Interpretation Letter 4(09)-32 (I) — Coordinated Operation of a Pedestrian Hybrid Beacon

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U.S. Department of Transportation
Federal Highway Administration

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

March 21, 2013

In Reply Refer To: HOTO-1

Mr. Jeffrey S. Polenske
City Engineer
City of Milwaukee
Department of Public Works
841 N. Broadway, Room 701
Milwaukee, WI 53202

Dear Mr. Polenske:

Thank you for your letter of February 14 requesting an official interpretation regarding the length of the flashing yellow interval for a pedestrian hybrid beacon that is being operated in a coordinated manner within a signal system. In particular, you are interested in knowing if the beginning of the flashing yellow interval needs to occur immediately upon pedestrian actuation or if there can be a delay in the beginning of the flashing yellow interval after pedestrian actuation.

In your letter you mention that the first sentence of Paragraph 2 in Section 4F.03 says, "Upon actuation by a pedestrian, a pedestrian hybrid beacon face shall display a flashing CIRCULAR YELLOW signal indication, followed by …" You also mention that the second step in the sequence shown in Figure 4F-3 is labeled as "Flashing Yellow Upon Activation".

Although neither the first sentence of Paragraph 2 in Section 4F.03 nor the label for the second step in the sequence shown in Figure 4F-3 says "immediately upon actuation (activation)", it is easy to understand how a practitioner could be confused as to whether a delay in the beginning of the flashing yellow interval after pedestrian actuation would be permitted.

As you mention in your letter, the length of the flashing yellow interval would have to be extended, sometimes for almost the entire cycle length if the pedestrian actuation occurs soon after the yield point of the pedestrian hybrid beacon. Because the purpose of the flashing yellow interval is to warn road users that the steady yellow change interval is about to begin, an excessively long flashing yellow interval would violate driver expectations and would cause drivers to be uncertain regarding how long the yellow signal indication will be flashing before the steady yellow change interval begins.

It is the FHWA's official interpretation that the length of the flashing yellow interval shall be of a fixed duration. This means that when the pedestrian hybrid beacon is being operated in a coordinated manner within a signal system that an interval of variable duration is permitted after pedestrian actuation during which the road users continue to see a dark signal face and during which the pedestrians continue to see an UPRAISED HAND signal indication. This variable duration dark interval would also occur at a pedestrian hybrid beacon that is not part of a signal system when the pedestrian actuation occurs prior to the timing out of the minimum dark interval following a previous actuation.

For recordkeeping purposes, we have assigned the following official ruling number and title: "4(09)-32 (I) — Coordinated Operation of a Pedestrian Hybrid Beacon." Please refer to this number and title in any future correspondence regarding this topic.

Thank you for your interest in improving the clarity of the provisions contained in the MUTCD.

Sincerely yours,

Original signed by:

Mark R. Kehrli
Director, Office of Transportation Operations