Source: Adapted from Rodrigue, J-P and T. Notteboom (2010) "Comparative North American and European Gateway Logistics: The Regionalism of Freight Distribution",  Journal of Transport Geography, Vol. 18, No. 4, pp. 497-507.
The North-American Container Port System and its Multi-Port Gateway Regions
The observed cargo concentration levels in the North American container port system are emanating from the increasing dominance of Long Beach/Los Angeles as the major gateways along the Pacific Coast, mainly catering for Asian import cargo. The Pacific Coast now accounts for 55% of the total container volume handled, up from 50% in 1990, placing intense pressures on its main gateways. The share of the Los Angeles / Long Beach port cluster of the total US container traffic grew from 25.6% in 1995 to 35.2% in 2005 and 36.5% in 2014. During the same period, New York/New Jersey's share increased slightly from 10.6% to 11.6% and 13.8%. Traffic doubled every decade, an indication of a rapid growth of international trade as well as the diffusion of containerization as a privileged mode of transportation. However, the extent to which this trend will endure is highly questionable as evidenced by the impacts of the financial crisis of 2008-09 and the subsequent fall and limited recovery of container volumes. The West Coast of North America is also the object of significant transloading activities, which account for about 30% of all the containers handled. The other 40% and 30% are respectively railed to inland destinations or trucked. Gateways have therefore different modal split depending on their role as consumption centers and points of distribution to the North American hinterland.
Along gateway regions, various long distance intermodal rail corridors have been established. The inland rail freight transport system of North America is unique in the world, not only because of its size, but also because of the direct link made between three different coastlines. Major North American hinterlands are changing, namely because of the relative decline of the industrial belt (which has been monitored for decades) and the industrialization of the "sun belt". These are long term shifts influencing the geography of production and consumption that are reflected in the gradual reorientation of trade. NAFTA also favors the setting of what can be labeled as natural gateways and corridors, since they reflect geographic advantages (market accessibility) as opposed to regulatory impositions (e.g. a mandated port of entry) that prevailed before. This particularly concerns Canada (Vancouver, Prince Rupert and Montreal) and Mexico (Lazaro Cardenas) that have experienced a gradual reorientation of traffic flows.