bluuebunny/crossref_metadata_2025 huggingface dataset:
Long-Term Availability of Railroad Services for U.S. Agriculture
Authors: Vachal Kimberly , Bitzan John
Published: April 2007

Future customer demands, service availability, and industry investment decisions will shape the modal marketing decisions of the grain-marketing sector. The Delphi technique is used to survey a cross section of grain-industry experts regarding future trends for the grain-marketing sector. The survey produces several interesting expectations, including further consolidation of the rail and elevator industries, increasing prominence of the heavy-axle cars in grain service, the upward trend in rail rates, increased use of market-based car-ordering systems and shuttles, expansion of the short-line rail network, and small market-scale, but large-volume, increases in the share of grain marketed via container. The insights are valuable in understanding the future of the rail grain industry. These expert opinions are important to identify research needs and discuss implications of government policy and market investment that affect the rail grain sector.
Truck-Trip Generation at Container Terminals: Results from a Nationwide Survey
Authors: Holguín-Veras José , López-Genao Yamilka , Salam Abdus
Published: April 2007

Research conducted on truck-trip generation at marine container terminals based on a nationwide survey gathered data from 21 container terminals in the United States. The main features of the data are analyzed to provide a characterization of the problem. The data were used to generate trip-generation rates as a function of the area of the container terminal, and through a set of regression models of one-way truck traffic, as a function of a set of independent variables—most notably, the number of 20-ft-equivalent units and the number of container boxes handled by the terminal in a given year. The analyses of both trip-generation rates and the regression models indicate that there are statistically significant differences in the regional patterns of trip generation.
O-Bahn Busway: Adelaide’s Experience
Authors: Rogers Lee H.
Published: April 2007

In 1980 the state of South Australia contracted with the German supplier of a new busway technology called O-Bahn. The project produced an 11.8-km busway alignment that was built in two phases with public operation in 1986 and 1989. Although the technology has functioned without fault and the safety record is excellent, the project has not experienced robust patronage growth or political success. During the 1990s public transit has been privatized and overall system ridership has declined by 30%. The long-term relationship between the foreign contractor and the local managers and staff failed to create a positive atmosphere for ongoing work, whether locally, nationally, or abroad. Although local and state officials provide positive public comment about their happiness with the technology, their management and policy actions suggest tepid belief in the concept.
Design and Implementation of Bus–Holding Control Strategies with Real-Time Information
Authors: Fu Liping , Yang Xuhui
Published: April 2007

A systematic study is described to address various design and implementation issues associated with the problem of real-time bus holding control. Two holding control models have been investigated. The first model follows the conventional threshold-based control logic that determines holding times on the basis of headway to the preceding bus. The second model makes use of both preceding and following headways in identifying optimal control decisions with the assumption that real-time bus location information is available for estimating future bus arrivals at the control stop. An extensive simulation analysis is performed using a real-fife bus route operated by the Grand River Transit of the region of Waterloo, Ontario. The simulation results have substantiated several conclusions and yielded new findings on various issues such as where to set the control point, how many control points should be used, what is the optimal control strength, and what is the value of real-time location information.
Platform Layout for the New Britain to Hartford Busway
Authors: Edison Watkins Kari , Sorenson Timothy , Garrick Norman
Published: April 2007

The New Britain to Hartford Busway is a two-lane, exclusive, bus-rapid-transit facility to be constructed along abandoned and active rail lines connecting the cities of New Britain and Hartford. The preliminary design and Environmental Impact Statement are currently being completed for this 15.1-km (9.4-mi), 12-station facility. As part of the preliminary design, a process of evaluating varying platform layout configurations was undertaken. To design the busway stations, many elements had to be taken into consideration. First, the busway is to provide multiple types of service, including express bus service, therefore requiring bus pull-offs. Second, the right-of-way along the busway corridor is narrow and the effect of this needs to be minimized; therefore, alternative platform layouts need to have a minimum width when possible. In addition, the busway operation and patron use had to be safe, secure, comfortable, and convenient while providing connectivity to the adjoining land use. Three platform configurations were investigated, including center platforms, traditional opposite platforms, and offset platforms. Although the offset platforms provided the narrowest design, their use was rare because they were perceived by many to be less safe for the rider than the opposite platform design. For most of the stations, a modified opposite platform design was chosen by the reviewing agencies and members of the public. The center platforms were eliminated because it was decided that the existing right-side-door fleet of buses would be used in conjunction with any new buses.
Design of Bus Routes: Methodology and the Santo Domingo Case
Authors: Ceder Avishai , Gonzalez Oneximo , Gonzalez Hugo
Published: April 2007

Growing traffic congestion, the importance of preserving the environment, and the problems of road safety are the main reasons to consider new initiatives worldwide in designing new urban transit routes. A need exists to develop a practical methodology for the construction of a new or improved network of bus routes along with intermodality considerations. An approach for the design of urban bus routes is presented with an example of designing new bus routes for the city of Santo Domingo in the Dominican Republic. Santo Domingo has major congestion, environmental, and safety problems. The presented approach involves a framework for the construction of operational objective functions for the bus-network-design problem. This framework takes into account passenger, operator, and community interests. The methodology combines the philosophy of mathematical programming approaches with decisionmaking techniques, so as to allow the user to select from a number of alternatives. The overall formulation is nonlinear and mixed-integer programming. The bus-network-design formulation used in the case study of Santo Domingo, a city with 3 million inhabitants, involved a large network of feasible bus routes subjected to the proposed method and resulted in 84 new bus routes. With other accompanied measures, the new bus routes will change the bus system image in Santo Domingo.
Simulation Analysis for the Management of an Electric Vehicle–Sharing System: Case of the Kyoto Public-Car System
Authors: Nakayama Shoichiro , Yamamoto Toshiyuki , Kitamura Ryuichi
Published: April 2007

A multistation electric vehicle (EV)–sharing system has been in operation on an experimental basis in Kyoto, Japan. Members of the system can check out EVs at a station and return them at any station. To reduce the cost of system operation, EVs are not reallocated to stations by the operator. This feature, at the same time, may delimit the efficiency of the system because of the mismatch between the spatial distribution of the demand and the distribution of EVs among the stations. A simulation model of system operation is constructed and the optimal management of the system configured using genetic algorithms, with the number of checkouts per vehicle set as the objective function to be maximized. The number of vehicles, parking capacity at each station, and number of members are among the decision variables. The results suggest that the optimal number of EVs is about half the total number of parking stalls. This implies that the efficiency of the system does not necessarily improve as more EVs are introduced. Also, the results suggest that even if a new station is introduced into the system, the efficiency does not necessarily improve.
Shared-Use Vehicle Systems: Framework for Classifying Carsharing, Station Cars, and Combined Approaches
Authors: Barth Matthew , Shaheen Susan A.
Published: April 2007

In recent years, shared-use vehicle systems have garnered a great deal of interest and activity internationally as an innovative mobility solution. In general, shared-use vehicle systems consist of a fleet of vehicles that are used by several different individuals throughout the day. Shared-use vehicles offer the convenience of the private automobile and more flexibility than public transportation alone. These systems are attractive since they offer the potential to lower a user’s transportation costs; reduce the need for parking spaces in a community; improve overall air quality; and facilitate access to and encourage use of other transportation modes such as rail transit. Shared-use vehicle systems take many forms, ranging from neighborhood carsharing to classic station car models. Given the recent proliferation in system approaches, it is useful to establish a classification system or framework for characterizing these programs. The classification system presented here outlines key program elements that can help policy makers and practitioners characterize and evaluate various aspects of this rapidly evolving field. Further, it helps researchers analyze and compare the various models, including their similarities, differences, and benefits. A shared-use vehicle classification system is provided that describes existing and evolving models; examples are provided of each. It is argued that carsharing and station car concepts can be viewed as two ends of a continuum, sharing many similarities, rather than as separate concepts. Indeed, many existing shared-use vehicle systems can be viewed as hybrid systems, exhibiting key characteristics of both concepts.
Transit User Perceptions of the Benefits of Automatic Vehicle Location
Authors: Peng Zhong-Ren , Yu Danlin , Beimborn Edward
Published: April 2007

An attitudinal survey on transit riders’ perception of the importance transit users place on features of an automatic vehicle location (AVL) system is reported. Onboard surveys and on-time field checks were conducted in the cities of Manitowoc and Racine, Wisconsin, to determine how users in those cities perceive their transit systems and how well each transit system performs. The surveys indicate that transit riders put a great value on increased on-time performance and improved schedule reliability. Passengers value features that AVL technology could bring, such as improving on-time performance, knowing when the next bus will arrive, knowing how long the delay is in case of delay, and knowing that another bus could be dispatched in case of breakdown. The surveys indicate that AVL technology could improve transit services and add value to passengers. The survey also found the expected ridership increase resulting from the AVL technology to be moderate. On-time performance surveys conducted in each city indicate that transit services in these communities generally operate on time at the route level. Although there are bigger variations at the timepoint level, transit services are usually on time. The implementation of AVL could further improve on-time performance, but maybe only marginally.
Sustainable Urban Transport in the 21st Century: A New Agenda
Authors: Schipper Lee
Published: April 2007

Trends in urban transportation and environment are reviewed, with a focus on developing countries. “Sustainable transportation” is defined to include economic and environmental sustainability as well as equity as key criteria. Governance sustainability is also important if policies and technologies are to reduce the main externalities of urban transport. It is important to relate emissions to traffic, modal share, fuel use, and fuel characteristics; transport policies must confront all of these components if emissions are to be reduced significantly. Urban areas in developing countries have become the most polluted and congested cities in the world because of barriers to serious transport sector reform addressing these ills. However, some policies and technologies are permitting regions in Latin America and Asia to begin to change. Strong actions by cities, backed by national government formulation of equipment and fuel standards and supported by private-sector initiatives, are all needed— together with political will—to reverse the unsustainable trends in urban transport in the largest urban areas today.
Comparison of Measured and Modeled Sound Levels in the Vicinity of Traffic Noise Barriers
Authors: Wayson Roger L. , MacDonald John M. , Arner Wayne , Lindeman Winfield M. , Berrios Mariano
Published: April 2007

A detailed noise prediction model was used to compare 11 highway noise barrier locations in Florida. Insertion losses, ground effects, shadow zones, and overall trends were determined or analyzed, or both. Each location was modeled using STAMINA2.0 (current FHWA regulatory model), STAMINA2.1 (Florida’s version of STAMINA2.0 with state-specific emission levels), the Traffic Noise Model (often referred to as TNM; this model will replace STAMINA2.0 in the year 2002), and the University of Central Florida Community Noise Model (CNM5.0). The modeled results were then statistically compared with the measured results. Statistical evaluation results were similar for all models for overall, absolute prediction compared with the measured value, with STAMINA2.1 being slightly better. All models provided adequate results, but ranges of error were significant. When the propagation components were explored, by comparing reference levels with those behind the barrier, the TNM was significantly better. The results also provided further insight into the benefited regions behind the barrier, a more detailed understanding of how the models perform for this complex interaction with the ground and sound wave, and how background levels change the actual size and shape of the benefited region.
Application of the Boundary Element Method to Prediction of Highway Noise Barrier Performance
Authors: Suh Sanghoon , Mongeau Luc , Bolton J. Stuart
Published: April 2007

The boundary element method has proven to be an important tool for the computational solution of many engineering problems. A commercial boundary element code was applied to traffic noise barrier analysis. First, it is shown that boundary element models may be used to quantify the accuracy of existing, approximate barrier models, for example, diffraction-based models. Diffraction-based models have been widely applied in noise control engineering applications owing to their relative ease of use. Recently, it was suggested that multipath diffraction components should be summed on a phase-coherent basis instead of on an energy basis. Here the accuracy of a phase-coherent diffraction model has been verified against the boundary element solution, showing limitations of the diffraction model. Second, the boundary element method was used to calculate a new barrier performance metric. In the past, the insertion loss has been considered the most important measure of noise barrier performance. However, insertion loss is normally defined at a particular receiver point in the shadow zone, and its value may vary significantly from point to point. The propagating sound power calculated on a recovery plane in the barrier shadow zone provides a more effective performance measure than does insertion loss when comparing the performance of different barrier designs.
Transverse-Tined and Longitudinal Diamond-Ground Texturing for Newly Constructed Concrete Pavement: A Comparison
Authors: Burgé Paul L. , Travis Keith , Rado Zoltan
Published: April 2007

The purpose of this study is to provide a comparison of longitudinal diamond-ground and transverse-tined pavement surface texturing for newly constructed portland cement concrete pavement (PCCP). The study area is located along a test section of I-190 in Buffalo, New York. The two PCCP surface treatment types under evaluation are compared based on safety, noise, construction cost, service life, rideability, handling, and maintenance requirements. The initial evaluation is documented, as is the analysis of follow-up noise and skid resistance measurements conducted approximately 1 year later. Analysis of the initial testing indicates that the relative skid resistance of the experimental longitudinal diamond-ground surface is as good or better than that of the transverse-tined surface. The results of the noise analysis indicate that the longitudinal diamond-ground surface is 2 to 5 dB quieter depending primarily on the traffic vehicle mix. Noise and skid resistance measurements conducted 1 year later showed little change. Although less construction time was required for the transverse-tined pavement compared with that for the diamond-ground pavement, the actual cost difference is not quantifiable. However, a higher initial cost for longitudinal diamond grinding would likely be partially offset by an extended service life.
Defining Reasonable and Feasible Traffic Noise Abatement: Consideration of Quantitative Approach
Authors: Lindeman Win
Published: April 2007

Where did all of this business about reasonable and feasible traffic noise abatement begin, and how can it best be incorporated into today’s environmental impact assessment process? These questions prompted a third: How can the decision-making process be improved when it comes to determining when traffic noise abatement is reasonable and feasible? Historically, the consideration of reasonable and feasible traffic noise abatement can be traced to FHWA’s directives issued in 1973. Following more than two decades of application by state highway agencies, FHWA issued a report in 1992 that questioned what criteria should be used to determine reasonable and feasible traffic noise abatement. This report prompted the Florida Department of Transportation (FDOT) to assess its process related to reasonable and feasible abatement. After nearly a decade of adjustment and tweaking of the current process, FDOT has developed an alternative methodology. This quantitative method could be used to assess noise abatement reasonableness and feasibility and help to remove the appearance that subjective abatement decisions are being made. The quantitative methodology that FDOT developed would reduce the appearance of subjectivity by applying a series of quantifiable criteria that use numeric values to produce a summed value. When the summed value is compared with an established range, it would indicate whether noise abatement is reasonable and feasible for the given situation.
Promoting Environmental Stewardship in Transportation: Maintenance and Operations at the New York State Department of Transportation
Authors: Nelson Debra A. , McVoy Gary R. , Greninger Laura
Published: April 2007

The New York State Department of Transportation (NYSDOT) is firmly committed to a proactive environmental ethic in providing a safe, efficient, balanced, and environmentally sound transportation system in the state of New York. This includes conducting maintenance, equipment management, and construction activities appropriately to prevent and minimize adverse impacts on the environment and to enhance the environment whenever possible. The maintenance and operations at NYSDOT show how the operational capabilities of a department of transportation can be brought to bear on the environmental stewardship responsibilities shared by all governmental organizations.
Integrated Approach for Identifying Potential Environmental Issues of Proposed Transportation Corridors
Authors: Bejleri Ilir , Zwick Paul , Lyons Andrew
Published: April 2007

Transportation projects often have delays, unnecessary duplication of efforts, and especially a lack of coordination among the involved agencies, leading to extra costs associated with the environmental review and approval process. The Florida Department of Transportation and University of Florida researchers are exploring several strategies for developing software tools to address such concerns. The goal is to identify major issues of the proposed transportation projects early in the planning phase so appropriate stakeholders can consult and resolve those issues before additional resources are invested in the project. Proposed is a methodological framework and a conceptual system design for building these software tools. The methodology for analyzing the impact is conceptualized as object-oriented, modular, and highly customizable. This approach offers analysis consistency and great flexibility for applications anywhere in the United States, provided that spatial databases are available. The system design strategy proposed for implementing the methodology takes an integrated approach between geographic information systems and relational database management systems. A prototype application developed based on the proposed framework proved effective in confirming the primary impact issues in a road extension pilot study in Florida. The tool quickly analyzed each of the proposed alignments and compared the levels of impact. Future directions will include expanding the focus from impact assessment to decision support with capabilities for selecting optimal road alignments.
Habitat Approach to Streamlining Section 7: Colorado Department of Transportation’s Shortgrass Prairie Initiative
Authors: Venner Marie
Published: April 2007

Starting in January 2000, FHWA, the Colorado Department of Transportation (CDOT), the U.S. Fish and Wildlife Service, and partners at public and private resource organizations came together to design an impact assessment and advance a mitigation and conservation banking process to aid in the recovery of declining species on Colorado’s Eastern Plains. The Shortgrass Prairie Initiative provides programmatic clearance for CDOT activities on the existing road network in the eastern third of Colorado for the next 20 years—through 2022; addresses 3 listed and more than 20 declining species with the greatest likelihood of being listed as threatened or endangered; and covers 90,000 acres of right-of-way in four of CDOT’s six regions. The agencies involved sought to invest resources, which would otherwise be spent on a project-by-project clearance process, in more comprehensive and proactive species conservation that would help alleviate the need for further listings and improve predictability in the project development process. Methodologically, the project focused on impacts to habitats rather than species individuals and estimated potential impacts using best available data, supplemented by expert opinion. The resulting project offers programmatic clearance with 1:1 (that is, 1 acre of impact to 1 acre of conservation/mitigation) habitat conservation, regulatory streamlining, cost savings in several categories, and more effective habitat and species preservation. The uniqueness of this project stems from its primary focus on species currently unlisted as federally threatened or endangered, coverage of major as well as minor projects, and the scale at which conservation is being pursued, including planned preservation of approximately 15,000 to 20,000 acres from 2002 onward.
Effect of Skip-Stop Policy on a Korean Subway System
Authors: Suh Wonho , Chon Kyung-Soo , Rhee Sung-Mo
Published: April 2007

An express subway system is planned for the Seoul, Korea, metropolitan area. Many problems are involved in operating an express subway system, such as installation of siding track and scheduling of passing locations and times for different headways. A skip-stop system can be considered as an alternative to express subway service. With a given origin-destination (O-D) demand matrix, distances between stations, headways, and maximum link speeds, the total time saving of a skip-stop schedule that satisfies safety conditions is predicted. In a field study, the time saving effects based on O-D data for Line 5 in Seoul, Korea, were simulated. From the simulation using C language, the peak-hour waiting time increased by 43.8% to 56.3%, but the travel time decreased by 10.8% to 12.9%, compared with the existing system. Waiting time was only 6.9% to 11.6% of the total system travel time—the total system time decreased by 7.1% to 7.8% and, in the maximum case, up to 9.8%. The skip-stop system can be advantageous to the existing system without constructing additional facilities. When the express line is installed, time saving effects and additional construction costs of the three systems (all-stop system, skip-stop system, and express line with siding track) could be compared.
Need for a New Commuter Car Entranceway Design for Mixed High- and Low-Level Platforms
Authors: Morlok Edward K.
Published: April 2007

Serious problems result from the use of both high- and low-level station platforms on U.S. commuter railroads (especially common in the Northeast). These problems include long dwell times and resultant slower service, passenger (and employee) accidents and injuries, difficulties in complying with Americans with Disabilities Act (ADA) accessibility requirements, increased train crew size, and problems accommodating freight trains on tracks with high-level platforms. Various partial solutions to these problems have been proposed, and many are being used. However, no solution deals effectively with all of the problems. The benefits of a single, comprehensive solution are identified, including improved service, increased ridership and revenue, meeting ADA accessibility requirements, and reduced costs. To indicate the importance of a solution to these problems, and to encourage thinking about solutions, some order-of-magnitude estimates of these benefits are developed. Finally, one design for dealing simultaneously with all of the problems is presented.
Bus Rapid Transit or Light Rail Transit—How to Decide?: Los Angeles Case Study
Authors: Stutsman John M.
Published: April 2007

The results of a real-world study comparing bus rail transit (BRT) with light rail transit (LRT) in the same corridor are highlighted. A major investment study (MIS)–environmental impact study (EIS) process was used, including community perspectives obtained from a significant outreach effort. In effect, this study represents a “plan-off” competition between the two modes, including ridership, cost-effectiveness, environmental impact, and community and political response. In 1994 the Los Angeles County Transportation Commission, predecessor agency to the current Los Angeles County Metropolitan Transportation Authority, environmentally cleared an Exposition Park Branch Line, which was an LRT branch line to the Los Angeles–Long Beach Blue Line. Because of financial constraints, the project languished until last year, when it was reconsidered through an MIS process for the Mid-City–Westside Transit Corridor Study. The MIS also called for a side-by-side comparison with BRT in the ElS–environmental impact review, which was publicly released on April 13, 2001. The findings to date indicate that LRT is environmentally superior to BRT (especially in relation to noise and traffic impacts) and has more new daily transit riders, whereas BRT is somewhat more cost-effective. From a community standpoint, LRT has generated more positive and negative reactions, perhaps because of the novelty of BRT to the general public in the western United States.
Socioeconomic, Community-Based Approach for Developing Integrated Mass Transit Systems: Application to City of Baltimore, Maryland
Authors: Goetz Phillips Claudia , Ruth Edwards Hazel
Published: April 2007

The city of Baltimore, Maryland, is now served by one heavy and one light rail line in addition to commuter rail service to Washington, D.C. However, the lines do not share any common stations and do not function as a network. The larger objective of this research was to evaluate ways in which the Baltimore transit system could be better integrated and contribute more to community well-being, environmental quality, and economic prosperity for all socioeconomic and racial and cultural groups. An underlying goal was to improve the mobility of a wider range of Baltimore residents so that their employment choices would not be limited by an underdeveloped transit system. This outcome was addressed in the context of the Intermodal Surface Transportation Efficiency Act of 1991, the Transportation Equity Act for the 21st Century, the Livable Communities Initiative, and the state of Maryland’s Smart Growth initiative. Only part of the larger agenda is presented here—the development of a community-based model for selecting and designing potential light rail line corridors in the larger system. The model used seven quality-of-life and livable community criteria—( a) potential to serve low-to moderate-income neighborhoods that have no direct access to public transportation (including bus access), ( b) high concentrations of employment opportunities along the route, ( c) highest number of intact commercial districts along the route, ( d) proximity to dense population centers (within a ¼-mi radius), ( e) proximity to numerous community social or cultural centers (including schools and churches), ( f) minimal physical environmental impacts, and ( g) the most potential to improve the pedestrian environment.
Rolling Stock Corrosion Control: Available Options and Implementation Issues
Authors: Krishnamurthy Balajirao G. , Shockley Thomas C.
Published: April 2007

The Maryland Transit Administration (MTA) operates a fleet of 53 light rail vehicles (LRV) to support Baltimore’s light rail system. The first 35 LRVs entered into service in 1992. This set of rolling stock is constructed primarily of low-alloy, high-tensile steel with characteristics similar to ASTM A-588 steel. The as-built exterior roof sheeting was coated with an epoxy-based system to protect against weathering. Over the years the coating system performance has degraded and allowed moisture to seep underneath, resulting in corrosion. The corrosion is evident throughout the fleet and is progressively damaging the thin roof substrate. To address this issue, MTA commissioned Booz Allen Hamilton, the rolling stock engineering consultant for MTA, to assess the extent of the corrosion problem, research available solutions, and define implementation requirements. Information is provided on commercially available technologies, associated costs and benefits, and the unique challenges faced in implementing a long-lasting solution for in-service rolling stock vehicles.
Ferry Service Market Analysis: National Parks of New York Harbor
Authors: Laube Melissa M. , Dyer Michael G.
Published: April 2007

A study team headed by the Volpe National Transportation Systems Center analyzed the feasibility of developing a water transportation system to serve the national parks of New York Harbor. This assessment was designed to address two principal objectives: ( a) determine the viability of water transportation as an access mode serving the parks and ( b) develop a preliminary ferry service concept plan. An analysis of market (demand) and site (supply) factors was critical to the assessment. The standard methods of demand forecasting could not be used in the market analysis, however, because most of the necessary data were lacking. Thus, an alternative approach was developed to perform this essential part of the assessment. Necessary market thresholds were estimated by applying a cost model. These thresholds were compared with ridership scenarios that were considered to be reasonable and conservative. From this analysis, the financial viability of the proposed ferry services was determined. For the particular application, the analysis results were sufficiently persuasive to suggest that proposed services should be implemented on a trial basis. This approach recognizes the practical limitations of demand forecasting in an environment in which data characterizing existing travel behavior are deficient and proposed services may attract substantially new markets with different socioeconomic and travel behavior characteristics. Because these limitations frequently apply to the planning of ferries and land-based modes serving parks and other recreational facilities, the described approach may have widespread applications.
Level of Snow Removal Service and Residents’ Willingness to Pay: Evaluation for Four Japanese Cities
Authors: Kishi Kunihiro , Takahashi Yohei , Hara Fumihiro , Satoh Keiichi
Published: April 2007

Residents were surveyed for their opinions on snow removal operations and the amount of money they would be willing to spend for snow removal service. From the results, basic policies are proposed for future snow removal operations in the four Japanese cities surveyed—Sapporo, Asahikawa, Kushiro, and Kitami, Japan. The results were analyzed by Kishi’s Logit PSM (KLP) to quantify the degree of snow removal desired by residents and the amount of money they would spend for this service. Residents rated maintenance of carriageway width and surface conditions on trunk roads fairly high and wanted significant improvements in snow removal on residential roads. Few residents wanted less snow removal service than they currently received. Most respondents wanted improvements. KLP analysis of the questionnaire results showed that Sapporo was the only city where the standard, acceptable cost to consumers was lower than its current snow removal cost. Many Sapporo respondents said that their current cost was unreasonably high, whereas many Asahikawa, Kushiro, and Kitami residents viewed their snow removal service as inexpensive.
Cost-Effective Preventive Maintenance: Case Studies
Authors: Baladi Gilbert Y. , Svasdisant Tunwin , Van Thomas , Buch Neeraj , Chatti Karim
Published: April 2007

With most of the highway systems in place, emphasis has shifted from design and construction to preservation and expansion. Unfortunately, the engineering skills, knowledge, and experience required to preserve the systems are significantly different than those required to originally design and build the systems. The experience gained in the initial phase, although important, is not in itself sufficient to preserve the systems. Pavement preservation is defined as the sum of all activities undertaken to provide and maintain serviceable roadways. This includes corrective maintenance and preventive maintenance, as well as minor rehabilitation projects. A cost-effective pavement preservation program requires a systematic and comprehensive engineering management of, and a solution to, pavement network problems. Preventive maintenance (PM) is defined by AASHTO as the “planned strategy of cost-effective treatments to an existing roadway system and its appurtenances that preserves the system, retards future deterioration, and maintains or improves the functional condition of the system (without increasing the structural capacity).” Hence, PM actions must be taken on pavements in relatively good condition. The development and implementation of a cost-effective PM program faces several obstacles: political debate, budget constraints, lack of education, and the existing practice of “worst pavements are first.” Some state highway agencies have overcome these obstacles, and they are harvesting the success of their PM programs. The state of the practice of three agencies—those of Arizona, Montana, and Pennsylvania—is presented and discussed.
Relationship of Design, Operating, and Posted Speeds on Horizontal Curves of Rural Two-Lane Highways in Nebraska
Authors: Schurr Karen S. , McCoy Patrick T. , Pesti Geza , Huff Ryan
Published: April 2007

Circular horizontal curves on rural two-lane highways in Nebraska with posted speeds of 55, 60, and 65 mph were investigated to determine the relationship of design and operating and posted speeds in an effort to provide guidelines for consistent roadway design along horizontal alignments. The mean, 85th percentile, and 95th percentile speeds; upper limit of the 16-km/h (10-mph) pace; and percent of vehicles within the pace of free-flowing passenger cars in dry, daytime conditions were analyzed at tangent approach and curve midpoint locations. Highway design guidelines suggest that the posted speed should represent the 85th-percentile speed of the vehicles using the facility and that the roadway alignment should be designed to support the 95th percentile speed. Multiple regression analysis was used to develop prediction equations for the mean, 85th percentile, and 95th percentile speeds at approach and curve midpoint locations. At the midpoint, the deflection angle and length of curve influenced the mean, 85th percentile, and 95th percentile speeds. As the posted speed increased so did the mean speed; as the approach grade increased, the 85th percentile speed decreased; and as the average daily traffic (ADT) increased, the 95th percentile speed decreased. Inferred design speed based on the 2001 AASHTO model does not appear to have an influence on 95th percentile operating speeds in Nebraska. At the approach locations, the 85th percentile and 95th percentile speeds were influenced by posted speed and ADT. The majority of drivers tend not to significantly reduce their speed when traveling from a tangent segment to a horizontal curve (for curves with radii greater than 350 m [1,146 ft]).
Assessment of NCHRP Report 350 Test Vehicles
Authors: Mak King K. , Bligh Roger P.
Published: April 2007

The appropriateness of test vehicles specified in NCHRP Report 350 was assessed, including ( a) whether the 2000-kg, three-quarter-ton pickup truck should continue to be used as a test vehicle, and if not, what replacement vehicle would be appropriate; ( b) whether the 820-kg passenger car should continue to be used as a test vehicle, and if not, what replacement vehicle would be appropriate; and ( c) whether another test vehicle should be added to the matrix—for example, an intermediate-sized passenger car. From the analysis, the following conclusions and recommendations were drawn: ( a) The three-quarter-ton pickup truck appears to be a good surrogate for the light truck subclasses. The recommendation is to keep the 2000-kg, three-quarter-ton pickup truck as one of the design test vehicles in the update of the guidelines for NCHRP Report 350. ( b) A potential problem is the availability of three-quarter-ton pickup trucks with standard cabs. An alternative design test vehicle may be an intermediate-sized sport utility vehicle, ( c) The availability of the 820-kg passenger car design test vehicle will be a problem within the next few years. The recommendation is to keep the current test vehicle as long as it is still readily available, or until the NCHRP Report 350 guidelines are updated, and to increase the curb weight to a level consistent with the curb weights of the two smallest passenger cars with reasonably high sales volume. ( d) The addition of a third design vehicle—for example, a 1500-kg intermediate-sized passenger car—to ensure that a roadside feature performs satisfactorily across the entire vehicle spectrum is highly desirable but cost-prohibitive. The addition of an intermediate-sized design test vehicle is therefore not recommended except in situations in which there is a perceived concern that the device may not function properly when impacted by an intermediate-sized vehicle.
Improved Truck Model for Roadside Safety Simulations: Part I—Structural Modeling
Authors: Reid John D. , Marzougui Dhafer
Published: April 2007

Computer simulation is now a mainstream tool for design and analysis of roadside hardware. For the past several years, researchers at the National Crash Analysis Center, Worcester Polytechnic Institute, and the University of Nebraska–Lincoln have been improving various features of a 2000-kg pickup truck model, the most widely used vehicle model for roadside safety simulation. Many modeling techniques have been learned, and an improved model has been developed that should aid analysts at other locations who are performing similar simulations. The various effects and difficulties of “reducing” a finite element model to decrease computational costs are examined, including the elimination of initial penetrations, free-edge tangling, snagging, and “shooting nodes.” The elective refinement of mesh density, the elimination of manipulated material densities to achieve desired masses, the improvement of connections between components, and the inclusion of all significant parts to improve accuracy are analyzed. The significance of not oversimplifying critical components is emphasized, as well as the importance of realistic model behavior. Evolutionary changes to vehicle models are required as more information is obtained about modeling and truck behavior in roadside safety applications. Different research groups will have different modeling approaches, but by sharing the details of those approaches and by sharing models, the collective capabilities in roadside safety simulation will improve, ultimately resulting in better roadside hardware. The models described are thought to be a tremendous improvement over previous-generation models of the reduced pickup truck.
Improved Truck Model for Roadside Safety Simulations: Part II—Suspension Modeling
Authors: Tiso Paolo , Plaxico Chuck , Ray Malcolm
Published: April 2007

The 2000-kg pickup truck is a very important vehicle in roadside safety research because it is specified in many of the tests in NCHRP Report 350. The characteristics of the pickup truck make it a very demanding crash test vehicle. Because the 2000-kg pickup truck is an important crash test vehicle, it was the very first vehicle chosen for development of a finite element model. The nonlinear finite element program LS-DYNA has become an important feature of roadside hardware design and analysis in recent years, and much of the success of these modeling efforts is partly caused by the availability of a good 2000-kg pickup truck model. Like all models, the model has evolved over the past decade. New features and improvements have been added continuously to the model by many different teams to solve specific analysis problems. One particular area where there has been a great deal of activity is in the area of modeling the suspension properties of the vehicle. Suspension response is particularly important for 2000-kg pickup truck impacts because the vehicle often experiences stability problems in impacts with roadside hardware. A number of improvements and modifications to Version 9 of the NCAC 2000-kg pickup truck model are summarized. These improvements involved changing the finite element model, changing element properties, and obtaining suspension response properties from physical tests. The 2000-kg truck model was then validated against a series of low-speed, live-drive tests with an instrumented pickup truck. The improved model provides more realistic vehicle suspension response than earlier models and should prove to be a valuable addition to future finite element modeling activities.
Box-Beam Burster Energy-Absorbing Single-Sided Crash Cushion
Authors: Reid John D. , Rohde John R. , Sicking Dean L.
Published: April 2007

A new box-beam burster energy-absorbing single-sided crash cushion (BEAT-SSCC) was designed and crash tested. This energy-absorbing crash cushion is designed to shield a rigid hazard, such as the end of a concrete safety-shaped barrier. Energy-absorbing capabilities of the BEAT-SSCC are based on the bursting tube technology, similar to that used with the box-beam burster energy-absorbing terminal. Five full-scale vehicle crash tests were conducted to evaluate the impact performance of the BEAT-SSCC in accordance with guidelines set forth in NCHRP Report 350: ( a) Test Designation 3-31—pickup truck head-on test; ( b) Test Designation 3-38—pickup truck critical impact point test (two tests to evaluate two different critical impact points); ( c) Test Designation 3-39—pickup truck reverse direction test at midpoint of crash cushion, and ( d) modified Test Designation 3-39—pickup truck reverse direction test at connection to the concrete barrier. The crash cushion performed as designed, and the BEAT-SSCC meets all evaluation criteria for a Test Level 3 crash cushion set forth in NCHRP Report 350. The BEAT-SSCC is being evaluated by FHWA for approval to be used on the National Highway System.
Performance of First Structure Built with High-Performance Concrete in Virginia
Authors: Ozyildirim Celik
Published: April 2007

The preparation and placement operations, concrete properties, costeffectiveness, and 5-year performance were evaluated for the first bridge containing high-performance concrete built by the Virginia Department of Transportation. High-performance concrete was used in the prestressed beams and cast-in-place substructure and deck concrete. The concrete in the beams contained silica fume, and the concrete in the cast-in-place substructure and deck contained slag. A high compressive strength was specified for the prestressed beams, normal strengths were specified for the cast-in-place substructure and deck concretes, and low permeability was specified for all concretes. Steam-cured specimens for the beams had high early strengths, but moist-cured specimens developed high long-term strengths. The permeability was much lower than specified. Concretes were easily placed, and the strengths were higher than specified. The structure was monitored during construction and surveyed after construction and at 5 years. Some cracking occurred in the deck, but the cracks were tight. High-strength concrete is recommended for use in beams if economically feasible. Temperature-matched curing should be used to determine the strength of elements where high temperature increases are expected, and pozzolans or slag should be used to reduce permeability.
Multimodal Transit Services with Heterogeneous Travelers
Authors: Lo Hong K. , Wan Quentin K.H. , Yip Chun-Wing
Published: April 2007

Public transit systems play a pivotal role in serving the transportation needs of many major cities. In Hong Kong, for example, more than 90% of the 11 million daily trips are provided by public transit services. The planning and design of these services, therefore, are important welfare considerations. The situation is particularly intriguing if these services are to be provided by the private sector whose primary objective is not to ensure welfare gains or an efficient utilization of the road space but to maximize profit. Analyses are of significant interest and potential application to many transit-oriented cities. In metropolitan areas in which multi- or intermodal trips are common, modeling the multimodal route-choice characteristics of heterogeneous travelers and the strategic interactions among the many private firms are important issues. In this study, mode-choice models were integrated in a network of competing transit operators. A novel network structure, designated as the state-augmented multimodal (SAM) network, was developed via a state augmentation approach. With this SAM network, the effect of fare competition and regulations on social welfare as well as on profitability of the companies could be examined. A case study of the ground transportation system connecting the Hong Kong International Airport with the city’s downtown was conducted.