Article Abstracts
Volume 2, No. 2, 1999
Time-Distance Diagrams: A Powerful Tool for Service Planning and Control
Eric C. Bruun, National Transit Institute, Rutgers University
Vukan R. Vuchic, Department of Systems Engineering, University of Pennsylvania
Yong-Eun Shin, Dong-Eui University, Pusan, KoreaAbstract
Graphical scheduling is an old technique that has been neglected, or never acquired, in many North American transit agencies. It retains its advantages in basic schedule design and analysis as it eases the solution to problems that are difficult to solve analytically. Even information about simple routes is enhanced by the detailed operating characteristics inherent in detailed vehicle trajectories and by the relative ease with which accelerated service and service recovery strategies can be investigated. It also can be used to confirm and refine solutions that are generated by analytic methods. The methodology is reviewed in the context of such planning applications. Graphical scheduling has additional advantages in operational control with the advent of modern ITS technologies. By movement of the cursor on a terminal screen, detailed information about all activity along a route becomes available. It is possible to link the altering of trajectories through clicking and dragging to the automatic issuance of control commands and updates of passenger information. These and other possible uses of the technique in an operational context are presented.
Stakeholder Preferences in Advanced Public Transportation System Planning
Jonathan Levine, The University of Michigan
Soonae Park, The University of Michigan
Steven E. Underwood, The University of Michigan
Richard R. Wallace, The University of MichiganAbstract
Transportation planning in general and planning for intelligent transportation systems (ITS) in particular are notable both for multiple goals and for multiple constituencies. In response to complex policy environments such as this, multicriteria decision analysis often was utilized to assist in the evaluation of alternative investments or policy directions. This approach is extended here to assess stakeholder valuation of broad goals of an ITS planning process, the Suburban Mobility Authority for Regional Transportation (SMART) operational field test in the metropolitan Detroit area. Two levels of goals were considered: broad system-wide goals (e.g., energy savings, interagency coordination, congestion reduction) and specific service characteristics, such as advance reservations, scheduling, and reliability. Using a modified Analytical Hierarchy Process, implicit preference weights for transportation planning goals were derived, and inter- and intragroup comparisons were made. Overall, there was less variation between groups in preferences than might be expected, indicating a fair degree of common ground in desired outcomes of transit planning. The ability to provide for the trips that people request, referring both to the accommodation of trips and the match between requested and scheduled times, were important goals across various stakeholder groups. Similarly, the provision of reliable service was generally valued highly. Information provision appears to be a lower priority. Thus, to the extent that automatic scheduling and dispatch assists improved scheduling, trip reservation, and routing, it is likely to meet stakeholders' preferences. The study characterizes the various groups' preferences for transit service along a continuum ranging from "expansive" to "incremental." The expansive vision seeks to develop new forms of service for transit and paratransit customers better, while under the incremental view, consolidation of and improvements to existing service are a higher priority. The expansive position appears most clearly among citizens' groups, social service agencies, and business people. The business community is particularly interested in expansion of the hours of service, presumably to facilitate travel by customers or employees during evenings and weekends. The more incremental view is held by transportation professionals and SMART employees who are aware of the constraints under which they work.
The "Ins and Outs" of APCs: An Overview of Automatic Passenger Counters
Michael R. Baltes, University of South Florida, Tampa
Joel R. Rey, University of South Florida, TampaAbstract
Experience has shown that manual data collection via ridechecks is one of the most cost-effective data collection methods for most transit systems when evaluating ridership levels and system performance. Unfortunately, this manual method of collecting ridership data and system operational information produces both limited systemwide and route specific reports due to the amount of manual ridechecking required and the manual data processing involved. This is especially true for larger transit systems. One possible alternate solution for a transit system to meet its need for reliable, accurate, detailed, up-to-date, and cost-effectively-obtained ridership data is through the use of automatic passenger counters, or APCs. Unlike manual ridechecks, an APC system provides a transit system with an automated method for collecting information on the number of passenger boardings and alightings at a variety of system levels including route, route segment, or specific bus stops by time of day and by day of week, for example. This paper provides a general overview of APC systems. Included is a discussion of APC components, a review of typical transit system data needs, a list of current worldwide APC vendors, the results of a survey of North American transit systems related to APC usage, and a summarization of important issues for transit systems to consider when contemplating integrating APC systems on board their vehicles.
Development and Evaluation of Transit Signal Priority Strategies
Michael Garrow, Barton-Aschman Associates, Inc.
Randy Machemehl, The University of Texas at Austin
Abstract
Research describing the effectiveness of providing signal priority to transit vehicles is presented. Results from previous studies indicate that the effectiveness of transit signal priority depends on a number of factors, including the type of transit route, the transit usage level, and the time of day. This research describes and evaluates several transit signal priority provision methods during both peak and off-peak times. Results indicate that providing signal priority during off-peak times is often justified, due to excess capacity available within the transportation network. However, during peak times, transit signal priority use is justified only when the transit usage level is high.
The Advanced Technology Bus and the Evolution of Workplace Expertise
David W. Partain, Metropolitan Atlanta Rapid Transit Authority
Abstract
The purpose of this paper is to define and explore the immediate and long term effects and the resulting organizational dynamics of advancing technology on maintenance workplace expertise in transportation. In the past ten years the face of maintenance in the transportation workplace has completely changed as computerization has taken over the control of transmissions, engines, and bus/truck environmental systems and transformed them from "closed" stand alone components to an interdependent "open system" in a state of constant communication. The immediate future brings with it the advanced technology of the Intelligent Transportation System with its Geographic Information System, in-vehicle logic system, automated annunciation, signal prioritization, global positioning, and live audio and visual data links with a central control center. This complexification of the transportation maintenance workplace is being compounded by the growing use of alternative fuels, and the resultant requirement for the maintainer to learn a new operational set of skills and competencies. This evolution of technology in transportation has caused a revolution in technical training for which the maintainers of transportation resources must reskill immediately to meet the demands of the technology invasion. The paper examines the need for an accelerated evolution of workplace expertise using a combination of motor skill and cognitive training competency based learning techniques to evolve the maintainer through the phases of basic operation, to systems expert, to system creator. This evolution is accomplished through the use of a four step implementation strategy which begins with the determination of training sources, the development of an effective resource investment strategy, the development of a model trained cadre, and concludes with the expansion of this model to improve the overall baseline of workplace expertise.