bluuebunny/crossref_metadata_2025 huggingface dataset:
Rubblization of Concrete Pavements: Field Investigation
Authors: Niederquell Michael , Baladi Gilbert G. , Chatti Karim Y.
Published: April 2007

Substantial resources are required to preserve aging highway systems. Various alternatives have been used for the rehabilitation of concrete pavements, including bonded and unbonded overlays, full-depth repair, crack and seat and asphalt overlay, joint and crack repairs, asphalt overlay, and rubblization with asphalt surface overlay. Presented are the results of extensive field investigation of rubblized concrete pavements. Various trenches were made in the rubblized pavements before the asphalt surface was placed. Some trenches were made at midslab, and others were made at old joints and cracks. In some trenches, permeability tests were conducted. Advantages and shortcomings of the rubblization procedures are presented and discussed. It is shown that well-executed rubblization procedures lead to durable pavements and that, for certain concrete pavements, rubblization is not a viable option because it may lead to inadequate pavement performance.
Evaluation of Concrete Pavement Rehabilitation Techniques on I-65 in Indiana
Authors: Gulen Sedat , Samy Noureldin A.
Published: April 2007

Construction of hot mix asphalt (HMA) overlays on top of old concrete pavements is the most common concrete pavement rehabilitation strategy. These overlays, however, usually are subject to reflection cracking related to the movement of the old concrete slab. In addition, these overlays may be vulnerable to rutting when subjected to large traffic volumes of heavy trucks. Concrete overlays have the advantage of being rut resistant compared with HMA overlays. However, the current national experience of the performance of these overlays is limited, compared with HMA overlays. Doubts often are raised about the cost-effectiveness of these overlays, the ease of their rehabilitation at the end of their design life, and the time required to close the road to traffic for ongoing and postconstruction operations. Presented is an evaluation of three concrete pavement rehabilitation techniques employed on I-65 in Indiana: ( a) a fiber-modified HMA overlay on top of cracked and seated concrete pavement; ( b) an HMA overlay on top of rubblized concrete pavement; and ( c) an unbonded concrete overlay on top of 30-mm intermediate HMA layer on top of old concrete pavement. Evaluation of these techniques will continue until 2002. Performance of these rehabilitation techniques was assessed considering the performance of restoration (no overlay) techniques applied in 1985 on the same highway segment. It was concluded that all rehabilitation techniques performed satisfactorily. The unbonded concrete overlay segment exhibited the best performance in reflection cracks elimination, structural capacity, and skid resistance. The rubblized segment exhibited the best performance in ride quality and uniformity of structural capacity. Life-cycle cost analysis suggested that the unbonded concrete overlay was the most cost-effective segment.
Conditional Bus Priority at Signalized Intersections: Better Service with Less Traffic Disruption
Authors: Furth Peter G. , Muller Theo H. J.
Published: April 2007

Conditional priority for buses at signalized intersections means that late buses are given priority and early buses are not. This scheme is a method of operational control that improves service quality by keeping buses on schedule. A conditional bus priority implementation in Eindhoven, the Netherlands, is described. Results show the strong improvement in schedule adherence compared with a no-priority situation. Traffic impacts at an intersection were studied for three scenarios—no priority, absolute priority, and conditional priority. Compared with no priority, absolute priority increased delays significantly while conditional priority had almost no impact.
Dynamic Right-of-Way for Transit Vehicles: Integrated Modeling Approach for Optimizing Signal Control on Mixed Traffic Arterials
Authors: Duerr Peter A.
Published: April 2007

Public transit and general traffic on many urban arterials are controlled by the same set of signals and must compete for shared road space. In these situations, transit vehicles typically face considerable delays because their dwell times at transit stops remove them from the coordinated green wave for general traffic flow. Although existing control systems allow for local adjustments of signal timings to provide transit priority, these short-term actions often contradict the network control scheme and may preclude a priority scheme or significantly disrupt traffic flow. A new concept for a corridor control system is introduced—the dynamic right-of-way, which serves the demands of public transit and general traffic using an integrated model for evaluation and optimization. The control system is intended to ( a) reduce critical interferences between both modes of transport by dynamically controlling inflow and outflow for all network links, ( b) provide a green signal whenever a transit vehicle approaches an intersection, and ( c) minimize general traffic disruption by maintaining overall signal coordination. Through linking an event-based simulator with a genetic algorithm-based optimization routine, delay-minimizing multicycle signal control schemes are calculated. In offline experiments, the potential for achieving substantial reductions in delays is demonstrated. Finally, a method is presented by which these control schemes are implemented and adjusted dynamically, based on online measurements and a control modification function derived from a neural network model.
Internet-Based Decision Support for Advanced Public Transportation Systems Technology
Authors: Stone John R. , Ahmed Tahsina , Nalevanko Anna
Published: April 2007

Intelligent transportation systems (ITS) have the potential to improve public transportation service and productivity in small urban and rural areas. Advanced technologies include computer-aided dispatch and scheduling software, automatic vehicle location via satellite, mobile data terminals, smart cards, and Internet technologies. Transit operators, especially those with smaller systems, may feel, however, that they lack the experience and technical background to implement ITS technologies. An extensive website is discussed that will help transit managers define their transit needs and choose potential technology solutions. The website is based on contemporary decision-support questionnaires and the experience of transit managers and researchers. Decision-making factors such as transit service area, service type, daily ridership, and fleet size provide a framework for matching appropriate technologies to transit-manager needs. Further, the website provides extensive tutorial information, technology specifications and costs, and vendor contacts. Perhaps most important, the website identifies small urban and rural transit managers who have been pioneers in ITS applications, summarizing their successes and failures. The website address is http://www2.ncsu.edu/eos/service/ce/research/stone_res/tahmed_res/www/index.html.
Effectiveness of Taxi Partitions: Baltimore, Maryland, Case Study
Authors: Stone John R. , Stevens Daniel C.
Published: April 2007

Questions are answered as to whether taxicab partitions between drivers and passengers reduce assaults. Assaults on Baltimore, Maryland, taxi drivers decreased 56 percent the year following a citywide mandate requiring partitions between taxi drivers and passengers. Data also show that between 1991, when only 5 percent of cabs had shields, and 1998, when all taxis had shields, assaults decreased 90 percent. Confounding factors such as annual changes in city population, crime rate, robberies, unemployment, and drug arrests are addressed by comparing the 1991 assault rate for the shielded cabs of one taxi association with a similar association without shielded cabs. This analysis shows that in 1991 an unshielded Baltimore taxi driver was five times more likely to be assaulted. Using linear regression to account for the time variation in factors from 1991 to 1998, the results indicate that reduced driver assaults correlated the most with population changes, improved policing, decreases in robberies, and the percentage of shielded taxis. A related economic analysis yielded a 17-to-1 benefit-to-cost ratio of estimated savings from reduced injuries versus the costs of citywide shield installation. The results support the Baltimore shield mandate and argue for shields in other cities.
Evaluating Real-Time Bus Arrival Information Systems
Authors: Mishalani Rabi G. , Lee Sungjoon , McCord Mark R.
Published: April 2007

Real-time transit passenger information systems are intended to improve the level of service provided by transit agencies. For example, passengers are given real-time information on the expected arrival times of buses on various routes at bus stops. These real-time systems reflect emerging applications in public transit, and methods to evaluate their benefits are limited. An evaluation method is presented that focuses on the potential benefits of bus arrival information systems to passengers waiting at bus stops. Passenger arrivals and transit bus operations are modeled as a stochastic system in which the operator uses real-time bus location data to provide bus arrival-time information that maximizes passengers' utilities. Simulation results reveal the nature of the dependence of system benefits on the type of real-time data available to the operator and the bus operations characteristics. An application to an existing bus transit system demonstrates the feasibility of the developed method and its role in assessing the value of real-time bus arrival information systems to passengers.
Intelligent Transportation System Technology in a Shared Electric Vehicle Program
Authors: Barth Matthew , Todd Michael , Murakami Hiroshi
Published: April 2007

To be successful, shared vehicle systems must be responsive, convenient, and easy to manage. By applying a variety of intelligent transportation system (ITS) technologies (e.g., vehicle location and identification, dispatching, smart cards), these attributes can be achieved. Further, intelligent transportation technology is useful for collecting data on user behavior and vehicle usage. These data add to the understanding of shared vehicle systems and of how to design systems for the future. The University of California-Riverside (UC Riverside) and Honda Motor Company have implemented a shared electric vehicle system test bed named UCR IntelliShare, which consists of 15 shared electric vehicles, moving among three stations on and near the UC Riverside campus. The system, described here, uses highly developed ITS technology, including smart cards, touch-screen registration kiosks, vehicle monitoring and tracking hardware, and sophisticated management software. The system has operated since April 1999, and abundant data are collected every day. Preliminary results are provided, describing user behavior, vehicle operation, and many shared vehicle trip characteristics. These data are being used to study shared vehicle systems and to refine shared vehicle system simulation modeling tools. These tools can assist in designing other shared vehicle systems, greatly reducing the implementation risks and liabilities that may be associated with future, full-scale shared vehicle system implementations.
Buses as a Traffic Probe: Demonstration Project
Authors: Hall Randolph W. , Vyas Nilesh
Published: April 2007

The congestion probe feature of the Orange County Transportation Authority (California) bus probe project was evaluated by comparing automobile and bus trajectories and examining alternative congestion detection methods. The focus was city streets on which delays occur at signalized intersections and bus delays at bus stops. The analysis revealed that when automobiles have long delays, buses traveling nearby on the same route are also likely to be delayed. The reverse situation, however, is not always true, because buses frequently wait for extended periods when they run ahead of schedule. Any useful bus probe algorithm needs to distinguish between actual congestion and a stopping delay. Although the transit probe was designed to measure congestion on roadway segments, a more useful approach would be to measure congestion approaching major intersections, where delays are likely to occur. Moreover, because delays randomly fluctuate according to a vehicle’s arrival time relative to the signal cycle, the most sensible approach is to set off a "congestion alarm" when a vehicle is delayed by more than one cycle at an intersection. A congestion alarm would indicate oversaturation and delay well above normal.
Simulating Bus Operations with Enhanced Corridor Simulator: Case Study of New Jersey Transit Bus Route 39
Authors: Ding Yuqing , Chien Steven I-Jy , Zayas Noreen A.
Published: April 2007

The corridor simulator (CORSIM)-based microscopic program, which can simulate realistic bus operations, has been enhanced with some newly developed features; these are validated. Transit operations-related data for New Jersey Transit Bus Route 39 were collected to assess the reliability of the enhanced CORSIM program. On the basis of the mean average percentage error and the root mean square error, this study demonstrated that simulation output can represent realistic bus operations, such as the disruptions of transit headways caused by ridership fluctuations at bus stops and delays at intersections. The proposed program provides a potential basis for evaluating advanced transit management and control strategies and real-time transit traveler information systems in the advent of advanced public transportation systems.
Technology Transfer in the Transit Industry
Authors: Nakanishi Yuko J. , Abd Elrahman Ossama
Published: April 2007

The unprecedented advances taking place in the technology industries (computer, electronics, telecommunications) can benefit the transit industry by enabling safer, cleaner, and more reliable transit vehicles; easier maintenance; better customer service; and faster and more efficient scheduling and operations. Without an effective technology transfer process, however, the technologies may not reach the proper audience in the transit organization, or they may fail to elicit the appropriate response from transit staff. The two key elements of successful technology transfer in the transit industry are discussed—effective technology transfer infrastructure and technology transfer (T2) agents. Effective technology transfer infrastructure consists of an organizational culture that is open and flexible, a comprehensive evaluation mechanism, an efficient transfer design, and an effective training program. T2 agents are individuals or organizations that bring new technologies and information to agencies, which then can transform the technology and information into useful products, processes, or programs. Also discussed are intra- and interagency barriers, such as strict adherence to rule books and bureaucratic organizational structures, and examples are provided of how some agencies are addressing these problems.
Road Pricing on the Basis of Congestion Costs: Consistent Results from Two Historic U.K. Towns
Authors: Santos Georgina
Published: April 2007

The idea of road pricing as a function of congestion costs in the United Kingdom (U.K.) was put forward in a seminal report published by the U.K. Ministry of Transport in 1964. After 35 years, little has been done and the reasons behind this delay are mainly political, as the failure to implement congestion metering in Cambridge at the beginning of the 1990s shows. The subject has taken on a new urgency now that the U.K. government has announced its intention to authorize local councils to introduce road charges. Road pricing has a strong theoretical basis, but congestion costs must be quantified before it can be implemented. For that purpose, a simulation model is used. The social costs of congestion are measured by the deadweight loss and calculated from the difference between the marginal social costs and the price actually paid by trip makers. An exercise was done for two similar towns, Cambridge and York, and potential road charges differing by only 8 percent on average were obtained. This seems to strengthen the idea that finding road charges in a few cases, each one characteristic of a larger set of towns, would allow the provision of guidelines to local councils. In that way, fair road prices could be established across the U.K. The use of revenues from public-accepted road charges is also discussed.
Katy Freeway High-Occupancy Vehicle Lane Value Pricing Project, Houston, Texas: Evaluation of Usage
Authors: Hickman Mark , Brown Quanta , Miranda Alejandro
Published: April 2007

Usage of the QuickRide program on the Katy high-occupancy vehicle (HOV) lane in Houston, Texas, is described. The QuickRide program allows two-person carpools to use the HOV lane for $2.00 during peak periods when the lane is restricted to three or more persons. Use of QuickRide during its first year is described, and an analysis of the demand for the program is presented. QuickRide usage, reported travel behavior, and demographic data are used to analyze user travel patterns, travel time savings, and frequency of use. In the 1-year demonstration, demand averaged slightly over 100 vehicles per day, with more than 60 percent of these vehicles traveling in the morning peak. Participants' average use of QuickRide was only about 0.9 times per week, and very few participants used it more than five times per week. Yet a sampling of travel days indicates that, for the $2.00 fee, the average vehicle saves about 20 min of travel time. Responses to a mail-back survey show a significant mode shift from drive-alone to QuickRide, amounting to more than 50 percent of QuickRide trips. A substantial shift was also seen in the time of travel into the peak hour, totaling about one-third of QuickRide trips. Finally, larger household sizes and higher incomes appear to be good predictors of QuickRide use. Interestingly, previous use of the HOV lane was not a good indicator, either positively or negatively, for the frequency of use of QuickRide. These results suggest that ( a) the total demand for HOV-2 value pricing may be limited in major travel corridors, despite large potential time savings; ( b) substantial shifts in mode and time of travel are possible with HOV-2 value pricing; and ( c) household size and income are good indicators, but HOV lane use is a poor indicator, of the frequency of use of an HOV-2 value pricing program.
Variable Toll Pricing Program, Lee County, Florida: Revealed Preference Telephone Survey Findings
Authors: Yelds Ashley , Burris Mark
Published: April 2007

Variable time-of-day toll pricing was introduced in Lee County, Florida, in August 1998, on two of the area’s five bridges. Discounted tolls were offered to drivers with transponders (required for electronic toll collection) traveling in time periods just before and after typical peak demand travel periods. A telephone survey of 400 Lee County residents was conducted in late 1998. This survey was designed to collect information on driver travel behavior and determine participation levels in the variable pricing program. The survey found that the true participation level in the variable pricing program is in the range of 2.25 percent to 9.25 percent of survey respondents. The survey also examined potential adverse effects of changes in toll prices (induced demand, changes in mode of travel); perceptions of inequity by those unable to benefit from time-of-day toll pricing; and the socioeconomic characteristics of variable pricing participants. Eligibility for the discounted tolls was restricted to only those drivers who pay their tolls electronically. Participants and nonparticipants in the variable pricing program appear to differ by type of employment and household type. Those stating they do participate in variable pricing were less likely to be employed full time than those who do not participate. Differences were also found in the primary trip purposes of participants and nonparticipants. Commuters and drivers on work-related travel were less likely to participate in the program. It can be inferred that those with flexibility in their travel plans can, and do, change their travel to take advantage of the variably priced tolls.
Potential Response to Road User Charging in Dublin, Ireland
Authors: O’Mahony Margaret , Geraghty Dermot , Humphreys Ivor
Published: April 2007

Transport strategies in Dublin before 1990 were primarily road based with particular emphasis on increasing road space within the city for the car. In the early 1990s, however, the Dublin Transportation Initiative recommended a more innovative strategy, the core of which centered on public transport. Implementation of the strategy is currently under way, but increased economic activity, with associated increases in car ownership and usage, has undermined the potential to address the imbalance between transport demand and supply, particularly in the shorter term. As a result, feasible and reliable public transport alternatives do not currently exist for car users on some radial corridors. The ongoing implementation of bus lanes and an increase in the number of buses should go some way in improving the reliability of the service. It is against this background that road use pricing is considered. The potential user response to road user charging is examined by means of a pilot action project to investigate whether further evaluation of the measure would be justified on a larger sample. The distance-and-time-based time-differentiated pricing method used in the pilot action induced a significant decrease of 22 percent in car trips and a 23 percent reduction in distance traveled during the peak period, reflecting the relatively high road use charges applied in that period. The total distance traveled decreased by 13 percent. The road user charge reflects the marginal external costs of car travel in the peak period in Dublin.
Major Corridor Investment-Benefit Analysis System
Authors: Kaliski John G. , Smith Stephen C. , Weisbrod Glen E.
Published: April 2007

The major corridor investment-benefit analysis system recently developed for the Indiana Department of Transportation (INDOT) is discussed. The purpose of the system is to provide an analytical tool for use by INDOT in evaluating and comparing the impacts of major corridor highway investments in the state. The system combines a statewide travel demand model, a user benefit-cost analysis model, and a regional econometric model. The conceptual approach behind the model is described, and the results from an application of the model to analyze the transportation and economic impacts of the upgrade of US-31 between Indianapolis and South Bend, Indiana, to Interstate level of service is presented. Issues addressed by the model include the impact of travel time savings and other user benefits on business users of the highway, as well as the potential for the study corridor to attract new businesses or tourists as a result of improved access to markets.
Optimal Fare Structure for Transit Networks with Elastic Demand
Authors: Lam William H. K. , Zhou Jing
Published: April 2007

A bilevel model is presented to optimize the fare structure for transit networks with elastic demand under the assumption of fixed transit service frequency. It is known that the transit fare structure has significant effects on passengers' demand and route choice behavior. The transit operator therefore should predict passengers' response to changing fare charges. A bilevel programming method is developed to determine the optimal fare structure for the transit operator while taking passengers' response into account. The upper-level problem seeks to maximize the operator’s revenue, whereas the lower-level problem is a stochastic user equilibrium transit assignment model with capacity constraints. A heuristic solution algorithm based on sensitivity analysis is proposed. Finally, a numerical example is given together with some useful discussion.
Congestion, Stochastic, and Similarity Effects in Stochastic: User-Equilibrium Models
Authors: Prashker Joseph N. , Bekhor Shlomo
Published: April 2007

Different effects in stochastic user-equilibrium formulations are compared. The starting point is the logit assignment formulation for the stochastic user-equilibrium model. Recently, extended logit-based models were developed as solutions of equivalent stochastic user-equilibrium problems. These extended logit models are theoretically superior to the simple logit model, because they take into account the similarity among routes. The similarity indexes were defined based on physical parameters of the network, such as link lengths, and therefore did not depend on congestion. The assumption that similarity coefficients are independent of congestion means that the similarity effect and the congestion effect are treated separately. However, both similarity and congestion effects are taken into account in the equilibrium formulations. Simple network examples are presented to illustrate the sensitivity of the link flow pattern (and path flow pattern) to the three different effects in stochastic assignment models: the congestion effect, the stochastic effect, and the similarity effect. The relative influence of those effects on the flow patterns is discussed.
Probit-Based Sensitivity Analysis for General Traffic Networks
Authors: Clark Stephen D. , Watling David P.
Published: April 2007

The probit-based stochastic user-equilibrium (SUE) model is widely recognized as one of the most intuitively robust traffic network assignment techniques. Its advantages include explicit consideration of random perceptual differences in utility across the driver population and the ability to take proper account of the correlations in these utilities between overlapping routes, which the simpler logit SUE is unable to do. Its main drawback is the potentially heavy computational demands of the method, but various efficient approximation methods have been observed to provide reasonable solutions. This computational complexity was previously, however, thought to preclude a consideration of the sensitivity analysis of probit-based SUE, whereby an approximation to changes in the equilibrium solution is deduced as its input parameters are perturbed. An efficient computational method for performing such an analysis in general networks is described. A simple network example is described in detail to illustrate the method, and it is followed by a larger network example that further demonstrates the practical nature of the method.
Road Safety Engineering: Role for Insurance Companies?
Authors: Zein Sany R. , Navin Frank
Published: April 2007

Over the last 10 years there has been a growing trend among automobile insurance companies to become involved in road safety engineering programs. While the involvement of insurance companies in driver education and vehicle design initiatives is common, insurance company initiatives aimed at the engineering element of road safety is a relatively new trend. This research summarizes the major road safety engineering programs undertaken by six insurance companies in Australia, Canada, and the United States, and presents some of the results achieved. The research finds that the immediacy of the benefit derived from road safety engineering improvements, coupled with an expanding knowledge base in this field, are contributing to the growth in interest in road safety among insurance companies. The financial interest of insurance companies in reducing crash frequencies and severities, as well as any related positive public image that road safety advocacy can generate, will likely mean that more insurance companies will be exploring avenues for participation in road safety programs. Opportunities exist for cooperation between the insurance industry and transportation engineers, and they should be pursued for mutual benefit. Although the ultimate responsibility and authority for roads should remain with public agencies, the incentive and emphasis that insurance companies place on road safety provide a unique opportunity to help reduce the daily risks that we face in a mobile world.
Using Focus Groups to Investigate Issues of Red Light Running
Authors: Wissinger Leanne M. , Hummer Joseph E. , Milazzo Joseph S.
Published: April 2007

Red light running (RLR) has been an important issue among transportation officials seeking to make intersections safer for drivers and pedestrians. Many cities in the United States have started programs aimed at reducing the number of red light violations, and many of these programs include the use of automated enforcement utilizing a camera to record violations. Previous research on such enforcement has quantified the rate of its public acceptance through surveys; however, little research has been performed probing the reactions and concerns of the public toward red light cameras. For this study, focus groups were used to investigate the attitudes, beliefs, and perceptions of the public toward RLR and red light cameras. Fifteen focus groups were held throughout North Carolina with representatives from organizations interested in and knowledgeable about traffic safety, traffic engineering, and traffic law enforcement, as well as with people not professionally involved in law enforcement or traffic engineering. Some of the focus group discussions involved such issues as determining an appropriate RLR grace period, developing an educational campaign, addressing financial issues, and determining appropriate penalties for RLR violations. Participants voiced their opinions on both sides of the issues; for instance, many participants said they strongly believed there should be some sort of grace period with automated enforcement, whereas others said they felt a zero-tolerance policy should be used. Also, many participants voiced their unequivocal support for automated enforcement, whereas others expressed concerns.
Seasonally Changing Speed Limits: Effects on Speeds and Accidents
Authors: Peltola Harri
Published: April 2007

Summarized are the results of studies that examined the effects of speed limits that were changed on a seasonal basis on Finnish main roads. The first of these studies was an experimental study (1987–1989) in which speed limits were changed according to time of year. A follow-up study was then conducted on the resulting and greatly expanded use of lower speed limits during the winters of 1989 to 1996. Reasons for lowering wintertime speed limits involved primarily adverse road and driving conditions, including slippery roads, the use of studded tires, frequent heavy rain or snowfall, and darkness. In the 2-year study, a statistically significant accident reduction of 14 percent was detected, and the followup suggests an even greater accident reduction. This significant accident reduction was achieved by cutting mean speeds as little as 3.8 km/h. Interviews with drivers showed they accepted the lower speed limits surprisingly well, most likely because they understood the reasons for them. Although significant safety advantages have been gained in poor driving conditions, the gains have been even greater in good conditions on roads of reasonably high standard because such roads are where speed limits dropped the most. Lower wintertime speed limits have had a positive safety effect, even on roads with a fixed 100-km/h speed limit. As a result, most 100-km/h speed limit signs in Finland are now changed manually to 80 km/h at the end of October and back to 100 km/h in early March. These safety measures have proven to be both cost-effective and well accepted. Lower wintertime speed limits are now being planned in other northern European countries.
Red Light Violations and Crashes at Urban Intersections
Authors: Datta Tapan K. , Schattler Kerrie , Datta Sue
Published: April 2007

High approach speeds coupled with aggressive driving often lead to the running of red lights at intersections. When motorists see a yellow light as they approach an intersection, they are supposed to stop unless such sudden stopping is unsafe. Entering an intersection during the red signal is a citable offense, and several states are working to legalize video detection and enforcement using red light violation camera systems. Such enforcement is targeted toward driver behavioral modification; in the absence of an all-red interval the motorist who enters an intersection during the red signal runs an extremely high risk of being struck by cross-street traffic. A study was performed in the city of Detroit, Michigan, to compare the red light violation characteristics of intersections with properly designed all-red intervals and those intersections without all-red intervals. In the absence of before violation data, a comparative parallel experimental study was used. It was hypothesized that providing an all-red interval following a yellow change interval would reduce right-angle crashes. A before-and-after crash analysis was performed at the all-red-interval treatment sites (sites that targeted a reduction of right-angle and injury crashes). The analysis indicated significantly lower red light violations at the treatment sites. The analysis also indicated an extraordinary reduction in right-angle and injury crashes. This study demonstrated that substantial benefits, in terms of reducing red light violations and right-angle crashes, can be achieved by introducing a well-designed all-red interval.
Integration of the Motor Carrier Safety Status Measurement System into the Roadside Inspection Selection System
Authors: Lantz Brenda M.
Published: April 2007

The roadside Inspection Selection System (ISS) was developed in response to a 1995 congressional mandate that called for the use of prior carrier safety data to guide the selection of commercial vehicles and drivers for roadside inspections. The program was developed in part by the Federal Motor Carrier Safety Administration (FMCSA) of the U.S. Department of Transportation. As ISS has developed, FMCSA’s Performance and Registration Information Systems Management (PRISM) program has also been evolving. One objective of PRISM is to identify relatively unsafe carriers by assigning Safety Status Measurement System (SafeStat) scores and also encouraging those drivers to improve their safety performance or risk losing registration privileges. SafeStat was designed to prioritize carriers for monitoring and compliance reviews, but ISS was designed to prioritize carriers for roadside inspection. Both algorithms, however, use similar data to define a relatively unsafe carrier. It would be advantageous therefore to have a single uniform rating system for all FMCSA programs. This research briefly describes the PRISM and SafeStar algorithms; discusses the integration of the SafeStat algorithm into ISS; and presents conclusions on the initial testing of the resulting system, ISS-2. An analysis of over 213,000 roadside inspections reveals that ISS-2 is as effective as the original ISS in meeting the goals for which it was designed. It successfully identifies and prioritizes for roadside inspection the vehicles and drivers of carriers with poor prior safety performance, as well as those with few or no previous inspections. In addition, safety inspectors who have tested the system say they are pleased with the new algorithm and its added features.
Overnight Truck Parking Along Tennessee’s Interstate Highways and Rest Areas
Authors: Chatterjee Arun , Wegmann Frederick J.
Published: April 2007

Truck parking spaces in the public rest areas and pull-out areas along Tennessee’s Interstate highways are filling up at night, and large trucks are parking along the shoulders of ramps to these areas. Trucks are also parking along regular interchange ramps and in some cases along through lanes. This is a potentially hazardous situation for travelers. A detailed survey was performed at public rest areas in Tennessee at night, covering all 7 days of the week, to learn about the occupancy characteristics of trucks. Availability of space in private truck stops near interchanges also was examined. This research presents the findings of these surveys in quantitative terms. Several truck drivers were interviewed and all neighboring states were contacted to learn more about why some drivers prefer to park along highways and what strategies are being used by other states to alleviate this problem. Findings related to these issues are presented in this research.
Public Transport and the Compact City
Authors: le Clercq Frank , de Vries Jaap S.
Published: April 2007

The compact-city policy is a prudent strategy for carrying out city intensification and expansion. Similarly, public transport is seen as the most appropriate mode of transportation for this urban form. The connection between the two is clear—public transport makes sense in a compact city, and the compact city seeks to increase the use of public transport. However, the validity of this claim from the perspective of the residents is questionable. The length of trips made by city residents in compact cities tends to be so short in the Netherlands that these trips are often carried out by nonpublic transport modes, such as bicycle and car. Moreover, by increasing densities in and around the compact city, public-transport systems no longer can meet the disperse pattern of transportation demands of all citizens. An evolutionary relationship exists between urban expansion and types of public transport. When a transport system is developed on a regional scale, a choice will need to be made between two alternatives—the commonly used line-by-line approach and the integration and nodal approach. In the first case, success will depend on land use policies, whereas the latter tends to correspond better to the increasing diffuse travel patterns of residents and to evolve according to the features of the city structure and the opportunities for expansion within the system.
Asking Transit Users About Transit-Oriented Design
Authors: Ewing Reid
Published: April 2007

Visual-preference surveys are becoming popular in “visioning” projects, design charrettes, and other physical planning activities in which intensive public involvement is desired. In a survey, transit users, nonusers, and professionals were shown a series of paired slides of bus stops, asked to choose the stop from each pair at which they would prefer to wait, and asked to rate each stop chosen as a place to wait. Slides then were analyzed for content, with 19 features of bus stops and surroundings measured and quantified. Subsequent analysis showed that transit-oriented design features most affecting both choices and ratings are a bus shelter at the stop, trees along the street leading to the stop, a vertical curb at the stop, the setback of the stop from the street edge, and a continuous sidewalk leading to the stop. Such a survey may help transit planners choose the best transit-stop locations and devote financial resources to the most promising transit-stop amenities, given the inevitable trade-offs involved.
Grand Canyon National Park: Assessment of Transportation Alternatives
Authors: Laube Melissa M. , Stout Robert W.
Published: April 2007

Continuing traffic growth on roadways in the Grand Canyon National Park is a significant problem, detracting from the park as a natural, scenic environment and generating unacceptable levels of noise, air pollution, and congestion. A 1995 General Management Plan for the park identified transportation as the most significant issue affecting preservation of the park’s unique natural resources. In FY 1999, the U.S. Congress directed FTA and FHWA to undertake a review of the transportation alternatives considered by the National Park Service for the Grand Canyon. These alternatives included light rail, standard bus, articulated bus, and articulated bus on busway. The review concluded that transit is an appropriate solution to the transportation problems in the popular South Rim area of the Grand Canyon because of the concentration of visitors at a small number of destinations requiring motor-vehicle access and the viability of walking and bicycling as modes of transportation within the park that can complement transit service. Light-rail service, which is the preferred alternative identified by the National Park Service, has the advantage compared with bus service that it can accommodate high levels of peak-hour, peak-season demand. Although the lowest-cost alternative considered is articulated bus operated on a busway, the costs of several light-rail and bus alternatives are not substantially higher. The use of transit services by park visitors will result in substantial environmental benefits, reducing vehicular emissions and noise dramatically through a major reduction in the use of private vehicles.
Yosemite Regional Transportation Strategy: Creating a Public-Private Partnership
Authors: Weinstein Nelson Bonnie , Tumlin Jeffrey
Published: April 2007

In 1992 the Yosemite Area Regional Transportation Strategy (YARTS) group began meeting to discuss access and transportation needs of visitors to the Yosemite region. The group included representatives of the five rural counties surrounding Yosemite National Park, the National Park Service, the state department of transportation, and eventually the U.S. Forest Service and other state and federal agencies. Urgency increased after the park instituted a program of gate closures to address congestion and parking problems within Yosemite Valley. Although the closures lasted only a matter of hours, the impact was felt for months to come as visitors changed their plans in the face of potential closures. Two years later, a flood permanently removed infrastructure within the park, including parking spaces and camping sites, making access from the surrounding communities even more critical. After 8 years of planning, YARTS has implemented the first regional transit service ever focused on the 4 million annual visitors to Yosemite. The 2-year demonstration service plan is not intended to replace automobile access to the park but rather to provide an alternative mode of access. The plan is creating a unique partnership between YARTS and private vendors who will provide the service and assume much of the start-up risk. The plan provides a working outline of the service, including anticipated service levels and fares. All of these plan highlights are discussed, along with a history of the YARTS organization, which describes the technical and political challenges to implementation.
Get Me to the Ball Game on Time: Access Time Patterns at Baseball Stadia
Authors: Grava Sigurd , Nangle Fred
Published: April 2007

Arrival patterns at three baseball stadia under varying conditions are observed. These conditions include proximity to downtown, availability of transit facilities, and the vagaries of the playing season. Patterns are assessed at Shea Stadium in New York City, Jacobs Field in Cleveland, and Anaheim Stadium in Orange County, California. At Shea Stadium, a simulated sellout game, a typical game between the Mets and their divisional rivals, and a September game for die-hard fans are analyzed. The general conclusions that were reached are as follows: ( a) efficient and dependable highway access produces sharp arrival peaks that require efficient parking facilities at and nearby the stadium; ( b) good transit also will create sharp arrival peaks close to game time; ( c) with good access, efficient spectator processing within the stadium is highly necessary to seat last-minute arrivals before the first pitch; ( d) the intuitive notion that die-hard fans will have a better idea of how well the stadium access system works and tend to be better at planning their arrivals is borne out by the analysis; ( e) when superior rail-transit access is available, under typical or better U.S. conditions, it will carry up to 40 percent of all spectators; and ( f) good transit appears to reduce the predicted average vehicle occupancy (AVO) from 2.5 to between 2.2 and 2.3. Without good rail transit, the AVO is approximately 2.6.
Measuring Cost Variability in Provision of Transit Service
Authors: Taylor Brian D. , Garrett Mark , Iseki Hiroyuki
Published: April 2007

The cost of producing public-transit service is not uniform but varies by trip type (e.g., local or express), trip length, time of travel, and direction of travel, among other factors. However, the models employed by public-transit operators to estimate costs typically do not account for this variation. The exclusion of cost variability in most transit-cost-allocation models has long been noted in the literature, particularly with respect to time-of-day variations in costs. This analysis addresses many of the limitations of cost-allocation models typically used in practice by developing a set of models that account for marginal variations in vehicle-passenger capacity, capital costs, and time-of-day costs. FY 1994 capital and operating data are used for the Los Angeles Metropolitan Transportation Authority (MTA). This analysis is unique in that it combines a number of previously and separately proposed improvements to cost-allocation models. In comparison with the model currently used by the Los Angeles MTA, it was found that the models developed for this analysis estimate ( a) higher peak costs and off-peak costs, ( b) significant cost variation by mode, and ( c) lower costs for incremental additions in service. The focus is on the limitations of the rudimentary cost-allocation models employed by most transit operators and not on the Los Angeles MTA per se. This analysis found that an array of factors addressed separately in the literature can be incorporated simultaneously and practically into a usable cost-allocation model to provide transit systems with far better information about the highly variable costs of producing service.
Performance of Geopier Reinforced Soil Foundations During Simulated Seismic Tests on I-15 Bridge Bents
Authors: Lawton Evert C.
Published: April 2007

Results are presented from full-scale tests on geopier foundations subjected to simulated seismic activity. The foundations were subjected to large cyclic lateral and uplift-compression loads as well as significant overturning moments produced by the horizontal forces. For the conditions of the tests, including large loads, poor subsurface soils, and no embedment of the foundations, the magnitudes of the maximum displacements and rotations were relatively small. Furthermore, the permanent displacements at the end of the tests were small. Overall the results indicate that geopier foundations are ductile and can sustain large displacements—such as those generated by earthquakes—without significant damage and can thereby maintain serviceability after an earthquake.