FIGURE 3-9b U.S. International Merchandise Trade Weight by Transportation Mode: 2015
NOTES: 1 short ton = 2,000 pounds. The U.S. Department of Transportation (USDOT), Bureau of Transportation Statistics estimated 2015 weight data for truck, rail, pipeline, and other and unknown modes using value-to-weight ratios derived from imported commodities. Totals for 2015 differ slightly from the Freight Analysis Framework (FAF) due to variations in coverage and FAF conversion of values to constant dollars. Numbers may not add to totals due to rounding.
SOURCES: Total, water and air data: U.S. Department of Commerce, U.S. Census Bureau, Foreign Trade Division, FT920 - U.S. Merchandise Trade: Selected Highlights (Washington, DC: February 2016). Truck, rail, pipeline, and other and unknown data: U.S. Department of Transportation, Bureau of Transporation Statistics, North American Transborder Freight Data, available at www.bts.gov/transborder as of March 2016.