|Location||Passengers, cars, buses, and light trucks||Heavy single-unit trucks||3- and 4-axle combination trucks||5-axle or more combination trucks|
NOTES: Based on data from the Truck Weight Study that are collected by the states for varying time periods each year and are not adjusted to typify annual averages. Loadings are based on equivalent single-axle loads, a standard unit of pavement damage based on the amount of force applied to pavement by an 18,000-pound axle, which is roughly equivalent to a standard truck axle. Raw data are not available.
SOURCE: U.S. Department of Transportation, Federal Highway Administration, Highway Statistics 2002 (Washington, DC: 2003), table TC-3, "Percentage Distribution of Traffic Volumes and Loadings on the Interstate System," available at http://www.fhwa.dot.gov/policy/ohim/hs02/pdf/tc3.pdf, as of February 2004.