Improved Reactive Tabu Search for Optimal VehicleRouting Considering Allocation of Secondary Depots in Case of Natural Disasters

Abstract

This paper proposes improved reactive tabu search for optimal vehicle routing of vehicles considering allocation of secondary depots in case of natural disasters. In recent years, many large-scale disasters have occurred in Japan and large-scale disasters may occur in the near future, unfortunately. In case of large-scale disasters, emergency relief supply logistics is an important issue since it will affect lives of evacuees. The proposed method modifies a stored method of a tabu list, introduces aspiration criteria, and applies a searched list using a hash function for simultaneously solving the optimal number of secondary depots, the optimal placement and the distribution areas of secondary depots, and the optimal routes of vehicles in the distribution area of secondary depots. It is verified that the proposed method can generate higher quality optimal vehicle routing and reduce computation time than the conventional reactive tabu search based method with actual evacuation facility data of Chiba City, which are planned to be used in case of natural disasters. The results are confirmed by Wilcoxon test.