Institute of Transportation, MOTC

Student：Chia-Wei Tu, 2006.07
Institute of Traffic and Transportation National Chiao Tung University

　　Most of literature about vehicle routing problem are focused on static planning. However, in recent years, advances in communication, automatic vehicle location and geographic information system technologies afford opportunities for using real-time information enhance the performance of commercial vehicle operations. Hence, dynamic vehicle routing problem gradually become an important issue.

　　In dynamic vehicle routing problems, one potential use of real-time information is to divert a vehicle away from its current destination to serve a request that just occurred in the vicinity of its current position.This new assignment strategy may result in reduced travel distances and improved efficiency, but diversion issues still do not received enough attentions now Therefore, the purpose of this study is to design models including a diversion strategy for pick-up and delivery vehicle routing problem with soft time windows ,and make dispatchers adjust the routes of en-route vehicles to react to new service requests immediately and properly and take more potential advantage of real-time information. The optimization solution is obtained from LINGO, which employ exact procedures to search the optimum of integer linear problems.

　　Two small scale examples with nine fixed requests and one new pick-up demand, one with short time windows modified from the Solomon R101 example and the other with relaxing time windows, are experimented to compare the model with and without diversion strategies. The results imply that the former can obtain the savings and could enhance the development of future study and the practice in the real world.