Table  4-20,,,,,,,,,,,,,,,,
Energy Intensity of Passenger Modes,,,,,,,,,,,,,,,,
(Btu per passenger-mile),,,,,,,,,,,,,,,,
,,1960,1965,1970,1975,1980,1985,1990,1991,1992,1993,1994,1995,1996,1997,1998
AirR,,,,,,,,,,,,,,,,
Certificated air carrier,,,,,,,,,,,,,,,,
  Domestic operations,,"8,633","10,118","10,185","7,746","5,727","5,047","4,932","4,671","4,564","4,558","4,444","4,382","4,183","4,146","4,123"
  International operations,,"9,199","10,292","10,986","8,465","8,866","5,103","4,546","4,609","4,258","4,099","4,145","4,173","4,108","4,168","4,278"
Highwayb,,,,,,,,,,,,,,,,
Passenger car,,"4,495","4,455","4,841","4,743","4,348","4,267","3,812","3,654","3,703","3,785","3,771","3,721","3,702","3,657","3,672"
Other 2-axle 4-tire vehicle,,N,N,"6,810","6,571","5,709","4,971","4,451","4,277","4,256","4,275","4,345","R4,539","R4,560","R4,563","4,591"
Motorcycle,,a,a,"2,500","2,354","2,125","1,896","1,990","1,917","1,990","2,063","2,135","R2,227","R2,250","R2,295","2,330"
Transit motor bus,,N,N,N,N,"2,742","R3,396","R3,723","3,767","R4,038","R3,944","R4,162","R4,155","R4,196","R4,228","P3,729"
Amtrak,,N,N,N,"2,383","R2,164","R2,094","R2,064","1,978","R2,035","R2,023","1,935","1,838","R2,148","2,200","2,138"
a  Included in passenger car.,,,,,,,,,,,,,,,,
"b  For 1995 and subsequent years, highway passenger-miles were taken directly from Highway Statistics rather than derived from vehicle-miles and average occupancy, as is the case for 1960-1994.",,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
KEY: Btu = British thermal unit; N = data do not exist; P = preliminary; R = revised.,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
"NOTES: To calculate total Btu, multiply fuel consumed (see tables 4-21, 4-22, 4-24, 4-25) by 135,000 Btu/gallon for air carrier, 125,000 Btu/gallon ",,,,,,,,,,,,,,,,,,,,,,,,,,,,,,
"for passenger car, other 2-axle 4-tire vehicle, and motorcycle, and 138,700 Btu/gallon 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 Transportation Association, Public Transportation Fact Book (Washington, DC: March 2000), tables 30, 42; and 65.",,,,,,,,,,,,,,,
Amtrak:,,,,,,,,,,,,,,,
"1975-98: Amtrak, State and Local Affairs Department, personal communications.",,,,,,,,,,,,,,,
,,,,,,,,,,,,,,,