Accessible Pedestrian Signals
Authors: Lloyd Rue and Janet Barlow
Description
Accessible pedestrian signals (APS) provide audible and/or vibrotactile information
coincident with visual pedestrian indications. Loud audible tones during the walk interval
from across the street (such as the commonly used cuckoo-cheep speakers mounted
on the pedestrian signal head) are not necessary, or useful, in most situations. New
types of APS, now required for U.S. installations, provide the audible WALK indication
from a speaker located at the pushbutton, at a volume audible
only six to twelve feet from the pushbutton. Installing the APS
devices in separated locations on each corner, near each
crosswalk line furthest from the center of the intersection,
assists in determining which signal is sounding. The audible
indication is either a rapid ticking sound or a speech message;
a tactile arrow also vibrates during the WALK indication. The
audible and vibrotactile signals let pedestrians know,
particularly those with vision impairments or vision and hearing
impairments, when the walk interval begins. An additional quiet
tone, a pushbutton locator tone, repeats continuously once per
second during flashing and steady DON’T WALK to assist
Courtesy of Janet Barlow pedestrians who are blind in knowing that there is a pushbutton
and in locating the push button. The APS device also includes
a tactile arrow aligned with the direction of travel on the crosswalk to provide directional
information. APS can also provide a customized speech message identifying the street
or crossing or additional information about signalization or geometry of the intersection.
Benefits
APS can provide information to pedestrians about the presence and location of a
pushbutton. The audible information provides unambiguous information about the
WALK indication and which crossing is being signaled, if installed properly, to those who
are unable to see the WALK.
Considerations
Volume of APS should be carefully adjusted and controlled. APS that automatically
adjust in response to ambient sound levels are now required by the MUTCD when APS
are installed. If not adjusted properly, sounds produced by APS may disturb neighbors
and prevent pedestrians who are visually impaired from hearing the traffic sounds,
which they need to hear in addition to the APS.
See Accessible Pedestrian Signals: A Guide to Best Practices1 at www.apsguide.org
provides extensive information on uses of APS by pedestrians who are blind or visually
impaired, a tool for prioritizing installation locations, and information on various features
of APS including audible beaconing,. Audible beaconing refers to providing a louder
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signal from the opposite side of the street to provide directional information. Audible
beaconing should be used only where necessary; Additional research on audible
beaconing is ongoing.2, 3 . Careful installation is also very important to proper
functioning of the devices. In addition to the APS guide, Common Problems arising in
the installation of Accessible Pedestrian Signals4 provides installation information and
guidance.
The 2009 Manual on Uniform Traffic Control Devices (MUTCD)5 includes standards and
guidance for APS and APS detector (pushbutton) placement in sections 4E.09 through
4E.13 Section 4E.08 provides new standards and guidance on the placement of all
pedestrian detectors, and figures 4E-3 and 4E-4 show typical pushbutton locations.
On July 26, 2011, the U.S. Access Board released for public comment proposed
guidelines for accessible public rights-of-way, Proposed Accessibility Guidelines for
Pedestrian Facilities in the Public Right-of-Way.6 As indicated in the preamble to the
notice of proposed rule, the guidelines provide design criteria for public streets and
sidewalks, including pedestrian access routes, street crossings, curb ramps and
blended transitions, on-street parking, street furniture, and other elements. The
specifications comprehensively address access that accommodates all types of
disabilities, including mobility and vision impairments, while taking into account
conditions and constraints that may impact compliance, such as space limitations and
terrain.
The guidelines, once finalized and implemented as standards, will apply to newly
constructed or altered portions of public rights-of-way covered by the Americans with
Disabilities Act (ADA). They will also apply to public rights-of-way built or altered with
funding from the Federal government under the Architectural Barriers Act (ABA) and the
Rehabilitation Act. Existing pedestrian networks not undergoing alteration will not be
required to meet these requirements. The rights-of-way guidelines complement, and in
some areas, reference the Board's ADA and ABA Accessibility Guidelines for buildings
and facilities.
These guidelines and additional information can be found at www.access-board.gov
under Public Rights-of-Way. Portions of the applicable standard are shown below:6
R209 Accessible Pedestrian Signals and Pedestrian Pushbuttons
R209.1 General. Where pedestrian signals are provided at pedestrian street
crossings, they shall include accessible pedestrian signals and pedestrian
pushbuttons complying with sections 4E.08 through 4E.13 of the MUTCD
(incorporated by reference, see R104.2). Operable parts shall comply with R403.
Advisory R209 Accessible Pedestrian Signals and Pedestrian Pushbuttons.
An accessible pedestrian signal and pedestrian pushbutton is an integrated
device that communicates information about the WALK and DON’T WALK
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intervals at signalized intersections in non-visual formats (i.e., audible tones and
vibrotactile surfaces) to pedestrians who are blind or have low vision.
R209.2 Alterations. Existing pedestrian signals shall comply with R209.1 when
the signal controller and software are altered, or the signal head is replaced.
Required language for speech WALK messages and pushbutton information messages
is provided in the MUTCD. Some of the research that led to those requirements can be
found in an Institute of Transportation Engineers (ITE) Journal article. 7
Early Adopters/Case Studies
From APS: A guide to best practice1, with updated information for this report.
1. Portland, Oregon
a. Portland began installing APS in late 1970s.8
b. As of December 2011, APS have been installed at 148 intersections; that
amounts to more than 35% of the total intersection locations with
pedestrian detection. 75 of those are equipped with the new APS with
push button locater tones.
2. Maryland Department of Transportation9
a. Maryland is installing pushbutton-integrated APS at all intersections with
pedestrian signals by 2015. APS are installed during construction or
reconstruction of intersections. A prioritization checklist is used to rate
intersections where APS are requested (when no construction is planned
at that location).
b. 394 APS projects were completed by January 2009; design was underway
for approximately 450 more intersections.
3. Charlotte, North Carolina
a. Installations began in the year 1999
b. APS have been installed at 59 intersections, as of December 2011, with
15 more planned in the succeeding six-month period.
4. San Francisco, California
a. As a result of a negotiated agreement with the California Council of the
Blind, in June 2007, San Francisco committed to install accessible
pedestrian signals at no fewer than 80 intersections over the next two and
a half years. As of December 2011, 125 intersection installations have
been completed.
Cost to implement
$1000 to $10,000 estimated per crosswalk (2009 estimates), as a feature added to an
existing intersection not equipped with APS. The variability in the estimated cost to
implement is due to the variations in the amount of electrical or construction work
needed to place devices and pushbutton poles in appropriate locations. However, if the
2009 MUTCD guidance for location of all pushbutton poles is followed, pushbuttons will
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be in the proper location for APS installation, so the costs should be lower. APS
devices average $600. per device.
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Illustrations
Audible and vibrotactile pushbuttons,
ref. 1
Optimal location of pushbutton-integrated APS, ref. 1
Photos courtesy of Janet Barlow, Accessible Design for the Blind, Asheville, NC
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References
1. Harkey, D.L., Carter, D.L., Barlow, J.M. & Bentzen, B.L. Accessible pedestrian
signals: A guide to best practice. National Cooperative Highway Research
Program Web-Only Document 150, Washington, DC: National Cooperative
Highway Research Program. (2007) www.apsguide.org
2. Harkey, D.L., Carter, D.L., Barlow, J.M., Bentzen, B.L., Myers, L. & Scott, A.
Guidelines for accessible pedestrian signals final report. Contractor’s Final
Report for NCHRP Project 3-62, National Cooperative Highway Research
Program Web-Only Document 117B, Washington, DC: National Cooperative
Highway Research Program. (2007)
3. Barlow, J.M., Scott, A.C., Bentzen, B.L. Audible Beaconing with Accessible
Pedestrian Signals. AER Journal: Research and Practice in Visual Impairment
and Blindness, Vol. 2, Number 4, (2009): 149 – 158. [NIHMS167632]
4. Barlow, J.M. Common problems arising in the installation of accessible
pedestrian signals. U.S. Access Board, Washington, D.C., (2009) http://accessboard.gov/research/pedestrian-signals/bulletin.htm
5. U.S. Department of Transportation, Federal Highway Administration. Manual on
Uniform Traffic Control Devices, 2009 Edition. ATSSA/ITE/AASHTO (2010).
http://mutcd.fhwa.dot.gov/.
6. U.S. Access Board. Proposed Accessibility Guidelines for Pedestrian Facilities in
the Public Right-of-Way. Washington, D.C.: Architectural and Transportation
Barriers Compliance Board. (2011). http://www.accessboard.gov/prowac/nprm.pdf
7. Bentzen, B.L., Barlow, J.M. and Franck, L. Speech Messages for Accessible
Pedestrian Signals. ITE Journal, 74-9, (2004): 20-24.
8. Kloos, B. Briefing Paper on Intersection Traffic Control Wayfinding Cues at
Intersections Workshop; accessed December 2011
http://www.ite.org/accessible/curbramp/Kloos_%20Briefing.pdf
9. Maryland State Highway Administration. Americans with Disabilities Act (ADA)
Quarterly Report to FHWA (January 2009); accessed December 2011
http://www.sha.maryland.gov/opr/FHWA_Report_Jan_09_FINAL.pdf.
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Related Publications:
Ashmead, D.H., Wall, R.S., Bentzen, B.L., & Barlow, J. M. Which crosswalk? Effects of
accessible pedestrian signal characteristics. ITE Journal, 74-9, (2004): 26-31:
Barlow, J.M., & Franck, L. Crossroads: Modern interactive intersections and accessible
pedestrian signals. Journal of Visual Impairment and Blindness. Vol 99, (10), (2005):
599-610.
Barlow, J.M., Bentzen, B.L. & Bond, T. Blind pedestrians and the changing technology and
geometry of signalized intersections: Safety, orientation and independence. Journal of
Visual Impairment and Blindness. Vol. 99:10, (2005): 587-598.
Barlow, J. M. Common Problems Arising in the Installation of Accessible Pedestrian Signals.
Washington, DC: U.S. Access Board, (2009).
Bentzen, B.L., Barlow, J.M. & Bond, T. Challenges of Unfamiliar Signalized
Intersections for Pedestrians who are Blind: Research on Safety. Transportation
Research Record: Journal of the Transportation Research Board, 1878, (2004):
51 -57.
Bentzen, B.L., Scott, A.C., & Barlow, J.M. Accessible pedestrian signals: Effect of device
features. Transportation Research Record: Journal of the Transportation Research
Board, No. 1982. (2006): 30-37.
Carter, D.L., Harkey, D.L., Bentzen, B.L., & Barlow, J.M. Development of an intersection
prioritization tool for accessible pedestrian signal installation. Transportation Research
Record: Journal of the Transportation Research Board, No. 1982, (2006): 13-20.
Marston, J.R. and Golledge, R.G. Towards an accessible city: Removing functional
barriers for the blind and vision impaired: A Case for Auditory Signs. Final
Report. University of California Berkeley: University of California Transportation
Center. (2000)
Noyce, D.A. and Barlow, J.M. Interfacing Accessible Pedestrian Signals with Traffic
Signal Control Equipment. Washington, D.C.: U.S. Access Board. (2003)
Accessed at www.access-board.gov
Noyce, D.A., Gates, T.J. & Barlow, J.M. Pedestrian and bicyclist safety at intersections, In
Toolbox on intersection safety and design. Washington, DC: Institute of Transportation
Engineers, (2004).
Scott, A.C., Barlow, J. M., Bentzen, B.L., Bond, T.L.Y. & Gubbe, D. Accessible pedestrian
signals at complex intersections: Effects on blind pedestrians. Transportation Research
Record: Journal of the Transportation Research Board, No. 2073, (2008): 94–103.
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, No. 1939, (2006): 69-76.
Wall, R.S., Ashmead, D.H., Bentzen, B.L., & Barlow, J. Directional guidance from
audible pedestrian signals for street crossing. Ergonomics. (2004): Vol. 47, (12),
1318 – 1338.
Williams, M., Van Houten, R., Blasch, B., Ferraro, J. Field comparison of two types of
accessible pedestrian signals. Transportation Research Record: Journal of the
Transportation Research Board, No. 1939, (2005): 91-98.
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