Brief Review on Simultaneous Pick-up and Delivery Vehicle Routing Problems

Simultaneous pick-up and delivery vehicle routing problems mainly studies the transportation and distribution problems of customers with both delivery and pick-up demands. In this paper, the basic model of VRPSPD is discussed, and then the research progress is discussed, mainly from four parts: time window, fuzzy requirements, heterogeneous vehicles and dynamic scheduling. Secondly, the algorithm of VRPSPD is reviewed, and the solution methods of the problems are divided into three categories: structural heuristics, modern heuristics and hybrid heuristics. The differences between the different algorithms, as well as the advantages and disadvantages are detailed. Finally, the research on VRPSPD is summarized and some new research directions are prospected.