U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
October 26, 2021
Table HM-18M
| FUNCTIONAL SYSTEM | FEDERAL-AID HIGHWAYS | NON- FEDERAL-AID HIGHWAYS |
TOTAL | ||||
|---|---|---|---|---|---|---|---|
| NATIONAL HIGHWAY SYSTEM | OTHER | TOTAL | |||||
| INTERSTATE | OTHER | TOTAL | |||||
| Rural: | |||||||
| Principal Arterial: | |||||||
| Interstate | 47,214 | - | 47,214 | - | 47,214 | - | 47,214 |
| Other Freeways and Expressways | - | 10,485 | 10,485 | 67 | 10,552 | - | 10,552 |
| Other | - | 141,283 | 141,283 | 4,818 | 146,100 | - | 146,100 |
| Subtotal | 47,214 | 151,767 | 198,981 | 4,885 | 203,866 | - | 203,866 |
| Minor Arterial | - | 4,241 | 4,241 | 212,798 | 217,038 | - | 217,038 |
| Major Collector | - | 756 | 756 | 655,732 | 656,487 | - | 656,487 |
| Minor Collector | - | 4 | 4 | - | 4 | 417,992 | 417,996 |
| Local | - | 35 | 35 | - | 35 | 3,233,898 | 3,233,933 |
| Total Rural | 47,214 | 156,803 | 204,017 | 873,414 | 1,077,431 | 3,651,889 | 4,729,320 |
| Small Urban: | |||||||
| Principal Arterial: | |||||||
| Interstate | 4,538 | - | 4,538 | - | 4,538 | - | 4,538 |
| Other Freeways and Expressways | - | 2,210 | 2,210 | 75 | 2,285 | - | 2,285 |
| Other | - | 18,738 | 18,738 | 2,817 | 21,555 | - | 21,555 |
| Subtotal | 4,538 | 20,948 | 25,486 | 2,893 | 28,378 | - | 28,378 |
| Minor Arterial | - | 655 | 655 | 32,892 | 33,548 | - | 33,548 |
| Major Collector | - | 70 | 70 | 45,644 | 45,713 | - | 45,713 |
| Minor Collector | - | 14 | 14 | 8,782 | 8,796 | - | 8,796 |
| Local | - | 25 | 25 | - | 25 | 248,587 | 248,612 |
| Total Small Urban | 4,538 | 21,712 | 26,250 | 90,210 | 116,460 | 248,587 | 365,047 |
| Urbanized: | |||||||
| Principal Arterial: | |||||||
| Interstate | 26,714 | - | 26,714 | - | 26,714 | - | 26,714 |
| Other Freeways and Expressways | - | 17,022 | 17,022 | 250 | 17,273 | - | 17,273 |
| Other | - | 77,609 | 77,609 | 8,444 | 86,053 | - | 86,053 |
| Subtotal | 26,714 | 94,631 | 121,345 | 8,694 | 130,040 | - | 130,040 |
| Minor Arterial | - | 2,389 | 2,389 | 145,643 | 148,032 | - | 148,032 |
| Major Collector | - | 648 | 648 | 165,777 | 166,424 | - | 166,424 |
| Minor Collector | - | 54 | 54 | 25,298 | 25,352 | - | 25,352 |
| Local | - | 181 | 181 | - | 181 | 1,182,743 | 1,182,924 |
| Total Urbanized | 26,714 | 97,904 | 124,618 | 345,412 | 470,030 | 1,182,743 | 1,652,773 |
| Total Urban: | |||||||
| Principal Arterial: | |||||||
| Interstate | 31,252 | - | 31,252 | - | 31,252 | - | 31,252 |
| Other Freeways And Expressways | - | 19,233 | 19,233 | 325 | 19,558 | - | 19,558 |
| Other | - | 96,346 | 96,346 | 11,262 | 107,608 | - | 107,608 |
| Subtotal | 31,252 | 115,579 | 146,831 | 11,587 | 158,418 | - | 158,418 |
| Minor Arterial | - | 3,045 | 3,045 | 178,535 | 181,580 | - | 181,580 |
| Major Collector | - | 717 | 717 | 211,420 | 212,138 | - | 212,138 |
| Minor Collector | - | 68 | 68 | 34,080 | 34,148 | - | 34,148 |
| Local | - | 206 | 206 | - | 206 | 1,431,330 | 1,431,536 |
| Total Urban | 31,252 | 119,615 | 150,867 | 435,623 | 586,490 | 1,431,330 | 2,017,820 |
| Total Rural and Urban | 78,465 | 276,419 | 354,884 | 1,309,037 | 1,663,921 | 5,083,219 | 6,747,140 |
(1) Includes the 50 States, Puerto Rico, and the District of Columbia. Due to conversion from English to metric units and to rounding, individual cell values may not agree with corresponding mileage table cell values.
