Energy consumption,pollutant production,and dollar costs of diesel suburban commuter trains

The results presented in this report are based on data obtained from Chicago's three largest diesel commuter railroads. Those aspects of their operations that relate to energy and pollution are described. Service characteristics, such as average occupancy and average trip distance, are presented. Energy consumption results are presented and discussed. With energy efficiency measured in passenger-miles per Btu, it is found that trips by diesel commuter train are 3.5 times more energy efficient than Chicago Central Area auto trips. The total trip from home to suburban station, then by train to a downtown terminal, is found to be 2.2 times more energy efficient than Chicago Central Area auto trips. Pollutant production rates are presented for five pollutants. For every pollutant except sulfur oxides, trains are found to be less polluting per passenger-mile than autos. Per passenger-mile pollutant emissions from trains are, overall, less damaging by a factor of 5.5 than the per passenger-mile emissions from autos. Travel on these diesel commuter trains is less costly to society than auto travel (1972 suburban-based autos). This is the case whether one compares the train trip alone with an auto trip or the home-to-suburb an-station-tlien-to-a-downtown-terminal trip with a home-to-downtown auto trip.     

Automated transit vehicle size considerations

Synthesis of cost-effective transit alternatives using automated vehicles requires consideration of a wide range of factors that are moot in determination of the optimum size of manually driven vehicles where the need to amortize driver wages dominates the economics. Discussions of many of these factors have appeared in previous papers. This article brings them together into consideration of one specific system characteristic: the optimum automated-transit-vehicle size.     

Empirical modelling of the relationship between bus and car speeds on signalised urban networks

Vehicle speed is an important attribute for analysing the utility of a transport mode. The speed relationship between multiple modes of transport is of interest to traffic planners and operators. This paper quantifies the relationship between bus speed and average car speed by integrating Bluetooth data and transit signal priority data from the urban network in Brisbane, Australia. The method proposed in this paper is the first of its kind to relate bus speed and average car speed by integrating multi-source traffic data in a corridor-based method. Three transferable regression models relating not-in-service bus, in-service bus during peak periods and in-service bus during off-peak periods with average car speed are proposed. The models are cross-validated and the interrelationships are significant.     

Local organization of transportation planning activities in the United States

This study provided an examination of the alternative means used by Metropolitan Planning Organizations (MPOs) to carry out transportation planning activities in different areas of the U.S.A. This has been done by first developing a general profile of the nature and functions of the MPOs in the 100 largest regions in the U.S. and by an in‐depth analysis of seven regions. The purpose of these activities was to examine similarities and differences between MPOs and to identify factors that appear to lead to the effectiveness or non‐effectiveness of MPOs in different areas. From the analysis, it is evident that there are wide differences between MPOs in their organization, function, and degree of effectiveness in carrying out transportation planning. These differences do not appear to be related to any structural characteristics of MPOs, but rather are the result of past history and the attitudes of people involved.     

A planning model for multiple‐mode transportation system operations

The problem of generating a set of “good” transportation alternatives during the early and intermediate stages of transportation planning is addressed in this paper. A linear programming model of a multi‐modal transportation system is developed. The model is run interactively to determine optimal operating levels for all modes for various transport policy decisions. The model described is a component of a composite network generation model incorporating dynamic changes. The linear programming component determines optimal operating policies for given points in time. The composite model incorporates these in a dynamic programming framework to determine optimal staged investment policies over several time periods.     

The past,present, and future of urban cable propelled people movers

The evolution of urban cable propelled people mover technology from the early 1800′s through the 1990′s is reviewed, with emphasis on systems developed since 1980. Technologies can be classified by the means of vehicle support and the type of service provided. The simplest systems serve as shuttles moving back-and-forth between a pair of terminal stations; more complex systems feature vehicles which are launched continuously at short headways. Advances have occurred in the design and aesthetics of guideways, vehicle operating speed, the spectrum of capacities available, and automated features. The characteristics of the individual systems in urban environments throughout the world are described.     

A review of the state of the art of personal rapid transit

The paper begins with a review of the rational for development of personal rapid transit, the reasons it has taken so long to develop, and the process needed to develop it. Next I show how the PRT concept can be derived from a system‐significant equation for life‐cycle cost per passenger‐mile as the system that minimizes this quantity. In the bulk of the paper I discuss the state‐of‐the‐art of a series of technical issues that had to be resolved during the development of an optimum PRT design. These include capacity, switching, the issue of hanging vs. supported vehicles, guideways, vehicles, control, station operations, system operations, reliability, availability, dependability, safety, the calculation of curved guideways, operational simulation, power and energy. The paper concludes with a listing of the implications for a city that deploys an optimized PRT system.     

Short run supply functions with decreasing user costs

This note shows, with an example, that user costs on transportation systems need not remain constant or increase with increasing volume, even with design and operational options fixed.     

Handling Characteristics of Car-Trailer Systems; A State-of-the-Art Survey

Work relevant to the state of the art as regards passenger cars towing trailers is referenced and reviewed. Not only included is the very limited amount of work specifically dealing with passenger cars towing trailers, but also reviewed is the much larger body of work having a bearing on car-trailer systems. Topics included are aerodynamic forces, tire forces, the compliance concept, relevant work on vehicles without trailers, vehicles with trailers, and the role of the driver. The types of stability problems exhibited by car-trailer systems are discussed.

The state of the art as regards ability to predict vehicle response to specific steering inputs is shown to be fairly advanced. Recent significant advances include the appearance of experimental data useful for validating theoretical models. However, the state of the art as regards definition of what constitute desirable handling characteristics is still at a primitive stage, largely because of a lack of understanding of the roles played by drivers as part of the vehicle -driver - environment systems.

Throughout the review an effort was made to point out topic areas where it is likely that significant future contributions to the state of the art can be made. These areas are reviewed in the conclusions.     

Measuring Truck Travel Time Reliability Using Truck Probe GPS Data

Truck probe data collected by global positioning system (GPS) devices has gained increased attention as a source of truck mobility data, including measuring truck travel time reliability. Most reliability studies that apply GPS data are based on travel time observations retrieved from GPS data. The major challenges to using GPS data are small, nonrandom observation sets and low reading frequency. In contrast, using GPS spot speed (instantaneous speed recorded by GPS devices) directly can address these concerns. However, a recently introduced GPS spot-speed-based reliability metric that uses speed distribution does not provide a numerical value that would allow for a quantitative evaluation. In light of this, the research described in this article improves the current GPS spot speed distribution-based reliability approach by calculating the speed distribution coefficient of variation. An empirical investigation of truck travel time reliability on Interstate 5 in Seattle, WA, is performed. In addition, correlations are provided between the improved approach and a number of commonly used reliability measures. The reliability measures are not highly correlated, demonstrating that different measures provide different conclusions for the same underlying data and traffic conditions. The advantages and disadvantages of each measure are discussed and recommendations of the appropriate measures for different applications are presented.