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Changes and Experimentations for the Manual on Uniform Traffic Control Devices

The standard for traffic control devices in Washington state is the 2009 Manual of Uniform Traffic Control Devices (with Revisions 1 and 2 Incorporated), as modified by Washington Administrative Code (WAC) 468-95 . The following is information on interpretations and approved changes for the MUTCD and on experimentations and interim approvals for devices not yet in the MUTCD.

Federal Highway Administration's (FHWA) MUTCD database

Federal Highway Administration's (FHWA) Official Rulings database of MUTCD interpretations, approved changes, and approved experimentations in Washington and other states.

Request an experimentation for a traffic control device that has not been tested

Local and state agencies can request an experimentation from FHWA to test a new traffic control device that is either:

  • Not in the 2009 MUTCD and has not been tested.
  • In the 2009 MUTCD but the device would be used in a new way (different size, type, or location) that has not been tested.

Request to be included in WSDOT's statewide interim approval to use a traffic control device that has been tested but is not in the MUTCD

Local and state agencies that want to use a traffic control device that has been tested or is in the process of being tested and is being considered for addition to the next edition of the MUTCD can request an interim approval from FHWA. Agencies can request site specific approval or jurisdiction-wide approval.

WSDOT has received the following statewide approvals for use by all local jurisdictions. A local jurisdiction that wants to use WSDOT's statewide approval may do so. The agency must first contact WSDOT by email to notify us that it will use the device under the statewide approval. As a condition of our approval from FHWA, the agency must either 1) provide WSDOT a list of all locations where the traffic control device will be installed and must provide an updated list when locations are added or removed or 2) keep a list of all locations where the traffic control device is installed. This works like a recall. If FHWA should find the device to not be effective, FHWA will ask WSDOT to notify all the agencies using the device to remove them.


WSDOT statewide interim approvals for use on all local jurisdiction-owned roadways and state highways. Get specific requirements here.

  • IA-12.5 -Traffic Signal Photo Enforced Sign
  • IA-13.2 - Alternative Electric Vehicle Charging General Service Symbol Sign
  • IA-14.20 - Green Colored Pavement for Bike Lanes
  • IA-18.35: Optional Use of Intersection Bicycle Boxes
  • IA-19.8: Alternative Signal Warrant 7 - Crash Experience
    Note: Since RCW 46.61.085 requires WSDOT approval for all traffic control signals installed on state highways, the three-year period for data will be the only option allowed by WSDOT under this interim approval for state highways.
  • IA-20.17: Optional Use of Two-Stage Bicycle Turn Boxes

WSDOT statewide interim approvals for use on all local jurisdiction-owned roadways and not on state highways. Get specific requirements here.

  • IA-17.7 - Optional Use of Three-Section Flashing Yellow Arrow Signal Faces

WSDOT statewide interim approval no longer available - IA-11.113: Rectangular Rapid Flashing Beacon
Statement from MUTCD web page: "FHWA Interim Approval 11 was issued during the time that the 2003 MUTCD was in effect. (The approval) was not incorporated into the 2009 MTUCD and the FHWA does not intend to incorporate it into any future edition of the MUTCD. Interim Approval 11 was terminated by the FHWA in a memorandum dated 12/21/17 and is no longer in effect...The installation of any new or replacement rectangular rapid flashing beacons by any highway agency, including those who received the FHWA's approval to use rectangular rapid flashing beacons under Interim Approval 11, shall be prohibited. However, any existing rectangular rapid flashing beacon that was installed prior to 12/21/17, that complies with the terms of Interim Approval 11 may remain in place until it reaches the end of its useful service life."
- Interim Approval IA-11 Termination Memorandum (HTML, pdf 37 kb)
- Informational Brief: Treatments for Uncontrolled Marked Crosswalks (HTML, pdf 963 MB)
- Archived information: Interim Approval IA-11)
Memorandum (HTML, pdf 963 MB)

WSDOT has an alternative device, called a rapid flashing beacon. Get details.

Contact us

Traffic Services Manager