Modal Gateways

Many gateways are linked to a specific mode, but the largest tend to have a combination of modes. Modal gateways can be classified in three categories:

Land gateways commonly have a simple transit function, since they are obligatory points of passage, with in some cases logistics and manufacturing activities. When a border is concerned, this involves a concentration of custom related activities, such as document preparation, inspection and clearance. For instance, the lengthy US/Canada border has several gateways imposed by the local geography (e.g. along the St. Lawrence and Great Lakes) or by the necessity to restrict entry at a few specific locations (e.g. along the Great Plains). If there are important differences in the level of economic development between both sides of the land gateway, there is often a specialization of function where one side will concentrate on manufacturing (the side where labor costs are advantageous) and the other on logistics. The Maquiladoras exemplify this situation along the US - Mexico border, as Shenzhen does for Hong Kong (SAR) and China.
Air gateways are linked with important metropolitan areas with regional air or road connections. They tend to have more inland locations as they are not bound to strong transshipment constraints. Air gateways are jointly the outcome of their respective centrality or intermediacy. A significant trend in recent years has been a growing divergence between passengers and freight air gateways. Due to the flexibility of their operations, specific freight gateways and hubs have emerged.
Maritime gateways are large terminals with high capacity inland connections (rail and road). Due to congestion and lack of space for logistical activities near maritime terminals, the emergence of satellite terminals or inland freight distribution centers appear to be a significant trend, well developed in Europe.