Study of Operational Research Models for Intermodal Transportation

Intermodal transportation may be defined as the transportation of a person or a load from its origin to its destination by a sequence of at least two transportation modes, the transfer from one mode to the next beingperformed at an intermodal terminal. Although both people and freight transportation can be examined from an intermodal perspective, we limit thescope of this paper to freight. Since their introduction in the 1960s, containers represent the standard unit load concept for international freightand the backbone of international trade. The transshipment of containersbetween different parties in a supply chain involves manufacturers producing goods for global use, freight forwarders, shipping lines, transferfacilities, and customers. Container terminals primarily serve as an interface between different modes of transportation. In one of its most widelyaccepted meanings, intermodal freight transportations refers to a multimodal chain of container-transportation services. This chain usually links theinitial shipper to the final consignee of the container (so-called door-to-door service) and takes place over long distances. Transportation is oftenprovided by several carriers. In a classical example of an inter-continental intermodal chain, loaded containers leave a shipper’s facility by truck eitherdirectly to port or to a rail yard from where a train will deliver them to port. A ship will move the containers from this initial port to a port on the othercontinent, from where they will be delivered to the final destination by a single or a combination of land” transportation means: truck, rail, coastal orriver navigation. Several intermodal terminals are part of this chain: the initial and final sea-port container terminals, where containers aretransferred between the ocean navigation and land transportation modes, as well as in-land terminals (rail yards, river ports, etc.) providing transferfacilities between the land modes. Almost all types of freight carriers and terminal operator may thus be involved in intermodal transportation, either by providing service for part ofthe transportation chain or by operating an intermodal transportation system (network). We limit the scope of the paper to the latter with a particularfocus on container-based systems.