Manual on Uniform Traffic Control Devices (MUTCD) arrows logo

Interpretation Letter 4-357(I) - Red Light Cameras

PDF Version, 81KB

You will need the Adobe Acrobat Reader to view the PDF on this page.

DOT Logo

U.S. Department of Transportation
Federal Highway Administration

1200 New Jersey Avenue, SE.
Washington, D.C. 20590

February 19, 2009

In Reply Refer To: HOTO-1

Ernest F. Mallard, P.E.
Forensic Engineering Incorporated
5116 Departure Drive
Raleigh, NC 27616-1814

Dear Mr. Mallard:

Thank you for your February 13 letter requesting an official interpretation of the Manual on Uniform Traffic Control Devices (MUTCD). Specifically, you asked whether "red light cameras" are traffic control devices.

Section 1A.13 of the MUTCD defines "traffic control device" as follows:

Traffic Control Device - a sign, signal, marking, or other device used to regulate, warn, or guide traffic, placed on, over, or adjacent to a street, highway, pedestrian facility, or shared-use path by authority of a public agency having jurisdiction.

A "red light camera," typically called a "photo enforcement system" in the transportation industry, does not regulate, guide, or warn traffic. The traffic signal itself regulates traffic. A red traffic signal indication is what prohibits drivers from entering the intersection. A red light camera is an electronic device that performs the same function as a police officer, detecting violations of the traffic signal and issuing citations for such violations, but doing so in an automated rather than human fashion.

The MUTCD does include standards for signs that may be used to warn road users that photo enforcement systems are in operation. Such signs are traffic control devices under the definition cited above. The photo enforcement systems or "red light cameras" are not traffic control devices and are not governed by provisions of the MUTCD.

I hope that this interpretation answers your question. Thank you for writing on this subject. If you have any questions, please contact Mr. Scott Wainwright of our staff by e-mail at or by telephone at 202 366 0857. Please note that we have assigned your request the following official interpretation number and title: "4-357(I) - Red Light Cameras." Please refer to this number in any future correspondence regarding this issue.

Sincerely yours,

/s/ Hari Kalla

Hari Kalla
Acting Director, Office of Transportation Operations

Incoming Letter

Forensic Engineering Incorporated
Professional Engineers / Consultants

February 13 , 2009

Mr. W. Scott Wainwright, P.E., PTOE
Highway Engineer, MUTCD Team
Federal Highway Administration
Office of Transportation Operations, HOTO-1
1200 New Jersey Avenue, S.E., E84-447
Washington, DC 20590

Dear Mr. Wainwright:

This is to follow up on our telephone conversation earlier this week. I would appreciate an FHWA Official Interpretation of the Manual on Uniform Traffic Control Devices on the following question:

Are Red Light Cameras traffic control devices?

Thank you again for you assistance.

With best regards,

/s/ Ernest Mallard

Ernest F. Mallard, PE

5116 Departure Drive, Raleigh, North Carolina, 27616-1814
Tel: 919-790-2217, Fax: 919-790-2219