Trucks carried 59.4 percent of the total amount of trade in September — $94.4 billion — between the countries. Truck trade was up 5.4 percent in September from the same month last year and accounted for $29.1 billion in U.S. exports and $27 billion in imports.
Rail carried the next highest amount of freight — 16.1 percent. Surface transportation as a whole, which consists of truck, rail and pipeline, moved 82.7 percent of the total.
Following trends in 2012 and 2011, NAFTA trade dropped month over month, though, down in September from $96.5 billion in August.
Trade with Canada in September totaled $53.1 billion — up 5.7 percent from the same month in 2012. Surface transportation made up $44.2 billion (83.3 percent).
Trade with Mexico totaled $41.3 billion — a 4.1 percent increase from September 2012. Surface trade carried $33.8 billion (81.8 percent) of that.