According to the North American Freight Numbers released by the Bureau of 
Transportation Statistics (BTS) of the U.S. Department of Transportation, trucks transported 60.8 percent of U.S.-NAFTA trade in May 2013. Rail moved 15.1 percent of freight in May followed by vessels at 8.6 percent, pipelines at 6.8 percent and air at 3.9 percent. Combined surface trade transportation modes (truck, rail and pipelines) carried 82.7 percent of the total NAFTA freight flows.
Freight flows by all modes of transportation between the U.S. and its NAFTA partners was down 0.4 percent in May from April. Freight moved by truck in May was up by only 0.02 percent compared to April, while freight moved by rail decreased by 0.4 percent.
In May trucks carried 55.2 percent of freight between the U.S. and Canada followed by rail at 16.5 percent, pipelines at 11.4 percent, vessels at 6.4 percent and air at 4.6 percent. Truck, rail and pipelines combined carried 83.2 percent of the total U.S.-Canada freight flows in May.
Trucks carried 67.8 percent of the freight transported between the U.S. and Mexico in May followed by rail at 13.4 percent, vessel at 11.4 percent, air at 3.0 percent and pipelines at 0.9 percent. The surface transportation modes (truck, rail and pipelines) in May carried 82.1 percent of the total U.S.-Mexico freight flows.
Michigan led all states in goods transported between the U.S. and Canada in May. Increasing 21.8 percent, Washington had the largest year-to-year increase, while Minnesota had the largest decrease at 13.0 percent. mineral fuels was the top commodity category transported between the U.S. and Canada in May.
Texas continued to lead all states in goods transported between the U.S. and Mexico. The state with the largest year-to-year increase was Illinois at 20.1 percent. The top commodity category transported between the U.S. and Canada in May was mineral fuels, two-thirds of which were crude petroleum.
