Scheduling dial-a-ride paratransit under time-varying, stochastic congestion

• Published in: Transportation research. Part B: methodological Vol. 36; no. 6; pp. 485 - 506
• Main Author: Fu, Liping
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.07.2002; Elsevier
• Series: Transportation Research Part B: Methodological
• Subjects: Applied sciences; Exact sciences and technology; Ground, air and sea transportation, marine construction; Paratransit; Transportation planning, management and economics; Travel time; Vehicle routing and scheduling; Vehicle routing and scheduling; Travel time; Paratransit; Costs; Probabilistic approach; Transportation; Routing; Scheduling; Urban area; Modeling; Optimization; Arrival time; FIFO system; Dial a ride; Problem solving; Feasibility; Traffic congestion
• ISSN: 0191-2615; 1879-2367
• DOI: 10.1016/S0191-2615(01)00014-5

This paper discusses a study on the dial-a-ride paratransit scheduling problems arising in paratransit service systems that are subject to tight service time constraints and time-varying, stochastic traffic congestion. Different from existing methodologies, we explicitly incorporate a time-dependent, stochastic travel time model in the problem formulation. A set of recursive relations is first identified to approximate the distribution parameters of arrival times at individual stops of a given route which, coupled with a first-in-first-out (FIFO) assumption, allows us to extend the conventional heuristic algorithms for solving the proposed problem with only marginal increase in computational complexity. Results from a series of numerical experiments on a set of hypothetical problems are described, aiming to illustrate the computational efficiency of the proposed algorithm and the sensitivity of solutions to various model parameters.