## Table 4-20M. Energy Intensity of Passenger Modes (Thousand joules per passenger-kilometer)

1960 1965 1970 1975 1980 1985 1990 1991 1992 1993 1994 1995 1996 1997 1998
AirR
Certificated air carrier
Domestic operations 5,664 6,639 6,682 5,082 3,757 3,311 3,236 3,065 2,994 2,991 2,916 2,875 2,744 2,720 2,705
International operations 6,036 6,753 7,208 5,554 5,817 3,348 2,983 3,024 2,794 2,689 2,719 2,738 2,695 2,735 2,807
Highwayb
Passenger car R2,949 R2,923 R3,176 R3,112 R2,853 R2,800 R2,501 2,397 2,429 2,483 2,474 R2,441 R2,429 R2,399 2,409
Other 2-axle 4-tire vehicle N N R4,468 R4,311 R3,746 R3,261 R2,920 2,806 2,792 2,805 2,851 R2,978 R2,992 R2,994 3,012
Motorcycle a a R1,640 R1,544 R1,394 R1,244 R1,306 1,258 1,306 1,354 1,401 R1,461 R1,476 R1,506 1,529
Transit motor busN N N N R1,799 R2,228 R2,443 2,471 R2,649 R2,588 R2,731 R2,726 R2,753 R2,774 P2,447
AmtrakN N N R1,563 R1,420 R1,374 1,354 1,298 R1,335 R1,327 1,269 R1,206 R1,409 R1,443 1,403

a Included in passenger car.
b Energy intensity for highway vehicles may not match similar values in table 4-22 due to rounding error.

KEY: N = data do not exist; P = preliminary; R = revised.

NOTE: To calculate total joules multiply fuel consumed by 37,626,700 joules/liter for air carrier and 34,839,537 joules/liter  for passenger car, other 2-axle 4-tire vehicle, and motorcycle, and 90,999,114 for transit motor bus and Amtrak.

SOURCES:
Air:
Certificated air carriers:
Passenger-miles:
1960-99: Air Transport Association, Internet site http://www.air-transport.org/public/industry, as of July 5, 2000.
Fuel consumed:
1960-99: U.S. Department of Transportation, Bureau of Transportation Statistics, Office of Airline Information, Internet site http://www.bts.gov/oai/fuel/fuelyearly.html, as of July 5, 2000.
Highway
Passenger car:
1960-94: U.S. Department of Transportation, Federal Highway Administration, Highway Statistics Summary to 1995, FHWA-PL-97-009 (Washington, DC: July 1997), table VM-201A.
1995-98: Ibid., Highway Statistics (Washington, DC: Annual issues), table VM-1.
Other 2-axle 4-tire vehicle:
1970-94: Ibid., Highway Statistics Summary to 1995, FHWA-PL-97-009 (Washington, DC: July 1997), table VM-201A.
1995-98: Ibid., Highway Statistics (Washington, DC: Annual issues), table VM-1.
Motorcycle:
1970-85: Ibid., Highway Statistics Summary to 1985, FHWA-PL-97-009 (Washington, DC: July 1997), table VM-201A.
1990-98: Ibid., Highway Statistics (Washington, DC: Annual issues), table VM-1.
Transit motor bus:
1980-98: American Public Transit Association, Public Transportation Fact Book (Washington, DC: 2000), tables 30, 42, and 65.
Amtrak:
1975-93: Amtrak, State and Local Affairs Department, personal communication.
1994-98: Ibid., Personal communication, June 25, 1999.