SOURCES: U.S. Department of Transportation, Bureau of Transportation Statistics:
Estimates of vehicle-miles traveled (vmt) calculated from data in U.S. Department
of Transportation, Federal Highway Administration, Highway Statistics
(Washington, DC: 1984–2000).
Estimates of transportation expenditures calculated from data in U.S. Department
of Labor, Bureau of Labor Statistics, “Consumer Expenditure Survey,” 1984–2000,
available at http://www.bls.gov.cex/
home.htm, as of June 2002.
