Of course, says Suran, the capital-letters NAFTA does play a role in the growth of inland markets, as the majority of trade among the three nations travels through the central regions rather than along the coasts. But she believes trade among the US, Canada and Mexico is likely to grow whatever happens with the agreement itself. Two years ago, Canadian National Railway began a $100 million of its Memphis train yard, its second largest US facility after Chicago, and the carrier is looking to substantially upgrade rail service to inland cities in both Canada and the US from the recently completed Port of Prince Rupert. Similarly, Kansas City Southern is upgrading the tracks and facilities between Mexico's Port of Lazaro Cardenas and Kansas City to accommodate growing trade along that route.

While as much trade among the three NAFTA countries still travels by road as by rail, the future appears likely to tell a different story. First, establishment of regular truck transport between the US and Mexico faces growing opposition in Congress. Even the pilot program allowing a limited number of trucks to pass freely across the Mexico-US border, rather than having to transfer goods from one nation's trucks to the other's at the border, is threatened with elimination.

Second, opposition is growing to the increasing number of tractor-trailers on US roads. In July, Demographia, a market research and urban policy consultancy based in Belleville, IL, issued the Congestion Relief Index, a study of traffic congestion in 82 major urban areas. The study mintains that switching 25% of freight volume from trucks to rail could save US drivers an average $985, 79 gallons of fuel and 41 hours of delays a year by 2026. It also says the switch would reduce air pollution by 920,000 tons annually.

"We can surely expect NAFTA traffic to increase regardless of whether a NAFTA Super Highway is constructed," says Suran. "Taken together, these trends lead me to believe that regardless of any changes to NAFTA, external economic forces will bring about a US industrial market that is shaped more by our northern and southern neighbors than in past years." With that change, she adds, will come greater reliance on rail and intermodal facilities.