HAWK beacon

HAWK Signal
Animation demonstrating the operation of a HAWK beacon (Click to animate)

A HAWK beacon (High-Intensity Activated crossWalK beacon) is a traffic control device used to stop road traffic and allow pedestrians to cross safely. It is officially known as a Pedestrian Hybrid Beacon (PHB). The purpose of a HAWK beacon is to allow protected pedestrian crossings, stopping road traffic only as needed. Where standard traffic signal 'warrants' prevent the installation of standard three-color traffic signals, the HAWK beacon provides an alternative.

A HAWK beacon is used only for marked crosswalks. Similar hybrid beacons are allowed at driveways of emergency service buildings such as fire houses.[1]

History

The first beacon was developed in Tucson, Arizona by Transportation Administrator R. B. Nassi, P.E., Ph.D., and installed in 2000. The bird name HAWK was suggested by his wife. Until December 2009, the HAWK beacon was categorized as an experimental device. United States transportation agencies wishing to use a HAWK signal were required to obtain approval from the Federal Highway Administration, as well as collect and submit data on the effectiveness of the device. It was finally included in the 2009 edition of the US Manual on Uniform Traffic Control Devices as a "Pedestrian Hybrid Beacon."[2]

Design and operation

A HAWK beacon on the campus of Texas A&M University–Commerce

The vehicular signal faces have three sections, consisting of two horizontally-arranged circular red sections over a single circular yellow section. There must be at least two HAWK signal faces facing each vehicular approach to the crossing. Normal pedestrian signal faces control pedestrian traffic.

The Manual on Uniform Traffic Control Devices has guidelines that should be met before a HAWK beacon is installed. The guidelines consider pedestrian and vehicle traffic volumes, vehicle speeds, and roadway width.

Unlike an ordinary traffic signal, the vehicular faces of a HAWK beacon are dark until activated by a pedestrian who wishes to cross. The pedestrian faces operate normally, displaying an upraised hand (don't walk) signal during the time that vehicles have the right of way.[3] When a pedestrian activates the beacon (generally by a push-button), the HAWK beacon sequence is started, first with flashing yellow, then steady yellow, and finally steady red over a period of several seconds. Pedestrian signal heads at either end of the crosswalk display the upraised hand (don't walk) signal until the HAWK beacon displays the steady red signal, at which time, the pedestrian heads display the walking-person (walk) indication.

As at conventional signalized crossings, the pedestrian signals display flashing "don't walk" indications when typical pedestrians no longer have enough time to cross before the HAWK beacon releases cross traffic.[2] At the same time as the flashing "don't walk" indication, the HAWK beacon displays an alternating flashing red indication to vehicular traffic (the equivalent of a stop sign). During this interval, vehicles on the roadway must stop, and may proceed after yielding to pedestrians in the crosswalk. When vehicle traffic is about to restart, the pedestrian signal goes to steady "don't walk". Then, the HAWK beacon goes dark and the pedestrian signal remains in "don't walk" mode until the signal is activated by another pedestrian.

Effectiveness

One study released by the Federal Highway Administration found that, after a HAWK signal was installed, vehicle/pedestrian crashes were reduced by 69%.[4] As many as 97% of motorists comply with the HAWK beacon, higher than signalized crossing, or crossings with flashing yellow beacons.[5]

Some motorist confusion has been reported at newly installed HAWK beacons. When first introduced to an area, enforcement and public education are needed until users understand how the beacon works. When the beacon has not been activated, some drivers have acted as if the signal is dark due to a power outage, but that has not been experienced by all jurisdictions with HAWKs in operation. The flashing red phase is sometimes misunderstood by drivers farther back in the queue, and they followed the lead driver through the crosswalk instead of stopping at the stop line as required.[4] Additionally, motorists sometimes remain stopped during the flashing red phase when the crosswalk is clear due to the similarity to a railroad crossing signal.[6]

Conflicting meanings of HAWK signal indications

The meanings of several of the signal indications employed by HAWK beacons differ materially from the meanings of the same signal indications when used in other contexts:

  • It is illegal to proceed past an alternating flashing red (wig-wag) signal at railroad crossings, per the motor vehicle codes of some jurisdictions. However, this same signal indication has a different meaning (stop and proceed when clear) at HAWK beacons.
  • Some motor vehicle codes require that motorists stop at dark signal indications, which are typically indicative of an abnormality in the normal operation of the signal, such as a power failure. However, the dark signal indication is a normal display at HAWK beacons, where it designates the right-of-way for vehicular traffic.
  • Traffic may fail to appreciate the conversion of a flashing amber to a steady amber signal, and thence fail to apprehend that the signal is about to change from steady amber to red. Flashing amber signals in other contexts are simply caution markers, and do not convert to steady amber and thence to red in this way.

See also

References

  1. ↑ Manual on Uniform Traffic Control Devices. Federal Highway Administration. 2009.
  2. 1 2 Manual on Uniform Traffic Control Devices, Chapter 4F, Federal Highway Administration, 2009, http://mutcd.fhwa.dot.gov/pdfs/2009/part4.pdf
  3. ↑ Mike Chalmers, "New traffic signals make it safer for pedestrians". USA Today, August 9, 2010 Retrieved 2011-06-21.
  4. 1 2 Fitzpatrick, K.; Park, E.S. (July 2010). Safety Effectiveness of the HAWK Pedestrian Crossing Treatment (PDF). Federal Highway Administration.
  5. ↑ http://transport.ksu.edu/files/transport/imported/Thesis/RanjitPrasadGodavarthy2010.pdf figure 21
  6. ↑ Joel Funk (October 16, 2015). "WYDOT: Signals have caused some confusion". Laramie Boomerang.
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