Four major paradigm shifts (or revolutions) have taken place within containerized freight distribution systems, leading to their growing level of intermodal integration:
- Phase 1: Containerization of maritime transport systems. At first, the introduction of the container and its diffusion within maritime systems took place with the gradual introduction of specialized ships and port facilities. This was particularly the case from the mid 1965s when standardization resulted in common container size and latching systems. The efficiency of port transshipments improved, and inland services, dominantly relying on trucking, began to be established. Still, maritime services tended to be on a point-to-point basis and between major ports.
- Phase 2: Containerization of inland transport systems. Subsequently, containerization started to diffuse inland, mainly to improve the continuity already established within maritime transportation, particularly with the setting of pendulum services. The introduction of doublestacking rail services in the mid-1980s required the setting and redesigning inland container rail terminals in North America. The adoption of the container in Europe gained momentum when an intermodal system started to emerge in the late 1970s. For example, the shift from conventional and highly irregular barge services to scheduled and reliable container services in the second half of the 1970s gave impetus to a fast containerization process along the Rhine basin up to the main ports of Rotterdam and Antwerp.
- Phase 3: Intermodal and transmodal operations. Since containerization expanded to cover maritime and inland transport systems, the next phase dominantly aimed at improving its overall efficiency. This efficiency is mainly based on the reduction of the number of times a container is handled as well as the velocity at which intermodal and transmodal operations are performed. Also, the growth in containerized shipments placed additional pressures on intermodal transport systems, which for the maritime segment resulted in the setting of transshipment hubs (also known as intermediary hubs) acting as intermediary locations between major systems of maritime circulation. Growing intermodal volumes handled at ports favored the setting of satellite terminals and transloading. Inland transport systems accommodated a growing amount of traffic, which in many cases resulted in the setting of large inland freight distribution centers (inland ports).
- Phase 4: Integrated global shipping network. The prior phases (or revolutions) have permitted the setting of a global shipping network that is increasingly integrated. Further evolution of this network involves the setting of a high capacity circum equatorial route (CER) being the main support of east / west trade interactions. The route would link a series of transshipment hubs where north/south flows would be collected. This network is still in emergence.