Minimum cost delivery problem in intermodal transportation networks

Intermodal movements are those in which two or more different transportation modes are linked end-to-end in order to move freight and/or people from point of origin to point of destination. In the intermodal transportation network, the departure times of the transportation modes are pre-scheduled and there is a list of departure times associated with each transportation mode. This paper considers the problem of finding the minimum cost delivery route for an origin- destination pair where the total cost of a delivery consists of the transportation cost, the transition cost and the holding cost of possible transshipping. We provide a method which expends the intermodal transportation network on time-space into a general network in which each arc only associates with one attribute, namely, the arc cost. We show that given a release time at the origin and a due date at the destination, the minimum cost delivery problem is equivalent with a shortest path problem in the time-space network. Hence, the problem can be solved efficiently.