In the course of the entire freightage, there are usually different combinations of transport modes can be chosen. With the limit time of whole freight, the combination of transport modes which causes the lowest cost will be chosen as the optimization. Firstly, the virtual network map of different combinations of transport modes between the starting place and the destination is constructed. Through endowing the different transport cost to the sections in the virtual network, the optimal problem of the combination of transport modes is converted into the shortest path problem of the virtual net...
