Solving a Bi-Objective Dial-a-Ride Problem Using Multi-Directional Local Search

Abstract

Single-objective solution methods for the dial-a-ride problem usually minimize operational costs while ensuring a minimum quality level imposed by service level requirements. This solution technique emphasizes the fundamental nature of the problem by solving a bi-objective variant. Total user ride time, being the total time users spend aboard the vehicles, is explicitly minimized as an additional, quality-oriented objective without making a priori choices regarding the importance of both objectives. To this end, a multi-directional local search (MDLS) metaheuristic is developed, in which a variable neighborhood search (VNS) principle is embedded to perform local search.