The U.S. transportation system carried 20 percent more ton-miles of domestic freight in 2000 than in 1990 . This growth was unevenly distributed in terms of geography and mode. The Federal Highway Administration developed the Freight Analysis Framework (FAF) to estimate geographic freight flows on the nation’s infrastructure . These results can be depicted on maps like figure 9, figure 10, and figure 11.
Nearly one-third of urban Interstate highways carried more than 10,000 trucks each day on average in 1998,1 according to FAF estimates. By 2020, the portion of heavily used urban Interstates is expected to rise to 69 percent . Rail freight flows appear to be more concentrated than trucking flows. In addition to growth in domestic freight shipments, increased trade with Mexico and Canada has altered the distribution of freight movement within the United States, creating high traffic areas near borders .
For waterborne freight, domestic flows are highly concentrated along the Mississippi and Ohio Rivers. Domestic waterborne ton-miles decreased 23 percent between 1990 and 2000 .
1. U.S. Department of Transportation (USDOT), Bureau of Transportation Statistics (BTS), calculation based on USDOT, BTS, National Transportation Statistics 2002 (Washington, DC: 2002), table 1-44, also available at http:// www.bts.gov.
2. U.S. Department of Transportation, Federal Highway Administration, Freight Analysis Framework website, available at http://www.ops.fhwa.dot.gov/freight/adfrmwrk/index.htm, as of March 2003.
3. _____, The Freight Story (Washington, DC: November 2002), also available at http://www.ops.fhwa.dot.gov/freight/, as of March 2003.
1 At the time this report was prepared, 1998 was the most recent year for which data were available.