bluuebunny/crossref_metadata_2025 huggingface dataset:
Applicability of Biodiversity Impact Assessment Methodologies to Transportation Projects
Authors: Bardman Cynthia A.
Published: April 2007

Human activities often adversely affect natural landscapes or ecosystems. Natural landscapes typically consist of habitats differing in size, shape, structure, and composition. These components create biodiversity, which is broadly defined as the variety of the world’s organisms. Impacts on biodiversity—including direct impacts from development, secondary impacts, and impacts from active consumption—are increasing as the human population continues to grow. Impact on biodiversity is emerging as a concern of environmental groups. Highway construction may contribute to biodiversity loss because transportation corridors tend to disrupt normal patterns in the landscape. Transportation agencies, such as the Pennsylvania Department of Transportation, are interested in evaluating the need to analyze the effects on habitat fragmentation and biodiversity caused by roadway construction projects. Evaluation of such effects is a relatively new issue. There are currently no regulatory requirements to perform these types of evaluations. Therefore, the opportunity exists to develop rational and practical guidance to use on transportation projects. Even though no formal guidance exists, a number of similar methods in use could be modified for analyzing and quantifying impacts on biodiversity caused by highway projects. The decision whether to assess biodiversity for a project depends on the existing environment and the types of impacts the project will have on that environment. Whether mitigation of these biodiversity impacts should occur depends on the overall impacts on all resources by the proposed project. Much work still needs to be done in the development of an acceptable method for assessing the potential impacts of transportation projects on biodiversity. The general state analysis should be molded into an acceptable method for use by state departments of transportation. This method would need support in the form of a new mandate for implementation under the National Environmental Policy Act.
Perception of Traffic Noise Barrier Effectiveness: Public Opinion Survey of Residents Living near I-71
Authors: Herman Lloyd A. , Finney Michael A. , Clum Craig M. , Pinckney E.W.
Published: April 2007

The completion of the largest Ohio Department of Transportation traffic noise abatement project in 1995 was met with public controversy over the effectiveness of the noise barriers. A public opinion survey was designed to obtain the perceptions of the residents in the project area. In a departure from most surveys of traffic noise barrier effectiveness, the coverage was not limited to the first or second row of houses, but was extended to 800 m on each side of the roadway. It was found that the larger survey area was needed to avoid misleading conclusions. Overall perceptions of noise barrier effectiveness were found to vary with distance from the roadway and with noise barrier configuration.
Good Fences Make Good Neighbors: Highway Noise Barriers and the Built Environment
Authors: Billera Domenick , Parsons Richard D. , Hetrick Sharon A.
Published: April 2007

Noise barriers have become a prominent feature on today’s landscape. Unfortunately, they have also become a feature associated with insensitivity toward the built environment. Designers could avoid the negative visual impact that noise barriers frequently create by increasing their awareness of aesthetics in the design process. In an effort to improve the quality of noise barrier design, the New Jersey Department of Transportation’s, Bureau of Environmental Analysis (BEA) altered the design process for its I-76/I-295 Type II noise abatement study. The first objective of the study was to acoustically engineer a barrier that would abate the noise for residents along the affected roadway corridor. The second was to develop an architectural design that would be aesthetically pleasing to the corridor resident and the roadway users. Typically, architects were brought into the design process at the end to review the aesthetic impact of the wall and add architectural features. On the I-76/I-295 project, BEA initiated a parallel process with the architectural design running concurrent with the engineering. The architectural design process and the interfacing of this process with the engineering are described. Community involvement was essential to the architectural objective of designing an aesthetically pleasing barrier. Ideas reflecting community concerns and comments were refined into final recommendations for construction of a noise barrier with gateways and a unifying corridor theme. The noise barrier should then become a representation of the community and stand as an icon in the built environment. Noise barriers can have a positive impact on the built environment if a commitment is made to aesthetics throughout the design process.
Simulation Approach to Traffic Noise Modeling: American Automobile Manufacturers Association Community Noise Model Version 4.0
Authors: Wayson Roger L. , MacDonald John M. , Eaglin Ronald , Wendling Barbara
Published: April 2007

Several models are available for predicting traffic noise levels. The FHWA-promulgated model, STAMINA 2.0, is the most widely used noise model in the United States and is used to model free-flow vehicular traffic. STAMINA 2.0 cannot directly model interrupted-flow traffic. Sound levels from interrupted-flow traffic can be approximated with STAMINA 2.0 using the method presented in NCHRP Report 311. This method is time-consuming and difficult to use. These limitations demonstrate the need for a traffic noise model that can model the acceleration and deceleration behavior of interrupted-flow traffic. The University of Central Florida has developed the American Automobile Manufacturers Association Community Noise Model (CNM). The CNM is a traffic simulation model that determines sound levels at receivers by modeling vehicles as discrete moving point sources. The vehicle energy is determined from acceleration, deceleration, idle, and cruise reference energy mean emission level curves. Sound energy attenuation is calculated from distance, ground absorption, and user input barriers. The model sums the energy at receivers from all vehicles and then calculates the Leq noise level at the receivers. It is demonstrated that the CNM predicts receiver Leq levels that are very close to STAMINA 2.0 results for constant-speed traffic. The CNM can also accurately predict sound levels at receivers located before and after intersections. In addition to the advantages of a real simulation model, the CNM is user friendly, allowing the user to place lanes and receivers using the mouse.
Stop the Whine!: Narrow-Band Noise Level Measurements of Three Highway Pavements
Authors: Billera Domenick , Schmidt Bela , Miller Wayne
Published: April 2007

The origins of an annoying high-pitched sound emitted by highway traffic were investigated. Wayside noise levels of single vehicles passing over three types of pavement surfaces were measured using real traffic. Data based on a statistically significant number of samples are presented for automobiles and heavy trucks. All data were collected using a realtime analyzer with 1/3-and 1/12-octave band resolution. The measured data confirmed the transverse grooved pavement as the noisiest with a noticeable concentration of sound, often described as a “whine.” Data for the asphalt and longitudinally grooved surfaces indicated lower overall noise levels and a near absence of the whine.
Risk-Based Cleanup Objectives, Land Use, and Transportation
Authors: Schick J. Randle
Published: April 2007

Land use has always been a factor in developing site-specific cleanup objectives for contaminated property. However, land use is taking on major new significance in the “brownfield” legislation being enacted in a growing number of states. Under this method, a tiered approach is used to analyze the risk posed by contaminants and to derive cleanup objectives based on that risk. By many accounts on the leading edge of the brownfield movement, the Illinois Environmental Protection Agency (IEPA) is going so far as to propose a tiered approach to cleanup objectives (TACO) generally across its land pollution programs. TACO relies heavily on restricting land use to obtain less stringent cleanup objectives, and it is this aspect of TACO that represents both an opportunity and a challenge to Illinois transportation agencies and the shape of things to come nationally. The opportunity lies in much lower cleanup costs that these agencies will incur in dealing with contamination in their own yards and rights-of-way. The challenge lies in considering requests from property owners adjoining the rights-of-way for land use restrictions on the rights-of-way, in dealing with land use restrictions on property acquired through eminent domain, and in processing land use restrictions that will be imposed for IEPA’s own cleanups.
Bench-Scale Tests of Dry Photocatalytic Degradation of Two Nonpoint Runoff Model Compounds
Authors: Jones Alexander P. , Watts Richard J. , Schaftlein Shari M. , Molash Ed Molash
Published: April 2007

The destruction of two model petroleum hydrocarbons using a photocatalyst fixed on dry test surfaces was investigated as a basis for minimizing nonpoint hydrocarbon runoff to adjacent soils and receiving waters. The process is based on attaching photochemically active titanium dioxide (TiO2) to pavement surfaces. Hexadecane and anthracene were used as model contaminants because they are common hydrocarbon constituents of gasoline, diesel, and motor oil. Six materials containing TiO2 were evaluated for photocatalytic activity; concrete sealant and paint base were found to be the most effective materials tested. The TiO2-sealant formulations were effective in promoting the degradation of hexadecane, providing more than 99 percent removal in 48 hr. Although the TiO2-paint base formulation was less effective than the TiO2 sealant, 98.2 percent degradation of hexadecane occurred on a 50 percent TiO2-paint base surface in 72 hr. Anthracene degradation was not accelerated from the addition of the photocatalyst into the surface. On the basis of the capability of dry fixed TiO2 to enhance rates of hexadecane photolysis, a full-scale demonstration project has been initiated to evaluate the in situ destruction of nonpoint highway runoff.
Advancing Public Sector Priorities for Goods Movement Projects: A California Case Study
Authors: Scales Robert C.
Published: April 2007

Passage of the Intermodal Surface Transportation Efficiency Act of 1991, and subsequent federal, state, and metropolitan planning organization (MPO) efforts have provided leadership for advancing public sector priorities for goods movement projects. Nevertheless, progress has been slow. Lack of knowledge about freight transportation needs lies at the heart of the problem. The California Trade and Goods Movement Study set out to provide staff at all levels of government with information they could use to explain and document goods movement needs. The study also produced an executive report, targeted at elected officials, that emphasized the importance of efficient, uncongested transportation to the economic competitiveness of the state’s industries. The greatest challenge for the study was convincing MPOs, the state of California, and private industry that they needed one another to make things happen and that more energy was required to move faster. Reaching agreements required substantial dialogue because needed actions tended to change the balance of power among public agencies or affected individuals and causes. These concerns were overcome by the common goal of the study’s sponsors and participants, that is, to support the efficient and rapid movement of goods deemed vital to the state’s expanding domestic and international trade.
Proposed Advanced Commercial Vehicle Operations in Republic of Korea: Issues and Prospects
Authors: Kang Kyungwoo , Kwon OH Kyoung
Published: April 2007

Transportation infrastructure will provide the necessary capacity for freight movements and handling. However, the increase of physical infrastructure alone is not a sufficient condition for improvement of logistics systems. A logistics information capability that facilitates seamless flow of information is important in further enhancing the efficiency of logistics activities and potentially in reducing the demand for transportation infrastructure itself. The existing logistics information practices in the Republic of Korea are reviewed. Korea’s recent efforts to build the advanced logistics management systems and integrated logistics information systems are described. The relationship between these two systems is discussed, and issues that are important to successful implementation of the systems are raised.
Mexican Field Study To Obtain Basic Information on Truck Transport
Authors: Rico Alfonso , Mendoza Alberto , Gutiérrez José L. , Mayoral Emilio
Published: April 2007

A field study begun in Mexico in 1991 is described. This study has become an annual task without a deadline. The fieldwork seeks knowledge about truck traffic on Mexican roads, type of vehicles used, vehicle size and weight, tonnage transported, routes followed, type of freight moved in each case, origin and destination of movements, the packaging system for the transported freight, and whether the movement is related to domestic or to international trade. From these data, which are the core of the information gathered, other data can be obtained, such as each vehicle’s degree of compliance with current size and weight regulations, the economic value of the freight transported, age of the fleet examined, empty vehicles detected, occupancy rate of each truck (cargo tonnage/maximum payload), and fuel type used. This study is described, and some examples of the information it provides based on the collected data are provided. Also, some of the most important applications for the acquired information are enumerated.
Landside Access to Seaports in Urban Areas: A Case Study
Authors: Chatterjee Arun , Hummer Joseph E. , Clarke David B. , Ney Scott M.
Published: April 2007

Seaports in the United States usually are located in urban areas. They are major traffic generators on the landside. However, the landside access needs of ports often are overlooked by the transportation and land-use planning processes. A case study of three ports on the East Coast of the United States was performed: Savannah, Georgia; Wilmington, North Carolina; and Morehead City, North Carolina. Both highway and rail access issues were examined at regional and local levels. Several serious issues and problems are identified and discussed in the paper, including effects on local communities.
Implementation of Priority Systems for Containers at Marine Intermodal Terminals
Authors: Holguín-Veras José , Walton C. Michael
Published: April 2007

Research on the implementation of priority systems for containers is summarized. The results correspond to the areas of information technology and performance analysis. The analysis of information technology comprises several parts. First, idealized import and export processes are characterized in terms of activity networks. Then these characterizations are used to estimate the effect that implementing priority systems has on the information flow and to identify the desirable characteristics of the corresponding information system. Performance analysis focused on a selected group of possible priority systems that differ in the extent to which service differentiation by priority is implemented. The systems analyzed are ( a) base case (i.e., no service differentiation); ( b) “hot hatch” programs; ( c) service differentiation at the storage yard; ( d) service differentiation at the yard gate; and ( e) combinations of systems b, c, and d. The analysis was conducted by a simulation system specially designed to simulate priority systems. The performance of these systems was assessed for different combinations of the relevant experimental factors, namely, operational scheme, proportion of high priority containers, and number of incoming containers. By using the resulting performance measures, the impacts on the different segments of users were assessed for each of the systems. Finally, the policy implications were analyzed and conclusions drawn.
Feasibility of Advanced Vehicle Control Systems for Freight Terminals
Authors: Hopkins Jennifer S.
Published: April 2007

Within the freight transportation system, transfer facilities provide automated vehicle control systems (AVCS) to yield significant efficiency benefits. Freight movement operations often require goods to pass through several transfer points between an origin and a destination. Because these transfer terminals can limit system throughput, a variety of intelligent transportation systems technologies are now under consideration by the freight industry to reduce processing inefficiencies. Among those technologies, AVCS is potentially significant, even though it is also the least known within the industry. Given the controlled nature of freight terminals, as well as the dependence on human labor for performing even the simplest and most repetitive vehicle movements, AVCS is a logical improvement for terminal operations. Through a detailed examination of freight movement operations and available vehicle control technologies, opportunities for AVCS to improve the operational efficiency of freight terminals are explored and future directions for developing new systems are recommended.
Automating Movement of Freight
Authors: Vandersteel William , Zhao Yiyuan , Lundgren Thomas S.
Published: April 2007

A concept is introduced for a new mode of freight transportation in which general cargoes are “pumped” through underground or under-water pipelines. The concept itself is not new, but a recent technical breakthrough has transformed the technology to a point where tube freight could become a cost-effective alternative to surface freight, in particular, to truck and air freight. Although the study of this new mode is at the conceptual level, only the concept is based on an extensive body of knowledge, developed for pneumatic capsule pipelines for moving granular products, a well-proven technology backed by considerable operational experience. Tube freight has the potential to displace many long-haul trucks from U.S. highways. The principal driving forces are economics, safety, energy-conservation, and environmental impact. The system operates automatically under computer control, and deliveries are precisely predictable for meeting just-in-time production requirements. Preliminary studies suggest that tube freight is technically and economically feasible. The technology involved is state-of-the-art and nothing new needs to be invented. The major obstacle to tube freight’s implementation is that the concept is little known, and even less understood, by the transportation community.
Excuse Me for Barging In: Establishment of a Hazardous Materials Ferry Between Detroit and Windsor
Authors: Ward John T. , Ward Gregg M.
Published: April 2007

The barriers to entry encountered in establishing the Detroit-Windsor Truck Ferry Service are discussed. The ferry service was needed to transport hazardous-materials-laden vehicles, which were not allowed access to the bridge and tunnel linking the cities of Detroit and Windsor. Without the ferry, these vehicles were detoured 265 km to a northern bridge crossing for deliveries between the two border cities. The crossing between Detroit and Windsor is the most important North American border crossing in terms of volume of trucks and trade value of goods ($44.5 billion, U.S. dollars, in 1990). The efficient movement of all classes of freight is essential to the competitiveness of automobile and automobile-related industries in the region. A major challenge in establishing the ferry service was overcoming safety concerns. The start-up involved multiple jurisdictions in two countries. Firsthand experience in planning, establishing, and operating this business and relevant government regulations and bylaws, correspondence, and newspaper articles are cited. The successful establishment of this ferry service and its role in improving transport safety, enhancing the transportation infrastructure, and protecting the environment are demonstrated.
Development and Application of Portland Traffic System Performance Evaluation System
Authors: Bloomberg Loren , Throckmorton Jamie , Klim Terry
Published: April 2007

The city of Portland’s Traffic System Performance Evaluation (TSPE) system is an innovative, practical, and cost-effective tool for monitoring traffic system performance in response to federal, state, and local legislation. It has been designed, implemented, and applied using readily available traffic data. The TSPE goes beyond traditional level-of-service analysis and gives the city a means to identify operational deficiencies and provide a baseline for future performance monitoring. The TSPE includes five performance indicators that were crafted in response to questions about traffic performance and in recognition of the costs and availability of data to support performance evaluation. Each of the five indicators addresses a specific element of traffic performance. District accessibility measures the ease of access to and egress from major activity centers by examining the delay at gateway intersections. The street origin-destination characteristics indicator assesses the percentage of nonlocal trips on streets with different functional classifications. Travel time is measured on a set of specific routes between activity centers. The traffic flow indicator assesses the variation in speeds on major roadways. The multimodal service levels indicator assesses multimodal operational performance based on service levels for four different transportation modes (vehicular, transit, bicycle, and pedestrian) along a corridor. The system has proved to be relatively easy and inexpensive to apply. Other jurisdictions developing performance evaluation systems should consider integrating some components of the TSPE system.
Managing Incidents on Urban Arterial Roadways
Authors: Raub Richard A. , Schofer Joseph L.
Published: April 2007

Limiting the impact on traffic of nonrecurring events such as crashes, traffic stops, or disabled vehicles through effective incident management should be one objective for emergency response professionals. Moreover, such management is an integral part of Intelligent Transportation Systems planning. The Arterial Incident Management Study, sponsored by the Illinois Department of Transportation and conducted by Northwestern University, examined the impact and management of arterial street incidents to determine what steps could be taken to improve the handling of such events. Several approaches were used to accomplish this, including (a) analysis of incident data from police and fire agencies, (b) debriefings of responders about specific incidents, (c) observation and videotaping of incidents, and (d) an incident management simulation workshop involving police, fire, emergency medicine, tow operator, public works, insurance, and media professionals who have responsibilities for incident management. A series of incidents were simulated in a workshop and consensus was sought on specific and general management tactics. This paper describes study methods and summarizes the important issues and recommendations to improve incident management. Among the key needs identified are (a) response in a manner and with adequate resources to minimize the time an incident affects a scene, (b) rapid removal of vehicles and debris, (c) effective traffic control at and around the incident, (d) communication with motorists who may be affected by long-duration incidents, and (e) advanced, intra- and interagency planning for incident management. Recommended changes include education of drivers and professionals, legislation, communications, use of new technologies for communications and data collection, and advanced planning and coordination of on-site procedures, responsibilities, and priorities.
San Diego Field Operational Test of Smart Call Boxes: Institutional Issues
Authors: Banks James H. , Powell Patrick A.
Published: April 2007

Important institutional lessons learned in the course of the San Diego smart call box field operational test are presented. These lessons relate both to the conduct of the field test itself and to requirements for deployment of intelligent transportation systems similar to smart call boxes. The institutional issues were identified through review of project documents, interviews with participants, and the experience of the evaluator as a participant in the project. Issues were analyzed by preparing summaries that included a description and discussion of each issue, an assessment of its seriousness, identification of the organizational participants who raised it, a discussion of ways to avoid or mitigate any problems identified, and a list of actions to resolve the issue in the event of system deployment. Major institutional lessons include the potential impact of institutional arrangements on basic system concepts, the importance of involving potential users in the definition of system concepts and detailed design specifications, the need for quantitative market research to establish the potential profitability of intelligent transportation systems, the need for an adequate institutional infrastructure for deployment, and the importance of project organization schemes that minimize the number and complexity of formal agreements among participants.
San Diego Field Operational Test of Smart Call Boxes: Technical Aspects
Authors: Banks James H. , Powell Patrick A.
Published: April 2007

Smart call boxes are devices similar to those used as emergency call boxes in California. The basic call box consists of a microprocessor, a cellular transceiver, and a solar power source. The smart call box system also includes data-collection devices, call-box maintenance computers, and data recording systems at a central location. The goal of the smart call box field operational test (FOT) was to demonstrate that smart call boxes are feasible and cost-effective means of processing and transmitting data for tasks such as traffic census, incident detection, hazardous weather reporting, changeable message sign control, and video surveillance. The objective of the FOT evaluation was to determine the cost-effectiveness of smart call boxes, but because of schedule slippage the evaluation focused on only functional adequacy and capital costs. The concept for the smart call box system was found to be feasible but not necessarily optimal for the tasks involved. System integration was a major problem. Also, the number of external devices that can be attached to a single call box while maintaining the economic advantages of the system is restricted by wiring costs and limitations of the solar power supply. Test system performance was mixed. One subtest was canceled before the installation of equipment, functional systems were produced for only three of the four remaining subtests, and reliable operation was observed in only one case. In most cases, system costs will be dominated by the expense of installing wiring. Consequently, smart call boxes will be cost-effective compared with hardwire systems at many sites but may not be cost-effective compared with alternative wireless systems.
Organizing for Intelligent Transportation Systems: Case Study of Emergency Operations in San Francisco Bay Area
Authors: Lo Hong K.
Published: April 2007

Computer-integrated transportation (CIT) is envisioned as an integrated network of public and private transportation organizations, each with unique responsibilities but working toward a common mission of facilitating travel across all modes of transportation. Research on CIT is extended to emergency operations (EOs) and presented. EOs in California are examined and their role in gathering and using traffic incident information is identified. The basis of coordination between EOs and transportation management centers is established. Intelligent Transportation System (ITS) services and technologies that may be beneficial to EOs are identified, and the similarities and differences between California EOs and the emerging ITS national architecture are compared.
Short-Term Improvements To Increase Capacity of Highly Congested Mainline Toll Plazas in Puerto Rico
Authors: Pesquera Carlos I. , González Sergio L. , Colucci Benjamín , Contreras Carlos M.
Published: April 2007

In 1993 the Department of Transportation and Public Works of Puerto Rico (DTPW) implemented toll gates at expressway toll collection plazas because of significant losses in revenue caused by failure of motorists to pay the established fee. However, it was presumed that the use of toll gates as an enforcement device for effective traffic control might create additional delays, particularly during peak hours in already highly congested toll plazas near metropolitan areas. The lack of additional open space to expand the existing toll facilities combined with the negative public image associated with high levels of congestion, attributed to implementation of the toll gates, triggered the need to explore cost-effective, short-term alternative solutions. DTPW efforts to address the issues of congestion and negative public image in the highly congested toll facilities are described. A series of experimental studies were performed to assess the effectiveness of toll gates and automatic vehicle identification (AVI) technology in increasing the capacity of low-volume and highly congested toll facilities. The findings were analyzed for significant differences in delays and for potential changes in driver behavior that could assist in mitigating delays at the toll plazas. The results of the first study revealed that the implementation of toll gates creates additional delays for users. The second study found that AVI technology is fast, efficient, and reliable in the detection of vehicles when used in low-volume toll plazas; however, it is not efficient in highly congested toll plazas because of the additional delays generated from the queue. In the third study it was demonstrated that the use of ushers to collect coins from drivers and deposit them in the toll basket resulted in a significant increase in capacity at toll plaza stations, time savings, and fuel economy for users.
Effective Public Communication and Marketing of High-Occupancy-Vehicle Lanes: An Agency Perspective
Authors: Paiewonsky Luisa
Published: April 2007

The Massachusetts Highway Department (MassHighway) opened the Southeast Expressway high-occupancy-vehicle (HOV) lane on November 15, 1995. The 6-mi (9.6-km) contraflow lane, open to vehicles with at least three occupants, was MassHighway’s third attempt to create an HOV facility on the Southeast Expressway. Two previous HOV lanes, built in the 1970s, had closed because of operational problems and public opposition. Supported by FHWA, MassHighway developed a $558,000 marketing program to promote the new HOV facility and encourage its use by commuters. The difficulties in developing an HOV facility on the congested highway were mirrored in the marketing challenge faced by its agency managers. From the first 8 months of the campaign, Mass-Highway has learned several important lessons from the experience. Marketing should begin years before the project opens. The feasibility analysis offers agencies the opportunity to solicit community input and identify marketing themes for the later campaign. Agencies should allot at least 6 months to prepare for the marketing campaign. They should strongly consider the use of professional consultants in marketing, public relations, and advertising. The bulk of the marketing budget should be spent within the facility’s opening weeks. Agencies should assign their own staff, not outside consultants, to act as project spokespersons. Messages should be tailored to specific audiences identified in the campaign. Public perception of the facility will depend in large part on how well it is operated. Fair and uniform enforcement promotes the facility and maintains public acceptance. HOV-facility managers must be prepared to convert unforeseen incidents into positive press coverage. Reporting on lane conditions must be scrupulously accurate, because there likely will be intense public scrutiny of agency statements. MassHighway’s HOV-lane marketing program, ultimately successful, may be instructive to other states contemplating similar initiatives.
I-880 Field Experiment: Analysis of Incident Data
Authors: Skabardonis Alexander , Petty Karl F. , Bertini Robert L. , Varaiya Pravin P. , Noeimi Hisham , Rydzewski Daniel
Published: April 2007

The I-880 field experiment has produced one of the largest data bases on incidents and freeway traffic-flow characteristics ever compiled. Field data on incidents were collected through observations of probe-vehicle drivers before and after the implementation of freeway service patrols (FSPs) over a freeway section. Supplementary information was collected from the California Highway Patrol’s computer-aided dispatch system, FSPs, and tow-truck company logs. The incident patterns are described and the major factors affecting incident frequency and duration are identified. FSPs significantly reduced the response times but did not have a significant effect on the duration of all incidents.
ALINEA Local Ramp Metering: Summary of Field Results
Authors: Papageorgiou M. , Hadj-Salem H. , Middelham F.
Published: April 2007

Asservissement Linéaire d'Entrée Autoroutière (ALINEA), a local feedback ramp-metering strategy, has had multiple field applications, and more applications are planned in several European countries. The main features of ALINEA are presented and the field results achieved to date at both single and multiple ramps of the Boulevard Périphérique in Paris and at the A10 West motorway in Amsterdam are summarized. The reported results indicate easy application, flexibility, and high efficiency of ALINEA. Planned implementations are outlined.
Real-Time Estimation of Incident Delay in Dynamic and Stochastic Networks
Authors: Fu Liping , Rilett Laurence R.
Published: April 2007

The ability to predict the link travel times is a necessary requirement for most intelligent transportation systems (ITS) applications such as route guidance systems. In an urban traffic environment, these travel times are dynamic and stochastic and should be modeled as such, especially during incident conditions. In contrast to traditional deterministic incident delay models, the model presented explicitly considers the stochastic attributes of incident duration. This new model can be used for predicting the delay that a vehicle would experience as it travels through nonrecurring congestion brought about by an incident. The model is operational in the sense that it does not require significant data and computational abilities beyond that which is traditionally used and can be used within traffic models or within actual ITS implementations. A mixed discrete and continuous vehicle-delay model is first derived and estimators of the mean and variance of vehicle delay are identified. A sensitivity analysis subsequently is performed, and a method for updating the estimated delay as new information becomes available is provided.
Development of Traffic Control and Queue Management Procedures for Oversaturated Arterials
Authors: Abu-Lebdeh Ghassan , Benekohal Rahim F.
Published: April 2007

The formulation and solution of a new algorithm for queue management and coordination of traffic signals along oversaturated arterials are presented. Existing traffic-control and signal-coordination algorithms deal only with undersaturated steady-state traffic flow conditions. No practical algorithms are readily available for oversaturated flow conditions. The main idea of the procedure is to manage queue formation and dissipation on system links so that traffic flow is maximized by efficiently using all green time, preventing formation of de facto red, accounting for the non-steady-state conditions, and providing time-dependent control measures. The problem is formulated as a throughput maximization problem subject to state and control variables. The solution is then obtained using genetic algorithms. The results show that the control procedure can produce dynamic and responsive control so that traffic progression is attained and all undesirable conditions such as queue spill-back and de facto red are avoided.
Optimum Bus Headway for Preemption: A Simulation Approach
Authors: Khasnabis Snehamay , Rudraraju Rama K.
Published: April 2007

Preemption techniques are designed to provide preferential treatment for buses at signalized intersections. A preemption strategy, if properly designed, can provide continuous green phases for buses at successive intersections, thereby reducing travel times and delays along the bus route. However, the length of delay incurred by all the vehicles in the system may be affected by the different bus headways under preemption operation. Unfortunately, no formal technique is available to assess the cumulative delay consequences of bus headways. The application of a simulation model, NETSIM, to test the effect of different headways is presented. NETSIM was selected because it can microscopically simulate vehicular movements on a street network and because an animation feature within NETSIM is available that allows the user to track an individual vehicle from the source to the sink. A major bus route in Ann Arbor, Michigan, was used as the experiment site. The major conclusions are that NETSIM can generate delay data at various levels of aggregation (e.g., link, node, and route) that can be used to assess the operational consequences of bus headways under preemption conditions. For the volume levels studied in the project, the savings in delay along the bus route resulting from preemption appears to be a good measure for determining the optimum headway.
Methodology for Evaluating Effectiveness of Traffic-Responsive Systems on Intersection Congestion and Traffic Safety
Authors: Hanbali Rashad M. , Fornal Chris J.
Published: April 2007

In 1986, the city of Milwaukee applied for and received approval for a hazard elimination grant to reduce congestion and traffic accidents at the intersection of two major and one minor arterial on the northwest side of the city. The intersection complex had several approaches at or above capacity, associated long queues of traffic, and an annual traffic-accident rate of more than three per 1 million entering vehicles. The hazard elimination grant called for the installation of a closed-loop, traffic-responsive signal system to manage the congestion and to reduce traffic accidents. The intersection complex presented many constraints on traffic-responsive operation, the most critical of which was that the three arterials formed a signal triangle (three separate signalized intersections) with intersection spacing as short as 27.4m (90 ft). FHWA realized the unusual nature of this project and designated it an experimental project in 1987. The development of the traffic-responsive signal system within the many constraints of the location is described. After a lengthy process, the traffic-responsive system became operational in September 1993 and proved to be an operational success by reducing the length of traffic queues. After extensive data collection, an analysis and evaluation confirmed that the traffic-responsive signal system reduced the occupancy levels per vehicle on the system detectors and reduced the incidence of congestion-related traffic accidents.
Transit Service Design and Operation Practices in Western European Countries
Authors: Reilly Jack M.
Published: April 2007

Fundamental transit service design in a number of small cities in Western Europe, which have reputationally good transit systems, is discussed. This work was the result of a transit study tour sponsored by the Transit Cooperative Research Program of TRB. Key differences between transit design practice in Europe and the United States include longer distances between stops, superior customer information at bus stops, more frequent service, and downtown schedule coordination in the European systems. The combination of low-floor buses, off-board fare collection, long distances between stops, and multiple boarding doors on buses enables these systems to carry a large number of customers without deteriorating schedule speed. Several transit systems have used imaginative methods of providing service in low-density markets such as sparsely settled areas and evening and weekend transit service. These include the use of group taxis that travel between downtown and bus stops in the rest of the city. Compared with U.S. transit systems of comparable size, European transit systems are more technology driven. Even small cities have traffic-signal preemption systems, schedule adherence systems, and off-board electronic fare collection technology. Possible application of some of these techniques to transit practice in the United States is discussed.
Understanding Differences in Public Transit: Comparison of Boston and Toronto
Authors: Schimek Paul
Published: April 2007

Public transit systems in Toronto and Boston, two North American cities of similar size and income, are compared. Although Boston has a reputation as a transit-oriented city, there are about twice as many public transit trips in Toronto. Transit service in Toronto runs, on average, twice as frequently as service in Boston on a network of similar size. This level of service can be supported in part because population density does not decrease as much with increasing distance from the center of the city and because employment is more centralized. The transit system in Boston is constrained from emulating the Toronto transit system not only by a less transit-favorable distribution of population and employment but also by operating costs that are twice as high. The Massachusetts Bay Transit Authority’s higher costs are the result of more fringe benefits for employees and disproportionately more managers and fixed facilities.
Integrated Decision Support Tool for Evaluating Transit and Land-Use Coordination Policies
Authors: Fox Thomas D. , Bowlby William
Published: April 2007

Policy makers in many urban areas have begun to embrace the principles of transit-oriented development as a means to create more livable communities and of light rail transit as a means to address congestion and air-quality problems. A policy-oriented screening tool for applying rigorous technical analyses to transit-oriented development policies to give decision makers meaningful information about a wide range of potential land-use, transit service and financing, and parking management policies is described. The decision support tool (DST) uses a simplified version of the regional travel forecasting model and includes an air-quality analysis module. The DST was validated to the Memphis regional travel forecasting model, and enhancements were incorporated for studying the effects of specific land-use, transit, and parking-policy assumptions. DST provides policy-related output data such as percentage of development in the corridor; transit ridership; annual transit operating cost, revenue, deficit, and cost recovery ratio; annual transit capital cost; and air-quality benefits. A sample application of the model for the Poplar Corridor in Memphis, Tennessee, is presented.
Parking Supply Policy and Transit Use: Case Study of Atlanta, Georgia
Authors: Nelson Arthur C. , Meyer Michael D. , Ross Catherine B.
Published: April 2007

For two decades, the city of Atlanta, Georgia, has used special public interest districts (SPIDs) to attract new development to and improve transit ridership around Midtown rail transit stations operated by the Metropolitan Atlanta Rapid Transit Authority (MARTA). Buildings locating inside SPIDs need not provide any parking facilities and can be developed more intensively than buildings located outside SPIDs. Buildings constructed outside SPIDs must have at least two parking stalls for every 1,000 ft2 (92.9 m2) of gross leasable area and are limited to about 30 floors. The extent to which these policy objectives have been fulfilled by Atlanta’s parking supply policies as they are applied around Midtown MARTA stations is analyzed. Findings are mixed. Development was attracted to SPIDs, and transit ridership among employees working within SPIDs was substantially higher than among those working outside SPIDs. On the other hand, new parking has proliferated throughout Midtown with some evidence to suggest that transit ridership has fallen as a result. It is concluded that without areawide parking supply efforts, policies patterned after Atlanta’s SPID program will have limited success in improving transit ridership.
Mobility Analysis of Transit Systems
Authors: Galíndez Aníbal A. , McLaughlin James F. , Beard Callier , Spivack Gary S.
Published: April 2007

In this era of scarce transportation resources, there is a need for analytical techniques to examine the effectiveness and efficiency of transportation programs. Since the pioneer work of Fielding et al., there have been many measurement schemes that have purported to assess the productivity of transit systems. This plethora of statistics has resulted in an information overload for policy makers and transit planners. The effectiveness and efficiency of transportation programs have been measured, with people flow used as the unit of analysis. The mobility index measures people flow in the transportation system as passenger miles carried per vehicle hour. The index is computed by multiplying average vehicle occupancy times passenger speed. A cost-efficiency comparison for regional transit services results when the mobility index for a transit project is matched against the demand and the price of the services. Thus, this methodology combines efficiency and effectiveness measures to evaluate transit services at the regional and transit agency levels. The analysis is also applicable to individual transit lines at both the macro level and the route or line segment level by time period. Analysis of the entire line uses passenger miles divided by bus miles as the measure of average vehicle occupancy. At the route or segment level, average vehicle occupancy is assessed through the load ratio, which is defined as patrons onboard divided by the number of available seats. Because of advances in computing technology, these utilization coefficients can be plotted by time of day at each transit stop. Nonproductive route segments or times at which the transit route can be restructured to increase productivity and mobility are indicated in these plots. The time and location performance graphs can also be used to plot schedule reliability and infer running time adequacy by location and time period that affects passenger speed. The methodology is unbiased with respect to the operator organizational structure, whether public or private, because people flow is the basis for evaluation. The mobility analysis can define operator efficiency in different demand markets. Thus, it can serve as an analytical tool for regionwide performance standards. Strategies to improve transit service delivery, particularly in areas of low or fluctuating demand, are also suggested.