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National Transportation Statistics

4141

Energy Intensity of Passenger Modes (metric)

KEY: N = data do not exist; U = data are not available.

a Data from 2007 were calculated using a new methodology developed by FHWA. Data for these years are based on new categories and are not comparable to previous years. The new category Light duty vehicle, short wheel base replaces the old category Passenger car and includes passenger cars, light trucks, vans and sport utility vehicles with a wheelbase (WB) equal to or less than 121 inches. The new category Light duty vehicle, long wheel base replaces Other 2-axle, 4...

U.S. Vehicle-Kilometers

KEY: N = data do not exist; R = revised; U = data are not available.

a All operations other than those operating under 14 CFR 121 and 14 CFR 135. Data for 1996 are estimated using new information on nonrespondents and are not comparable to earlier years. Mileage in source is multiplied by 1.151 to convert to nautical-miles for 1985-1997.

b Data from 2007 were calculated using a new methodology developed by FHWA. Data for these years are based on new categories and are not comparable to previous years. The new category Light...

Energy Intensity of Light Duty Vehicles and Motorcycles (metric)

KEY: Btu = British thermal unit; N = data do not exist; U = data are not available.

aMotorcycle is included in Light duty vehicle, short wheel base (previously Passenger car) in 1960 and 1965.

b Energy Intensity (Btu/passenger-kilometer) is calculated by converting the fuel consumption in gallons to the energy equivalent Btu units and dividing by the passenger-kilometers. The heat equivalent factor used for Btu conversion is 125,000 Btus/gallon.

Federal Exhaust Emissions Standards for Marine Spark-Ignition Engines and Vehicles

KEY:  CO = carbon monoxide; g = gram; hr = hour; HC = hydrocarbon; kW = kilowatt; kWh = kilowatt hour; NOx = nitrogen oxide; P = rated power; yr = year. 

a The standards apply to marine spark-ignition outboard, personal watercraft, and jet-boat engines only. Marine compression-ignition engines under 50 hp are covered under the proposed nonroad compression-ignition engine standards. Federal standards are in development for marine compression-ignition engines over 50 hp. 

b The standards for personal watercraft did not go into effect until...