Index: 1990 = 1.00
|Energy efficiency (TM/BTU)||1.00||1.00||1.02||1.04||1.05||1.03||1.03||1.02||0.97||0.96||0.93|
KEY: BTU = British thermal unit; TM = ton-miles.
NOTES: General aviation data are excluded because passenger and freight operations data cannot be disaggregated. Marine gasoline use data are excluded from freight energy use total because marine gasoline is used primarily in recreational vehicles. Pipeline data are excluded because ton-miles data include all types of petroleum products, and energy consumption data are available for natural gas only. Commercial domestic aviation fuel consumption data for passenger and freight operations were estimated from the total commercial domestic aviation fuel consumption.
SOURCES: Ton-miles and energy use (unless otherwise noted)-U.S. Department of Transportation, Bureau of Transportation Statistics, National Transportation Statistics 2002 (Washington, DC: 2002), tables 1-34, 1-44, 4-6, and 4-8, available at http://www.bts.gov/, as of May 2003. Truck ton-miles for 2000-The Eno Transportation Foundation, Transportation in America, 19th Edition (Washington, DC: 2002), page 45.