bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of Delay Induced by Downstream Traffic Disturbances at Signalized Intersections
Authors: Ahmed Kamran , Abu-Lebdeh Ghassan
Published: January 2019

Macroscopic models that can be used to estimate the delay at signalized intersections caused by downstream traffic disturbances, such as queues in closely spaced settings, are presented. The models use basic traffic flow properties and control parameters at neighboring intersections. The models are applied to a hypothetical two-signal system. The results show that the delay caused by downstream disturbances can be significant and therefore must be included in level-of-service and capacity analyses. The results also show that control parameters, such as offsets and green splits at upstream and downstream approaches, play key roles in reducing delay. Validation by the use of microscopic traffic simulation shows close agreement between the delay estimates from the proposed models and that from the microscopic simulation model.
Effects of Parameter Distributions and Correlations on Uncertainty Analysis of Highway Capacity Manual Delay Model for Signalized Intersections
Authors: Ji Xiaojin , Prevedouros Panos D.
Published: January 2019

The uncertainty analysis of the Highway Capacity Manual (HCM) delay model often assumes parameter variances and distributions. In light of the difficulty in specifying distributions and estimating correlations, the present study investigated (a) the possibility of assumed distributions’ major effect on the results and (b) the effects of correlations on the accuracy of delay estimates. Field data from one intersection approach in Hawaii and nine intersection approaches in Illinois were used. All input variables in the delay model except for the analysis period were considered uncertain; the analysis period remained fixed at 15 min for consistency with HCM. The simulation results showed that the confidence intervals of delay can be large even if the variability of each input parameter is small. The degree of saturation (X) has a significant effect on the uncertainty of delay estimates for X values 0.9. The standard deviation of input parameters is the main factor affecting the uncertainty of delay estimates. The probability distributions have a slight effect. Correlations among input parameters are often overlooked, but they have a significant effect on the confidence intervals of delay estimates, especially when the variability of the input parameters is large and the input parameters are highly correlated. The frequency distribution of delay estimates is not normal; the shifted lognormal distribution provides a better statistical fit.
Land Use Impacts on Trip Generation Rates
Authors: Ewing Reid , Deanna Marybeth , Li Shi-Chiang
Published: January 2019

In the conventional four-step travel demand modeling process, the number of trips made by a household is modeled in terms of household size, income, and other sociodemographic variables; any effect of location, land use, or transportation service level is discounted. This is the same as discounting any effect of household accessibility to out-of-home activities as a factor in trip generation (accessibility depending on all three: location, land use, and transportation service level). In contrast to the practice of trip generation, theory tells us that trip rates must vary with accessibility, and some (not all) empirical studies have found that they do. In light of conflicting empirical studies, and the obvious need for more precise and policy-sensitive travel forecasts, this issue is revisited. The independent effects of land use and accessibility variables on household trip rates were tested for using data from Florida travel surveys. It was found that, after controlling for sociodemographic variables, residential density, mixed use, and accessibility do not have significant, independent effects on household trip rates. Conventional trip generation models, which generate person trips by vehicle (not by all modes) and do so without regard to residential location, may not be as bad as one would imagine a priori.
Forecasting Travel Time
Authors: Roden David B.
Published: January 2019

If travel time and speed are to be used as critical performance measures in congestion management systems and air quality analysis procedures, existing modeling techniques will need to be enhanced. Many of the simplifying assumptions that are built into traditional modeling techniques are described. Several relatively simple enhancements to existing models that can greatly improve the model's ability to estimate travel time and speeds are identified, and more advanced methods that could be considered as part of major model redevelopment efforts or detailed air quality studies are suggested. One of these methods involves simulation techniques. The problems and issues of integrating simulation models with travel demand forecasting techniques are outlined, and it is concluded that modeling speed is considerably more difficult than modeling volumes. The bottom-line criterion for any model enhancement is that the procedure supports decision makers in a timely and cost-effective way. This criterion is likely to limit the types of enhancements that are possible.
Developing Long-Range Transportation Plans for Small Urbanized Areas in the ISTEA Era: Tallahassee 2020 Plan Update
Authors: Schiffer Robert G.
Published: January 2019

Passage of the Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) has resulted in a number of new requirements for the development of long-range transportation plans sponsored by metropolitan planning organizations. Many of the published ISTEA discussions have revolved around large urbanized areas with significant air quality problems, large congested freeway systems already in place, and fixed-guideway transit systems either operating now or planned for the future. The Tallahassee–Leon County MPO is responsible for transportation planning activities for an area with a 1993 population of 206,000. Tallahassee has no significant air quality problems, only one Interstate facility (which does not even serve the downtown core), and a limited bus transit system. With this backdrop, the Tallahassee 2020 Transportation Plan Update has been conducted with an eye toward the ISTEA goals of providing for intermodal connectivity, developing multimodal solutions, evaluating the link between transportation and land use, and enhancing the public participation process. ISTEA consistency has been addressed in the Tallahassee 2020 Plan Update through a variety of means, including the following: (a) complete model calibration based on recently collected origin-destination data; (b) use of the 15 ISTEA as a framework for the adopted goals and objectives; (c) public presentations to a variety of civic groups and committees; (d) model testing and deficiency analysis of alternative future land use scenarios; (e) recommendations of improvements that provide for preferential treatment of high-occupancy vehicles; (f) identification of locations of future bicycle, pedestrian, and park-and-ride facilities; and (g) coordination with a separate study on the effects of enhanced transportation demand management software implementation.
Regional Place-Systems Analysis Applied to Long-Range Transportation Planning
Authors: Voellinger Leonard , Oakes Claudia
Published: January 2019

The Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA) requires the integration of environmental considerations into transportation planning. Although previous legislation has required the consideration of environmental elements during project planning, ISTEA necessitates a different approach. During project-specific planning, each environmental element is researched to determine baseline conditions, and project plans are superimposed to determine potential impacts and the need for mitigative measures. This approach is appropriate for project-specific planning, but it presents only a snapshot of existing conditions because environmental data are changing constantly. The integration of environmental considerations into long-range plans requires a much broader focus. It must allow dynamic systems to change without affecting the plan's validity. A case study is presented of the Oklahoma statewide intermodal transportation plan, which uses recent geographic theory to integrate planning and human activity at varying scales. This theoretical framework is based on ecological and societal units of interaction called bioregions or place-systems. The environmental baseline and analysis for Oklahoma begin with the identification of place-systems in the state: areas of biophysical and cultural similarity and context. The delimitation of such regional place-systems is sufficiently generalized and flexible to accommodate many data types and sources, yet rigid enough to be useful for planning. Both quantitative data and descriptive information are included in an analytical framework suitable to relational data bases and geographic information systems applications. These are used to create a series of map and data overlays to project potential environmental impacts and constraints, as well as opportunities for developing future transportation projects. The methods used to delineate regional place-systems in Oklahoma and their subsequent use in environmental analyses and planning are described.
Applying Urban Transportation Modeling Techniques to Model Regional Freight and Vehicle Movement
Authors: Prem Clyde E. , Yu Ping
Published: January 2019

The approach used to model freight movements in a large rural study area is described. The study conducted for the Quad County Regional Transportation Organization in Washington State is an example of one demonstrating that traditional urban transportation planning techniques can be applied in perhaps a new way to perform detailed analysis of freight movements. It is also an example of how quick-response methods (similar to those described in NCHRP Report 187) were applied to enable the project to be completed within 6 months at a lower cost.
Estimating Impacts of Transportation Control Measures on Work-Related Trips
Authors: Sivasailam Daivamani , Williams Jon
Published: January 2019

States and metropolitan areas are under increasing pressure to implement transportation control measures (TCMs) to reduce mobile source emissions. Many of these TCMs are aimed at commute trips (i.e., trips from home to work and back). A number of techniques are used to analyze the TCMs. Models use home-based work (HBW) trip tables as input; these consist of the trip from home to work and the trip from work to home, which account for 25 to 30 percent of all trips in a region. However, analysis of the Home Interview Survey data for Washington, D.C., indicates a large number of the nonwork trips were actually taking place either as part of the trip from home to work or from work to home, or during the workday. If a TCM is analyzed using only the HBW trip table, it is implicitly assumed that there will be no impact on the trip from home to work with an intermediate stop. However, it is possible that the TCM could alter the behavior of the person making the home-to-work trip with an intermediate stop. If this is not accounted for, the results of the analysis underestimate the impact of the TCM. Research undertaken for two distinct but related subjects is summarized. The amount of work-related nonwork travel in the Washington, D.C., metropolitan region is estimated, and the methodology developed to account for the effect of TCMs on total work is described.
Evaluating the Options in Urban Areas with Financial Constraints
Authors: Decorla-Souza Patrick , Everett Jerry , Gardner Brian , Culp Michael
Published: January 2019

Logic is devised for a needs test for new general-purpose lane (GPL) highway capacity in urban areas that have limited funding available for new infrastructure investments. GPL capacity is defined as mixed-flow lanes on which both single-occupant and high-occupancy vehicles are permitted. Methodologies to apply the needs test and to evaluate the options in urban areas facing limitations on new GPL capacity are developed. A case study is used to demonstrate the methodologies to evaluate the air quality and cost-effectiveness impacts of transportation system alternatives, illustrating how planners may develop the type of information that policy makers will need to help them make informed decisions about long-term options.
Accuracy of Traffic Forecasts and Cost Estimates on Large Transportation Projects
Authors: Skamris Mette K. , Flyvbjerg Bent
Published: January 2019

Little research has been carried out on before-and-after studies of traffic and construction costs in large transportation infrastructure projects. The few studies that do exist show that forecasts of construction costs tend to be underestimated and those of traffic, overestimated. An examination of construction costs and traffic in seven large Danish bridge and tunnel projects indicates that, on average, construction costs were underestimated and traffic was overestimated in the initial phases of planning. This pattern is also found for similar projects in other countries. When the results of all the projects are pooled, it is seen that cost overruns of 50 to 100 percent are common and that overruns above 100 percent are not uncommon. Traffic forecasts that are off by 20 to 60 percent when compared with actual development are frequent in large transportation infrastructure projects. The result of this overoptimism in the initial planning phases is that decisions are based on misleading forecasts that may lead to a misallocation of funds and underperforming projects.
Project-Level Air Quality Assessment Actions: Interrelating Conformity with National Environmental Policy Act Process
Authors: Frazier James A. , Henneman John L.
Published: January 2019

The procedural aspect of linking the transportation conformity process and the transportation alternatives development process that is part of the National Environmental Policy Act (NEPA) is discussed. The linkage is structured to ensure continuity between project-level design considerations developed during planning and programming and refined as part of the NEPA process. These issues are critical to the Pennsylvania Department of Transportation, Bureau of Environmental Quality, where air quality impacts delineated during the conformity process play a significant role in the continued development and refinement of the transportation system. For states like Pennsylvania, where transportation conformity requirements play a strong role in the transportation development process, providing a single set of air quality assessment actions can avoid the risk of conformity reevaluation or failure caused by project redesign during the NEPA process. A method to link the regional transportation conformity air quality analysis with project development and design conducted during the NEPA process is described. The linkage is made by using project-level air quality impacts developed during the regional conformity analysis and comparing the air quality impacts of transportation alternatives as they are developed during the NEPA process. Elements of the air quality impacts delineated during the regional conformity analysis act as the project-level air quality benchmark that is carried forward into the NEPA process.
Transportation Perspective of Ozone Trends in Clean Air Act Nonattainment Areas
Authors: Shiftan Yoram , Suhrbier John , Pickrell Don
Published: January 2019

There has been considerable renewal of interest over the seriousness and nature of the air quality problems in this country. The need for transportation and other forms of mobile source controls is dependent on the magnitude of the current problem and the rate at which air quality is improving. Trends in monitored ozone levels for 20 serious and severe nonattainment areas over the 14-year period, 1980–1993, are examined. Trends are examined using ambient air quality data contained in the Aerometric Information Retrieval System data base maintained by the Environmental Protection Agency (EPA). Trends in two measures are analyzed: the maximum hourly ozone value for the second highest violation day and the number of violation days per year. Tests of the statistical significance of air quality trends were conducted, including consideration of the effects of geographic scale, meteorological variables, and economic growth. The results show that, on a nationwide basis, there is a significant downward trend in ozone levels. However, not all the year-to-year variations can be explained by a simple trend, and there also are other factors that have an important influence on peak ozone concentrations. The analyses showed statistically significant results in different urban areas and geographic regions; it also showed that omitting meteorological variables results in an overestimation of the downward trend for the particular urban areas and time period analyzed.
Assessing Emissions Contribution of Intercity Trucking
Authors: Ostria Sergio J.
Published: January 2019

The contribution of intercity trucking to air pollution in a given region is readily recognized as significant by transportation and air quality planners. Other than emissions standards for newly sold trucks, neither the air quality nor the transportation planning communities has focused on implementing control strategies that directly mitigate emissions from intercity trucking. As nonattainment areas strive to comply with the National Ambient Air Quality Standards, the potential emission reduction benefits of truck-related control measures must be evaluated to ensure that all sources of emissions are considered in the planning processes. However, little is known about the contribution of intercity trucking to emissions inventories in regions across the country, particularly since the Environmental Protection Agency's MOBILE emissions factor model is not well-suited for this purpose. The incorporation of intercity trucking in emission inventory estimates is reviewed, and a methodology by which intercity trucking emissions can be easily isolated using information documented in state implementation plans (SIPs) is developed. Using SIP data for a select number of metropolitan areas and the Truck Inventory and Use Survey (TIUS), the emissions contributions of city-to-city truck transport and drayage operations are assessed. Furthermore, the contribution of intercity trucking to emission reductions in areas across the country is determined using information reported in 15 percent volatile organic compound reduction plans.
Emissions Comparison between Truck and Rail: Case Study of California I-40
Authors: Barth Matthew J. , Tadi Ramakrishna R.
Published: January 2019

A comprehensive goods movement study of the California Interstate 40 corridor (from Barstow to Needles) has recently been completed. This study attempted to characterize goods movement in the region, perform a corridor emissions analysis, and make recommendations in terms of capacity and improvements, as well as economic feasibility of using rail in conjunction with trucks for goods movement. The emissions analysis of goods movement along the I-40 corridor is examined, specifically emissions of carbon monoxide, hydrocarbons, nitrogen oxides (NOx), and particulate matter associated with both truck and rail traffic. Heavy-duty diesel truck emissions are estimated using truck activity data recorded along the corridor. A unique methodology is used to calculate these truck emissions, incorporating road grade factors and determining engine load on a link-by-link basis. These emissions are then compared with the emissions associated with freight trains that travel along this I-40 corridor. On the basis of current (1994) truck and rail volumes, it was found that goods moved by rail produces lower emissions, except for NOx, which is slightly higher for rail. The factor decrease of other pollutants ranges from 2.49 to 8.50, which is consistent with other recent studies. Given the amount of pollutants produced by trucks, shifting some of the freight from trucks to rail with a greater emphasis on intermodal business should reduce the total freight emissions along the I-40 corridor.
Emissions Analysis of Southern California Metrolink Commuter Rail
Authors: Barth Matthew J. , Younglove Theodore , Tadi Ramakrishna R.
Published: January 2019

The Southern California Regional Rail Authority began constructing a new commuter rail system called Metrolink in October 1992. When complete, the Metrolink system will form the nation's sixth largest commuter rail system and is expected to alleviate congestion and help obtain better air quality. To estimate the air quality impact, emissions of CO, HC, NOx, and PM associated with an automobile-only–based commute and a Metrolink-based commute from Riverside to Los Angeles are compared. Analysis of the Metrolink-based commuting scenario includes the emissions from the home-to-station automobile trip and the Metrolink diesel locomotive emissions. Essential data for the automobile emissions modeling process were obtained through a survey of Metrolink passengers and through remote emissions sensing of Metrolink passenger vehicles. Train emissions were estimated using emission rate data provided by recent diesel locomotive studies. Results indicated that at current ridership levels there is a reduction in total amount of all four pollutants combined through Metrolink commuting. On a pollutant-by-pollutant basis, it was estimated that the Metrolink commuting scenario reduces the emissions of CO and HC relative to the automobile-only commuting scenario; however, it increases the emissions of NOx and PM. The minimum amount of Metrolink ridership required to get a net emissions reduction from the system is predicted.
Simulating Automobile Emissions in an Integrated Urban Model
Authors: Anderson William P. , Kanaroglou Pavlos S. , Miller Eric J. , Buliung Ronald N.
Published: January 2019

The network component of an integrated urban model called IMULATE is interfaced with the MOBILE5.C emissions models. IMULATE produces estimates of traffic flows and average speeds on each link in an urban road network using a user equilibrium assignment algorithm. This information is combined with speed-dependent emissions factors generated by MOBILE5.C to calculate estimates of the three types of emissions on a link-by-link basis. The combined models are implemented for the Hamilton, Ontario, Canada, metropolitan area. Simulations are conducted to illustrate the spatial patterns of emissions in the morning peak period and to demonstrate the impact of congestion on emissions estimates. The incorporation of detailed network performance information yields significant benefits in the estimation of regional automobile emissions.
Operating Mode Fractions on Urban Roads Derived by Traffic Assignment
Authors: Chatterjee Arun , Reddy P. Murali , Venigalla Mohan M. , Miller Terry L.
Published: January 2019

The federal test procedure for vehicle emissions measurement treats the first 505 sec of engine operation as the transient mode. Using this definition as the basis, a special technique was developed and used to trace the elapsed time of vehicles from trip origins during the traffic assignment of zone-to-zone trips on a highway network and to determine the proportions of transient and stabilized operating modes on every link of the network. The travel models of the Sacramento (California) urban area were used to apply this technique and derive operating mode fractions for this urban area. The data from the Nationwide Personal Transportation Survey were used to distinguish between cold transient and hot transient modes. The operating mode fractions were stratified by functional class of roadways and the location within the urban area. The time of day of travel also was used for further stratification. The results show wide variations in the operating mode fractions among the different categories of roadway, location, and time of day.
What Really is the Growth of Vehicle Usage?
Authors: Lave Charles
Published: January 2019

The enormous jump in vehicle miles traveled (VMT) per person reported by the 1990 Nationwide Personal Transportation Survey (NPTS) conducted by the U.S. Census Bureau caused a great deal of concern among planners and policy analysts. Such a jump seemed to portend an era of ever-increasing travel, pollution, and energy consumption. Three alternative VMT estimates are developed using data from other national surveys and a massive odometer-based California study. The three new estimates are nearly identical but differ markedly from the NPTS results. (Reanalysis of the 1990 NPTS shows that it oversampled new vehicles: since new vehicles are driven two to three times as much as old ones, VMT per average vehicle is overestimated.) VMT per vehicle actually grew at only half the rate estimated by the NPTS.
Impacts on Home Heating Costs of Incentives for Alternative Fuel Vehicles
Authors: Kornfield Thomas , Lawrence Michael F.
Published: January 2019

Regulatory incentives for increased usage of alternative fuels in motor vehicles could have an impact on home heating costs, potentially increasing the price of natural gas and liquefied petroleum gas (LPG, or propane) while decreasing the price of home heating oil. The Alternative Fuels Trade Model (AFTM) is used to estimate these end-use cost impacts by comparing price results from two scenarios: a base case and an unconstrained case. The AFTM is a macroeconomic simulation model for determining prices and quantities that balance the interrelated world oil and gas markets given assumptions about supply, demand, and costs. Under the base case, alternative fuel usage is set at 5.5 percent of total light-duty motor vehicle fuel usage, while under the unconstrained case, alternative fuel-usage levels increase to 32 percent. All prices and expenditures are estimated for the year 2010 and are expressed in 1992 dollars. Increased usage of compressed natural gas (CNG) and LPG by alternative fuel vehicles as a result of either regulatory incentives or market forces will tend to increase annual natural gas and LPG home heating costs, while reducing distillate fuel-oil home heating costs. Per household, natural gas and LPG annual home heating costs are predicted to increase by $4.14 and $20.65, respectively, while annual distillate fuel-oil home heating costs are predicted to decrease by $3.17. The increase for LPG amounts to a 3.7 percent increase over the base case expenditures. These cost impacts are estimated at the national and regional levels and by income classification.
Potential Coverage of Alternative Fuel Industries under EPACT Section 501
Authors: Hu P. S. , Wang M. Q. , Vyas A. , Mintz M. , Davis S. C.
Published: January 2019

The Energy Policy Act (EPACT) has the goal of replacing 10 percent of transportation petroleum fuel with alternative fuels and replacement fuels by the year 2000 and 30 percent by 2010. Sections 501 and 507 of EPACT mandate use of alternative fuel vehicles (AFVs) in fleet applications. In particular, Section 501 requires that certain percentages of new light-duty vehicles (LDVs) acquired by alternative fuel providers be AFVs. The first step in estimating the effects of these mandates entails identifying affected fleets that are covered by the act. An assessment of potential fleet coverage of Section 501 is presented. This assessment concludes that a limited number of companies in the methanol, ethanol, propane, and hydrogen industries are likely to be covered by this mandate. On the other hand, many of the large crude-oil producers, petroleum refiners, natural-gas producers and transporters, and natural gas and electric utilities are likely to be subject to this mandate.
Potential Impacts of Energy Policy Act on Electricity and Natural Gas Provider Fleets
Authors: Vyas Anant D. , Wang Michael Q.
Published: January 2019

Section 501 of the 1992 Energy Policy and Conservation Act (EPACT) mandates that alternative fuel providers who sell such fuels for transportation acquire alternative fuel vehicles (AFVs). The potential impacts of this mandate on the two largest groups of alternative fuel providers—electricity and natural gas (NG) providers—are presented. Nationwide, 166 electric-only utilities, 127 NG-only utilities, and 55 dual-utilities are covered by EPACT. Together, these companies own or operate nearly 122,000 light-duty vehicles in EPACT-defined metropolitan areas. Some 63 NG producers and transporters, which have 9,700 light-duty vehicles, are also covered. Covered fuel providers are expected to purchase 2,710 AFVs in 1996 and 13,650 AFVs by 2001. NG companies already have 19.4 percent of their existing light-duty vehicle stocks as AFVs, dual companies have 10.0 percent, NG producers and transporters have 7.0 percent, and electric companies have 1.6 percent. If the existing AFVs count toward meeting the Section 501 requirements, NG providers (utilities, dual utilities, producers, and transporters) will need to make little effort, but electric companies will have to make substantial commitments to meet the requirement.
Planning Innovative Public Transportation Systems for Arlington, Texas
Authors: Faria David A. , Smith Wilma
Published: January 2019

A study was done to develop various innovative transportation strategies to address the changing travel needs of Arlington, Texas, residents. The study was guided by the Arlington Community Transportation Study Committee. It developed the transportation niche concept: the ability to use alternative community transportation services to address specific needs of the community in different parts of the city. Five high-priority niches were studied in detail. The success of the individual niches in particular and the integrated transportation system in general will rely heavily on the cooperation and coordination between the public and the private sectors and the acceptance of the niche concept by the general public.
Exploration of Long-Distance Interregional Commuting Issues: Analysis of Northern California Interregional Commuters Using Census Data and Focus Group Interviews
Authors: Lee Richard W.
Published: January 2019

Recent national and local travel surveys indicate substantial increases in types of travel that are not well explained by most applications of traditional travel demand models. Understanding phenomena such as nonwork travel, the travel patterns of nontraditional households, or long-distance interregional commuting requires new basic research. A promising approach to primary travel demand research was developed and is described. A case study of interregional commuting in Northern California that combined quantitative analysis of census and travel survey data with focus group techniques is presented. Census data provided the basis for defining various types of commuters; the characteristics of these types were then elaborated via the focused interviews including “rolling focus groups” aboard commuter vans. Approximately 40 commuters were interviewed in depth. The interviews illuminated important issues that clarify the census and travel survey data. The findings indicate that an affordable single-family home is the primary motivation of interregional commuters; a variety of personal, household, and schedule adaptations make commuting palatable; and key prerequisites for interregional commuting include a job and lifestyle that permit adherence to a routine. Interregional commuters appear to be good candidates for shared-ride modes.
Infrequent Riders: One Key to New Transit Ridership and Revenue
Authors: Oram Richard L. , Stark Stephen
Published: January 2019

The mass transit industry has long focused on regular riders, large numbers of trips, and daily commuting. Captive rider and transit dependency concepts are also common in the transit industry's view of its markets. However, recent research challenges these views, especially the frequency of use. Results from three sources are discussed: onboard surveys, fare structure changes, and the transit voucher (commuter check) fare subsidy plan. The findings suggest that infrequent riders are a critical transit market and perhaps the key to building transit ridership and revenues.
Implementing a Visioning and Strategic Planning Process at CTTransit
Authors: Lee David A. , Sanders Michael A.
Published: January 2019

At CTTRANSIT “visioning” has proved to be an effective process for rethinking transit management. Although various strategic planning processes used in business and government perform similar organizing functions, visioning enabled CTTRANSIT to transform basic organizational values at a time when significant internal and external changes were occurring. A key element of the visioning process at CTTRANSIT was the participation of state department of transportation officials and union leaders.
Immediate Benefits: The Reason for the Car's Success and Transit's Failure
Authors: Huey Jennifer A. , Everett Peter B.
Published: January 2019

The “delay of reinforcement” concept proposes that immediate benefits or disadvantages resulting from one's behavior are more potent and are more likely to affect behavior than delayed benefits or disadvantages. Data from consumer choice of travel modes are used to support this concept; questionnaire results show that the benefits of using a car (e.g., convenience and privacy) are very immediate to the user, whereas the disadvantages (e.g., maintenance costs and pollution) are delayed in time. This environment encourages consumers to buy and use a car rather than alternative transportation modes such as mass transit, for which the benefits are delayed in time (e.g., reduction in pollution and congestion) and the punishers are more immediate (e.g., longer travel times and exposure to poor weather). Consumer behavior is also affected by who actually receives the benefit, the individual or society. The study found that individuals accrued the benefits of car use, whereas society received the disadvantages. In contrast, alternatives to the private car yielded benefits to society, whereas the individual received the majority of the disadvantages. Time delay to benefits or disadvantages is very critical in changing and maintaining consumer behavior, and the consumer must be convinced that he or she is a direct receiver of the benefit that a particular behavior yields.
Management Framework for Transit Pricing
Authors: Oram Richard L. , Mitchell Eric C. , Becker A. Jeff
Published: January 2019

A management framework for developing and managing a fare strategy for Tidewater Regional Transit (TRT) is suggested, and the underlying rationale and decision-making steps are illustrated. Results of roundtable meetings held with TRT management and staff in January 1994 and experiences organizing and implementing pricing strategies in corporate, nonprofit, and other transit organizations throughout North America are reported. It is proposed that TRT focus its pricing strategy on a clear understanding of its primary and secondary management objectives and on how the various pricing components can help fulfill these objectives. In providing this framework, examples of relevant pricing strategies in other nonprofit and commercial entities are highlighted. An understanding of positive and negative facets of discount programs is provided to illustrate effective discount methods and common pitfalls. A simple, sequential process for managing pricing strategy effectively is outlined and recommendations offered on how to maintain an effective pricing strategy within an organization.
Effects of Smart Cards on Transit Operators
Authors: Chira-Chavala T. , Coifman B.
Published: January 2019

The results of an evaluation of the first transit smart card field operational test in California are presented. The smart card technologies deployed were radio frequency and integrated circuit contact systems, and the evaluation included the cost and productivity implications of smart cards relative to those of fare boxes as well as the perceptions of transit personnel. Data input for the evaluation came from interviews with transit personnel and onboard observations. The results indicate that smart cards work well and reliably in real-world bus operations. Passengers and transit personnel liked smart cards because they were faster and more convenient than cash fares. Smart cards could reduce passenger boarding times, vehicle downtime due to malfunctions of the fare system, and driver workload and stress. Furthermore, smart cards enhance the collection and quality of transit data.
Simulation Models for French Praxitele Project
Authors: Arnaldi Bruno , Cozot Rémi , Donikian Stéphane , Parent Michel
Published: January 2019

The Praxitele project was charged with designing a new kind of transportation in an urban environment, which consisted of a fleet of electric public cars. These public cars are capable of autonomous motion on certain displacements between stations. The realization of such a project requires experimentation regarding the behaviors of autonomous vehicles in the urban environment. Because of the danger connected with these kinds of experiments at a real site, it was necessary to design a virtual urban environment in which simulations could be done. To perform an authentic simulation of a real environment composed of a large set of vehicles (some of which are autonomous and others of which are controlled by the user or by some specific control law), different models need to be implemented: geometric modeling of the environment, mechanical simulation, motion control models, driver models, sensor models, and visualization algorithms. To implement these different models into a unique system, a new simulator system was designed. This simulator takes into account real-time synchronization and communication between cooperative processes implementing the models mentioned earlier. First, the aims and goals of the Praxitele project are presented. The motion control algorithm for automatic platooning of autonomous vehicles is then briefly presented. The focus is on the simulation of a virtual urban environment that includes Praxitele vehicles. The implementation of all of these models is described. Finally, results of a simulation of cooperative driving of the Praxitele vehicles in a virtual urban environment are given.
Typology and Analytical Model of Violent Incidents in Public Transit
Authors: Hundenski R.J.
Published: January 2019

Violent incidents in and around public transit vehicles and facilities take a number of forms, with current classification systems separating them by type. Incidents are differentiated by level of interaction between actor and target and by severity of outcome (damage or injury). Frequencies of more specific incident types can be plotted, with the interaction dimension the y-axis and the severity of injury and damage the sections of the x-axis to the right and left, respectively, of the origin. Thus qualitative (type) and quantitative (frequency and severity) information can be provided from a single graph. The value of the suggested method is its ability to be prescriptive and descriptive. Violent incidents that are played out through intense interpersonal interaction may be more amenable to prevention or intervention efforts that have social skills as the focus, with those skills learned through training. Conversely, the incidents that involve no interaction between persons, such as vandalism, might be better dealt with by environmental controls or equipment modifications. An analytical model is used to elucidate motivating factors behind aggressive or violent interaction. From an interactionist perspective, aggressive action or reaction is seen as a means of demonstrating, preserving, or enhancing social status.
Fire and Life Safety Systems at Washington Park Station: North America's Deepest Underground Transit Station
Authors: Fordyce Patty L.
Published: January 2019

Tri-Met is building an extension of its MAX Light Rail System in Portland, Oregon. The extension includes a tunnel 4.8 km (3 mi) long with an underground station under the Washington Park Zoo. Washington Park station will be the deepest underground light rail station in North America when it opens for service in September 1998. A fire or other incident in the tunnel or platform area can have serious consequences for passengers waiting for trains on the platform and for those on the trains. Fire and life safety systems will play a significant role in ensuring the safety of all passengers. The systems are required to detect and control the incident, notify passengers when there is an incident in the tunnel or platform area, and provide safe egress of passengers. The fire and life safety systems that have been designed for Washington Park station and the decisions that became the basis for the design of the systems are discussed.
Analyzing a Transit Subway Station during Fire Emergency using Computational Fluid Dynamics
Authors: Abu-Zaid Sameer A.
Published: January 2019

Computational fluid dynamics is used to analyze a transit subway station during fire emergency conditions. The analysis is based on solving the partial differential equations governing the transport of mass, momentum, and energy within the station geometry. A steady source of heat (e.g., fire) equivalent to 90 MBtu/hr is placed in the station. Steady state results for temperature distribution and air velocity field for three fire locations are presented. The results indicate that safe evacuation of patrons cannot be achieved without mechanical ventilation.
Analytical Model for Sight Distance Analysis on Three-Dimensional Highway Alignments
Authors: Hassan Yasser , Easa Said M. , Abd El Halim A. O.
Published: January 2019

Existing sight distance models are applicable only to two-dimensional (2-D) separate horizontal and vertical alignments or simple elements of these separate alignments (vertical curve, horizontal curve). A new model is presented for determining the available sight distance on 3-D combined horizontal and vertical alignments. The model is based on the curved parametric elements that have been used in the finite element method. The elements presented are rectangular (4-node, 6-node, and 8-node elements) and triangular. These elements are used to represent various features of the highway surface and sight obstructions, including tangents (grades), horizontal curves, vertical curves, traveled lanes, shoulders, side slopes, cross slopes, superelevation, lateral obstructions, and overpasses. The available sight distance is found analytically by examining the intersection between the sight line and the elements representing the highway surface and the sight obstructions. Application of the new model is illustrated using numerical examples, and the results show that existing 2-D models may underestimate or overestimate the available sight distance. The proposed model should be valuable in establishing design standards and guidelines for 3-D highway alignments and determining the effect of various highway features on sight distance.
Preliminary Validation of a Speed-Profile Model for Design Consistency Evaluation
Authors: Collins Kent M. , Krammes Raymond A.
Published: January 2019

The validity of a speed-profile model for design consistency evaluation was tested, including (a) the speed reduction estimation ability of the model and (b) assumptions about deceleration and acceleration characteristics approaching and departing horizontal curves. Detailed speed data were collected at a sample of 10 horizontal tangent-curve sections on two-lane rural highways in Texas. The results indicate that the model provides a reasonable, albeit simplified, representation of speed profiles on horizontal alignments consisting of long tangents and isolated curves. The model provides reasonable estimates of speed reductions from long approach tangents to curves but does not account for the effect of nearby intersections on speeds. The results also indicate that the assumed 0.85 m/sec2 value is reasonable for deceleration rates approaching curves that require speed reductions but may overestimate acceleration rates departing curves. The model's assumptions that deceleration occurs entirely on the approach tangent and that speeds are constant throughout a curve were not confirmed by observed speed behavior. The observations that deceleration continues after entering a curve and that speed adjustments occur throughout a curve are indicators of the difficulty drivers experience in judging appropriate speeds through curves.
Predicting Operating Speeds on Low-Speed Urban Streets: Regression and Panel Analysis Approaches
Authors: Tarris Joseph P. , Poe Christopher M. , Mason John M. , Goulias Konstadinos G.
Published: January 2019

This study compares different statistical approaches to modeling the geometric and driver effects on operating speeds along low-speed urban streets. Linear regression on speed data obtained through data aggregation, linear regression on individual speed data, and panel analysis are discussed. Data collected from ongoing research examining operating speed on low-speed urban streets were modeled by the three techniques. The findings of the modeling techniques are compared and their influence on predicting probable operating speeds of a facility are presented. Traditionally, empirical analysis of operating speed has relied on regression models, using descriptive statistics such as 85th-percentile speed or mean speed to describe the data. This study demonstrates how the use of descriptive statistics obtained through data aggregation misleadingly reduces the total variability and nature of the variability associated with the statistical relationship. The fit of the regression function may appear to be increased, but the influence of the geometric elements may be overstated or understated. Data aggregation also affects inferential and prediction measures. Predictions from models based on aggregate data may appear to be more precise, but this does not imply that they are more reliable. Regression models of speed choice at a specific location within the roadway alignment may explain the effect of geometry but may not capture the effect of individual driver speed choice. As demonstrated in this study, the individual driver effect and geometric variable effect are important. The preliminary conclusion is that the driver's speed choice is highly dependent on roadway geometry and individual driver behavior.
Effect of Intersection Channelization and Skew on Driver Performance
Authors: Tarawneh Mohammed S. , Mccoy Patrick T.
Published: January 2019

This field investigation studied the effects of the geometries of right-turn lanes on the turning performance of drivers with respect to driver age and gender. Right-turn performance of 100 subjects within three age groups (25–45, 65–74, and 75+ years old) was evaluated under normal driving conditions at four intersections of different right-turn lane channelization and skew. The results indicated that right-turn channelization affects the speed at which drivers make right turns and the likelihood that they will stop before making a right turn on red (RTOR). Drivers, especially middle-aged (25–45 years old) drivers, turn right at speeds 5 to 8 km/h higher on intersection approaches with channelized right-turn lanes than they do on approaches with unchannelized right-turn lanes. Also, drivers are much less likely to stop before making an RTOR on approaches with channelized right-turn lanes. Drivers are less likely to attempt to make an RTOR at a skewed intersection where the viewing angle to traffic from the left on the cross street is greater than 90 degrees. Also, drivers turning right at these locations are more likely to use their side mirrors than they are when making an RTOR at nonskewed intersections.