and commuter rail), bicycling, and walking. In an effort to enhance the overall functioning of the transportation system in the campus area, the university has partnered with the City of Philadelphia to improve the design and operation of facilities. This paper describes those efforts, emphasizing the jurisdictional and institutional challenges. The principal objectives of the campus redesign are to increase pedestrian and bicycle safety, to upgrade transit image and performance, to maintain or increase vehicular capacity, and to accommodate the reliable movement of goods. The achievement of these objectives is complicated by several issues. The campus is traversed by State Highway 3, portions of which were designed to standards that are inconsistent with the campus goals. Design and operational considerations are influenced by the access needs of the university hospitals. Institutionally, challenges arise from within the university community, particularly on questions of parking, and from within the public agencies, with regard to modern traffic engineering practices. Efforts to achieve the transportation goals can be considered a work in progress. Several positive design and operational upgrades have been successfully implemented; and these, in turn, have established new acceptable design criteria. Other design projects remain in the evaluation phase. Several policy actions or statements require attention. The lessons learned and technical standards developed are transferable to other older cities throughout North America.
Development of Internet-Based Traffic Simulation Framework for Transportation Education and Training
Authors: Liao Chen-Fu , Morris Ted , Donath Max
Published: May 2018

Many traffic simulation software packages are available to help traffic engineers and researchers study and evaluate the potential impact of proposed traffic management strategies and policies. However, the existing tools require a significant investment in time to learn how to create models, perform calibrations, and, finally, analyze the results. This substantial learning curve severely restricts their application and makes it difficult for engineering students, the general public, and policy makers to take advantage of these tools. An Internet-based traffic simulation framework was developed to enhance the learning experience for transportation students and engineers. Pregenerated traffic scenarios were first implemented as part of an undergraduate civil engineering class. An interactive simulation tool was developed to allow users to make changes to the model and examine the impacts on traffic. This now allows students, for example, to minimize the queue length at the traffic signal by changing the cycle length or splits. This interactive traffic simulation tool was deployed and tested in an undergraduate class of 73 students. Feedback was collected from the instructors and the students and will lead to additional enhancements of the laboratory module. This web-based traffic simulation framework can also incorporate larger road networks that allow one to consider a multiplicity of traffic management strategies, thus providing a valuable tool for educating and training transportation professionals.
Need for Culvert Asset Management
Authors: Perrin Joseph , Dwivedi Rajesh
Published: May 2018

Through Governmental Accounting Standards Board Statement No. 34 (GASB 34), departments of transportation (DOTs) are required to track their infrastructure costs and conditions through asset management practices. GASB 34 is applied primarily to roadways and bridges; access and inspection of that visible infrastructure are comparatively easy. However, underground culvert infrastructure is also a critical component in asset management. With the growing problem of culvert deterioration across the country, it is important to consider these underground assets in the inventory and inspection process. As part of this report, all 50 U.S. state DOTs were sent a survey concerning culvert asset management issues. The resulting 28 responses identified that several states are working toward developing an inventory database and planning to implement an inspection program. Many are not yet considering applying asset management practices to their culvert infrastructure. Several agencies did identify failure as a primary reason for developing the inventory and inspection programs. Because culvert failures are often the motivation for agencies to respond, some recent failure examples are reviewed. Previous research recommended a national tracking of culvert failures to understand the risks and costs better. This paper builds on that idea and identifies the benefits of culvert asset management. These benefits include up-to-date inventory, reduced failures through regular inspection, reduced emergency repair costs and unplanned financial burden, better budget planning for repair and replacement, and long-term ability to identify actual life cycle and performance of various pipe materials.
Transportation Asset Management in For-Credit Higher Education Course Offerings
Authors: Bittner Jason
Published: May 2018

Transportation asset management is a systematic process of operating, maintaining, and upgrading transportation facilities cost-effectively. It combines engineering and mathematical analyses with business practice and economic theory. Asset management systems are goal driven and include components for data collection, strategy evaluation, program selection, and feedback. The asset management model explicitly addresses integration of decisions made across all program areas. The purpose is simple: to maximize the benefits of a transportation program to its customers and users, on the basis of well-defined goals within available resources. This concept is emerging prominently in several state and local transportation agencies. In 2005 a study was commissioned by the Michigan Asset Management Council and the FHWA to develop a thorough catalog of existing training opportunities in the field of transportation asset management. Part of that effort included an analysis of university-based courses or programs reflecting the elements of transportation asset management. This paper reflects the university-level analysis and presents nine common elements among the various courses embracing the current state of the practice in transportation asset management. The final part of this analysis compares the National Highway Institute's (NHI) professional development–training short course modules with the common elements of the university-based programs. It is contended that there are gaps in the information presented in existing university courses and the NHI-sponsored effort. That may complicate the adoption of transportation asset management.
Implementing the European Transport Information System
Authors: Ballis Athanasios
Published: May 2018

The development of the Trans-European Networks and the formulation of a common transport policy are essential elements in the economic and social development of the European Union. Such activities require significant information about current status (passenger and freight transport volumes, congestion, environmental impacts, etc.) and reliable forecasts. The relevant information exists in dispersed, heterogeneous, and autonomous databases throughout Europe, as well as in pertinent transport studies. The European Transport Information System under development is intended to support decisions on transport policies and the Trans-European Transport Networks by accommodating policy-related information in a repository that will be kept up-to-date through well-defined procedures under the control of experts and will be accessible through an Internet-based software tool. A hierarchical structure of criteria, subcriteria, indicators, and variables is used to link policy questions to relevant data sets, which are populated by collected data and statistics or alternatively by data generated through the use of models. The scope of this current work is to give an overview of the structure, functionality, and current content (data sets, variables, indicators, etc.) of the information system above.
Matching Hourly, Daily, and Monthly Traffic Patterns to Estimate Missing Volume Data
Authors: Zhong Ming , Sharma Satish
Published: May 2018

Missing values are an important issue for traffic data programs and lead to difficulties in data analyses and application. Previous research accurately imputed missing hourly volumes of a range from a few days up to one and a half weeks for various types of traffic counts. However, imputation errors of the applied hourly models increase dramatically after some reliable imputing periods; this indicates their limitations in real applications. Therefore, this study investigates pattern-matching algorithms to fill large missing data intervals. The algorithms use historical data to develop a series of candidate patterns and compare them to patterns with missing data. Data from the best-fit pattern is then used to estimate the missing data. The algorithms show improved accuracy over traditional models used in practice and prove suitable to impute missing hourly, daily, and monthly traffic volume data.
ITS Devices Used to Collect Truck Data for Performance Benchmarks
Authors: McCormack Edward , Hallenbeck Mark E.
Published: May 2018

This paper documents the development of data collection methodologies that can be used to measure truck movements along specific roadway corridors in Washington State cost-effectively. The intent of this study was to design and test methodologies that could provide information to ascertain the performance of freight mobility roadway improvement projects. The benchmarks created would be used to report on speed and volume improvements that resulted from completed roadway projects. One technology tested consisted of Commercial Vehicle Information System and Networks electronic truck transponders, which were mounted on the windshields of approximately 30,000 trucks traveling in Washington. These transponders were used at weigh stations across the state to improve the efficiency of truck regulatory compliance checks. With transponder reads from sites anywhere in the state being linked through software, the transponder-equipped trucks can become a travel time probe fleet. The second technology tested involved Global Positioning Systems (GPS) placed in volunteer trucks to collect specific truck movement data at 5-s intervals. GPS data made it possible to locate when and where monitored trucks experienced congestion. With this information aggregated over time, it was possible to generate performance statistics related to the reliability of truck trips and even to examine changes in route choice for trips between high-volume origin–destination pairs. The study found that both data collection technologies could be useful; however, the key to either technology is whether enough instrumented vehicles pass over the roadways for which data are required.
Freight-Specific Data Derived from Intelligent Transportation Systems
Authors: Srour F. Jordan , Newton Diane
Published: May 2018

Freight planning is an increasingly visible topic in the arena of transportation planning. Freight planning metrics and benchmarks can help state agencies select and assess the impact of improvement projects with respect to freight mobility. Given the unique patterns of freight flow, freight metrics are most valuable when derived from freight-specific data. Extraction of timely freight-specific data to support freight planning efforts is not, however, always straightforward. Washington State, the primary focus of this study, has been developing potential methodologies for extracting and applying freight-specific data in benchmarking freight projects. The Freight Mobility Strategic Investment Board (FMSIB) of Washington State deployed intelligent transportation systems (ITS) technologies [Global Positioning Systems (GPS) and automated vehicle identification (AVI)] with the stated goal of collecting freight-specific data. An examination of the data collected for the FMSIB benchmarking test reveals that both sources of data—GPS and AVI—can support the freight planning process. This paper highlights results of the FMSIB study, the comparative accuracy of the two data sources, and the uses of each for planning purposes.
Establishment-Based Survey of Urban Commercial Vehicle Movements in Alberta, Canada
Authors: Hunt J. D. , Stefan K. J. , Brownlee A. T.
Published: May 2018

This paper describes a project to develop a more complete understanding of the nature of urban commercial vehicle movements in the Calgary and Edmonton regions, the two principal urban regions in the province of Alberta, Canada, each with a population near 1 million. It covers the design and implementation of the survey and an overview of the results. Slightly more than 3,000 business establishments in the Calgary region and 4,300 business establishments in the Edmonton region were interviewed concerning the commercial movements that they generated on an assigned survey day. The surveys were performed in fall 2000 in the Calgary region and in fall 2001 through spring 2002 in the Edmonton region. The survey was done to obtain indications of the full range of commodities being transported, including goods and services, together with descriptions of the associated person and vehicle movements arising with this transportation activity. The establishment-based process used was analogous to the household-based approach used in personal travel surveys. Results show that in the two regions commercial vehicle movements are an important component of all vehicle movements on a typical weekday—representing about 12% of vehicle distance traveled. There are more movements for services than there are for goods and more by light commercial vehicles (passenger cars, vans, and pickup trucks) than by heavier vehicles. About 30% of all commercial stops in a typical weekday are for service deliveries, compared with about 25% of stops for transportation and handling services.
Enhanced Bridge Replacement Cost Models for Indiana's Bridge Management System
Authors: Rodriguez Marcela M. , Labi Samuel , Li Zongzhi
Published: May 2018

Bridge managers have a duty to monitor and update the costs of bridge preservation activities and to implement cost-effective actions that are in the best interests of taxpayers. This paper presents details of replacement cost modeling for each bridge component (superstructure, substructure, approach, and other costs) for bridges with concrete slab, concrete beam, or steel superstructures. This was done with recent bridge construction data on the Indiana state highway network. It was determined that costs other than substructure and superstructure costs accounted for more than one-half of total replacement cost. The present study supports earlier studies by asserting that basic bridge characteristics such as type, length, and deck area may generally be used to derive reliable estimates of bridge replacement costs. The study also shows that economies of scale can play a significant role in reliable bridge cost estimation. It was determined that the average overall unit cost of replacement for steel superstructure bridges was generally lower than that for concrete superstructure bridges. It was seen that differences in replacement costs across bridge types are attributable not necessarily to cost differences in material and construction procedure only but also to economy-of-scale effects. Cost models can be used to predict total costs of future bridge replacements and are therefore useful for vital bridge management functions such as needs assessments, budgeting, and programming.
Impact of Increasing Roadway Construction Standards on Life-Cycle Costs of Local Residential Streets
Authors: Titus-Glover Leslie , Hein David , Rao Shreenath , Smith Kelly L.
Published: May 2018

With increasing damage due to the combination of increasing traffic load applications, adverse climate, and increasing frequency of trench cutting and patching associated with utility work, residential streets are requiring more frequent, extensive, and costly maintenance and rehabilitation (M&R) to maintain adequate levels of serviceability during pavement design life. Increased cost of M&R and eventual reconstruction are an added burden on already limited city budgets. To rectify this situation, city managers and engineers are looking at enhancing current structural design standards for residential streets to increase their load-carrying capacity. With an increase in load-carrying capacity, it is hoped that frequency of M&R will be reduced and the design life of such pavements will be extended. However, adopting a higher design standard has significant cost implications. The question then becomes, Will the expected increase in initial cost be offset by the significant decrease in M&R costs and corresponding increase in pavement life that will delay eventual reconstruction? The Minnesota Department of Transportation (DOT), on behalf of the Local Road Research Board, initiated a study to evaluate the impact of enhancing residential street pavement design standards to accommodate greater axle loads on life-cycle costs. The primary focus was to compare the life-cycle costs of residential streets designed using Minnesota DOT's 5- to 7-ton and 9- to 10-ton design standards. The study concluded that life-cycle cost for the 5- to 7-ton and 9- to 10-ton design standards was not significantly different at the 95% significance level.
Viscoelastic Model to Describe Mechanical Response of Bituminous Sealants at Low Temperature
Authors: Elseifi Mostafa A. , Dessouky Samer H. , Al-Qadi Imad L. , Yang Shih-Hsien
Published: May 2018

To establish a clear understanding of the behavior of hot-poured bituminous-based crack sealants at low service temperature and to predict their field performance, the constitutive stress–strain relationship must be described. The description of this relationship would allow accurate prediction of crack sealants’ field responses to thermal and traffic loading. The objective of this paper is to describe crack sealant constitutive behavior at low temperature by linear viscoelastic modeling (Prony series expansion). The suggested model was fitted to creep measurements obtained from a modified bending beam rheometer test setup. The experimental program included testing of three soft crack sealants having a relatively high level of polymer modification content at a temperature ranging from −28°C to −40°C. A Prony series expansion was fitted to the experimental results. To determine the time-dependent responses of crack sealants to a constant creep load, the fitted material parameters were incorporated into a three-dimensional finite element model. Measured and calculated deflections were in good agreement. This finding suggests that the constitutive behavior of crack sealants can be accurately described by the linear viscoelastic regime at low service temperatures.
Automated Adaptive Traffic Corridor Control Using Reinforcement Learning
Authors: Jacob Celine , Abdulhai Baher
Published: May 2018

Advancements in intelligent transportation systems and communication technology could considerably reduce delay and congestion through an array of networkwide traffic control and management strategies. The two most promising control tools for freeway corridors are traffic-responsive ramp metering and dynamic traffic diversion using variable message signs (VMSs). The use of these control methods independently could limit their usefulness. Therefore, integrated corridor control by using ramp metering and VMS diversion simultaneously could be beneficial. Administration of freeways and adjacent arterials often falls under different jurisdictional authorities. Lack of coordination among those authorities caused by lack of means for information exchange or “institutional gridlock” could hinder the full potential of technically possible integrated control. Fully automating corridor control could alleviate this problem. Research was conducted to develop a self-learning adaptive integrated freeway–arterial corridor control for both recurring and nonrecurring congestion. Reinforcement learning, an artificial intelligence method for machine learning, is used to provide a single, multiple, or integrated optimal control agent for a freeway or freeway–arterial corridor for both recurrent and nonrecurrent congestion. The microsimulation tool Paramics, which has been used to train and evaluate the agent in an offline mode within a simulated environment, is described. Results from various simulation case studies in the Toronto, Canada, area are encouraging and have demonstrated the effectiveness and superiority of the technique.
Set of New Traffic-Responsive Ramp-Metering Algorithms and Microscopic Simulation Results
Authors: Sun Xiaotian , Horowitz Roberto
Published: May 2018

A novel switching traffic-responsive ramp-metering controller adapts to different traffic dynamics under different congestion conditions: free-flow or congested. The approach of multirate linear quadratic control with integral action is used to compensate for disturbances and to accommodate the difference between the model sampling time and the metering-rate update interval. In addition, a queue length regulator is designed to prevent the queue from exceeding the ramp storage capacity and yield improved performance over the current ad hoc queue override scheme. Subsequently, a queue length estimator is designed to provide feedback to the queue length regulator with the queue-detector speed data that are available in the field. A local ramp-metering control strategy is proposed to achieve the control goal of reducing the spatial and temporal span of the congestion, while satisfying the on-ramp storage capacity constraints, by using locally available information. Test results on a calibrated microscopic traffic simulator demonstrate the performance and effectiveness of the switching ramp-metering controller, the queue length estimator and regulator, and the overall control strategy. The total vehicle and passenger congestion delays are both reduced by 16%, and the total travel time is improved by 5.6%. As a comparison, simulation results of ALINEA are also presented.
Validating Dynamic Message Sign Freeway Travel Time Messages with Ground Truth Geospatial Data
Authors: Monsere Christopher M. , Breakstone Aaron , Bertini Robert L. , Deeter Dean , McGill Galen
Published: May 2018

U.S. transportation agencies have invested more than $300 million in dynamic message sign (DMS) systems for communicating important messages to travelers, including weather conditions, incidents, construction, and homeland security and AMBER alerts. Recent FHWA policy encourages states to use their DMS infrastructure more effectively by displaying reliable travel-time information along freeway corridors. The Oregon Department of Transportation (ODOT), which maintains a freeway surveillance system in the Portland metropolitan area, calculates and reports travel-time estimates derived from inductive loop detector data. These estimates can be reported via 18 DMS and other traveler information systems but are displayed on a limited basis at key junction points during peak periods. Results are presented of an evaluation of ODOT's travel-time reporting capabilities by comparing the ODOT travel-time estimates with probe vehicle (ground truth) travel times. The freeway network was divided into 17 key corridors, and 87 probe vehicle runs were collected under various traffic conditions with handheld Global Positioning System devices. This evaluation used the regional transportation data archive, Portland Regional Transportation Archive Listing, to generate the ODOT travel-time estimates. Probe estimates were compared to travel estimates on the corridors with a paired t-test. The evaluation found that travel times on a majority of links were reasonably accurate under most traffic conditions but were affected by the presence of an incident or by poor detector placement.
Estimation of Incident Delay and Its Uncertainty on Freeway Networks
Authors: Li Jibing , Lan Chang-Jen , Gu Xiaojun
Published: May 2018

Estimating incident-induced delay on freeways is important for measuring the impacts of incidents. Information regarding delay can be used for transportation planning or the assessment of traffic improvement projects. Traditional delay estimation methods cannot account for the stochastic attributes of dynamic traffic networks. Introducing the incident duration model and the reduced capacity model into the traditional deterministic queuing model allows researchers to understand better the stochastic characteristics of dynamic networks and to develop a new stochastic incident-induced delay model. The mean delay, the variance of delay, and the expected total delay are estimated on the basis of the proposed model. The analysis shows that the deterministic queuing model can estimate the mean delay as well as the stochastic delay model, but it seriously underestimates the variance of delay and the expected total delay in dynamic networks, which are found to be dominated by incident duration. In addition, depending on the parameter values in the probability distribution of incident duration and reduced capacity, the standard deviation of delay can be higher than the mean delay.
Transportation and Emergency Services
Authors: Shepherd Kristen E. , Baird Malcolm E. , Abkowitz Mark , Wegmann Fred
Published: May 2018

Transportation and emergency services agencies have many shared and overlapping responsibilities in myriad situations, ranging from routine traffic incidents to large-scale events that threaten public health and safety. The importance of effective coordination among these groups is heightened by the need to improve highway operations, ensure homeland security, and enhance all-hazards emergency management. Research was done to identify and evaluate the underlying obstacles and opportunities for improving coordination among highway transportation and emergency services organizations. Institutional, operational, technological, and financial factors were considered. Most findings and conclusions are based on a survey administered to transportation and emergency services professionals in five states. On the basis of the survey results and subsequent focus group discussions, recommendations are offered for short-term improvement of emergency transportation operations and for additional research.
Amber Alert and Major Catastrophe Messages on Dynamic Message Signs
Authors: Ullman Brooke R. , Dudek Conrad L. , Trout Nada D.
Published: May 2018

The Texas Department of Transportation wanted to expand its dynamic message sign (DMS) design and display manual to include information related to Amber alerts and specific major catastrophes. Focus groups were conducted in six Texas cities to obtain initial responses from drivers concerning information needs and to help develop messages for further study. In Amber alert situations, there was no consensus as to which descriptor would best convey that a child had been abducted. The descriptors “Amber alert,” “kidnapped,” and “abducted” implied a sense of danger or urgency that would be appropriate to the situation. Additionally, participants were not able to recall license plate or phone numbers easily after having viewed a message for 8 s. Participants were split as to whether they would continue to drive if the message “flooded” were displayed on a DMS. The consensus of those who would continue driving was that the message should include information regarding the location of the flooding or an exit to take. Also, no consensus was found for a term describing this situation, although “flooded” was used in messages designed by five of the six groups. For both hurricanes and terrorist attacks, the information needs identified far exceed what can be accommodated via DMS. However, the information needs cited provide valuable insight into the perspectives of motorists during evacuation and disaster situations. This information should be considered along with situational perspective and engineering judgment to determine how it could be used for an event.
Video Incident Detection Tests in Freeway Tunnels
Authors: Prevedouros Panos D. , Ji Xiaojin (Jerry) , Papandreou Konstantinos , Kopelias Pantelis , Vegiri Vily
Published: May 2018

European regulations for the management of roadway tunnels became much more stringent after the 1999 Mount Blanc inferno. Several video image processing (VIP) devices for traffic surveillance have automated incident detection (AID) capabilities. Autoscope, Citilog, and Traficon were invited to make installations for testing their VIPs with eight preexisting cameras in Attica Tollway tunnels. The suppliers of the competing devices were responsible for setting and calibrating the devices for best results. No literature was found in which VIPs developed in 2000 or later were evaluated for incident detection. A 3,013-incident database was used to derive the detection rate and false-alarm rate for each device for the whole database, separately for each closed-circuit television camera, and by type of incident. Changes in detection performance after each manufacturer's intervention were evaluated. T-tests were conducted on the significance of effects of low, medium, and high volume in weekday and weekend traffic, and natural or artificial lighting. A separate analysis was conducted for incidents that were artificially generated by Attica Tollway engineers and staff at off-peak times. The results show promise, but the evaluated performance was poor because of three reasons: low maturity of the technology, complex algorithms due to the provision of extensive functionality, and suboptimal camera location and height for image processing, but VIP devices must adapt to tunnel limitations.
Using Real-Life Dual-Loop Detector Data to Develop New Methodology for Estimating Freeway Travel Time Reliability
Authors: Emam Emam B. , Al-Deek Haitham
Published: May 2018

Travel time reliability is an important system performance measure for freeway traffic operations. It captures the variability experienced by individual travelers, and it is an indicator of the operational consistency of a facility over an extended period. Real-life transportation data were used to develop a new methodology for estimating travel time reliability of the I-4 corridor in Orlando, Florida. Four different travel time distributions were tested: Weibull, exponential, lognormal, and normal. The developed best-fit statistical distribution (lognormal) can be used to compute and predict travel time reliability of freeway corridors and report this information in real time to the public through traffic management centers. When compared with existing Florida and buffer time methods, the new reliability method showed higher sensitivity to geographical locations, which reflects the level of congestion and bottlenecks. Another advantage of the new method is its ability to estimate the travel time reliability as a function of departure time.
Operational Effect of Single-Occupant Hybrid Vehicles in High-Occupancy Vehicle Lanes
Authors: Breiland Christopher , Chu Lianyu , Benouar Hamed
Published: May 2018

In an effort to reduce the environmental impact of automobile travel, legislatures across the country are considering laws that would allow single-occupant hybrid vehicles to use high-occupancy vehicle (HOV) lanes. In time, single-occupant hybrid vehicles could increase congestion in HOV lanes such that the travel time incentive would be lost. A microscopic simulation method is presented; it examines the possible effects of a proposed California state hybrid HOV law that would allow single-occupant hybrid vehicles into the state's HOV network. The results from a 12-by-16-mi freeway network being simulated around Irvine, California, under several travel demand scenarios show that the policy would not have a significant effect on HOV lane operations in the study area. Although the addition of single-occupant hybrids may have only a modest impact on short-run HOV lane operations, policy implementation opens the door to more difficult long-term policy questions.
Safety Evaluation of Buffer-Separated High-Occupancy Vehicle Lanes in Texas
Authors: Cooner Scott A. , Ranft Stephen E.
Published: May 2018

In Texas, high-occupancy vehicle (HOV) lanes are an integral part of urban mobility. Although an extensive system of permanent HOV lanes is planned for the Dallas–Fort Worth area, the Texas Department of Transportation and Dallas Area Rapid Transit have implemented interim HOV lanes by retrofitting them into existing freeways. Safety is examined for Dallas's buffer-separated concurrent-flow HOV lanes, which were implemented by lane widths being reduced and by the inside shoulder being converted to an HOV lane on I-35 East and I-635. Injury crash data from each corridor were analyzed on the basis of crash rates, frequency trends, and manually reviewing police reports. The analysis considered the impact of design elements, including buffer width, shoulder presence, and lane width. Operationally, the analysis considered the impact of speed differential between the HOV and general purpose lanes. This evaluation resulted in three key findings: (a) both corridors had an increase in crash rates after implementation of the HOV lane, (b) the increase in crashes is primarily focused on the HOV lane and the first adjacent general purpose lane, and (c) the increase in crashes is primarily attributed to the speed differential between the HOV and the general purpose lanes and the reduced HOV cross section. The recommendation, based on these findings, is to provide greater width for the total HOV cross section (inside shoulder + HOV lane + painted buffer) than that provided in the two interim corridors. An absolute minimum of 18 ft between the freeway barrier and the general purpose lanes may mitigate many types of crashes that occur because of the speed differential, with full inside shoulders being the desirable cross section.
Financing Local Roads
Authors: Forkenbrock David J.
Published: May 2018

Local governments are changing the ways that they finance streets and roads. As the motor fuel tax becomes less productive, the states and the federal government have been devolving the responsibility for financing these vital facilities to local governments, which in turn have relied on general fund revenue and have increasingly adopted local option taxes. Generally, these local taxes have no direct relationship to actual road use and thus tend to be inequitable and inefficient. Without policy innovations, the dependence on non-use-related financing of local roads will increase as new vehicle propulsion systems such as electric hybrids and hydrogen fuel cells penetrate the market. Several possible policy directions to increase the role of direct road user charges are evaluated. A mileage-based user charge is found to have considerable potential both as a financing mechanism and as a means for implementing road pricing. Among the policies that can be supported are congestion pricing, privately operated tollways, use of environmentally friendly vehicles, and improved travel demand analyses. Above all, more of the financing burden for local roads can be shifted from those paying property and sales taxes to actual users of the roads within a community.
Minimum Income Guarantee in Transportation Infrastructure Concessions in Chile
Authors: Vassallo José Manuel , Soliño Antonio Sánchez
Published: May 2018

Many governments are increasing private participation in providing and financing transportation infrastructure through concession contracts. One of the main challenges in the definition of those contracts is the correct allocation of risks between the public and the private sectors. Traffic risk has usually been difficult to allocate because neither the concessionaire nor the government can reasonably control it. In addition, traffic forecasts have proved to be inaccurate. Consequently, many governments are implementing traffic risk mitigation mechanisms in concession contracts. One of these mechanisms is based on the establishment by the government of a minimum income guarantee. Results of the implementation of a minimum income guarantee in Chile are presented: 38 transportation concessions were awarded in the past 12 years. The economic crisis that struck Chile from 1998 to 2002, reducing traffic levels below forecasts, makes the analysis of the performance of that mechanism particularly interesting. Despite the economic crisis, the implementation of a minimum income guarantee in Chile worked well because it encouraged private participation and was not very costly for the government. However, that mechanism did not reduce renegotiation pressures from concessions’ shareholders as a consequence of the crisis.
Sharing the Wealth
Authors: Loveless Shirley M.
Published: May 2018

Economic development benefits are often cited as a justification for transportation investments. For a variety of reasons, federal transportation funds go mainly to large, regional-scale projects with identified regional economic benefits. Local benefits to low-income communities—when they exist—are usually incidental. The transportation and economic development needs of such communities generally get overlooked in transportation project planning. This may lead to distributive inequity. A review of state- and regional-level transportation programs found few that target transportation investments to local economic development in disadvantaged communities, either in effect or in stated purpose. The Transportation and Community Development Initiative (TCDI) program administered by the Delaware Valley Regional Planning Commission (DVRPC) is one of the small number of such programs. While the DVRPC's municipal eligibility criteria for the TCDI now go beyond strictly disadvantaged communities to serve other goals such as regional growth management, the intended economic development benefits are still aimed primarily at disadvantaged communities. This program can point to some impressive results in local economic revitalization of disadvantaged neighborhoods that probably would not have occurred without the impetus the TCDI provided. On balance, the TCDI program is a good model for integrating transportation and economic development planning for the purpose of reviving disadvantaged communities. However, even TCDI's emphasis on revitalization of such communities is no guarantee that their inhabitants will benefit from economic development that might be generated by the program's projects.
Highway-Induced Development
Authors: Gunasekera Kumudu , Anderson William , Lakshmanan T. R.
Published: May 2018

When transport investments are made in newly industrializing regions that are relatively infrastructure poor, the consequences extend beyond growth effects to some transformational changes. Induced transformation implies an emergence of a new socioeconomic market with new opportunities; this results in a change in the pattern of behavioral relationships within and among households, that is, with shifts in occupation, income, health, and education levels. This paper attempts to capture wider socioeconomic transformations induced by a highway improvement project in Sri Lanka. Specifically, it captures transformational changes in individual household structure with the use of two models: the income effect model and the demand function model. These models provide evidence of a shift in individual households’ incomes, consumption patterns, and underlying factors influencing their earning potentials—a shift toward occupations that are less land intensive and less labor intensive, and a shift toward skilled employment. The value of this research lies in the empirical estimation of the direction and magnitude of some of the consequent transformational changes as they pertain to Sri Lanka's household sector. In light of the observed results, it is likely that traditional infrastructure impact studies, by failing to incorporate transformational shifts, significantly underestimate project benefits and costs.
Evaluation of Combined Traffic Impacts of Time-of-Day Pricing Program and E-ZPass Usage on New Jersey Turnpike
Authors: Ozbay Kaan , Yanmaz-Tuzel Ozlem , Holguín-Veras José
Published: May 2018

The traffic impacts of two stages of the New Jersey Turnpike (NJTPK) time-of-day pricing program are studied. The annual and daily traffic trends indicate that demand has continued to increase, exhibiting a similar behavior before and after the time-of-day pricing initiative. Combined with NJTPK traveler survey analysis, the findings demonstrate a statistically insignificant shift to other modes and routes after the time-of-day pricing initiative. Traffic impact analysis on the basis of aggregate data shows a slight shift to off-peak periods after the first stage and to peak periods after the second stage. However, because of a lack of detailed traffic and travel time data, reliable conclusions cannot be drawn from this aggregate analysis. Disaggregate analysis is then conducted, using traffic and travel time information for each origin–destination (O-D) pair of NJTPK between October 2002 and March 2003, 3 months before and 3 months after the initiation of the second stage. Findings show 53% of E-ZPass users preferred peak periods with lower travel times and higher tolls instead of peak shoulders with higher travel times but lower tolls. For most of the highly used O-D pairs, E-ZPass traffic at periods with the highest travel time has decreased after the second stage of the time-of-day pricing program. However, this reduction is statistically insignificant. Given the small price differential between peak and off-peak periods, it is likely that NJTPK E-ZPass users are trying to avoid congestion rather than slightly higher tolls. The results are assessed, and the findings are compared with those of similar studies.
Evaluation of Impacts of Time-of-Day Pricing Initiative on Car and Truck Traffic
Authors: Ozbay Kaan , Yanmaz-Tuzel Ozlem , Holguín-Veras José
Published: May 2018

The traffic impacts of the time-of-day pricing program initiated by the Port Authority of New York and New Jersey (PANYNJ) on March 25, 2001, are analyzed. The analyses are based on the traffic data routinely collected at all toll lanes by PANYNJ. Since terrorist attacks at the World Trade Center disrupted the transportation network and made it impossible to isolate and analyze user reaction to the PANYNJ toll prices, only the period before the events of September 11, 2001, was considered. The research has confirmed a statistically significant shift toward prepeaks, in both mornings (5 to 6 a.m.) and afternoons (3 to 4 p.m.), in car traffic percentage share after the time-of-day pricing. Also, weekday truck traffic percentage share showed a statistically significant shift to morning prepeak (5 to 6 a.m.) and afternoon postpeak hours (7 to 8 p.m.). However, weekend car and truck traffic percentage shares did not have statistically significant changes during peak shoulder hours (11 a.m. to 2 p.m. and 8 to 9 p.m.). These findings indicated that PANYNJ time-of-day pricing initiative was successful in spreading weekday peak period traffic to the hours just before or after the peak toll rates are in effect, mainly for passenger cars. As observed from descriptive analysis of commercial surveys, however, even though PANYNJ time-of-day pricing gives truckers an incentive to shift their travel periods, it is not the only factor affecting the truckers’ travel pattern.
Feasibility of Truck-Only Toll Lane Network in Atlanta, Georgia
Authors: Meyer Michael D. , Saben Larry , Shephard Whitney , Steavens Erik
Published: May 2018

Many U.S. metropolitan areas are expecting significant growth in the amount of truck travel on their road networks. For those areas, such as Atlanta, Georgia, where the region experiences not only substantial truck movements internal to the region but also large numbers of through truck trips, this growth presents a significant challenge. A proof-of-concept analysis was undertaken in Atlanta to examine the likely impacts of various truck-only toll (TOT) lane strategies for the regional freeway network. Three strategies are examined: building new lanes along major truck corridors, allowing trucks to use existing high-occupancy vehicle (HOV) lanes inside the central area, and turning all proposed HOV lanes in the region into TOT lanes. The analysis of these strategies is presented, and the conclusion is that turning proposed HOV lanes into TOT lanes provides the greatest transportation benefit to the region.