Cost-Saving Properties of Schedule Coordination in a Simple Trunk-and-Feeder Transit System

TLDR: In this article, an idealized system that delivers its users to a common destination by requiring each to transfer from a feeder to a trunk-line vehicle is considered, and it is shown that coordination can be Pareto improving, meaning that operator and user costs both diminish.

Abstract: Coordination of vehicle schedules in a public transit system affects generalized costs. An idealized system that delivers its users to a common destination by requiring each to transfer from a feeder to a trunk-line vehicle is considered. Continuum models are used first to analyze cases in which the trunk-line vehicle schedule is given exogenously. When feeder vehicles are dispatched in coordination with this exogenous trunk-line schedule, the reduction in user cost often outweighs the added cost to the feeder operation. In cases when the frequencies of trunk and feeder services can be established jointly, the models show that coordination can be Pareto improving, meaning that operator and user costs both diminish. Conditions that give rise to these cost savings are specified. Practical implications are discussed.