Index: 1991 = 1.00
NOTES: Ton-miles is the sum of individual ton-miles for air carriers, intercity trucks, Class I rail, and domestic water transportation. Energy consumption is the sum of usage by air carriers, single unit 2-axle 6-tire trucks, combination trucks, Class I rail (distillate/diesel fuel), and water transportation (residual and distillate/diesel fuel oil). Truck 2001 ton-miles are preliminary. Marine gasoline use data are excluded because marine gasoline is used primarily in recreational vehicles. Commercial domestic aviation fuel consumption data were estimated from total commercial domestic aviation fuel consumption. General aviation data are excluded because passenger and freight data cannot be disaggregated. Pipeline data are excluded because ton-miles data include all types of petroleum products, and energy consumption data are available for natural gas only.
SOURCE: U.S. Department of Transportation (USDOT), Bureau of Transportation Statistics (BTS), calculations based on USDOT, BTS, National Transportation Statistics 2003, tables 1-44, 4-6, and 4-8, available at http://www.bts.gov/, as of March 2004.