bluuebunny/crossref_metadata_2025 huggingface dataset:
Control of Superpave Gyratory Compactor's Internal Angle of Gyration
Authors: Romero Pedro , Pradhan Murari M. , Niederhauser Steve , Biel Tim
Published: May 2018

The State of Utah Department of Transportation started a program to use the dynamic angle validator (DAV) to measure the internal angle of all Superpave® gyratory compactors (SGCs) used in the construction of hot-mix asphalt in the state. Results show that differences in internal angle exist unless the compactors are calibrated regularly and technicians are trained in laboratory procedures. Once the program was in place, the internal angle of 36 of the 46 SGCs tested was within the limits of 1.16° ± 0.03°. However, seven SGCs, all of one model, had angles between 0.860° and 1.212°, with an average angle of 1.026° even after calibration. If the limits are narrowed to 1.16° ± 0.02°, then only 28 of 46 (60%) of the SGCs will be within the range. Results also show that it is possible to obtain acceptable density values on specimens compacted using machines that have internal angles outside the proposed range. It was concluded that the internal angle limits of 1.16° ± 0.03° were too restrictive for the machines and types of mixes used in the state of Utah. It was recommended that the equipment be calibrated often, that molds be checked for cleanliness and dents, and that temperature measuring devices be verified. When large differences in measured properties of compacted samples remain even after repeated calibration, the internal angle should be verified because it was noted that external calibration did not always correct the internal angle. That will help reduce conflict between state labs and consultants.
Design of a Specific Bituminous Surfacing for the World's Highest Orthotropic Steel Deck Bridge
Authors: Héritier Bernard , Olard François , Loup Frédéric , Krafft Serge
Published: May 2018

This paper presents a rational approach for the performance-based design of bituminous wearing surfacings on orthogonally anisotropic steel bridges. The behavior of bituminous surfacings on steel orthotropic decks under heavy truck traffic and environmental conditions is highly complex. Both the geometry of the structure and the high flexibility of metallic plates make the deformations and stresses severe in steel bridge surfacings. In particular, the repeated loading makes the fatigue strength an important parameter for the design of such bituminous wearing courses. In addition, these specific surfacings must have durability over the expected temperature range, and they must be resistant to thermal cracking at low temperatures and to rutting at high temperatures. The technical studies that were conducted in parallel with the construction of the Millau Viaduct (France)–-the world's highest bridge–-have provided in particular the opportunity for progress in the development of appropriate laboratory testing equipment and of an original polymer-modified surfacing. A comprehensive research program, including both a large laboratory testing campaign and a finite element parametric study, was performed to develop a useful tool for the design of plate surfacings.
Performance Evaluation of Hot-Mix Asphalt Using Rotary Loaded-Wheel Testing
Authors: Buchanan M. Shane , Smith Benjamin J.
Published: May 2018

Permanent deformation and moisture damage (i.e., rutting and stripping) are two predominant hot-mix asphalt (HMA) distresses. Rutting can be caused by many factors, including stripping, which result in reduced HMA shear strength. Hot-mix asphalt stripping evaluation is a source of significant industry discussion and debate. Transportation agencies use a number of methods to evaluate stripping, with many methods customized depending on local concerns and environmental conditions. Today, many agencies use some type of loaded-wheel testing, with associated mix “pass–fail” criteria, as part of the mix design acceptance procedure. This process is often referred to as “proof” testing and provides a higher confidence that the HMA mix will perform satisfactorily during service conditions. A new device, the rotary wheel tester, has been developed to evaluate the rutting and stripping performance of HMA mixes. This device operates on a principle similar to that of the Hamburg wheel tester: the main difference is that the specimen is loaded along its diameter instead of from the top. The cost of the rotary wheel tester is less than half that of the Hamburg wheel tester. Testing was conducted to determine whether the rotary wheel tester could distinguish between good- and poor-performing mixes and to determine whether PG 76-22 or PG 67-22 plus hydrated lime improved mix performance. Results indicate that the rotary wheel tester is an easy-to-use testing device that appears to provide reasonable prediction of the rutting and stripping performance of HMA mixes. It also appears that PG 76-22 asphalt binder improves mix performance to a greater extent than does PG 67-22 plus hydrated lime.
Application of the Dissipated Energy Concept in Fatigue Endurance Limit Testing
Authors: Shen Shihui , Carpenter Samuel H.
Published: May 2018

A fatigue endurance limit has been postulated to exist in hot-mix asphalt pavement performance. It cannot be observed and studied with the use of traditional phenomenological approaches as seen by the totally different fatigue behavior at low strain–damage levels close to the fatigue endurance limit. The ratio of dissipated energy change succeeds in defining and investigating the existence of a fatigue endurance limit with a unique relationship between plateau value (PV) and fatigue life (Nf), regardless of strain–damage levels, mixture types, loading modes, and other testing conditions. To determine a fatigue endurance limit requires an extraordinarily long time to conduct testing. This paper applied the PV to the study of a fatigue endurance limit to validate a shortened laboratory testing procedure. Statistical analysis shows that the shortened test can predict the PV with sufficient accuracy. By applying the validated relationship between PV and Nf, the extremely long fatigue life under low strain–damage condition can be predicted without performing millions of loading cycles.
Evaluation of the Gradation Effect on the Dynamic Modulus
Authors: Birgisson Bjorn , Roque Reynaldo
Published: May 2018

The importance of aggregate characteristics has been emphasized in the Superpave® asphalt mixture design procedure. However, criteria for guidelines for the selection of suitable aggregate gradations–-other than gradation limits for different nominal maximum size aggregate blends, including the restricted zone–-have been neglected. With the move toward mechanistic–empirical pavement design, the dynamic modulus is used to account for mixture properties in the pavement design. It is of significant importance to mix designers to possess a framework for determining how to optimize a mixture for ensuring an adequate dynamic modulus. This paper presents the results from a study of the effects of gradation characteristics on the dynamic modulus. Power law–based gradation factors are obtained for 13 aggregate gradations (coarse and fine graded) composed of limestone and granite aggregates. These gradation factors were used to identify and evaluate relationships between gradation factors and the dynamic modulus at higher temperature (40°C). Subsequently, a tentative framework was established for optimizing mixture gradations for dynamic modulus values. Findings illustrate that gradation factors based on power law parameters can be used to optimize mixture gradations for key mixture properties, such as the dynamic modulus. Results also demonstrate the critical nature of aggregate gradation in achieving desired mixture properties.
Practical Procedure for Developing Dynamic Modulus Master Curves for Pavement Structural Design
Authors: Bonaquist Ramon , Christensen Donald W.
Published: May 2018

A dynamic modulus master curve for asphalt concrete is a critical input for flexible pavement design in the mechanistic–empirical pavement design guide developed in NCHRP Project 1–37A. The recommended testing to develop the modulus master curve is presented in AASHTO Provisional Standard TP62–03, Standard Method of Test for Determining Dynamic Modulus of Hot-Mix Asphalt Concrete Mixtures. It includes testing at least two replicate specimens at five temperatures between 14°F and 130°F (–10°C and 54.4°C) and six loading rates between 0.1 and 25 Hz. The master curve and shift factors are then developed from this database of 60 measured moduli using numerical optimization. The testing requires substantial effort, and there is much overlap in the measured data, which is not needed when numerical methods are used to perform the time–temperature shifting for the master curve. This paper presents an alternative to the testing sequence specified in AASHTO TP62–03. It requires testing at only three temperatures between 40°F and 115°F (4.4°C and 46.1°C) and four rates of loading between 0.01 and 10 Hz. An analysis of data collected using the two approaches shows that comparable master curves are obtained. This alternative testing sequence can be used in conjunction with the simple performance test system developed in NCHRP Project 9–29 to develop master curves for structural design.
Application of Discrete Element Modeling Techniques to Predict the Complex Modulus of Asphalt–Aggregate Hollow Cylinders Subjected to Internal Pressure
Authors: You Zhanping , Buttlar William G.
Published: May 2018

An extension of the discrete element modeling (DEM) approach, or clustered DEM, was used to simulate the hollow cylinder tensile (HCT) test, in which various material phases (e.g., aggregates, mastic) are modeled with bonded clusters of discrete elements. The basic principle of the HCT test is the application of internal pressure to the inner cavity of a hollow cylinder specimen, which produces circumferential strain. In the present study an experimental program was conducted to measure the complex modulus of asphalt concrete mixtures at various loading rates and temperatures. The HCT test was then modeled with a two-dimensional, linear elastic DEM simulation. The current approach uses the correspondence principle to bridge between the elastic simulation and viscoelastic response. The two-dimensional morphology of the asphalt concrete mixture was captured with a high-resolution scanner, enhanced with image-processing techniques, and reconstructed into an assembly of discrete elements. The mixture complex moduli predicted in the HCT simulations were found to be in good agreement with experimental measurements across a range of test temperatures and loading frequencies for the coarse-grained mixtures investigated. Ongoing work in the area of viscoelastic constitutive modeling, fracture modeling, and three-dimensional tomography and modeling will extend the capabilities of this promising technique for fundamental studies of asphalt concrete and other particulate composites.
Using the Three-Stage Weibull Equation and Tree-Based Model to Characterize the Mix Fatigue Damage Process
Authors: Tsai Bor-Wen , Harvey John T. , Monismith Carl L.
Published: May 2018

The primary purpose of this paper is to demonstrate the applicability of the three-stage Weibull equation to describe the fatigue damage process using flexural controlled deformation fatigue tests. A data set of 179 beam fatigue tests originally designed for exploring the fatigue performance of conventional dense graded asphalt concrete (DGAC) and asphalt–rubber hot-mix gap-graded (ARHM-GG) mixes was used to inspect the three-stage Weibull parameters that were estimated using a genetic algorithm. The tree-based regression–category models were then used to uncover the data structure of the estimated parameters as a function of material properties, conditioning methods, temperatures, compaction methods, and strain levels. In general, the three-stage Weibull equation provides satisfactory fitting results for the three-stage fatigue damage process occurring in a beam test. It was found that the tree-based models of three-stage Weibull parameters associated with the crack initiation stage were statistically adequate and reliable compared with the models of parameters related to the warm-up stage and the crack propagation stage. It might suggest that these crack initiation parameters are better indexes to assess the fatigue performance.
Evaluation of the Effectiveness of Connection Protection in Improving Successful Light Rail–to-Bus Transfers
Authors: Jenq Jeffrey H. , Pierce Bennett , Pate Alan
Published: May 2018

The quantitative evaluation results of the nation's first light rail–to-bus connection protection (CP) system implemented by the Utah Transit Authority are presented. The CP system was designed to improve the reliability of transfers from the higher-frequency light rail TRAX trains to the lower-frequency bus services. The CP system examines the estimated arrival time of TRAX trains for the next three stations and issues a “hold at {station name} until {time}” message to buses waiting at the connecting rail stations, via the buses’ onboard mobile data terminals, if the lateness of trains is within a predetermined threshold (e.g., 3 min). The evaluation consisted of a quantitative analysis of the successful rail-to-bus connections with an analysis of the rail and bus operations data and a qualitative assessment of the perspectives and opinions of users based on individual experience (both riders and bus operators). The focus was the quantitative analysis that employed an unmatched with-and-without experimental design. Overall, the analysis results showed that CP did significantly increase the percentage of successful train-to-bus connections. Train riders meeting a bus trip when CP was active and a “hold until” message was issued to the bus operator were between 3.1 and 3.9 times more likely to have had a successful connection than were train riders meeting the same bus trips when CP was inactive, depending on the wait time assumption for a successful connection to take place.
Metro Service Delay Recovery
Authors: Schmöcker Jan-Dirk , Cooper Shoshana , Adeney William
Published: May 2018

This study was conducted to identify the strategies used by operators to provide a high level of service. The research distinguishes between punctuality and regularity of service and proposes that metro passengers primarily value regularity. The focus of this research is not on incident prevention, but on strategies that can be implemented after an incident to restore service swiftly and to minimize delay. The research identifies the recovery strategies used by six metros and summarizes advantages and disadvantages of these strategies. The influence of the type of delay on the choice of strategy is described. Similarly, the impact of constraints such as line length, service frequency, and passenger crowding on the effectiveness of each strategy is also discussed. It was found that it was generally sufficient to distinguish minor incidents, slow-moving delays, and major incidents. A case study shows that those metros with higher inbuilt flexibility can return more easily to normal service. This finding will have implications for metro management. The research has been carried out by the Railway Technology Strategy Centre at Imperial College London in collaboration with the Community of Metros benchmarking group. The performances and service qualities of six metros (three European, two American, and one Asian) have been analyzed and compared. The study consists of a quantitative analysis of the performance of two lines from each metro, together with a more qualitative assessment of the strategies used to optimize performance, through structured interviews with key operational and managerial staff.
Shared-Use Rail Corridors
Authors: Resor Randolph R. , Hickey T. R.
Published: May 2018

Many urban rail transit systems share a common transportation corridor or right-of-way with FRA-compliant freight or passenger trains. Existing federal railroad safety statutes do not specify requirements for this sort of application. As the mileage of shared-use corridors increases, there is increasing concern among federal and state regulators, railroads, and transit agencies about the potential for accidents that could stem from FRA-compliant and noncompliant rolling stock operating near each other in a shared-use corridor. This paper describes the extent and characteristics of shared-use corridors in the United States, derived from a recent survey undertaken on behalf of the FRA. The paper provides an overview of current practice in the design and operation of shared-use corridors and suggests a need for research leading to standardizations of practice to address potential safety and regulatory concerns.
Directly and Indirectly Reducing Visual Impact of Electric Railway Overhead Contact Systems
Authors: Boorse Jack W.
Published: May 2018

This paper discusses the visual impact of the overhead wiring, known more formally as an overhead contact system, that is an integral part of a light rail transit network. In situations in which this type of impact causes community concern, the traditional approach has been to employ design concepts that minimize the amount of visible electrical hardware that is installed. This is a valid and worthy objective, but there are additional ways to address this issue. This paper explores various components of a traction power distribution system, including contact wires, feeder cables, and supporting structures. It discusses past and current practices to make some of these components less intrusive and suggests additional methods that might be employed. It also suggests, in some situations, applying design concepts that would address the issue of visual impact in a different manner. The essence of this initiative is that the visible elements might be reconfigured into a form of street art so that their appearance would actually enhance the local environment. It suggests that the concept of art in transit, now largely oriented to station areas, might be expanded to include the traction power infrastructure along the entire line.
Analysis of Metro-Link Performance in Saint Louis, Missouri
Authors: Tennyson Edson L.
Published: May 2018

In 1946 St. Louis Public Service Company, Missouri, the eighth largest transit system in the United States, was a highly respected metropolitan operation. In 1993 the St. Louis transit system was no longer among the 30 largest systems. The precipitous decline paralleled a 61% decline in the city of St. Louis population, offset by only modest suburban population growth. In an effort to restore transit viability to the St. Louis metropolitan area, an 18-mi light rail transit line was inaugurated in 1993. Using abandoned railroad facilities, including a downtown tunnel and Mississippi River bridge, the new light rail line connected Lambert Airport in Missouri with East St. Louis, Illinois. The results were immediate and positive. Patronage exceeded comfortable car capacity. More cars were acquired. Voters in Illinois and Missouri approved funding to expand light rail 17 mi into Illinois and 8 mi into suburban Missouri. Transit use increased 40%. Light rail carried 49% of the region's transit passenger miles in only 25% of the area. The cost of service slowed its inexorable rise as light rail moved people for 25 cents per passenger mile, down from 51 cents by bus in 1993. With fewer trunk lines and more feeder routes, bus service costs increased to 80 cents per passenger mile. Casualties declined significantly. St. Louis again has a functional transit system.
Light Rail in Britain and France
Authors: Vigrass J. William , Smith Andrew K.
Published: May 2018

Great Britain and France have experienced a dramatic resurgence of light rail in the past two decades. Beginning in the early 1980s, following a 30-year abandonment of street railways in favor of motorbuses, cities in both countries developed new light rail transit systems as a response to declining transit ridership, faded downtowns in need of revitalization, and the high construction costs of heavy rail and metro. Britain and France have pursued greatly different approaches to the implementation of light rail. The purpose of this paper is to point out these differences and, through the use of case studies, draw conclusions as to the efficacy of each approach. A few cities in each country were studied with secondary sources. Commonality within each country was observed with great divergence between the two countries. In Britain, the requirements for light rail are onerous: a specific act of Parliament is needed for each new start. Each system must achieve full recovery of operating and maintenance costs and contribute toward capital investment while competing against unregulated buses. That some British systems have been built and successfully attract traffic is to the credit of their proponents. France has a more uniform approach published in government circulars. All French cities of substantial size must have a “versement transportes,” a 1% to 2% tax on salaries and wages dedicated to regulated and coordinated public transport. French new starts, which have no need to attain 100% cost recovery (the versement transportes covers operating losses), have been implemented in about half the time of those in Britain.
Learning from a Failed Innovation Process
Authors: van Zuylen Henk , Ouwehand Arlieneke
Published: May 2018

The technological and institutional innovation process in public transport is slow and difficult to control. Because many forces work on this process, predicting its outcomes is difficult. This was demonstrated in a project in Eindhoven, the Netherlands, where a pilot was prepared to demonstrate the potential of personal rapid transit. The pilot was part of an innovation process to lead to a more sustainable urban transport system. The guidelines of the bureau for sustainable technological development were followed to guarantee the long-term feasibility and effectiveness of the process. Although the process was designed carefully with concern for the predictable risks, the pilot had to be stopped because of unforeseen political problems. A change of policy priorities and key people caused the project's failure. In addition, strict regulations for tendering bids slowed the process and favored bidders without project knowledge. This paper analyzes the different risk factors and gives conclusions for improving chances for success in future similar innovation projects. Checklists provide a tool to make an ex ante analysis of an innovation project's feasibility and to give guidance for optimal conditions for success.
Doubling Personal Rapid Transit Capacity with Ridesharing
Authors: Johnson Robert E.
Published: May 2018

A new personal rapid transit (PRT) operating policy is specified; it can often double peak period capacity with moderate wait times. When a passenger selects a destination for a vehicle, the destination is displayed for all to see. Any waiting passenger going to the same destination can also board. However, vehicles are not delayed just to gather additional riders. Fares are charged per person, rather than per vehicle. If the passenger queue length happens to equal the number of destinations and all destinations are equally likely, it is shown that on average one extra passenger will board each vehicle and that vehicle occupancy and line capacity will approximately double. The average wait time in this case will be approximately N/(2R), where N is the number of destinations and R is the vehicle arrival rate at the origin station. A station layout that facilitates this ridesharing policy is presented, and security measures are described for strangers traveling together. Simulation results give occupancy values up to 18% higher than expected from a simple model. During peak periods with directional flows, passengers facing a long wait can choose to travel to a destination near their own with no passenger queue and from there immediately board a vehicle to continue to their original destination. This makes ridesharing feasible in relatively large PRT systems.
Accounting for the Impact of Heavy Truck Traffic in Volume–Delay Functions in Transportation Planning Models
Authors: Yun Seongsoon , White Wade W. , Lamb Daniel R. , Wu Yongqiang
Published: May 2018

Truck traffic accounts for a substantial fraction of the traffic stream in many regions and is often the source of localized traffic congestion. This paper presents the analysis and findings that recommend updated volume–delay relationships for transportation planning models that account for total volume, roadway capacity, and the mix of heavy truck traffic. The traditional Bureau of Public Roads function representing the speed–flow relationships for roadway facilities is modified to include the impact of truck traffic specifically. Several new speed–flow functions based on microsimulation results for freeways and urban arterials have been developed.
Making Household Microsimulation of Travel and Activities Accessible to Planners
Authors: Walker Joan L.
Published: May 2018

There is a large gap between the aggregate, trip-based models used by transportation planning agencies and the activity-based, microsimulation methods espoused by those at the forefront of research. The modeling environment presented here is intended to bridge this gap by providing a palatable way for planning agencies to move toward advanced methods. Three components to bridging the gap are emphasized: an incremental approach, a demonstration of clear gains, and a provision of an environment that eases initial implementation and allows for expansion. The modeling environment (called STEP2) is a household microsimulator, developed in TransCAD, that can be used to implement a four-step model as well as models with longer-term behavior and trip chaining. An implementation for southern Nevada is described, and comparisons are made with the region's aggregate four-step model. The models perform similarly in numerous ways. A key advantage to the microsimulator is that it provides impacts by socioeconomic group (essential for equity analysis) and individual trip movements (for use in a vehicle microsimulator). A sensitivity analysis indicates that the microsimulation model has less inelastic cross elasticity of transit demand with respect to auto travel times than the aggregate model (aggregation error). The trade-off is that microsimulators have simulation error; results are presented regarding the severity of this error. This work shows that a shift to microsimulation does not necessarily require substantial investment to achieve many of the benefits. One of the greatest advantages is a flexible environment that can expand to include additional sensitivity to demographics and transportation policy variables.
Philomath Couplet
Authors: Schwartz Marcy , Willis John , Erickson Bruce
Published: May 2018

Values associated with statewide freight and tourist mobility; traffic, pedestrian, and bicycle safety; and small-town livability create competing objectives that are difficult to balance when main streets of small towns are also state highways. Many communities opt for bypass solutions to these issues, but the Philomath Couplet Project represents a main street solution that is sensitive to both the demands of the state highway system and the character of the local community. The controversial 10-month decision process culminated in the selection of a preferred alternative. Final design is under way, and construction is scheduled for 2006. Although many projects are developed according to context-sensitive solution principles, the Philomath Couplet Project represents a class of projects with characteristics likely to be faced throughout the United States in relation to the management of state highways that are also main streets of small towns. The difficulties encountered in conducting this project provide important insights to guide context-sensitive solutions implementation in these circumstances. The lessons learned shared in this paper highlight the need to manage the “end game” of small-town politics, the value of time and cost constraints, the need for a structured decision process, and the usefulness of evaluation criteria based on interactions of land use and transportation.
Spatial Economic Model for Forecasting the Percentage Splits of External Trips on Highways Approaching Small Communities
Authors: Anderson Michael D.
Published: May 2018

The main difficulty in forecasting traffic volumes in small urban communities is identifying the amount and destination of the external traffic. Three methods exist for determining the percentage of external traffic destined for the study community (external–internal trips) or through the study community (external–external trips): a comprehensive origin–destination study, a cordon line origin–destination study, and the use of regression equations. This paper examines the possibility of the use of an alternative technique, based on a spatial economic model, to determine the traffic distribution. The project uses an economic model, which includes surrounding community factors, to determine the trip rates for three communities within Alabama and compares the results obtained from this model with the results given by a commonly accepted regression equation and a recently completed cordon line origin–destination study performed by using video surveillance. It is demonstrated that the economic model performs well for the case study cities, and this model is recommended for use in providing estimates that incorporate a community's economic relationship to neighboring towns for traffic forecasting.
Lagrangian Relaxation Heuristic for Selecting Interdependent Transportation Projects under Cost Uncertainty
Authors: Tao Xianding , Schonfeld Paul
Published: May 2018

The capital budgeting process for a transportation system is usually complicated by the interdependencies of projects and the uncertainty of project costs. The existence of project interdependence in transportation systems makes it difficult to evaluate the project effects with analytical methods. Furthermore, when the construction costs of candidate projects are uncertain, the budget constraints that bind project selection become chance constraints, and this may render most existing approaches inapplicable. This paper formulates the project selection problem as a nonlinear integer optimization problem whose objective function is implicit but can be evaluated with network simulation. The Lagrangian method is applied to relax the complex project constraints that are nonlinear under cost uncertainty. An efficient genetic algorithm is developed to solve the Lagrangian subproblems. This paper applies an equilibrium traffic assignment model to evaluate the project impacts and the objective values of the Lagrangian subproblems. Experiments are designed to test the performance of the developed approach on a fairly generic highway system. The experiment results show that the developed approach can effectively solve the problem of selecting interdependent projects under cost uncertainty.
Trade-Off for Road Pricing between Transportation Performance and Financial Feasibility
Authors: DeCorla-Souza Patrick
Published: May 2018

This study estimates the transportation performance and financial impacts of express toll (ET) lane and high-occupancy toll (HOT) lane concepts, with and without new bus rapid transit (BRT) service. Estimates are made for a prototypical suburban transportation corridor in a major metropolitan area with the use of the Spreadsheet Model for Induced Travel Estimation, Managed Lanes (SMITE-ML), which was enhanced to analyze the conventional build concept with no priced lanes. The analysis demonstrates that in a typical case a HOT alternative may mitigate congestion more cost-effectively than an ET alternative. Combining BRT with ET may make this alternative much more effective, perhaps more effective than a HOT alternative with no BRT. BRT increases the benefits and economic efficiency of both ET and HOT alternatives, but it reduces financial feasibility because of the need for public tax support for transit. ET alternatives tend to be more financially feasible than HOT alternatives primarily because of the additional revenues generated from tolls; under this alternative, HOVs are not exempt from tolls. These conclusions hold up for the case study corridor even under extreme assumptions with regard to demand elasticity and value of time.
Cost Functions and Efficiency Estimates of Midwest Bus Transit Systems
Authors: Harmatuck Donald J.
Published: May 2018

Short-run variable cost functions are estimated with the use of a sample of 68 bus systems in the U.S. Midwest operating in the 1996 to 2002 period. Variable costs are specified as functions of outputs, input prices, bus stocks, and network size. Various output, input price, network, capacity, and disturbance specifications are examined. The cost functions are estimated with the use of ordinary least squares, switching regression, seemingly unrelated regression, and stochastic frontier cost models. The results indicate constant returns with vehicle outputs, increasing returns with passenger outputs, inelastic input demands, and substantial technical efficiencies that vary by firm and by state.
Economic Activity and Transportation Access
Authors: Targa Felipe , Clifton Kelly J. , Mahmassani Hani S.
Published: May 2018

Several studies of transportation and economic development impacts have recognized the extent to which changes in accessibility triggered by transportation improvements may translate into business cost savings and contribute to a region's economic competitiveness. This paper specifies and empirically tests a general model that captures the intensity of business activity (at the zip code level) as a function of local and regional accessibility, agglomeration economies, and region-specific effects. The geographic area of analysis is a four-county region in Maryland. The econometric analysis establishes a significant association between transportation supply and business activity in the study area. The findings suggest a clear positive association between access to primary highway facilities and the level of economic activity. The results also confirm expectations that roads with higher functional form and capacity are likely to be spatially associated with a higher intensity of economic activity. The models described in the paper provide the basis for examining regional economic effects related to new transportation facilities.
Transportation Programs Linking to Economic Development
Authors: Gupta Manisha , Weisbrod Glen , Weiss Martin
Published: May 2018

This paper examines highway-related economic development programs operated by state transportation agencies. These programs have common features that reflect similar objectives, goals, selection criteria, and organizational needs. Some, however, employ distinctive, recommendable best practices: economic scoring processes, job tracking systems, and measurements of economic impact. A development model or set of guidelines that integrates these best practices may help decision makers explore and appraise transport infrastructure investments in a more systematic and effective manner.
Assessing the Time Lag between Transportation Investment and Economic Development by the Data Envelopment Approach
Authors: Alam Jobair B. , Sikder Saiyid H. , Goulias Konstadinos G.
Published: May 2018

Efficient allocation of resources is of paramount importance in building reliable and efficient transportation systems. This is particularly true because of the key role that transportation plays in the economic development of any region. Despite continuing efforts by economists, planners, and transportation system analysts to determine the relationship between transportation investment and economic development, the correlation is yet to be understood clearly. One of the most intriguing matters is the time lag between the two. Transportation investments have a complex, dynamic influence on economic systems. They generate both direct and indirect benefits, and they have short-term effects such as an increase in construction-related employment and an increase in markets for local goods and services, as well as longer-term effects such as the establishment of new industries that are attracted by increased access to local goods and services. The time lag between transportation investment and economic return significantly affects how the benefits of an investment are evaluated. This paper examines a framework for evaluation based on the data envelopment analysis technique that captures the dynamic relationship between transportation investment and economic development. In the analysis performed, a strong correlation was observed between the relative scarcity of transportation infrastructure, as compared with other input parameters in the production process, and a lag time between investment and the materialization of economic return. Short-, medium-, and long-term time lags were analyzed in the study, and it is suggested that current demand for increased accessibility is correlated with the dynamic characteristics of time lag with spatial variation.
Comparison of Second-Best and Third-Best Tolling Schemes on a Road Network
Authors: De Palma André , Kilani Moez , Lindsey Robin
Published: May 2018

Much of the road pricing literature has focused on deriving second-best optimal tolls when only parts of a network can be tolled or tolling is constrained in other ways. A drawback of second-best tolling is that it requires extensive information on speed–flow curves and demand elasticities throughout the network. Such information is often not readily available, and errors in estimating key parameters could result in tolls that are nonoptimal or even welfare reducing. The purpose of this paper is to explore a simpler alternative policy, dubbed “no-queue” tolling, whereby time-varying tolls are imposed selectively on a road network with the objective of eliminating queuing on the tolled links. No-queue tolling is an example of third-best pricing because the effects of the tolls on other links are disregarded. To explore the merits of no-queue tolling, a dynamic traffic simulator (METROPOLIS) was used to compute no-queue tolls for individual links and cordon rings on a laboratory network. For comparison, second-best flat and time-varying tolls were also computed on the same sets of links. Two results stood out. First, even without accounting for the likely computational and acceptability advantages of no-queue tolling, it appeared to dominate flat tolling and performed relatively well compared to step tolling. Second, the benefits from no-queue tolling exhibited approximately constant returns with respect to the number of links that are tolled. This suggests that no-queue tolling could fruitfully be selectively implemented now, rather than waiting a decade or more for comprehensive road pricing to become feasible.
Analysis of Time-of-Day Pricing Impacts at Port Authority of New York and New Jersey Facilities
Authors: Ozbay Kaan , Ozmen-Ertekin Dilruba , Yanmaz-Tuzel Ozlem , Holguín-Veras Jose
Published: May 2018

Time-of-day pricing policies provide lower toll rates during off-peak hours to reduce peak-hour traffic congestion. Time-of-day pricing was introduced at the Port Authority of New York and New Jersey (PANYNJ) bridges and tunnels on March 25, 2001, for E-ZPass users only. According to PANYNJ, 2 months after the implementation of the program, preliminary statistics indicated greater use of E-ZPass and some increase in off-peak travel. PANYNJ operates six toll facilities: George Washington Bridge, Lincoln Tunnel, Holland Tunnel, Bayonne Bridge, Goethals Bridge, and Outerbridge Crossing. In this paper, the relationship between toll price and travel demand at PANYNJ facilities was investigated with traffic data before and after the introduction of the time-of-day pricing program. Two main approaches were used. First, short-term elasticities were calculated with monthly traffic data from April through August for 2000 and 2001. Next, medium-term elasticities were calculated with monthly traffic data from May through August for 2000 and 2002. Seasonal variations in the database were also considered by performing related statistical tests.
Achieving Majority Public Support for Urban Road Pricing
Authors: Cain Alasdair
Published: May 2018

This paper contends that majority opposition from the voting public is the major barrier to urban road pricing implementation. The reason that majority opposition typically exists is investigated at the aggregate level by a consideration of the main factors that determine whether an individual will vote in favor of or against such proposals. Responses to a 2003 survey of southeast Scotland's population were used to assess public views toward Edinburgh's road pricing proposal. Majority opposition to the proposal was observed in aggregate terms. A bivariate correlation analysis showed that car usage was the primary determinant of stated voting behavior. Further analysis showed that a significant majority of car users and non–car users agreed that urban congestion was a significant problem that needed to be reduced and that considerable support existed for implementing road pricing as a way of achieving this. It appears that the public dislike the concept of employing road pricing as a demand management measure and would prefer to view road pricing as a means of raising revenue for public transport improvements, which they believe will lead to congestion being reduced. The paper contends that achieving majority support for urban road pricing implementation requires winning the acceptance of voting car users. The existence of reasonable alternatives to car travel was identified as being crucial to achieving this. Car users who would not change their travel behavior and those who would be forced to change their travel time or destination showed majority opposition; those who would change their travel mode or make fewer trips showed majority support. This finding reinforces the hypothesis that providing high-quality modal alternatives to car users, ahead of road pricing implementation, is a minimum requirement for any proposal seeking to achieve majority support.
Flexible Charge Measures Used on Toll Roads
Authors: Matsuda Waka , Tsukada Yukihiro , Kikuchi Masahiko
Published: May 2018

In fiscal 2003, the Road Bureau of the Ministry of Land, Infrastructure, and Transport in Japan performed demonstration projects concerning diverse and flexible charge measures for toll roads. The goals were to promote the effective use of roads by encouraging traffic to switch from general purpose roads to toll roads, improving roadside environments, mitigating congestion, and promoting traffic safety measures. This study analyzes the results of the 22 projects. As a result of the bureau's efforts, traffic on the toll-free general purpose roads decreased and traffic on the toll roads increased, with traffic congestion in the affected areas subsequently eased. The projects that were intended to eliminate commuter congestion in regional cities were in many cases particularly effective. However, this effectiveness varied according to the setting of the toll and the interchange section, the type of vehicles involved, the discount time zone, and the locational relationship between the general road and the toll road.
Effect of Auto Restraint Policies on Travel Behavior
Authors: Shiftan Yoram , Golani Arnon
Published: May 2018

Auto restraint policies are becoming increasingly popular among urban planners and policy makers as a way of managing travel demand and traffic in city centers. Because urban access is considered crucial to the economic success of a downtown area, certain constituencies, such as business and retail, have historically been opposed to such policies. To address these concerns and design appropriate policies, it is important to understand how visitors to a city center are likely to respond to new policies. This paper presents a model for estimating the likely response to two potential auto restraint policies in the center of Tel Aviv, the largest metropolitan area in Israel: an increase in parking cost and the use of congestion pricing in the form of a cordon around the city center. The models are based on the responses of center visitors to a stated preference survey. The results show that for both workers and nonworkers, most drivers who respond to the policy will do so by changing their mode of travel, and, in the case of congestion pricing, by also changing the time of their trip. The minority will respond by changing their destination or canceling their trip. This is an encouraging result from a policy point of view because changing time or mode is considered a positive shift, whereas changing destination or canceling the trip is considered negative. The results indicate that auto restraint policies can be effective in reducing traffic congestion and air pollution in city centers without hampering their economic vitality.
Value Pricing and Public Outreach
Authors: Munnich Lee W. , Loveland Joseph D.
Published: May 2018

The feasibility and worth of value pricing transportation projects are well documented, but gaining approval for projects has been thwarted by an inability to sell the public and key stakeholders on the concept. Value pricing advocates in Minnesota struggled with this challenge for more than a decade. After several Minnesota value pricing projects failed because of a lack of public support, Minnesota supporters implemented a revised public outreach strategy in 2001. With the use of that strategy, they met with success in 2003 in the approval of the I-394 MnPass project, which will be implemented in spring 2005. The communications-related lessons learned in Minnesota during the decade-long case study may be instructive for others struggling to gain approval for their own projects.
Choosing Congestion Pricing Policy
Authors: Safirova Elena , Gillingham Kenneth , Harrington Winston , Nelson Peter , Lipman Abram
Published: May 2018

Marginal cost pricing has been long advocated as an efficient way of distributing scarce road resources. In practice, however, policy makers have to retreat to second-best pricing schemes that are associated with lower transaction costs and are simpler for potential users to understand than the first-best marginal cost tolls. To date, the majority of practical applications and theoretical models in Europe and Asia are represented by cordon or area pricing mechanisms, while in North America, variations of link-based tolls have become dominant. This paper compares welfare effects of two second-best cordon pricing schemes with those of second-best link-based tolls for the Washington, D.C., transportation network. START, a strategic and regional transport planning model that features elastic travel demands as well as mode, time period, and route choice, is used to analyze the impacts of the two pricing approaches. Distributional effects of cordon and link-based tolls are also examined in the hope of understanding why one scheme might be preferred over another. Because Washington, D.C., in many respects resembles a European city, cordon policies are more likely to be effective there than in more typical North American cities. Although overall net welfare benefits achieved by the three schemes are found to be similar, their dependence on revenue recycling and distributional impacts are quite different. Although the small cordon puts a higher share of costs on low-income travelers than do other pricing schemes, in absolute terms these costs are lower. The exact distributional impact of a larger cordon is uncertain because it depends on the revenue recycling method employed.