Skip to contentUnited States Department of Transportation - Federal Highway AdministrationSearch FHWAFeedback
Policy Information

Non-Regulatory Guidance for Public Road Mileage Certification

Implementing 23 CFR 460 for Apportionment of Highway Safety Funds

Attention to those involved in handling the annual public road mileage certification submissions from the 50 States, District of Columbia, Puerto Rico, Virgin Islands, Guam, American Samoa, Northern Mariana Islands, and the Bureau of Indian Affairs.

Public road mileage certifications are due no later than June 1 of each year to FHWA Headquarters, HPPI-20. FHWA Field Division Offices may set an earlier date. The certifications shall be provided in an electronic format (e.g., MSWord document, Adobe Acrobat PDF) via email sent to the FHWA Office of Highway Policy Information official electronic mailbox (

Please note that the FHWA Division Office assists in obtaining a valid public road mileage certification from the State and transferring a copy of it to HPPI-20. In addition, the Division Office makes their recommendation to the HPPI-20 (within a few days) about the extent of the State's certified public road mileage.

Measurements and Routes

All certified centerline public road mileage should be based on actual driven measured distances (estimates are not acceptable). If there are any doubts about the extent of a local jurisdiction's or Federal agency's ownership of a facility, then adequate information should be gathered and documented to sufficiently verify or appropriately correct any deficient measurements prior to reporting. Do not submit any duplicates for a route.

The public road mileage reported should be as of the end of the preceding calendar year in which the certification is made (23 CFR 460.3) to ensure that Federal funds are apportioned correctly nationwide.

Governor or Governor's Designee

Certifications shall be signed by the current Governor of the State, or their designee (by title or a specific named person), or handled as prescribed by acceptable State Statute. If the Governor elects to delegate, then provide a copy of the letter of delegation to FHWA. If the Governor or certification designee has changed, then provide a new copy of the official letter of delegation (with signature) to FHWA. If this is for a U.S. Territory, please handle as traditionally done.

If a State statue applies in lieu of the Governor's certification, then a copy of the pertinent section(s) of the law should also be provided. If there is any question about the application of the State statute, then FHWA needs a legal opinion by their chief counsel to explain who is authorized to sign the public road mileage certification. The legal opinion should conclude that a certain designee (or position within the State) has been delegated this responsibility pursuant to a valid and lawful delegation under State law and laying out the authorities and/or relevant documents comprising this delegation.

Federal Agency & Indian Reservation Roads

When applicable:

  • Public road mileage on Indian reservations within the State shall be identified and included in the State mileage (23 CFR 460).
  • Public roads of Federal Agencies recognized under Title 23, U.S.C., within the State, should be included in the certified mileage.

Each year FHWA encourages the Federal Agencies owning public road mileage to furnish information to FHWA that can be provided to the States. This information (by installation, park, or county) is used to determine the amount of miles reported in the annual public road mileage certification as well as the HPMS database. Some States have discovered problems with the reported Federal Lands Management Agency information and that the applicable agency may be slow in making corrections. Use caution when working with some of this information and appropriately document any issue found. The State should work with their Federal Agency points of contact to get maps of where these facilities are actually located.

Division Office Recommendation

Please note that the FHWA Field Division Office in concert with the Federal Highway Administrator actions (23 CFR 460.3) needs to make a recommendation within a few days whether it agrees with the extent of the State's certified public road mileage. Normally the note transmitting the mileage certification is accepted as the Division's recommendation. In some cases a "quality" review needs to be undertaken to prove that only eligible public roads are actually being reported (with no duplications) under the existing collection processing procedures.

These actions must be timely to allow sufficient time for HPPI-20 to transmit the applicable certified data to NHTSA by mid-September for use in apportioning 23 USC 402 funds for the next fiscal year.

Updated: 06/30/2017

United States Department of Transportation - Federal Highway Administration