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Interpretation Letter 10-66(I) - LRT Signals for Bus Queue Jumper Lane

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U.S. Department of Transportation
Federal Highway Administration

400 Seventh St., S.W.
Washington, D.C. 20590

October 6, 2006

In Reply Refer To: HOTO-1

Mr. Richard G. Sarchet
Region 1 Interim Traffic Operations Engineer
Colorado Department of Transportation
18500 East Colfax Avenue

Aurora, CO  80011

Dear Mr. Sarchet:

Thank you for your September 1 letter, requesting an interpretation of Part 10 of the Manual on Uniform Traffic Control Devices (MUTCD) regarding the use of special light rail transit (LRT) traffic signal indications to control a bus "queue jumper" lane at signalized intersections.

A similar issue involving the use of LRT signal indications for control of bus rapid transit (BRT) at signalized intersections was reviewed by this office in 2003 and, as a result, we issued Official Interpretation number 10-59 (I) titled, "Light Rail Transit Signals for Bus Rapid Transit System Lanes" in April of 2003. That interpretation found that the LRT signal indications as shown in Figure 10D-1 and discussed in Section 10D.07 may be used for control of BRT operations to reduce road user confusion that might otherwise occur if standard traffic signal indications were used to control BRT movements at signalized intersections.

Your request involves a series of signalized intersections along an arterial highway, at which public transit buses will use a "right turn only" lane to advance to the stop line during the red phase, where they will be detected and thus call into operation a special brief "queue jumping" signal phase immediately prior to the normal approach green phase. This special phase will allow the bus to proceed straight into the intersection while parallel through traffic (and all other conflicting traffic) continues to be displayed red signal indications. It is our understanding that the "right turn only" lane becomes a channelized, yield-controlled "free right" just before reaching the intersection and buses will, in effect, be on the right shoulder between the through lane and the channelizing island where they are detected at the stop line.

Your proposal is to display the "go" indication of an LRT signal (vertical white bar) for the brief queue jumper phase in a signal section installed directly above the existing standard circular red-yellow-green traffic signal face on the far right corner of the intersection. There would be a "BUS SIGNAL" sign located immediately above the vertical white bar signal section. During signal intervals and phases other than the brief bus queue jumper phase, the signal section with the LRT signal display would be dark and any buses approaching the intersection would be controlled by the normal red-yellow-green traffic signals for the approach.

We have reviewed your request and we agree that the use of the special LRT vertical white bar "go" signal for this type of bus queue jumper operation is appropriate and would be less confusing to road users than other alternatives involving standard traffic signal indications. Such alternatives would necessitate a separate, visibility-limited circular red-yellow-green signal face to control the bus at the stop line. The display of a green indication in such a signal face during the queue jump phase might still be visible to some road users and could cause confusion and incorrect responses.

It is important to note that Section 10D.07 states that "LRT signal faces should be separated vertically or horizontally from the nearest highway traffic signal face for the same approach by at least 0.9 m (3 ft.)." Therefore, you should revise your display on the far right corners of the intersections to comply with this provision. The "BUS SIGNAL" sign should accompany the LRT signal section in its separated location.

In summary, it is our interpretation that the LRT signal indications shown in Figure 10D-1 and discussed in Section 10D.07 may be used for control of public transit buses in "queue jumper" operations at signalized intersections to reduce road user confusion that might otherwise occur if standard traffic signal indications were used to control the bus queue jumper movements. Bus drivers assigned to routes using the queue jumpers should be educated on the meaning of the special signal displays and how to correctly respond to them.

Thank you for writing on this subject. If you have any questions, please e-mail Mr. Scott Wainwright of our staff at or call him at 202-366-0857. Please note that we have assigned your request the following official interpretation number and title: "10-66(I)—LRT Signals for Bus Queue Jumper Lane." Please refer to this number in any future correspondence.


/s/ Anthony T. Furst

Anthony T. Furst
Acting Director, Office of Transportation Operations