Common Problems Arising in the Installation of Accessible Pedestrian Signals

Audible WALK indications

Audible WALK indications are broadcast from a speaker that is incorporated into the pedestrian pushbutton housing. When the pedestrian pushbutton is properly located close to the departure curb, a low-volume WALK signal will be adequate for usability. Although most devices can also provide on-demand audible beaconing, the standard audible indication is not intended to be heard across the street. As with pushbutton locator tones, the 2003 MUTCD requires that the volume of the audible WALK indication be carefully adjusted to be heard a minimum of 1.8 m (6 feet) and a maximum of 3.7 m (12 feet) from the pushbutton, or to the building line, whichever is less.

Device technology automatically samples audible output and compares it to ambient sound, adjusting volume accordingly. Note that louder is not better -- an installation that is too loud may mask critical vehicle sounds and be difficult to localize and use for guidance.

Rapid tick WALK indication. Where pushbutton APS are located on separate poles, the recommended audible WALK indication is a fast ticking or beeping percussive sound at 8-10 repetitions per second. Research shows that using the same sound for both crossings results in more accurate and faster responses than two different sounds or speech messages if APS are separated and each is located close to the crossing it signals.³

Speech WALK indication. When two APS are mounted on the same pole, or are located closer than 10 feet to each other, using different tone indications (such as the cuckoo/chirp of older technology) provides ambiguous information that could result in a pedestrian crossing on the wrong signal.^4 5 6 7 When two APS must be located closer than 10 feet apart in an alteration where it is infeasible to separate them, speech WALK indications and other features are needed to distinguish the crossings. If speech messages are used, the recommended WALK message is “[street name], WALK sign is on to cross [street name]. For example, “Peachtree, WALK sign is on to cross Peachtree, Peachtree, WALK sign is on to cross Peachtree”. This message is repeated for the duration of the WALK indication. Speech WALK indications should be accompanied by tactile arrows and Braille labels so that pedestrians who are blind can determine street names.⁸

^3. Ashmead, D.H., Wall, R.S., Bentzen, B.L. and Barlow, J.M. Which Crosswalk? Effects of accessible pedestrian signal characteristics. ITE Journal. 2004. 74-9, pps 26-31.

⁴.Bentzen, B.L., Barlow, J.M., and Franck, L. Addressing barriers to blind pedestrians at signalized intersections. ITE Journal. 2000. 70-9, pps. 32-35. 

^5.Carroll, J. and Bentzen, B.L. American Council of the Blind survey of intersection accessibility. The Braille Forum, 1999. 38(7), pps. 11-15.

^6.Uslan, M.M., Peck, A.F., and Waddell, W. Audible traffic signals: how useful are they? ITE Journal, 1988. 58, pps. 37-43.

^7.Bentzen, B.L., Barlow, J.M., Franck, L. Speech messages for accessible pedestrian signals. ITE Journal. 2004. 74-9, pps 20-24.

^8.MUTCD NPA contains specifications of features required with speech messages in 4E.09.  Federal Register Volume 73, Number 1, pages 312-313, January 2, 2008.