U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000
Washington Division
FHWA requires inspections of all structures defined as a highway tunnel on all public roads, on and off Federal-aid highways, including tribally and federally owned tunnels. This program was initially mandated in the Moving Ahead for Progress in the 21st Century Act of 2012, which led to the National Tunnel Inspection Standards established in the Federal Register in 2015.
The NTIS (23 CFR 650, Subpart E) require States to:
In Washington State there are 62 tunnels carrying public roads that are subject to the Federal inspection requirements. Of those structures, 48 are State owned, 8 tunnels are owned by local agencies, and 6 are owned by other agencies (Federal, Tribal, Parks, etc.).