he quality of vehicle routing and scheduling has a great impact on the operating cost and service quality of any paratransit service. The difficulties associated with many-to-many trip requests, vehicle availability and capacity constraints, traffic patterns, and geographical obstacles are such that the process, when done manually, is error prone, labour intensive, and difficult to optimise. The development of computer software that creates paratransit schedules can, in addition to addressing these problems, significantly reduce the cost of generating schedules and improve the overall efficiency of providing service. COMSIS Corporation has developed the COMSIS Routing and Scheduling System (CRSS) to address these issues. It uses a highway network to model point-to-point travel times that recognises geographical obstacles. CRSS takes a set of trip requests entered by means of a paratransit management information system and generates vehicle manifests. The program also tracks the estimated vehicle locations and remaining vehicle capacity throughout the day. The software is processed in batch after all requests have been received. CRSS has been implemented at a number of paratransit agencies, and comparisons have been made. Manually generated schedules have been compared with CRSS schedules in the areas of service quality and operating cost and the results are favourable. Areas for further development have been identified.
Abstract