Do Small Detours Deliver Big Gains? Online Accept/Reject Policies for Overlapping Bus Lines

Claudio Szwarcfiter

Keywords: off-corridor excursions, overlapping bus lines, online accept/reject policies, discrete-event simulation, transit reliability, passenger accessibility, headway regularity, demand-responsive transit, real-time decision-making, public transportation operations

TL;DR: Small, rule-based bus detours can expand access for riders at side stops without disrupting main-line reliability.

Abstract: We study whether fixed-route buses on partially overlapping corridors can use brief, rule-governed off-corridor excursions to serve nearby side stops without undermining headway regularity. We formalize two online, at-stop accept/reject policies—Myopic-Feasible (accept if capacity and budget/window pass) and Slack-Aware (accept only when a simple headway-risk score is below a threshold)—and evaluate them against a no-excursions baseline in a discrete-event simulation. Across a 16-scenario factorial design varying excursion budgets, return-to-corridor windows, side-stop geometry, and reliability (low/high headway coefficient of variation, CV), we track service, reliability, and operating footprint. Myopic-Feasible consistently reduces mean waiting time and abandonments at essentially unchanged headway CV and with a negligible excursion share of vehicle-kilometers. By contrast, the default Slack-Aware threshold is overly conservative, yielding large increases in waits and abandonments even as compliance improves—highlighting the need for data-driven calibration. Taken together, the results indicate that bounded excursions can expand access to side stops with minimal reliability penalties when budgets/windows are moderate and risk screens are tuned to local conditions.

Submission Number: 172