All modes of freight transportation, combined, generated 4.4 trillion domestic ton-miles in 2002, 18 percent more than in 1992 (box 1-B). This represents a growth rate of 1.7 percent per year during the period.
Domestic ton-miles for all modes, except water, grew during most of the 1992 to 2002 period (figure 1-9). Rail grew the fastest (46 percent), closely followed by truck (40 percent) and air (23 percent). Rail and truck accounted for the majority of domestic ton-miles at 37 and 29 percent, respectively, in 2002 (figure 1-10). Truck data, however, do not include retail and government shipments and some imports and, therefore, understate total truck traffic.
Water transportation and oil and natural gas pipelines accounted for 14 and 20 percent of domestic ton-miles, respectively, in 2002. Although domestic waterborne ton-miles decreased 29 percent between 1992 and 2002, waterborne vessels continued to play a prominent role in international trade . U.S. waterborne imports and exports, valued at $728 million, totaled 1.1 billion metric tons in 2002 . Oil and natural gas pipeline combined ton-miles, which grew 7 percent between 1992 and 1996, were stagnant or declining through the rest of the period.
Air freight declined between 2000 and 2001, from 15.8 billion ton-miles to 13.3 billion ton-miles, reflecting the economic downturn at the time, the impact of the terrorist attacks of September 11, 2001, and perhaps restrictions placed on the air transport of U.S. mail packages as a security precaution in late 2001. However, air freight rose again, reaching 13.6 billion ton-miles in 2002.
1. U.S. Department of Transportation, Maritime Administration, Office of Statistical and Economic Analysis, U.S. Foreign Waterborne Transportation Statistics, available at http://www.marad.dot.gov/, as of February 2005.
2. U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, U.S. International Trade and Freight Transportation Trends (Washington, DC: 2003).