Main North American Trade Corridors and Metropolitan Freight Centers

A North American lattice of trade corridors where freight distribution is coordinated by major metropolitan freight centers (MFC) has emerged in the recent decades. While MFCs are significant markets, they also command distribution within the market areas they service as well as along the corridors they are connected to. They thus have a significant concentration and logistics and intermodal activities. The extent of the market area of a MFC is mainly a function of the average length of domestic truck freight haul, which is around 550 miles (880 km). Like many segments of the North American economy and territory, globalization and integration processes, namely NAFTA, have impacted on the nature and function of continental production, consumption and distribution. For international trade, the gateways of this system are major container ports along coastal areas from which long distance trade corridors are accessed. About a third of the American trade took place within NAFTA in 2000, mainly through land gateways (ports of entry) that are gateways in the sense that they are obligatory points of transit commanding access to the United States. For truck and rail flows, virtually no intermodal activities take place at land gateways, although several distribution centers nearby borders and along corridors.

Land gateways are dominantly servicing an import function, expanded under NAFTA trade, and connected to corridors of continental freight circulation. These include three main longitudinal (north, central and south) and four latitudinal (west coast, central, NAFTA and east coast) axes. The NAFTA Corridor links the two largest land gateways of North America, Detroit, Michigan and Laredo, Texas. It dominantly relies upon trucking as about 65% of the value of the NAFTA trade is serviced by this mode. However, it is far from being a continuous corridor as northbound flows of Mexican imports and the southbound flows of Canadian imports dwindle as the distance from their respective borders increases. The equilibrium point is around the Tennessee / Kentucky range, past which the respective flows are very small. About a third of the volume involves auto parts produced in Southern Ontario and in the Maquiladoras of Mexico, which are used for low-cost car manufacturing in the Southeast states.