Inland flows of containerized freight present several challenges, namely the repositioning of empty containers. The above figure provides a synthetic representation of the flows between a port and a hinterland composed of importers (consignees) and exporters (consigners). In a standard system, three possible systems of circulation are possible:
- One-way import loop (A). A container is trucked from the port terminal to the importer’s facility, unloaded, and then brought back to the terminal empty.
- One-way export loop (B). When an export load is available, an empty container is picked up from the port terminal, brought to the facility of the exporter, loaded, and then moved back to the port terminal.
- Cargo rotation (C). On some rare occasions, an empty container can be brought directly from the importer to the exporter and then back to the port terminal. This system of cargo rotation is the most efficient but requires close coordination, often lacking for inland freight distribution.
The standard system can function well when volumes are relatively low, when there is limited congestion to access the port terminal and when the import and export activities are in proximity. As containerized flows between the port and its hinterland grow, the setting of an inland port or container depot provides additional options with an expanded system. Loaded containers can still be brought to and from the port facility, but empty containers can be brought back to the inland port instead. They are thus more readily available for exporters since the inland facility is closer, has lower storage costs, and is less congested. There are also several options available to link the inland terminal facility and the port, depending on the concerned distance and modal availability. Truck, rail, and barge shuttle services can transport loaded and empty containers back and forth in a time and cost-effective way.
An inland port and available cargo for exports can also help expand or secure the market area (hinterland) of a port. For instance, a shipper would prefer to have cargo routed to a port terminal if, on the return trip, an empty container can be filled with export cargo. Thus, a port is called for this cargo not necessarily because it is the best option for the inbound distribution, but because it enables to provide paying cargo for the outbound trip.