|Mode||Value (percent)||Weight (percent)|
|NAFTA trade, total||100.0||100.0|
|Other and unknowna||5.0||0.4|
|U.S.-NAFTA imports, total||100.0||100.0|
|Other and unknown||3.2||0.2|
|U.S.-NAFTA exports, total||100.0||100.0|
|Other and unknowna||7.4||0.8|
a BTS estimated the export weight for truck, rail, pipeline, and other and unknown based on value-to-weight ratios from the import data, because export weights for surface modes are not currently reported. Weight for water and air exports and imports are from the U.S. Department of Commerce, U.S. Census Bureau.
Note: U.S. North American Free Trade Agreement (NAFTA) refers to U.S. trade with Canada and Mexico, our partners in this agreement.
Sources: Water and air-U.S. Department of Commerce, U.S. Census Bureau, Foreign Trade Division, FT920 U.S. Merchandise Trade: Selected Highlights, December 2007, available at http://www.census.gov/foreign-trade/Press-Release/ft920_index.html as of October 2008. Truck, rail, pipeline, and other and unknown-U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, Transborder Freight Data; and special calculation, October 2008.