bluuebunny/crossref_metadata_2025 huggingface dataset:
Accident Prediction Models for Urban Unsignalized Intersections in British Columbia
Authors: Sayed Tarek , Rodriguez Felipe
Published: April 2007

A study was designed to develop accident prediction models for estimating the safety performance of urban unsignalized intersections. The models were developed with the generalized linear modeling approach, which addresses and overcomes the shortcomings associated with conventional linear regression. The safety predictions obtained from the models were refined by the empirical Bayes approach to provide more accurate, site-specific safety estimates. The study made use of sample accident and traffic volume data corresponding to unsignalized (T-leg and four-leg) intersections located in urban areas of the Greater Vancouver Regional District and Vancouver Island, British Columbia. Four applications of the models are described: identifying accident-prone locations, developing critical accident frequency curves, ranking the identified accident-prone location, and evaluating before-and-after safety. These applications show the importance of using accident prediction models to reliably assess the safety of unsignalized intersections.
Incomplete Accident Reporting: Meta-Analysis of Studies Made in 13 Countries
Authors: Elvik Rune , Mysen Anne
Published: April 2007

A meta-analysis of studies of road accident reporting in official accident statistics made in 13 countries is described here. A rigorous comparison of reporting levels between countries is difficult because of differences in the definitions of reportable accidents, reporting levels, and data sources used to assess reporting levels. Based on 49 studies in 13 countries, it is concluded that reporting of injuries in official accident statistics is incomplete at all levels of injury severity. In rounded values, the mean reporting level in the countries included was found to be 95 percent for fatal injuries according to the 30-day rule, 70 percent for serious injuries (admitted to hospital), 25 percent for slight injuries (treated as outpatients), and 10 percent for very slight injuries (treated outside hospitals). Reporting levels vary substantially among countries, ranging from 21 to 88 percent for hospital-treated injuries. Reporting is highest for car occupants and lowest for cyclists. In particular, single-vehicle bicycle accidents are very rarely reported in official road accident statistics.
Performance Evaluation of Automated Vehicle Locator and Digital Map Accuracy in Transit Application
Authors: Greenfeld Joshua
Published: April 2007

New Jersey Transit (NJT) is investigating acquisition of an automated vehicle locator (AVL) system. The purpose of the AVL system is to monitor the location of buses. Knowing the location of a bus allows the operator to manage the bus fleet more efficiently and to provide customers with up-to-the-minute information on bus arrivals and departures. To monitor the location of the buses, their positional information (as determined by the AVL) is displayed on a digital map such as a geographic information system. To ensure accurate information, the location (coordinates) of the bus must be consistent (or within a small tolerance) with those of the digital map. If this is not the case, the system can yield incorrect information. This problem might become especially critical in an urban area where the system would be most valuable. The methodology that was developed for testing and evaluating the accuracies of AVL systems and available digital maps is described. The AVL system analyzed is the continuous positioning system by Andrew Corporation. Digital mapping products evaluated were TIGER, Navtech, and Digital Orthophotos. These data sets were evaluated with an accurate network of control points measured by a global positioning system. Some recommendations on the appropriateness of the tested AVL system and NJT’s digital mapping data are made.
Economic Impact of Rural Transit Services
Authors: Burkhardt Jon E.
Published: April 2007

Great economic benefits are attributed to transit systems serving large urban areas, such as providing mobility, reducing costs associated with automobile use (congestion and air pollution), encouraging greater economic growth in areas served, and increasing the nation’s overall economic productivity. Like the larger urban public transit systems, rural public transit systems have real benefits for the communities they serve. Unlike those of their larger counterparts, the contributions that rural transit systems have made to the economic health and well-being of the communities they serve have gone largely unrecognized. A new report measures for the first time the economic benefits of rural transit operations. The report develops benefit estimates from 22 case studies of rural transit systems and from national transportation and economic data. Large economic benefits were found, demonstrating that public transportation is a good investment for rural communities.
Assessing Means of Transit Information Delivery for Advanced Public Transportation Systems
Authors: Peng Zhong-Ren , Jan Oliver
Published: April 2007

One of the important functions of advanced public transportation systems (APTS) is to provide timely information to transit users. Information delivery systems thus become an essential part of APTS. Described and categorized are means of information dissemination systems and their roles in advanced traveler information systems. An evaluation framework is developed to assess different media on the basis of seven criteria: accessibility, versatility and interactivity, information carrying capacity, user friendliness, costs to install, costs to use, and ease of implementation. The evaluation shows that the Internet and kiosks have the highest overall ranking. These are capable of delivering a variety of information, can provide interactivity to users, and if designed properly can have a user-friendly interface. Variable message signs and closed-circuit televisions are ranked as good for their modest costs and the variety of information they can deliver. They are appropriate to both wayside and in-terminal information displays. Other emerging technologies, such as automated voice annunciators and personal communication devices, are promising for the future but are not ready for implementation.
Optimal Inspection and Maintenance Policies for Infrastructure Systems: Facility and Network Problems
Authors: Madanat Samer , Smilowitz Karen , Lago Alejandro
Published: April 2007

State-of-the-art infrastructure management systems use Markov decision processes (MDPs) as a methodology for maintenance and rehabilitation (M&R) decision making. The underlying assumptions in this methodology are that an inspection is performed at the beginning of every year and that inspections reveal the true condition state of the facility, with no error. As a result, after an inspection, the decision maker can apply the activity prescribed by the optimal policy for that condition state of the facility. Previous research has developed a methodology for M&R activity selection that accounts for the presence of both forecasting and measurement uncertainty. This methodology is the latent Markov decision process (LMDP), an extension of the traditional MDP that does not necessarily assume the measurement of facility condition to be free of error. Both a transient and a steady-state formulation of the facility-level LMDP are presented. The methodology is extended to include network-level constraints. This can be achieved by extending the LMDP model to the network-level problem through the use of randomized policies. In addition, both a transient and a steady-state formulation of the network-level LMDP are presented. A case study application demonstrates the expected savings in life-cycle costs that result from increasing the measurement accuracy used in facility inspections and from scheduling inspection decisions optimally.
Heuristic Optimization Models for Service-Request Vehicle Routing with Time Windows in a Geographic Information Systems Environment
Authors: Wei Heng , Li Qiang , Kurt Carl E.
Published: April 2007

The construction of effective heuristic optimization models for the service-request vehicle routing with time windows (SRVRTW) problem is addressed. Three basic models and the method of their software package development in a geographic information systems environment are introduced. Among the three basic models, the hard TW model improves Solomon’s model in terms of insertion criteria and defines the objective for SRVRTW problems. The effects of contributing factors on routing solutions are analyzed, and appropriate values for these parameters are suggested on the basis of tests carried out in a case study. Second, the negotiable TW and many-to-many models are proposed on the basis of the demand of real-life service-request problems. The software package developed, which uses MapInfo integrated with C++, provides an effective tool for SRVRTW problems. A real-life case study is described, illustrating major functions and the execution of the package. With the use of good programming procedures and attention to the related database structure, excellent performance and functionality were experienced.
Real-Time Dynamic Traffic Assignment and Path-Based Signal Coordination; Application to Network Traffic Management
Authors: Abdelghany Khaled F. , Valdes Didier M. , Abdelfatah Akmal S. , Mahmassani Hani S.
Published: April 2007

As an example of integrating signal control with network traffic assignment, the notion of path-based signal coordination in transportation networks is introduced and illustrated. The use of a real-time dynamic traffic assignment system allows prediction of the traffic flow patterns and identification of the dominant paths in the network. The signalized intersections along these paths, which may consist of combinations of straight sections and turning movements, are coordinated to increase the capacity of the freeway and the surface street system to efficiently absorb diverted traffic from the freeway. A set of experiments is designed to compare the network performance under the path-based coordination scheme with no coordination and arterial-based coordination. The experiments are conducted for both pretimed and vehicle-actuated signal control. An actual network, which represents the south-central part of the Fort Worth area, is used in these experiments. The network consists of a freeway (I-35W) surrounded by a street network with a total of 178 nodes and 441 arcs. The path-based coordination scheme is shown to outperform arterial-based coordination in the cases of both pretimed fixed control and vehicle-actuated signal control. A significant reduction in the network average travel time under the path-based coordination scheme is observed compared with the other schemes. This application further illustrates the benefits of real-time dynamic traffic assignment for advanced traffic management under incident conditions.
Very-Early-Strength Latex-Modified Concrete Overlay
Authors: Sprinkel Michael M.
Published: April 2007

The installation and condition of the first two very-early-strength latexmodified concrete (LMC-VE) overlays constructed for the Virginia Department of Transportation are described. The overlays were prepared with a special blended cement rather than with the Type I/II cement used in the conventional latex-modified concrete (LMC) overlay. LMC-VE mixture proportions, installation equipment, and procedures are similar to those used for conventional LMC overlays. However, when working with LMC-VE, the contractor must work faster because the concrete loses slump rapidly and the curing period is approximately 3 rather than 72 hours. Tests of the compressive strength of the LMC-VE overlay performed during the early hours after installation indicated that traffic could be placed on the overlay within 3 hours rather than within the 4 to 7 days required for the conventional LMC overlay. Tests of bond strength and permeability to chloride ion indicated that the overlays are performing satisfactorily and can be used as an alternative to LMC to extend the life of bridge decks. Pending continuing favorable test results, it is anticipated that LMC-VE overlays can be used when construction during short lane-closure periods is highly desirable. The use of LMC-VE may reduce inconvenience to motorists, allow for installation at night, provide negligible to very-low permeability, and provide high strength, particularly high early strength.
Cracking Damage/Deterioration and Rehabilitation Considerations of Some Birmingham, Alabama, Interstate Bridge Decks
Authors: Ramey George E. , Stallings J. Michael , Oliver Russell S.
Published: April 2007

The Alabama Department of Transportation (ALDOT) has more than 4830 m of major Interstate bridges (three to five lanes wide) near downtown Birmingham, Alabama, that have significant levels of deck cracking and deterioration. The bridges are part of the Interstate 65 and Interstate 59 highway system through the city and are approximately 27 years old. It appears that deck cracking is primarily the result of (a) early drying and thermal shrinkage, (b) early concrete obstructed settlement, (c) thin and flexible decks, (d) light and flexible superstructures, and (e) heavy traffic volume and loadings. The deck condition versus age and the crack classification/width versus age curves are presented for three typical bridge decks, along with a photographic portrayal of the state of deck cracking and deterioration. Comparisons of experimental and theoretical load deflection behavior of two of the bridges are presented. The rehabilitation or replacement of the bridge decks that are approximately 55 740 M2 is a matter of great concern to ALDOT. Actions the agency is currently taking and actions it plans to take are also presented.
Virginia’s Approach to Evaluation of Concrete Resistant to Alkali-Silica Reactions
Authors: Lane D. S.
Published: April 2007

Beginning in the late 1980s, the Virginia Department of Transportation (VDOT) observed that concrete made with aggregate containing micro-crystalline, strained, or highly fractured quartz was failing earlier than expected due to alkali-silica reactions (ASR). These reactive constituents are widespread in the aggregate resources available for use in Virginia. Difficulties have been encountered in accurately classifying aggregates with regard to their potential reactivity. Consequently, VDOT instead is attempting to identify and use cementitious materials that prevent or hinder ASR. These materials, pozzolans and slag, have been shown to reduce both ASR and permeability, resulting in a more durable concrete. Two newly developed tests were used to evaluate the effects of cementitious materials (ASTM C1260 and ASTM C1293) on the ASR potential of construction aggregates. The results of these tests were compared with the results of a more accelerated test (ASTM C441) that uses an extremely reactive synthetic aggregate. Differences in test results were noted: the C441 test, using more stringent criteria, predicted higher replacement levels for a given pozzolan or slag with a portland cement of a given alkali content than are interpreted from the C1260 or the C1293 tests. However, although a greater degree of confidence in long-term performance can be placed in material levels that “pass” the C441 test, the material replacement levels that meet the criteria specified in the C1260 and C1293 tests have been generally observed to provide acceptable performance in the field.
Use of a Lithium-Bearing Admixture To Suppress Expansion in Concrete Due to Alkali-Silica Reaction
Authors: Thomas Michael D. A. , Stokes David B.
Published: April 2007

The findings of a laboratory study on the effects of a lithium-based admixture on alkali-silica reaction are presented. The admixture essentially represents an intermediate stage in the lithium extraction process of the ore spodumene. Spodumene ore is normally crushed and fired in a kiln to “untie” the lithium prior to its extraction. The material at this stage is known as decrepitated spodumene (DS). DS is basically an amorphous alumino-silicate that contains significant quantities of “available” lithium. As such, DS has the potential to act both as a pozzolanic mineral admixture as well as a chemical suppressant of alkali-silica reactivity. Laboratory testing included pore solution studies of pastes and mortars containing DS and expansion studies of mortar bars containing Pyrex glass (ASTM C311) and concrete prisms containing reactive aggregates from three different sources in North America. The results show that significant quantities of lithium are released by the DS into the pore solution of pastes and mortars over time. After 1 year, the Li+ concentration of pastes with 15 to 20 percent DS (mass replacement of high-alkali cement) was approaching 0.3 moles/liter. The efficacy of DS in controlling expansion in concrete containing reactive aggregates was found to depend on the nature of the reactive aggregate. Higher quantities of DS were required with more reactive aggregate. This is thought to be due to the rapid expansion observed for concretes containing such aggregates. The expansion occurs before significant lithium is released from the DS, and thus higher levels of DS are required. It is possible that the efficiency of DS with such aggregates may be improved by increasing the fineness or modifying the manufacturing process.
Effect of Microcracking on Durability of High-Strength Concrete
Authors: Aldea Corina-Maria , Shah Surendra P. , Karr Alan
Published: April 2007

The relationship between cracking and chloride and water permeability of high-strength concrete (HSC) was studied. Two different mix designs were used: HSC_1 (w/b = 0.31) and HSC_2 (w/b = 0.25). The effects of crack width and sample thickness on permeability were examined. Cracks of designed widths were induced in the concrete specimens using the feedback-controlled splitting tensile test. Chloride permeability of the cracked samples was evaluated by using a rapid chloride permeability test. The water permeability of cracked concrete was then evaluated by a low-pressure water permeability test. Among the materials tested, only high-strength concrete with a very low water-to-cement ratio conductivity is sensitive with respect to cracking. The water permeability of cracked HSC significantly increases with increasing crack width. Among the parameters considered, crack parameters significantly affect water permeability, and there is little thickness effect. The results indicate that the water permeability is significantly more sensitive than conductivity with respect to the crack width used.
Study for Highway 407 Transitway System Plan and Station Site Plan
Authors: Gorys Julius , Poulos Nicholas , Ruggero Al
Published: April 2007

A 36-km section of a tolled highway bypass of Toronto, the Highway 407 Express Toll Route, has been completed and is in operation. Included in the planning for the aforementioned is a “transitway” function. A property protection study was initiated to develop a transitway system plan and a station site plan. This study generated estimates of future transit ridership and developed hierarchical station configurations based on technology choices.
Transit Joint Development in San Diego: Policies and Practices
Authors: Bragado Nancy S.
Published: April 2007

The Metropolitan Transit Development Board (MTDB) in San Diego, California, has been steadily increasing its portfolio of joint development projects through an incremental approach to project development. A key element of MTDB’s policy toward joint development is that projects must benefit the transit system and the communities in which they are located. Benefits to the system are measured through increased ridership potential and, to a lesser degree, generation of an income stream. Projects that have met these criteria range from the landmark Metropolitan Transit System (MTS)/James R. Mills Building to vendor concessions. The agency has also been successful in influencing the development of properties it does not own that are adjacent to light rail stations and major bus corridors, in part through public education and outreach efforts supporting transitoriented development. In addition, MTDB has agreements with the cities and the county in its area of jurisdiction through which the cities route projects and policy plans to MTDB for review and comment. Several case studies are described that illustrate various types of joint development and private and redevelopment projects. In summary, MTDB has been successful in its joint development program because it has capitalized on a wide range of opportunities while maintaining long-term goals.
Modeling Level-of-Service Factors in Public Transportation Route Choice
Authors: Pursula Matti , Weurlander Minna
Published: April 2007

A combined revealed preference (RP) and stated preference (SP) survey that was done in the Helsinki, Finland, metropolitan area to reveal the importance of different level-of-service (LOS) factors in public transportation is described. The study was done as a route choice survey between origin-destination zone pairs with two route alternatives that had differences in total travel time, number of transfers, possibility of getting a seat, walking and waiting times, and fare. A separate SP game of transfer environment was also done. The SP study was undertaken among the RP respondents. The levels of the SP attributes were tailored according to the trip in the RP survey. The RP and SP data were analyzed together using structured-tree-type logit models to adjust the variances in different data sets. According to the study results one transfer equals about 10 min of door-to-door travel time, and passengers are willing to travel 15 min longer to get a seat for the trip. The experiences from the use of a tailored postal survey in a SP study were quite positive. However, regardless of study method a very careful definition of the attributes and attribute levels is needed. The results of the survey are quite in line with other similar studies reported in the literature and give an estimate of the passenger response to the public transportation LOS attributes included in the study.
Enhancing Transit in Tourist Areas Through Improved Modeling and Priority Initiatives: Case Study from Australia
Authors: Jepson Dale , Bitzios Damien , Ferreira Luis
Published: April 2007

Mode choice models developed thus far have not explicitly defined visitor mode choice and have therefore assumed that the mode choice characteristics of visitors are the same as those of residents. In areas such as the Gold Coast, Australia, visitors account for over 20 percent of the total population and provide transit patronage levels equivalent to those of residents. With the increasing emphasis on attracting higher transit mode shares, there is a need to understand the unique combination of factors that attracts visitors to various types of transport during their stay. Results are outlined of the first phase of a two-phase research program involving surveys of visitors to calibrate visitor mode choice models. Also dealt with specifically are bus priority treatments and their applicability to tourist areas. The current trends in bus priority treatments are addressed by considering a case study for the Gold Coast Highway, located on Queensland’s Gold Coast, approximately 100 km to the south of Brisbane, the capital city of the state of Queensland. An evaluation of bus priority treatments and conditions for justification for such measures is provided, and the impact of introducing bus lanes, transit lanes, bus priority at traffic signals, and improved ticketing systems for the Gold Coast Highway is summarized. The analysis indicates that journey time savings for buses of up to 20 percent may be achieved with these bus priority treatments.
Practical Issues in Prototyping National Public Transport Journey Planning System Using JourneyWeb Protocol
Authors: Fingerle G. P. , Lock A. C.
Published: April 2007

This research examined the requirements for multiple travelers to request a local, medium-distance, national, or international itinerary plan from any node of a public transport journey planner system using timetable or schedule data from numerous public transport companies and modes. It was resolved that a four-tier, client-server architecture and a distributed data service would best meet these requirements, using the Internet to exchange trip schedule data according to an agreed JourneyWeb protocol based on extended markup language. The JourneyWeb protocol is explained, and the field characteristics and attributes used in mutual data interrogation between itinerary planning services, allowing the web of services to expand, are defined. Successive iterations of a prototype system, first between two counties and then expanded to include a larger geographic area, demonstrate progress to date using real schedule data.
Strategies To Improve Job Accessibility: Case Study of Tren Urbano in San Juan Metropolitan Region
Authors: Zhang Ming , Shen Qing , Sussman Joseph
Published: April 2007

The question addressed is what policies should be recommended to complement rail transit investment in further enhancing job accessibility in the case of Tren Urbano, a new rail system in the San Juan, Puerto Rico, metropolitan region (SJMR). This discussion is a continuation of an earlier analysis of the spatial effects of Tren Urbano. First, policy scenarios based on two approaches to accessibility improvement—mobility and land use—are designed. Then the accessibility effects of these policies are examined using the Hansen accessibility model. The analysis results show that with supportive transportation and land use policies, the benefits of building the new rail system for job accessibility improvement can be significantly extended along the spatial dimension and more desirable social outcomes can be obtained. Four policy recommendations are made. First, high-flexibility transportation systems should be developed as complements to rapid rail transit. In the SJMR this means paying particular attention to the improvement and integration of Publico or similar van services. Second, higher land development intensity should be encouraged in station areas, that is, higher residential density (25 units or more per hectare) and a higher floor area ratio for nonresidential uses. Large surface parking areas surrounding stations should be avoided. Third, mixed land use should be promoted in station areas, with affordable housing and lower-wage jobs. Finally, pedestrian-friendly station environments should be created. A walkability index is introduced to evaluate the walking environment.
Evaluation of Charlotte’s Proposed Multihub Transit Service Plan
Authors: Presutti Elizabeth L. , Hartgen David T.
Published: April 2007

In 1998 Charlotte, North Carolina, considered a one-half-cent sales tax to improve transit service. One element of the expanded transit system proposes six new employment-centered hubs in suburban Charlotte, served by local circulator bus service and interhub connections. The likely ridership and costs of the multihub-based system are assessed. Population demographics in the areas immediately surrounding each hub are estimated using TransCAD 3.1. Ridership is estimated using equations relating per-capita ridership rates to automobile ownership and service (vehicle revenue hours) for existing routes and empirical ridership rates per vehicle hour for express and local circulator service. Scenarios are then tested on various levels of increased service. Results show that the new service, by itself, will add little to system ridership but will substantially increase the system deficit: for instance, adding about 44 percent more service solely as new circulator and interhub connections would raise ridership 14.0 percent, from 11.68 million to 13.31 million riders, while increasing the system’s deficit 56.4 percent from $14.87 million to $23.26 million because the new service would generally serve low-ridership areas of the city. On the other hand, if existing service was also expanded along with the hub circulator service, ridership would expand substantially: a 100 percent increase in base service along with the new service would increase ridership 76 percent, to 20.6 million riders, and increase the system’s deficit 173 percent, to $40.6 million. Taxpayers would pay about $2.90 for each new transit trip attracted.
Public Choice in Transit Organization and Finance: The Structure of Support
Authors: Levine Jonathan , Park Soonae , Wallace Richard R. , Underwood Steven E.
Published: April 2007

The nature of support for public transit spending and organizational structure in a heavily automobile-dependent region is explored thorough structural equation modeling based on survey data from 500 randomly selected households in southeast Michigan. Alternative factors underlying support for transit taxation are tested, including congestion relief, environmental conservation, social service provision, perceived future need, and general attitude toward government spending. The study finds a surprisingly strong endorsement of transit as a necessary social service and concludes that in automobile-dependent areas, transit’s primary task when appealing for locally generated financing is to demonstrate its success in serving as the bottom-line guarantor of mobility for the young, elderly, disabled, unemployed, and poor.
Structuring and Assessing Transit Management Response to Customer Satisfaction Surveys
Authors: Christopher Mary Kay , Stuart Darwin , Foote Peter J.
Published: April 2007

A random-digit-dial telephone Customer Satisfaction Survey of more than 2,400 Chicago Transit Authority (CTA) riders who had ridden CTA in the week before the survey was conducted in November 1997. A follow-up to a similar 1995 baseline survey, the survey revealed significant improvement in several key performance areas since 1995 for both bus and rail transit. Most of the improved satisfaction with transit service attributes could be directly tied to two types of service improvement launched between 1995 and 1997. First, an interdepartmental technical committee responded to the 1995 survey results to identify top-priority service improvement needs. Five action areas were inaugurated, with varying degrees of success. Second, three major ongoing agency initiatives—automated fare control implementation, a station improvement program, and administrative cost cutting—also addressed major concerns raised by customers. The relationship between these transit management efforts to improve customer satisfaction and the results of both surveys is described in terms of both the specific individual service attributes addressed (42 to 45 individual attributes) and nine different, broader performance dimensions developed to group these attributes. When asked about overall satisfaction with CTA, respondents showed a 9 percent increase in the share of those riders who were very satisfied between 1995 and 1977 (22 to 31 percent), increasing the share satisfied with CTA to 81 percent. Small but statistically significant improvements in customer satisfaction were achieved for both bus and rail modes, involving nine individual service attributes for bus and seven attributes for rail.
Transit Prepayment Challenges: Factors Influencing Customers’ Willingness To Purchase High-Value Tickets
Authors: Weinstein Aaron , Lockhart Robert , Rolandson Beth
Published: April 2007

Despite the availability of, and benefits associated with, prepaid storedvalue fare cards, many transit riders continue to select traditional singleride or round-trip tickets for payment of their fares. At the San Francisco Bay Area Rapid Transit District (BART), an effort was made to assess why many riders select low-value fare instruments and to evaluate potential actions to increase the share of riders buying higher-value tickets. The qualitative and quantitative research techniques utilized at BART to explore this issue are described. Focus groups were conducted to identify important decision-making factors, which were later quantified through a telephone survey. Fear of losing high-value tickets coupled with a lack of information regarding the availability of these tickets appears to limit high-value ticket sales. Some possible approaches to encouraging the purchase of high-value tickets may include a last-ride-free feature and increased awareness of the availability of discount tickets at off-site sales outlets. This study provides insight into the decision-making process of customers when purchasing stored-value tickets and can help inform the policy-making process regarding ticket systems.
Unique Voucher Programs To Increase Alternative Commuting
Authors: Allen George Q. , Lipton S. Gregory , Brooke Brian
Published: April 2007

King County Metro Transit developed its Commuter Bonus voucher programs to provide employers and their employees with effective commute trip reduction tools. The program consists of Commuter Bonus, an incentive program to encourage employees to use transit agency services (bus, vanpool, and ferry); and a Commuter Bonus Plus incentive program to encourage employees to carpool, walk, bicycle, or telecommute. The Commuter Bonus voucher programs are unique for several reasons: the Commuter Bonus program is the only known transit voucher program administered entirely by a transit agency, and the Commuter Bonus Plus program is the only known carpool voucher program operated by a transit agency. In addition, program implementations required state-of-the-art anticounterfeiting strategies and the design and integration of off-the-shelf and proprietary software. A recent program evaluation indicated that the Commuter Bonus program generated 84,000 annual transit passenger trips and 440 vanpool riders who would otherwise not have used transit. Their use generated additional revenue for participating transit agencies. Commuter Bonus Plus resulted in a significant decrease in vehicle trips while generating revenue for local retailers. The evaluation demonstrated that a large-volume voucher program could be operated in-house from a single desktop computer.
Exploring the Paradigm Shifts Needed To Reconcile Transportation and Sustainability Objectives
Authors: Litman Todd
Published: April 2007

A sustainable economy is sensitive to economic, social, and environmental constraints. Sustainability requires more efficient, equitable, and environmentally sensitive transport. This cannot be achieved simply by changes in vehicle design or improved traffic management. It requires changes in the way we think about transportation, and how we identify and evaluate solutions to transport problems—“paradigm shifts.” This paper discusses these changes and their implications for transportation decision making. Sustainability requires rethinking how we measure transportation. Transport planners often treat vehicle movement as an end in itself. Sustainable transportation planning focuses on access, which can often be improved with strategies that reduce the need to travel altogether, such as land use management and improved communications. Sustainability requires comprehensive decision making that takes into account indirect and interrelated effects. Sustainable transport planning begins with a community’s strategic plan, which individual transportation decisions must support. It requires policies that reward individuals, agencies, and communities for achieving sustainability objectives. There are many specific transportation strategies that can help support sustainability, including improved travel choices, more efficient pricing, and more efficient land use. Individually such strategies may have modest impacts, but implemented together they can provide substantial benefits. At least onethird of current motor vehicle use could be reduced by eliminating market distortions that encourage inefficient travel.
Economic and Sociodemographic Influences on Autolessness: Are Missing Variables Skewing Results?
Authors: Gardenhire Alissa D.
Published: April 2007

The factors that influence whether a household will be without a vehicle, termed herein as “autolessness,” are examined. First, national survey data in logistic regression models are used to examine the strength of three variables identified in the literature as key influences on autolessness: income, transit access, and urban residence. In a second model, however, the inclusion of social and demographic variables representing race, sex, and age of the household head and life-cycle status of the household reveals that they, too, exert substantial influence on the likelihood of a household being without a car. Furthermore, inclusion of these variables reduces the magnitude of the influence of the key variables. They exert influence along sociodemographic lines; for instance, female-headed households are more likely to be without a car than maleheaded households, controlling for the three key variables referred to above. However, these sociodemographic variables do not directly influence autolessness. It is hypothesized that they measure influences, such as savings, wealth, and access to credit, that are differentiated on sociodemographic lines. Inclusion of these variables in subsequent modeling efforts would explain many of the differences in autolessness attributed to sociodemographic variables in this model.
Costs of Automobile Dependence: Global Survey of Cities
Authors: Newman Peter , Kenworthy Jeff
Published: April 2007

Automobile dependence is assessed in terms of its direct and indirect costs for 37 global cities. The data show that cities with the most car use, road provision, and urban sprawl have the highest road expenditure, the least transit cost recovery, the most spent on commuting, the highest external costs from road deaths and emissions, and the largest proportion of city wealth going into transportation. As well, the newly developing Asian cities are showing that their automobile-oriented planning is proving to be costly in economic and environmental terms. The costs of automobile dependence in a globally competitive urban environment cannot be simply rationalized away due to apparent or perceived benefits of automobile-based lifestyles.
SPARTACUS System for Analyzing Urban Sustainability
Authors: Lautso Kari , Toivanen Sami
Published: April 2007

SPARTACUS (System for Planning and Research in Towns and Cities for Urban Sustainability) is a strategic urban planning system based on a state-of-the-art land use/transport model (MEPLAN) combined with a set of urban sustainability indicators, the geographic information system–based Raster method to calculate values for some of the indicators, the MEPLUS database and presentation module, as well as the decision-support tool USE-IT. The USE-IT system is used for evaluating the results of policy options based on weighted indicator values representing social, environmental, and economic effects of the policies. The SPARTACUS system has been used for assessing policy options in a systematic way in three cities: Helsinki, Bilbao, and Naples. More than 30 policy elements (i.e., individual policy measures) have been analyzed. The policy elements represent different pricing, regulatory, land use, transport planning, and investment measures. Based on the results, policies and policy combinations comprising several promising policy elements have been defined and analyzed. The results show that the level of sustainability can be increased in the test cities in a cost-effective way by using a variety of policies, especially pricing and regulatory policies and their combinations. Negative side effects of individual policies can be mitigated by combining policies, and innovative policy combinations can be found. Recommendations for sustainable urban policies and future research are given, based on the above studies.
Noise Barriers Using Recycled-Plastic Lumber
Authors: Hag-Elsafi Osman , Elwell David J. , Glath Gary , Hiris Melanie
Published: April 2007

Increasing public demand for reduced traffic noise levels is generating a growing need for more and better highway noise barriers. Those using conventional materials such as wood, steel, or concrete deplete natural resources and occasionally meet public criticism with respect to aesthetics. Disposal of accumulating plastic waste is another environmental challenge. Barriers that use recycled plastic thus are not only functional but also environmentally beneficial. Such barriers are proposed in this paper. The proposed material is recycled-plastic lumber, a material extruded into standard lumber sizes used by the timber industry. This material has many advantages. It is durable and requires little maintenance, can be cut and fastened like wood, provides several aesthetic alternatives in both color and texture, is highly resistant to insects and graffiti, is readily available, and is thus inexpensive compared to custom-made plastic shapes. Being denser, it should block noise more effectively than wood sheathing of similar thickness. Wood or steel frames are proposed for structural support, with maximum span of the plastic-lumber sheathing limited to 1.22 m (4 ft). The wood or steel frames can be arranged in many configurations for aesthetic purposes and designed to satisfy optimal cost requirements. The proposed systems are competitive with current barriers with respect to initial cost and may have long-term economic benefits because of greater durability, minimal maintenance, and low life-cycle cost.
Bus Accessibility for People with Sensory Disabilities
Authors: Hunter-Zaworski Katharine , Hron M. L.
Published: April 2007

With the passage of the Americans with Disabilities Act (ADA) it has become a civil rights violation to deny access to public transportation to people with disabilities. ADA requires transit agencies to provide accessible buses or equivalent services to people with mobility, sensory, or cognitive impairments. Issues concerning people with sensory impairments, and their access to fixed-route transit services, are examined in this study. The literature concerning access to public transit by people with sensory disabilities is summarized in this paper, along with exemplary training programs and technologies that have improved transit accessibility for people with sensory disabilities. A major conclusion of this study is that technological solutions may not increase bus accessibility for people with sensory impairments. One-on-one interaction is needed to solve many individual access problems of the transit users. Training for transit personnel is needed so personnel become aware of, and more sensitive to, the needs of all transit users. Training for the transit user is necessary so that use of the transit system is accomplished with grace, speed, efficiency, and dignity. Training for those who train people with disabilities is necessary so that transit travelers will be informed about all the available services offered by transit agencies. Visual signage must be consistent and highly legible to be effective and includes sign and information location, lighting, contrast, and content.
Accessible Transportation Technology Transfer Program: One Year Later
Authors: Suen S. LING , Smith Trevor N. , Zavergiu Richard M. , Struthers Stacey
Published: April 2007

The results of the $3 million (dollar figures in Canadian funds) Technology Transfer Program on accessible transportation that was managed by the Transportation Development Centre of Transport Canada are described in this paper. The period is from 1991 to 1996. This program was part of the National Strategy for the Integration of Persons with Disabilities. A description of Canadians with transportation disabilities, followed by an outline of the Technology Transfer Program’s framework, management, and project results, is presented, along with the highlights of several projects. The analysis sheds light on the benefits and risks inherent in the technology transfer process between governments, technology developers, and transportation service providers. Six aspects of the Technology Transfer Program are discussed: the selection process; the selection committee; the contribution agreement and the payback clause; liability and insurance; government standards; and government regulations. The authors conclude that, because the target population is both small and diverse, market response to similar accessible technology transfer products could be accelerated by the introduction and the enforcement of regulatory measures to reinforce accessible transportation policies.
Evaluation of a Fixed Anti-Icing Spray System
Authors: Friar Shawn , Decker Rand
Published: April 2007

Each year hundreds of automobile drivers have accidents caused by iced-over bridges adjacent to roads that are free from ice. Ice forms on bridges because the ground does not insulate them; therefore, the temperature of a bridge deck rapidly cools to the ambient air temperature, which is often well below freezing. This is particularly evident on the Interstate 215 overpass/exchange at 6200 South Street in Salt Lake City, Utah. This bridge averages more than 24 accidents per winter season because of snow and ice conditions. A system was installed at this location that applied the anti-icing liquid agent magnesium chloride (MgCl2) to the northbound lanes of the freeway bridge deck. The southbound lanes received no additional treatment, other than the efforts of the Utah Department of Transportation’s snow- and ice-removal operators. The anti-icing spray system is parapet-mounted and delivers approximately 360 L/lane-km/spray (95 gal/lane-km/ spray) event of MgCl2. The effectiveness of the spray system was analyzed for the 1997 and 1998 winter season. The system reduced the number of accidents caused by snow and ice on the northbound side of the road by 64 percent. The ratio of the number of accidents occurring on the treated northbound side of the road to the number of accidents occurring on the untreated southbound side was reduced from 1.4 to 0.7. The anti-icing system proved effective in reducing the number of accidents that occur on this very dangerous section of roadway in Utah.
Performance and Failure Modes of Louisiana Asphalt Pavements with Soil-Cement Bases Under Full-Scale Accelerated Loading
Authors: Li Y. , Metcalf J. B. , Romanoschi S. A. , Rasoulian M.
Published: April 2007

The performance and failure modes of conventional soil-cement base asphalt pavements and alternative pavements have been investigated under accelerated loading. Surface cracking was evaluated in terms both of the crack rate (in meters per square meter) and the AASHTO Class 1, 2, and 3 classifications. Pavement structural capacity was evaluated in terms of falling weight deflectometer (FWD) deflection-based back-calculated moduli of asphalt layer and soil-cement bases. Analysis showed that there was no significant difference in pavement performance among the soil-cement base pavements, although the cement content, strength, and construction procedures for the soil-cement bases were different. A significant improvement in pavement fatigue life was found for the “inverted” pavement structure, in which a stone crack relief layer was placed between the soil-cement base and the asphalt surfacing. The fatigue life of the inverted pavement was five to six times longer than that of pavements without the stone layer. Different failure modes were found between the inverted pavement and the others, and the corresponding failure mechanisms were analyzed on the basis of the observations from the pavement postmortem, when loading was terminated. Analysis of the FWD deflection data indicated that under accelerated loading there was a significant decrease in asphalt and soil-cement moduli for the inverted pavement, although the same trend was not observed on the other soil-cement bases. The crack data were used to evaluate two pavement fatigue life prediction models. It was found that the current models are not applicable to the soil-cement base pavement with a stone crack relief layer.