U.S. Department of Transportation
Federal Highway Administration
400 Seventh St., S.W.
Washington, D.C. 20590

DEC 1, 2005 Refer to: HOTO-1

Mr. Greg Miller
Business Development Manager Roadway Division
Carmanah Technologies
Building 4, 203 Harbour Road
Victoria, British Columbia
CANADA V9A 3S2

Dear Mr. Miller:

Thank you for your November 21 email to Mr. Scott Wainwright of this office, requesting an official interpretation of the Manual on Uniform Traffic Control Devices (MUTCD) regarding the applicability of the Institute of Transportation Engineers (ITE) Vehicle Traffic Control Signal Heads (VTCSH) specifications to signal sections used as flashing beacons.

Section 4K.01, which states the provisions for general design and operation of all types of beacons covered in Chapter 4K, including but not limited to Stop Beacons (4K.05) and Warning Beacons (4K.03), requires that "Flashing Beacon units and their mountings shall follow the provisions of Chapter 4D, except as specified herein." There are no exceptions stated in Chapter 4K that are related to this issue.

In Section 4D.18, the following language is very clear in making the ITE VTCSH specifications the governing document:

• "Standard: Except for the requirements of this section, the requirements of the "Standards for Vehicle Traffic Control Signal Heads" (see Section 1A.11) shall be met."
• "Guidance: The intensity and distribution of light from each illuminated signal lens should conform to the current "Standards for Vehicle Traffic Control Signal Heads" and "Traffic Signal Lamps" (see Section 1A.11)."

Therefore, it is our interpretation that the provisions of Section 4D. 18 regarding design, illumination, and color of signal sections apply to all types of beacons discussed in Chapter 4K. Thus, for signal sections used for any type of beacon, the ITE VTCSH specifications apply. Complying with the VTCSH specifications is a mandatory requirement for all aspects of design, illumination, color of the signal sections used for beacons, except that for the intensity and distribution of light complying with the VTCSH is recommended rather than mandatory.

Although the portion of Section 1A.11 (Relation to Other Publications) in which the ITE VTCSH specifications are listed is designated as "Support"--that is not pertinent to the issue of what requirements apply to beacons. The listing of documents in Section IA. 11 is labeled Support because it is for the information of the reader in the context of Part 1. It is also labeled as Support because it includes some documents that contain useful information related to traffic control devices but which are not required to be complied with by any text in Parts 2 through 10 of the MUTCD. The Standards and Guidance language in Sections 4K.01 and 4D.18 governs.

Thank you for writing on this subject. If you have any questions, please feel free to contact Mr. Wainwright at scott.wainwright@fhwa.dot.gov or call him at 202-366-0857. Please note that we have assigned your request the following official interpretation number and title: "4-300(I)-Flashing Beacons and VTCSH Specifications." Please refer to this number in any future correspondence on this matter.

Sincerely yours,

Regina S. McElroy
Director, Office of Transportation Operations

cc: Mr. Roger Wentz, ATSSA