|Source||Value (1997 $billion)||Tons (millions)||Ton-miles (billions)||Percent Value||Percent Tons||Percent Ton-miles||Value per ton (dollars)||Miles per ton|
|Commodity Flow Survey||6,944||11,090||2,661||81.1||74.9||69.1||626||240|
1 Based on additional estimates prepared for the Bureau of Transportation Statistics by Oak Ridge National Laboratory. The estimates cover out-of-scope farm-based truck shipments, truck imports from Canada and Mexico, rail imports from Canada and Mexico, air cargo imports and exports, and water imports and exports. The estimates exclude noncommercial freight shipments such as government shipments and municipal solid waste.
SOURCE: U.S. Department of Transportation, Bureau of Transportation Statistics and U.S. Department of Commerce, U.S. Census Bureau, 1997 Commodity Flow Survey, United States, EC97TCF-US (Washington, DC: 1999); and Oak Ridge National Laboratory data.