Common Problems Arising in the Installation of Accessible Pedestrian Signals

Location

Pushbutton-integrated APS rely on relative proximity to the crossing location, not on difference in sounds, to clarify which street crossing is being signaled. Proposed MUTCD revisions and draft PROWAG, supported by recent research², specify that each APS device shall be installed on a separate pole. Devices must be located a minimum of 3m (10 feet) apart, no more than 3m (10 feet) maximum from the curb line (and closer, if possible), and between the curb ramp landing and the outside crosswalk line, or no more than 1.5m (5 feet) maximum from the outside crosswalk line. See Figures 3 and 4 for illustrations of pushbutton locations.

Figure 3: Optimal location of pushbutton-integrated APS - two pushbuttons on one corner, mounted on two separated poles – rapid tick WALK indication.
Source: NCHRP Web Only Document 117-A, Accessible Pedestrian Signals: A Guide to Best Practice, Figure 6-8

Figure 4: Installation of APS on two separated poles, aligned with crosswalk lines
(APS devices circled)

Devices that are located on existing mountings may not be able to provide optimal usability, particularly for the vibrotactile feature. APS should be located so pedestrians using the audible or vibrotactile indications can align and prepare for the crossing while standing close to the device AND the crossing departure point, and that pedestrians who use wheelchairs and scooters are able to reach the pedbutton from a flat, paved surface.

For graphics showing APS at corners with 10 foot and 30 foot radii and various types of curb ramps, see the curb ramp library, Chapter 6, in Special Report: Accessible Public Rights-of-Way – Planning and Designing for Alterations and examples in Figure 4E-3 of the draft MUTCD.

^2. Scott, A.C., Myers, L., Barlow, J.M., and Bentzen, B.L. Accessible pedestrian signals: The effect of pushbutton location and audible WALK indications on pedestrian behavior. Transportation Research Record: Journal of the Transportation Research Board. 2005. Number 1939, pp 69-76.