North American Transportation Statistics
http://www.bts.gov/press_releases/2009/bts056_09/pdf/bts056_09.pdf
Reports that 107 million personal vehicles entered the U.S. in 2008, 28.7 million from Canada and 78.9 million from Mexico. Also provides statistics on merchandise trade with Canada and Mexico by freight mode of transportation and the top ten U.S. city gateways for such trade. From the Bureau of Transportation Statistics.
