bluuebunny/crossref_metadata_2025 huggingface dataset:
Transit Service Contracting and Cost-Efficiency
Authors: McCullough William Shelton , Taylor Brian D. , Wachs Martin
Published: April 2007

Contracting out for services is a controversial issue in public transit. Proponents argue that contracting always saves money in comparison with public operation, whereas critics respond that cost savings through contracting are overstated and come almost exclusively at the expense of labor. In order to determine the medium-term effectiveness of contracting out transit services, the impacts of contracting on the cost per vehicle-hour of fixed-route bus services are examined. A national sample of operators is studied, including some that contract out none of their routes, others that contract out all of their routes, and some that contract out a portion of their service. The effects of contracting on costs are examined for the years between 1989 and 1993. The findings show that bus services operated under contract are sometimes, but not always, less costly than directly operated services. A regression model is used to test the influence of a variety of factors on cost per vehicle-hour, and contracting is found not to be the most significant variable influencing operating costs. The findings indicate that vehicle and labor use have far more influence on cost-efficiency than either wages or contracting arrangement. It is concluded that cost-efficiency can be achieved in many different ways, depending upon local conditions, and contracting should not be assumed to be the most appropriate strategy in every situation.
Mandatory Employer-Based Trip Reduction: What Happened?
Authors: Dill Jennifer
Published: April 2007

During the 1980s and 1990s, California witnessed the widespread adoption and rejection of a policy known as mandatory employer-based trip reduction (EBTR). Mandatory EBTR was implemented largely through city and county ordinances and air district rules. EBTR rules and ordinances required employers to implement programs to reduce the number of employees driving vehicles to their worksite. The programs were adopted to reduce traffic congestion, pollutant emissions, or both. However, opposition to mandatory programs from the business community led to their prohibition in California in 1995. The purpose of this paper is to examine the history of mandatory EBTR and to help answer the broad question, What happened? The research found that key factors in the demise of mandatory EBTR included issues of problem definition, goal setting, adoption and implementation process, regulatory approaches, costs, analysis of results, and context.
Maryland Mass Transit Administration Fare Simplification: Effects on Ridership and Revenue
Authors: Taylor Simon R. H. , Carter Douglas W.
Published: April 2007

In the transit industry there is a general assumption that fare increases produce more revenues but decrease ridership. A recent fare policy change implemented by the Maryland Mass Transit Administration (MTA) challenges this tenet. The focus of this paper is how the MTA, by involving riders and operating staff in identifying strengths and weaknesses of the fare structure, was able to develop a fare system vision that stressed simplification and convenience and to design bold changes to the current fare structure that resulted in increased ridership and revenue.
Usage, Impacts, and Benefits of Innovative Transit Pass Program
Authors: Meyer James , Beimborn Edward A.
Published: April 2007

An evaluation of an innovative transit program, UPASS, is summarized. UPASS provides unlimited use of the Milwaukee County Transit System at any time and any place and for any purpose for all students enrolled at the University of Wisconsin-Milwaukee. The pass program, paid for by a special fee attached to students’ tuition, was implemented in fall 1994 and was extensively evaluated to determine its impact on ridership and other factors and to determine whether the concept has the potential for transfer to other organizations and employers. Benefits and disbenefits to transit users, nonusers, employers, and transit agencies are described. In addition, elements of a successful program are outlined.
Customer Satisfaction Contrasts: Express Versus Local Bus Service in Chicago's North Corridor
Authors: Foote Peter J. , Stuart Darwin G.
Published: April 2007

Results of customer satisfaction surveys conducted for five express and two local Chicago Transit Authority bus routes serving Chicago’s North Corridor are presented. More than 4,000 surveys were returned from bus routes typically carrying more than 58,000 daily riders. Survey respondents were asked to proceed through a list of 10 service quality attributes, first indicating how satisfied they were with that service aspect and, second, rating the importance of that service feature to them. Both local and express bus riders were most satisfied with safety from crime and driver courtesy. They were both least satisfied with ability to find a seat and on-time performance at their stop. Four service features were also together rated highest in importance by both rider types: safety from crime, reach destination quickly, on time at stop, and frequency of buses. By further matching satisfaction against importance scores, the highest priority for ongoing bus service improvement in the North Corridor was assigned to better on-time performance and frequency of bus service. Customer satisfaction components of a customer loyalty index were also analyzed. On-board survey methodology conclusions regarding the ability of survey respondents to complete both importance and satisfaction components on both express and local bus routes with surveyor prompting are also presented.
Automatic Vehicle Location: Implementation, Application, and Benefits in the United Kingdom
Authors: Hounsell Nick , McLeod Fraser
Published: April 2007

Automatic vehicle location (AVL) is playing an increasingly important role in public transport operations in the United Kingdom, providing support for real-time management and control of bus fleets and the platform for other beneficial functions including passenger information systems and bus priority. The current and emerging use of AVL in the United Kingdom for public transport is considered in this paper, focusing in particular on developments in London and Southampton where substantial use is being made of AVL. Following a summary description of AVL systems and technologies, examples are presented of the use of AVL for real-time passenger information at bus stops, particularly the COUNTDOWN and STOPWATCH systems in London and Southampton, respectively. Technical aspects are described together with evaluation results including passenger attitudes and financial criteria. Positive results in both cities have led to commitments for citywide implementations. The use of AVL in applications for bus priority at traffic signals is described, including a comparative review of different architectures and techniques that have emerged. Results of a feasibility study for the use of AVL in this context in London are presented. This study indicated that using AVL to target high-occupancy, high-headway buses with higher levels of priority could provide economic benefits for buses and passengers up to twice those achieved with current operations, where priority is equally available to all buses. Deployment details of this application, related to COUNTDOWN, are described. The paper concludes with the outlook for AVL, particularly for greater integration with traffic control systems, where significant potential benefits are outlined.
Current Practices in the Use of Service Evaluation Standards at Public Transit Agencies
Authors: Perk Victoria A. , Hinebaugh Dennis P.
Published: April 2007

Service standards provide a transit agency with a mechanism to evaluate its service in an objective, consistent, and equitable manner. During these times of shrinking operating budgets, service standards can provide the means by which limited resources are best allocated. Another major objective of service standards is the design and implementation of new service. This project was completed for the Miami-Dade Transit Agency (MDTA) in Southeast Florida. Its purpose was to review the current MDTA service planning guidelines to determine if more formal guidelines or standards should be adopted, develop an updated set of guidelines, and recommend a final set of guidelines and an implementation process. An early step in the development of the service guidelines was to conduct a survey of peer transit systems across North America. The survey identified the existing levels of standards use, including whether the standards are formally adopted, the process of implementing the standards, and their effectiveness in meeting the agency’s goals. The survey results uncovered passionate feelings for and against the use of strict standards among the agencies. Also, those surveyed shared their strategies for persuading their governing bodies to adopt staff recommendations for service adjustments. Public hearing and decision-making processes were also addressed in the survey. It was important to explore the relationships among transit planning staff, the agency’s governing body, and the public.
Triaxial Testing of Elastoplastic Materials Toward Scaled-Down Accelerated Pavement Testing
Authors: van de Ven Martin , de Fortier Smit André , Jenkins Kim
Published: April 2007

Small-scale testing of pavement materials provides an alternative means for preliminary indicator or ranking tests before, or in place of, expensive full-scale Accelerated Pavement Testing. To carry out scaled tests effectively, dimensional analysis considerations must be met. This implies that the laws of similitude require observation. In particular, scaled-down pavement layers must be subjected to the same stresses and strains as the full-scale pavement under equivalent loading. In addition, the material properties of the scaled-down layer must be equivalent to the full-scale materials. Research was carried out into the scaling down of different materials, including untreated and emulsion-modified granular materials. Various tests, including static and dynamic triaxial tests, were performed on the materials at full scale and at small scale (1: 10). The test results are discussed with a comparison between the full-scale and scaled-down material properties. Conclusions were drawn concerning the appropriateness of scaling down elastoplastic materials, the requirements of the laws of similitude, the main factors that require consideration for scaling, the need for additional research, and the direction that this research should pursue.
Thin-Section Petrography of Concrete Aggregates: Alternative Approach for Petrographic Number Evaluation of Carbonate Aggregate Soundness
Authors: Oyen Craig W. , Fountain Kendall B. , McClellan Guerry H. , Eades James L.
Published: April 2007

Traditional petrographic number (PN) ratings of concrete aggregates cannot work reliably in Florida because most of the state’s rocks are too fine-grained for use of macroscopic petrographic evaluations. This study designed a thin-section approach to PN calculations, based on relevant carbonate rock components that can be seen easily in thin section. The primary lithologic features chosen to differentiate the carbonates are the types of allochems, the porosity type, the kind of cement or matrix, and any additional noncarbonate minerals. Ten sets of aggregate samples were examined (eight carbonate and two noncarbonate sets) to test the method and ranking of thin-section PN determination. Prior work with PN values showed that aggregates with PN values of less than 140 yield good field performance, 140 to 160 have fair to poor field performance, and those greater than 160 normally have poor performance. Results of the thin-section PN method found values for our samples ranging from 100 (an ideal aggregate) to 149. By using factor weights (FWs) developed, six aggregates have PNs below 140 (good), and four scored between 140 and 160 (fair to poor) and may need additional testing. This method of PN calculation is easy to learn, clearly focused on carbonate aggregates like those in Florida and surrounding regions, and relatively inexpansive, and with it, soundness predictions can be determined quickly (in approximately 1 h per sample). Correlation of thin-section PN values with field performance information has not yet been completed, however, and this must be done before predicted performance can be considered reliable.
Thermogravimetric Analysis of Limestone Aggregates for Portland Cement Concrete
Authors: Cross Stephen A. , Abou-Zeid Mohamed Nagib
Published: April 2007

Durability of coarse aggregate has a major impact on the durability of portland cement concrete. Over the past years, there has been an increasing interest in developing and improving test techniques that provide a more accurate durability assessment, which ultimately leads to a better prediction of pavement performance. Thermogravimetric analysis is a relatively rapid technique that has shown good potential for use in the analysis of carbonate aggregates. Thermogravimetric technique (TG) was used to analyze 31 limestone aggregates. The specimens were heated to temperatures above 1000°C using two rates of temperature increase. The weight loss and the change in weight loss as a function of temperature were recorded. Results show a correlation between the slope before calcite transition and some durability aspects of limestone. Moreover, the TG output can be used to calculate the percent acid insoluble (AI) and the pavement vulnerability factor (PVF). Therefore, TG may be considered as a rapid method for AI and PVF determination.
Field Study of Shredded-Tire Embankment
Authors: Hoppe Edward J.
Published: April 2007

Interim data from the ongoing field study of an experimental shreddedtire embankment constructed near Williamsburg, Virginia, are presented. Approximately 1.7 million shredded tires, mixed with a conventional fill material, were used. The results to date indicate that the settlements are somewhat larger than usual in the embankment, but there are no problems with stability. Groundwater monitoring showed no abnormal concentrations. Infrared scans reveal no signs of a potential exothermic reaction in the embankment core.
Full-Scale Field Trials of Tire Shreds as Lightweight Retaining Wall Backfill Under At-Rest Conditions
Authors: Tweedie Jeffrey J. , Humphrey Dana N. , Sandford Thomas C.
Published: April 2007

A 4.88-m (16-ft), full-scale retaining wall test facility was constructed to investigate the use of tire shreds as backfill for conventional retaining walls. The facility can test backfill at at-rest and active conditions and is instrumental for measuring horizontal stress and interface shear. Tire shreds from three suppliers were tested. The results for at-rest conditions are presented. The average at-rest horizontal stress for tire shreds was about 45 percent less than expected for conventional granular backfill. Moreover, the at-rest horizontal stress was about the same for tire shreds from the three suppliers. Design parameters were developed by using two procedures. The first used the coefficient of lateral earth pressure and the other was based on equivalent fluid pressure. The horizontal and shear forces acting on the concrete face of the wall were used to determine the angle of wall friction, which ranged from 30° to 32° for tire shreds from the three suppliers.
Model for Resilient Modulus and Permanent Strain of Subgrade Soils
Authors: Muhanna A.S. , Rahman M.S. , Lambe P.C.
Published: April 2007

The resilient modulus and cumulative permanent strain of subgrade soils under anticipated repeated loading are important considerations for the design of a pavement against fatigue and rutting failures. A simple model was developed to evaluate the resilient modulus and accumulated permanent strain of cohesive subgrade soils under repeated loads. The empirical model was derived from the observed behavior of an A-6 cohesive soil. The model was tested against an A-5 soil. The proposed model was found to predict adequately the resilient modulus and the accumulated plastic strain for all A-6 and A-5 specimens with 90 percent confidence intervals of 0.61 and 1.4, and 0.66 and 1.39, respectively.
Pollution Prevention and Bilge Water Recovery
Authors: Bickerton Brooke J.
Published: April 2007

At American Commercial Barge Line Co. (ACBL), protection of the marine environment is a top operating priority. As part of this commitment, every effort is made, using ingenuity and technology, in pollution prevention. An example of pollution prevention in practice at ACBL is the recovery of petroleum from bilge water (an oil/water mixture that collects in the bottom of a towboat), which is then blended into virgin fuel for use on ACBL towboats or resold as a cutter stock to a petroleum company. The source of petroleum in the bilge water is the diesel engines that power the towboat. The petroleum fraction is typically 30 percent. The bilge water is pumped from containment tanks on the boat into larger storage tanks at fueling or repairing facilities. ACBL currently operates a certificated barge that is dispatched to the various fueling and repair facilities to collect bilge water. This barge takes the mixture to American Commercial Liquid Terminal (ACLT) in Memphis, Tennessee. A process separates the oil from the water. The recovered oil is then blended with virgin diesel fuel for ACBL’s towboat fleet, used as ACLT boiler fuel, or sold as a cutter stock for ocean vessels. The separated water moves through a series of treatment tanks and an ultrafiltration system. The purified water is discharged into the Mississippi River according to a Tennessee National Pollutant Discharge Elimination System (NPDES) permit. In 1996 and 1997 combined, this process recovered 4.2 million L (1.1 million gal) of oil, which is material that was disposed of as waste in the past. ACBL is making a difference and embracing the principles of pollution prevention.
Cooperative Problem Solving in Environmental Protection on the Inland Waterways
Authors: Wischmann Steven M.
Published: April 2007

The challenges and opportunities presented by cooperative problem solving between industry and government in the area of environmental protection are addressed. Factors believed to contribute to productive regulatory enforcement and compliance and the related value of inclusive processes aimed at enhancing understanding and respect between regulators and the regulated are explored. Cooperative problem solving is important to the inland transportation community because of its substantial participation in the transport of oil and chemical commodities. All of the inland transportation industry’s interests can be positively impacted by partnerships of high quality and preventive actions resulting from people’s initiatives and their associated dialogue. The U.S. Coast Guard formally established the Prevention Through People (PTP) Initiative in 1995 to emphasize the need for and benefit from cooperative relationships between the Coast Guard and the industries it is charged with regulating. Through focusing on prevention, the PTP effort and similar initiatives such as Quality Partnerships can energize all aspects of safe and efficient maritime operations. The pollution legislation passed over the past 25 years has in various ways intended to address minimizing spills or their impact. These legislative efforts cannot be effective without the thoughtful enactment and enforcement of laws by government officials and the committed adherence to the laws by the regulated industries. It is for this reason that the PTP Initiative resonates today—the various participants can work together to determine the best ways to achieve the goals of pollution prevention policy.
Optimization Through Simulation of Waterway Transportation Investments
Authors: Ting Ching-Jung , Schonfeld Paul
Published: April 2007

The cost of tow delays is a serious problem in a waterway network. One way to reduce the delay cost is to increase capacity at waterway locks. Planners must determine how much additional capacity to provide at particular lock sites and when to implement the capacity expansion projects. Answers for such project sizing and timing problems are difficult to obtain analytically. The use of a new approach for optimizing through simulation, called simultaneous perturbation stochastic approximation (SPSA), is investigated. This approach, which seeks optimal values for all decision variables after each pair of simulation runs, is quite promising for optimizing large problems relatively fast. A small numerical example tests how this simulation and optimization algorithm may be used to optimize lock capacities and implementation times.
Role of Adverse Weather in Key Crash Types on Limited-Access: Roadways Implications for Advanced Weather Systems
Authors: Khattak Asad J. , Kantor Paula , Council Forrest M.
Published: April 2007

Adverse weather can reduce visibility and road surface friction and thus increase crash frequency and injury severity. However, drivers may compensate for higher crash risk by reducing speeds, maintaining safe spacing, and driving more carefully. The impacts of adverse weather and its interactions with driver and roadway characteristics on the occurrence and injury severity of selected crash types are analyzed. Single-vehicle, two-vehicle sideswipe, and two-vehicle rear-end collisions on limited-access roadways are considered. To analyze differential impacts of adverse weather on crash type, binary probit models are estimated for single-vehicle versus the two types of two-vehicle crashes, and for rear-ends versus sideswipes. To analyze injury severity, ordered probit models are estimated. The 1990–1995 Highway Safety Information System (HSIS) database for North Carolina was used for analysis. The results indicate that, for the selected crash types, drivers appear to compensate for increased injury risks in that in adverse weather crashes are more frequent but injuries are less severe. Some implications for advanced weather systems are discussed.
Designing Advanced Traveler Information Systems from a Driver’s Perspective: Results of a Driving Simulation Study
Authors: David Yang C. Y. , Fricker Jon D. , Kuczek Thomas
Published: April 2007

The focus is on the design of advanced traveler information systems (ATIS) from the user’s perspective. Based on the experimental results of this research, types of ATIS information that meet drivers’ needs and capabilities and offer effective method(s) of conveying the information are identified. A driving simulator was developed to assist the investigation. The research results indicate that a driver’s familiarity with a given traffic network significantly affects his or her perception of the ideal type of ATIS information and the most effective information conveyance method. When traveling in a familiar network and encountering congestion and delay caused by an unexpected traffic incident, drivers need only short and simple information, such as the location of the incident and expected delay time, to assist them in making route diversion decisions. It was found that drivers prefer to receive an auditory ATIS message when traveling in a familiar traffic network. For navigation assistance in an unfamiliar environment, travelers strongly indicated the need for information such as alternative route recommendations and directions to alternative routes. The combined format of auditory message and visual display was perceived as the best way to transmit information in a network with which a driver is unfamiliar. Analysis of driving simulator results also confirmed that a visual display causes greater distraction from driving than an auditory message.
Analysis of Private Drivers’ Commuting and Commercial Drivers’ Work-Related Travel Behavior
Authors: Ng Linda , Barfield Woodrow , Mannering Fred
Published: April 2007

An analysis of private and commercial drivers’ information requirements for an advanced traveler information system (ATIS) is presented. The analysis is based on data from two nationwide surveys, one addressing private drivers’ needs and the other addressing commercial drivers’ needs. In these surveys, drivers rated the importance of four trip factors: ( a) increasing trip safety, ( b) decreasing trip time, ( c) reducing trip distance, and ( d) increasing trip enjoyment. Cluster analysis techniques were employed to identify groupings in the driver population on the basis of trip factors, and a multinomial logit approach was used to predict the probability of the drivers being placed in a specific cluster group. The results indicate that significant differences in trip behavior and socio-economic characteristics exist among the observed cluster groups.
User and Operator Perspectives in Transit Network Design
Authors: Ceder Avishai , Israeli Yechezkel
Published: April 2007

The basic construction of the objective functions of the transit network design problem is described, and a new approach taking account of both passenger and operator interests is proposed. The approach presented combines the philosophy of the mathematical programming approaches with decision-making techniques in order to allow the user to select from a number of alternatives. The nature of the overall formulation is nonlinear and mixed-integer programming.
Rural Transit Services: A Local Economic and Fiscal Impact Analysis
Authors: Peng Zhong-Ren , Nelson Arthur C.
Published: April 2007

Rural transit services are generally considered a tool to alleviate immobility for the elderly, the handicapped, and the carless and a form of income redistribution to them from society at large. But their economic impacts on local economies and governments are seldom realized and quantified. This study estimates two important transfer impacts of rural transit service on local (county) economies and governments in Georgia: the overall economic impacts and the fiscal revenue impacts. This study analyzed economic benefits of three major transit rider types in rural Georgia: elderly riders, work trip riders, and school trip riders. It found that rural transit services have a significant and positive economic impact on the local economy, indicating that, in addition to providing mobility and accessibility to the transportation disadvantaged, rural transit services promote local economic development. The fiscal revenue impact of rural transit service varies depending on the availability and the amount of federal transit subsidy. If the current level of federal transit subsidy continues, the fiscal revenue impact is positive and is larger than 1.0 for the state as a whole. It shows that providing transit service can bring positive fiscal revenues to local governments, realizing that some fiscal revenues are transferred from the federal government. Without federal transit subsidies, local governments would need to pay for all the costs. The revenue impact thus would become smaller yet still positive and greater than 1.0.
Assessment of State Procedures for Allocating Section 5311 Subsidies to Rural Public Transit Operators
Authors: Marshment Richard S.
Published: April 2007

The U.S. Department of Transportation provides monies to states to assist in the provision of transit services in small towns and rural areas under the Section 5311 program. The purpose of the Section 5311 program is to improve mobility for economically disadvantaged rural residents. In practice, states exercise considerable discretion over the operation of the program, including establishing eligibility criteria and funding levels for individual operators. Forty-one states grant monies to operators through a competitive process based on applications. The applications are used to rank operators according to one or more performance measures. States often employ scoring techniques in their evaluations. The remaining nine states award subsidies according to formulas. There are great similarities in state goals for rural transit service even though there is significant variation in the amounts of monies awarded to comparable operators. To better realize the purpose of the Section 5311 program, states might consider adopting an allocation procedure whereby monies are awarded using a formula based on equalizing the subsidy per passenger trip. States that establish minimum rural mobility standards could split their total allocation into two categories, apportioning one part by population and the other by the subsidy per passenger trip.
Simulation of the Effects of Intermodal Transfer Penalties on Transit Use
Authors: Liu Rongfang , Pendyala Ram M. , Polzin Steven
Published: April 2007

In recent times, the planning, analysis, and design of intermodal transfer facilities have been receiving increasing attention as planners attempt to overhaul public transportation systems that are losing ground to the ubiquitous automobile. However, recent research indicates that modeling tools currently used in practice do not adequately account for the effects of transfer penalties on transit ridership and network performance. In an attempt to fill this research need, transit system performance is simulated under different scenarios of intermodal and intramodal transfers. Using a controlled experimental design, transit ridership and system performance are simulated within a traditional four-step travel modeling framework assuming a variety of network configurations characterized by different transfer scenarios. Results show that the presence of a transfer on a transit line can substantially reduce transit ridership and that the extent of this reduction is highly dependent on the type of transfer encountered, that is, whether the transfer is intermodal (across different modes) or intramodal (within the same mode). The implications of the study results on the planning of intermodal transit systems are discussed in detail.
Track Time: Construction or the Customer
Authors: Palmer James W.
Published: April 2007

From the mid-1980s to the early 1990s, the Southeastern Pennsylvania Transportation Authority (SEPTA) undertook two major rail infrastructure projects that required disruption of service: one on the Market-Frankford Line and the other on the regional rail or commuter system (called Railworks). The decisions on how the rehabilitations would be carried out and passenger service provided resulted in significantly different approaches. In addition, lessons learned from the Frankford Elevated reconstruction were applied to the Railworks project, to mitigate both neighborhood impacts and losses of ridership. The decisions that went into the alternate approaches used on these two projects within the SEPTA organization and the actual results of the strategies pursued are evaluated. The evaluations that went into the decisions for the Frankford El reconstruction and the Railworks project—as well as the strategies used to minimize the impact on communities and riders—are reviewed. In addition, the ridership trends before, during, and after the projects are presented with an analysis of the factors that affected those trends. The following conclusions were reached: (a) the management of track outages or track time creates a very high potential for excessive risk cost (in this context, risk cost is the premium contractors include in their bids to cover unknowns); (b) the division of responsibilities in rail transit capital programs impedes the optimization of track time; (c) the capital funding environment is not effective in recognizing the ridership and thus the fare box impact of track outages; and (d) contractors need to be sold on the projects and included in the strategies used for providing service during the rehabilitation process.
Economic Impact of Existing and New Commuter Rail Service on Retail and Recreational Spending in the Vicinity of Station Areas
Authors: Marchwinski Thomas
Published: April 2007

A quantification is provided of the impact of both existing and new commuter rail services on the economies of local jurisdictions, and selectively on direct state government revenues. Specifically, an investigation and documentation have been conducted on increased spending by rail riders on retail services in local station areas and increased spending by recreational rail travelers in resort areas as a result of the presence of rail service. Actual ridership surveys conducted on three commuter rail lines in New Jersey during 1995 and 1996 are used to establish relationships between increased spending in local station areas, as well as other economic impacts, such as induced ridership and relocation of residents as a result of improved commuter rail service. The three surveys were large-scale surveys of two entire rail lines, the Morris and Essex Lines and the Atlantic City Line, and a weekend survey during the summer tourist season of the coastal portion of the North Jersey Coast Line. With a 40–60 percent return rate, these surveys represented a rich database for estimating the impact of commuter rail service on local economies.
Passenger Train Design for Increased Competitiveness
Authors: Kottenhoff Karl
Published: April 2007

Passenger trains have great potential to increase their market share, provided that good conditions are created for train traffic. This has been proven by modern, comfortable trains with good on-board service, high speed, and fewer quality shortcomings. One serious threat is that high ticket prices limit demand. Efficiency has to be increased. Operating costs can be reduced using modular train configurations, increased space utilization, double-deckers, or wide trains and higher speeds. The last example, higher speeds, also increases the attractiveness of traveling by train. Other factors to increase attractiveness—where stated preference interviews show that passengers’ willingness to pay is high—include low noise and vibration levels, good ventilation (air-conditioning), varied seat configuration with adjustable seats, play areas for children, and service attributes, such as radio/music outlets at seats and free coffee and tea in each car. The impression of modernity itself also plays an important role in enhancing the level of attractiveness.
Transit-Focused Development and Light Rail Systems: The Lite Connection
Authors: Porter Douglas R.
Published: April 2007

Building on a 19-region study of transit-focused development, some directions are suggested for evolving development opportunities associated with the light rail transit systems built and planned in recent decades. Transportation and land use planners continue to propound the concept of transit-focused development that can increase use of transit systems, reduce dependency on automobiles, create desirable living and working environments, and help to meet environmental goals. In their expectations of achieving a substantial amount of transit-focused development, however, planners must recognize the realities of the real estate markets, public policy trends, and the nature of rail lines themselves. Especially along the light rail lines that provide service in many regions, development opportunities will be influenced by changes in the development industry and its primary markets, increasing deference to neighborhood and community groups in decision making regarding development, and the generally lower intensity of use of suburban rail stations compared with many stations along heavy rail lines. Successful development around light rail stations, as with heavy rail systems, will require a timely confluence of market demand with supportive public policies and actions. Unlike experience with heavy rail systems, however, noncentral-business-district stations on light rail lines are more likely to attract relatively small, uncomplicated projects. Transit agencies and local governments will be required to invest more time and energy in nurturing these kinds of projects.
High-Capacity Light Rail Transit: Balancing Stationside and Railside Capacities
Authors: Mansel Douglas M. , Menaker Paul J. , Hartnett Gary
Published: April 2007

Many light rail transit (LRT) systems in North America currently serve major activity centers, such as stadiums/arenas, convention centers, university campuses (which typically have stadiums, arenas, and large gathering halls), and large downtowns (which may also function as major activity centers). Major activity centers generate pedestrian and/or passenger surge-type flows that must be accommodated by the LRT stations serving the major activity center, as well as the actual LRT line capacity (in passengers per hour per direction). Passengers must be able to flow through the station, from ticketing to the boarding/alighting platform, efficiently and safely. Bottlenecks to consider on the stationside include ticket vending machines, transport from the ticketing to boarding areas (if any), and the station platform itself. Bottlenecks to consider on the railside include light rail car capacity, LRT signaling systems, LRT right-of-way types, and maximum LRT train lengths. The key to designing LRT for major activity centers is to balance the stationside and railside passenger flows.
In-Service Performance of Integral Bridges and Jointless Decks
Authors: Alampalli Sreenivas , Yannotti Arthur P.
Published: April 2007

New York has been building integral bridges as well as jointless decks since the late 1970s. They performed well from the beginning, but a recent study evaluated their performance to identify details possibly needing improvement in future construction. Ratings obtained during a field survey of numerous integral bridges and jointless bridge abutments were analyzed, as well as condition ratings assigned by bridge inspectors during their biennial inspections. Results indicate that these bridges have been functioning as designed, but can be improved. Details needing improvement were identified and design changes implemented for future construction. The study and its results are summarized here.
Economic Analysis of Bridge Rehabilitation Options Considering Life-Cycle Costs
Authors: Johnson Bruce , Powell Tim , Queiroz Cesar
Published: April 2007

A method is described for performing an economic analysis of a large number of bridges to establish priorities and to make preliminary selection of rehabilitation options. Selecting the most cost-efficient rehabilitation scheme for bridges is a critical problem when resources are limited. The information required to perform the analysis is normally available from basic bridge inspection data. The method compares the cost and benefits of various rehabilitation alternatives with the consequences of not undertaking the rehabilitation. A program of bridge works can be selected on the basis of the highest ratios of net present value to capital cost. The computations are well suited to common spreadsheet computer programs. From the results of the computations, owners can prepare an appropriate budget to finance a bridge rehabilitation program. The method is particularly well suited to analyzing how expenditures should be allocated over time when funds are limited.
Fatigue Impacts on Bridge Cost Allocation
Authors: Laman Jeffrey A. , Ashbaugh John R.
Published: April 2007

The objectives of this project were to develop an analytical tool and to use it to evaluate the relative user responsibilities for fatigue damage to highway bridges. This tool was designed to be a general analytical tool to evaluate the current fleet mix database established by FHWA. It is a FORTRAN program designed to read standard format FHWA files for vehicle data and vehicle kilometers traveled. The output is a relative fatigue damage matrix for each vehicle class and weight group over 12 FHWA-established functional highway classes. The relative damage factors are then used as input into the highway cost allocation study to assign costs of fatigue damage. This study advances the analytical technique for evaluation of relative fatigue damage to highway bridges by incorporating the semicontinuum analysis method, the Palmgren-Miner hypothesis, and the rain-flow cycle counting algorithm. The analysis evaluates a database of 39 bridges selected as representative of those in the United States and contains several hundred fatigue-prone details for analysis. The vehicle database was developed by FHWA specifically for the highway cost allocation study. Reviewed in this paper are the basis of the fatigue analysis used for this study and all assumptions made in the development of the fatigue program. The vehicle database and bridge selection and database incorporated into this study are also described. Results of the analysis are summarized and presented.
Seismic Retrofit of San Francisco-Oakland Bay Bridge West Crossing
Authors: Reno Mark L. , Pohll Martin
Published: April 2007

From the toll plaza on the Oakland shores through the approach structures in San Francisco, the San Francisco—Oakland Bay Bridge, built at a cost of $78,000,000 in 1937, is an engineering marvel that carries over a quarter-million vehicles per day. Because of the different segments of the bridge and their inherent vulnerabilities, retrofitting was assigned to several groups within the California Department of Transportation. Briefly described are the analysis and design of the seismic retrofit of the West Crossing, which spans San Francisco Bay between the city of San Francisco and Yerba Buena Island. From the outset of this project, the goal was to keep the bridge in service following a magnitude 8.0 earthquake from the nearby San Andreas fault. Included in this discussion is a summary of analytical and engineering procedures used to model the seismic behavior and the performance of this complex, important structure. In addition there is some insight into the various levels of analysis that were utilized so that the project-specific performance-based design criteria could be met. Furthermore, there is discussion of how energy dissipation through foundation rocking and the use of viscous dampening devices made the overall design objective obtainable. Finally, there is some discussion on the retrofit details used to ensure compliance with the design criteria.
Profiles of Design Dimensions and Fundamental Natural Frequencies for Steel Interstate Highway Bridges in Southeastern Missouri
Authors: Dusseau Ralph Alan
Published: April 2007

Results from a research study funded by the U.S. Geological Survey as part of the National Earthquake Hazards Reduction Program are presented. The first objective of this study was the development of a database for all 211 bridges along Interstate 55 in the New Madrid region of southeastern Missouri. Profiles for five key dimension parameters (which are stored in the database) were developed, and the results for steel highway bridges are presented here. The second objective was to perform field ambient vibration analyses on 25 typical bridge spans along the I-55 corridor. These 25 spans included 17 steel girder spans. Eight seismometers were used to record ambient vibrations at four locations on each bridge span. These records of bridge motion versus time were each subjected to a fast Fourier transformation, and plots of amplitude versus frequency were generated. These plots were used to determine the fundamental vertical and lateral frequencies of the bridge spans measured. The third objective was to use these fundamental frequencies in conjunction with the dimension parameters stored in the database to develop empirical formulas for estimating fundamental frequencies. These formulas were applied to all 211 Interstate highway bridges in southeastern Missouri. Profiles for both the fundamental vertical and the lateral frequencies were then developed, and the results for the steel highway bridges are presented here.
Seismic Strengthening of Column-Pier-Cap Connections
Authors: Sanders David H. , Saiidi M. Saiid , Martin Troy
Published: April 2007

Many bridges constructed in the 1960s in regions of high seismic risk have column–pier-cap connections with inadequate column bar development and no shear reinforcement in the joint region. The study described in this paper focuses on highway bridges built on Interstate 80 in the Reno, Nevada, area during the 1960s. Two 0.4-scale specimens representing the essential features of the column–pier-cap connections in these bridges were constructed and tested. One test showed that the asbuilt specimen had little energy dissipation capacity and failed at less than 1 percent drift. A second specimen was used to test a potential strengthening technique. The technique included increasing pier-cap depth, adding a concrete bolster to the joint, and placing a steel jacket around the column. After strengthening, a plastic hinge formed in the column, the joint damage was minimized, and the energy dissipation capacity increased by a factor of 5.
Effect of Corrosion on Crack Development and Fatigue Life
Authors: Fisher John W. , Kaufmann Eric J. , Pense Alan W.
Published: April 2007

Fatigue and fracture as well as loss of section caused by corrosion are time-dependent performance characteristics that have the potential to jeopardize the integrity of bridge structures. During the past 25 years these conditions have developed in a number of bridges, resulting in loss of service, costly repairs, and concern about the safety of these structures. A review of the experience with such time-dependent damage since 1970 is presented. The experience is grouped into three categories: fatigue cracking resulting from changes in structural behavior as a result of corrosion, fatigue cracking resulting from development of corrosion notches in members, and stress corrosion of high-strength steel and weld metal. The examples cited illustrate the role of corrosion phenomena in bridge service and the need to control the corrosion conditions on bridge structures.
Behavior of Tension Splices for Reinforcing Bars Embedded in High-Strength Concrete
Authors: Azizinamini Atorod
Published: April 2007

Safety concerns and a lack of test data on bond capacity of deformed reinforcing bars embedded in high-strength concrete (HSC) have been reasons that the American Concrete Institute (ACI) 318 building code has imposed an arbitrary limitation of 69 MPa (10,000 psi) in the calculation of tension development and splice lengths. This limitation was first introduced in the 1989 revision of the ACI 318 building code. In an attempt to evaluate the impact of this limitation and develop provisions for its removal, a two-phase investigation was carried out at the University of Nebraska-Lincoln. During both phases of the investigation, 70 beam splices were tested. The parameters studied included diameter, length, and deformation type of the reinforcing bars; amount of transverse reinforcement over the splice length; casting position; and concrete compressive strength. Results of the investigation are used to discuss the differences that exist between normal concrete and HSC, develop hypotheses to explain these observed differences, and suggest alternatives for removal of the current concrete compressive strength limitations existing in the ACI 318 building code for calculating tension development and splice lengths.