Accessible Pedestrian Signals (APS)
What is an APS?
Accessible Pedestrian Signal and pedestrian pushbutton â€” an integrated device that communicates information about the WALK and DON'T WALK intervals at signalized intersections in non-visual formats (i.e., audible tones and vibrotactile surfaces) to pedestrians who are blind or have low vision. (Proposed Accessibility Guidelines for Pedestrian Facilities in the Public Right-of-Way, Advisory R209)
Note that the Manual on Uniform Traffic Control Devices (MUTCD) in paragraph 2 of Section 4E.11 requires that APS provide both audible and vibrotactile walk indications. The Proposed Accessibility Guidelines for Pedestrian Facilities in the Public Right-of-Way (proposed PROWAG),published in 2011,incorporate the MUTCD 2009 specifications regarding APS by reference.
Note that the Draft PROWAG definition states that an APS provides information in both audible and vibrotactile formats, while the MUTCD says audible "and/or" vibrating surfaces.
APS are known by different names in different countries:
- Acoustic signals
- Audio-tactile signals
- Audible pedestrian signals
- Audible traffic signals
- Audible pedestrian traffic signals
- Audible crossing indicators
Major functions of APS
APS can provide information to pedestrians about:
- Existence of and location of the pushbutton
- Beginning of the WALK interval
- Direction of the crosswalk and location of the destination curb
- Intersection street names in Braille, raised print, or through speech messages
- Intersection signalization with a speech message
- Intersection geometry through tactile maps and diagrams, or through speech messages
Benefits of APS
Research has found that APS improved crossing performance by blind pedestrians
- More accurate judgments of the onset of the WALK interval
- Reduction in crossings begun during DONT WALK
- Reduced delay
- Significantly more crossings completed before the signal changed
Sighted pedestrians also begin crossing faster.
See Appendix C for details of research.
Use in the U.S.
Although audible crossing indicators have been available for over 25 years, they have not been commonly installed in the United States. This is probably attributable to two factors:
- Disagreement among blind people on the need for, and effectiveness, of audible pedestrian signals
- Noise pollution and consequent community opposition
In the past ten years, changes in intersection design and signalization (see Chapter 3) have affected the traditional street crossing techniques used by blind pedestrians, making the pedestrian phase harder to recognize without seeing the visual pedestrian signal. In addition, it has become essential to cross during the pedestrian phase at many intersections. These changes have lead to more requests for APS and advocacy for their installation in recent years.
In addition, developments in technology have occurred. New types of APS have become available in the United States that provide more information and have addressed some of the previous noise concerns.
Use in other countries
In Japan, Australia, and some European countries, APS have been routinely installed at many intersections for at least 20 years.
Information about policies in these countries is included in Chapter 10, International Practice.
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