Heuristic methods for time-dependent vehicle routing problem

The general vehicle routing problem with time windows supposes that the travelling speed of vehicles is constant,while in practice the travelling speed is time-dependent,so,in recent years,the time-dependent vehicle routing problem has become one of the research focuses.This paper studies the solving strategy of the time-dependent problem and designs a two-phase heuristic method,in which in the first phase a "first-expired-first -serviced" heuristic is proposed to gain the initial solution,and in the second phase the simulated annealing algorithm is used to improve the initial solution.Experiment results show that the algorithm can solve the time-dependent vehicle routing problem effectively.