NOTES: Percentages may not
add to 100 due to rounding.
Loadings are based on equivalent single-axle loads
(ESALs), 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.
SOURCE: U.S. Department of
Transportation, Federal Highway Adminstration, Highway
Statistics 2001 (Washington, DC: 2002),
table TC-3.
