Highway Statistics Series

Highway Statistics 1998

PUBLIC ROAD LENGTH – 1998 1/

MILES BY TYPE OF SURFACE AND OWNERSHIP/FUNCTIONAL SYSTEM

NATIONAL SUMMARY

OCTOBER 1999
Table HM-12

1/ Includes the 50 States, the District of Columbia and Puerto Rico. Some differences from other tables may be noted because these are estimated from sample and summary data and do not include structures.

2/ Unpaved mileage includes the following categories: Unimproved roadways using the natural surface and maintained to permit passability; Graded and Drained roadways of natural earth aligned and graded to permit reasonably convenient use by motor vehicles and which have adequate drainage to prevent serious impairment of the road by normal surface water* surface may be stabilized; and Soil, Gravel, or Stone, a graded and drained road with a surface of mixed soil, gravel, crushed stone, slag, shell, etc.* surface may be stabilized.

3/ Paved mileage includes the following categories: Low Type, an earth, gravel, or stone roadway which has a bituminous surface course less than 1" thick* suitable for occasional heavy loads; Intermediate Type, a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness of less than 7"; High-Type Flexible, a mixed bituminous or bituminous penetration roadway on a flexible base having a combined surface and base thickness of 7" or more* also includes brick, block, or combination roadways; High-Type Composite, a mixed bituminous or bituminous penetration roadway of more than 1" compacted material on a rigid base with a combined surface and base thickness of 7" or more; High-Type Rigid, a Portland Cement Concrete roadway with or without a bituminous wearing surface of less than 1".

4/ Includes State highway agency, State park, State toll and other State agency roadways.

5/ State summary totals for rural minor collectors and rural and urban locals are shown separately below.