A school bus routing heuristic algorithm allowing heterogeneous fleets and bus stop selection

This paper addresses a school bus routing problem formulated as a capacitated and time-constrained open vehicle routing problem with a heterogeneous fleet and single loads. This problem incorporates several realistic features, such as student eligibility, maximum walking distances, bus stop selection, maximum riding times, different types of buses, multistops, and bus dwell times. A heuristic algorithm based on an iterated local search approach is proposed for this problem. It determines the selection of bus stops from a set of potential stops, the assignment of students to the selected bus stops, and the routes along the selected bus stops. The main objectives are minimizing the number of buses used, the total student walking distance, and the total route journey time. Other aims are balancing route journey times between buses and minimizing the total number of empty seats. A set of 20 real-world problem instances are used to evaluate the performance of the algorithm. Results indicate that the algorithm finds high-quality solutions in very short amounts of computational time