U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Highway Statistics 2007
Public Road Length - 2007 1/ Miles by Type of Surface and Ownership/Functional System National System
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; samples entirely on structures are not included. Indiana excludes 788 miles of Federal agency owned roads. Minnesota excludes 437 miles of local government ownd roads.
2/ Paved 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".
3/ Prior to 1999 included other state agency roads.