Bus holding control of running buses in time windows

Abstract

This work proposes a periodic bus holding control method where the bus holding times of all running trips are computed simultaneously within each optimization time period; thus, increasing the coordination among running buses to avoid bus bunching. We consider the adverse effects of the bus holding control on the in-vehicle travel times of on-board passengers and formulate holistic bus holding decisions by modeling the bus holding problem as a discrete, nonlinear, constrained optimization problem. Given the computational complexity of the bus holding problem, an alternating minimization approach is introduced for computing the optimal holding times at each optimization instance. The performance of the periodic control method is evaluated against the performance of event-based control methods using 5-month automated vehicle location and automated passenger count data from bus line 1 in Stockholm demonstrating an improvement potential of 5% for the in-vehicle travel times and 11% for the service regularity.