Transportation energy use grew 22 percent between 1991 and 2001, to 28 percent of the nation’s total energy consumption in 2001 (figure 111) . Highway vehicles consumed an estimated 81 percent of transportation sector energy .
Still, transportation energy use has grown more slowly than has the Gross Domestic Product (GDP) over the decade. As a result, the amount of transportation energy used per dollar of GDP declined at the average annual rate of over 1 percent between 1991 and 20011 [2, 3] (figure 112).
Over 96 percent of all transportation energy consumed comes from petroleum. Total U.S. petroleum usage increased 16 percent during the last decade, with transportation responsible for 83 percent of that rise . In 2001, transportation consumed 67 percent of all petroleum, up from 65 percent in 1991 (figure 113). Because over half of U.S. petroleum is imported, the United States, and especially the transportation sector, may be vulnerable to supply disruptions with fuel price fluctuations having the potential to contribute to economic instability.
1. Davis, S., Transportation Energy Data Book: Edition 22 (Oak Ridge, TN: Oak Ridge National Laboratory, September 2002), table 2.4.
2. U.S. Department of Commerce, Bureau of Economic Analysis, National Income and Product Account Tables, available at http://www.bea.doc.gov/bea/dn1.htm, as of February 2003.
3. U.S. Department of Energy, Energy Information Administration, Annual Energy Review 2001, available at http://www.eia.doe.gov/emeu/aer/contents.html, as of February 2003.
4. _____, Monthly Energy Review, February 2003, available at http://www.eia.doe.gov/emeu/mer/contents.html, as of February 2003.
5. U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics 2002 (Washington, DC: 2003), table 4-6.
1 GDP is in chained 1996 dollars.