Certified Public Mileage

Certified Public Mileage (CPM) is the total centerline mileage of all roads in the state that are open to public travel.  CPM is vitally important because it is the value used by the federal government to allocate transportation funds to each state.

All public road mileage (regardless of ownership or paved status) is to be included in the State’s CPM.  23 CFR 460 defines the criteria for a road to be counted towards CPM:

• Open to public travel

  • • The road must be open and available to anyone from the public

    • The road cannot be gated or otherwise restricted from public access

      • • The only exceptions are roads with size, weight, or class restrictions, roads closed for scheduled periods of time, or roads closed during emergency conditions

• Road must be passable by a four-wheel standard passenger car (e.g. Honda Civic)

  • • Unpaved roads can be counted towards CPM so long as a 4-wheel car can drive them

Yes.  The U.S. Secretary of the Interior submits the CPM for all public roads within Indian reservations to the FHWA. 

Yes.  While rare, if a private road is widely used or is a high traffic generator, then FHWA may allow the road to be counted towards CPM.  The road must still meet the criteria outlined in the above definition.

Yes.  As long as the road is publicly accessible and drivable by a standard four-wheel passenger car, an unpaved road can be counted towards CPM.

No.  Roads that are not accessible to the public due to gates or other restrictive boundaries are not considered public roads and cannot be counted towards CPM.

Yes.  Roads with truck weight or class restrictions may still be counted towards CPM.