Abstract
The advance of intermodal transportation during the 1980s and the recent growth in container‐vessel dimensions have strengthened the rationale of the load center concept. Ports are assuming the role of a link in the total transport chain rather than a terminus and break of bulk point. Intermodality introduced new dimensions into port competition. The quality of a port's access to inland transport networks, particularly railroads and double‐stack trains, becomes a vital factor for shipping lines in their selection of load center ports in North America. Concentration of traffic in load centers in Europe and the United States does not necessarily imply a more concentrated port system, however. Total traffic has grown and is shared among transportation enterprises with different itineraries and different ports of transit.