TRANSPORTATION RESEARCH DIGEST
ARIZONA TRANSPORTATION INSTITUTE
Computer-Aided Scheduling and Dispatch in Demand-Responsive Transit Services, TCRP Synthesis 57, by David S. Kessler (Transportation Research Board, 2101 Constitution Avenue, N.W., Washington, D.C. 20418; ph. 202-334-2934; ) (2004)
Most transit agencies have retained control over the procurement and operation of CASD software and hardware.
The study identified a number of important ways in which the procurement and implementation processes could be improved.
The scope of this synthesis is to (1) search out useful information on the use of computer-aided scheduling and dispatch (CASD) in demand-responsive transit (DRT) services, (2) develop an amalgamation or compendium of the current knowledge and successful practices used in computerizing the functions necessary to efficiently and effectively operate such DRT services, and (3) report on measures used to resolve specific problems in planning and implementing CASD. The ultimate objective in compiling a considerable storehouse of information is to make this information available to the public transit community. Private and nonprofit organizations that are providing DRT services will similarly benefit from a review of these results.
As with most TCRP synthesis studies, this synthesis identifies much of the past and ongoing research pertaining to the topic, and it assembles and analyzes information gathered through survey questionnaires from a selected number of transit agencies involved in providing DRT services. In addition, because of the unique way in which CASD activities are
implemented in the DRT industry, information has been elicited through survey questionnaires specifically targeted to DRT software vendors and major private service providers that operate as much as two-thirds of the nation's DRT services under contract to transit agencies.
It is especially illuminating to compare agencies' expectations with the vendors' views on the capabilities of the systems they have installed as well as the reasons why successful implementation of such systems is sometimes impeded. Moreover, the perspectives of other end users of CASD, such as private contract service providers, are important to consider because they are charged with using CASD as a tool to ensure that the performance and efficiency goals of transit agencies with which they contract are attained.
Completed surveys were received from 21 transit agencies, a 40% response rate. Of these, 14 represent agencies that are among the 75 largest DRT service providers, based on passenger miles of service. The experiences of two agencies that have recently- implemented entirely new CASD systems--Charlotte Area Transit System and New Jersey Transit Corporation--are reviewed as case studies. Those studies represent an in-depth look at some of the lessons learned and how particular agencies overcame impediments to successful implementation of CASD software.
More than 90% of the responding agencies enter into contracts for all or a portion of their services with the private sector. However, they have mostly retained control