Functional Classification is one determinant of eligibility for federal transportation funding.
Frequently Asked Questions
Functional classification is the process by which public streets and highways are grouped into classes according to the character of service they are intended to provide.
Generally, highways fall into one of four broad categories—principal arterials, minor arterials, collector roads, and local roads.
- Arterials provide longer through travel between major trip generators (larger cities, recreational areas, etc.).
- Collector roads collect traffic from the local roads and also connect smaller cities and towns with each other and to the arterials.
- Local roads provide access to private property or low-volume public facilities.
The table below lists the classifications by rural/urban areas.
Urban and Rural Areas | |
Principal Arterial (Interstate) | |
Principal Arterial (Freeways and Expressways) | |
Principal Arterial (Other) | |
Minor Arterial | |
Major Collector | |
Minor Collector | |
Local Access | |
All above as proposed/future roadway |
Urban areas have been established in each metropolitan area under federal transportation requirements (Title 23, Section 103, United States Code).
The FHWA’s Surface Transportation Program (STP) assistance program requires a small portion of the STP funds be spent outside the federal-aid urbanized areas and federal-aid urban area. The urban/rural boundaries of the map are also used to maintain the federal functional classification system for highways and arterials.
Known as the “federal-aid urbanized” and “federal-aid urban” areas, the map for King, Kitsap, Pierce, and Snohomish counties is designated by the Regional Council in cooperation with the Washington State Department of Transportation and the Federal Highway Administration (FHWA). The results from the 2010 federal census were used to update the map.
Functional Classification is one determinant of eligibility for Federal Transportation Funding.
All roadway projects using federal funds must be approved on the federally classified roadway system before projects on that roadway can be included in the Regional TIP (this includes proposed and new facilities).
Projects on a roadway with a Local Access functional classification are not eligible to use federal transportation funds unless they are one of these exceptions:
- Any bridge project that is using STP (BR) funds
- Any bicycle project and/or pedestrian project
- Projects using Highway Safety Improvement Program (HSIP) funds
- Projects not on a roadway and using CMAQ or other funds
- Any transit project, including equipment purchase and park-and-ride lot projects
National Highway Performance Program (NHPP) funds are only available for projects that are on the designated National Highway System (NHS.)
Adjustments to the urban area boundaries, Functional Classifications, and Federal Aid systems are needed to respond to various types of changes. These changes may be a result of residential, commercial and industrial development, revisions in corporate limits of municipalities, and modification of urbanized and small urban areas by the U.S. Census Bureau. These adjustments are required to establish the eligibility of specific highways, roads and streets for expenditure of federal aid funds for improvements. It may be necessary over time to amend the current FFC System to accurately reflect the classification of a particular roadway.
The Federal Functional Classification Map is available on the WSDOT website.
To request a Federal Functional Classification amendment, download the application and instruction booklet, Guidelines for Amending Urban Boundaries, Functional Classification and Federal Aid System , or obtain a copy from your regional WSDOT office. WSDOT Regional Local Programs contacts:
- Northwest Region: Mehrdad Moini (206-440-4734)
- Olympic Region: Bryan Dial (360-357-2666)
After completing the application, make a copy. If you have any questions, please contact:
- Gary Simonson (206-971-3276)
Submit the original application form to your WSDOT regional local programs contact for review. Submit the copy of the application to PSRC:
Gary Simonson
Puget Sound Regional Council
1201 Third Avenue, Suite 500
Seattle, WA 98101-3055
If your request involves another jurisdiction or you check “yes” on #8 on the Application, you must request concurrence from the neighboring jurisdiction. Please provide that concurrence with your Application or notify PSRC that it has been requested. PSRC staff will review the application to determine concurrence with the request. When complete, PSRC will send a letter to the WSDOT regional office, with a copy to the applicant.
Following PSRC and WSDOT Regional Office review, the WSDOT Planning & Programming Office (360-570-2441) will review the request for consistency with federal guidelines. For further information on the WSDOT portion of the process, please visit the WSDOT site.
Next the application will be forwarded to FHWA for a final decision. Once the review is complete, the applicant will be informed of the outcome of the request.
- FHWA WA Division: Sidney Stecker (360-753-9555)
The FHWA Approval (or denial) status of a requested functional classification change and whether an updated map is yet available can be checked at the WSDOT site.

If you have any general questions, please contact Gary Simonson (206-971-3276).