Urban pickup and delivery problem considering time-dependent fuzzy velocity

The velocity in vehicle routing problem is usually fuzzy and uncertain, which would influence the flexibility and feasibility of the dispatch result of vehicles. In this paper a realistic model is proposed to solve urban pickup and delivery problem with consideration of time-dependent fuzzy velocity of vehicles. Firstly, based on collected traffic data of typical roads in an urban city, the membership function of fuzzy velocity was created and simulated. Then the fuzzy arriving time to customers was calculated with Alfa- Cut Set Algorithm. Next, the urban pickup and delivery problem under time-dependent fuzzy velocity was described, and a modified Tabu Search was used to solve the problem. Finally, the paper introduces a real pickup and delivery problem with 28 customers in a logistics company to illustrate the proposed method. The results show the dispatch result considering fuzzy velocity is more feasible and robust than that with deterministic velocity, and the improved Tabu Search could be used to solve the urban pickup and delivery problem with shorter computation time.