Transcript Accessible Pedestrian Signal Features: New possibilities

Accessible Pedestrian Signal
Features
New possibilities for access in
the US
Janet M. Barlow
Accessible Design for the Blind
Asheville, North Carolina
4/4/2008
Accessible Design for the Blind
Slide 2
Old types of audible signals =
loudspeakers mounted on
pedestrian signal heads
4/4/2008
Accessible Design for the Blind
Slide 3
Pedhead-mounted APS problems
Too loud – mask vehicular sounds that
blind pedestrians want to hear
 Too loud – bother neighbors
 Confusing – users have to know what
direction they’re facing to figure out
which street the signal is indicating
 Confusing – users not sure if sound is
APS or bird (for cuckoo/chirp signals)

4/4/2008
Accessible Design for the Blind
Slide 4
Pushbutton-integrated
Accessible Pedestrian Signals (APS)
NOT
cuckoos and
chirps from
pedheads!
4/4/2008
Accessible Design for the Blind
Slide 5
Pushbutton-integrated APS

Continuous
pushbutton
locator tone
with rapid
tick WALK
indication
Sounds attached; click on
photo to hear sounds
4/4/2008
Accessible Design for the Blind
Slide 6
Pushbuttonintegrated APS

Continuous
pushbutton
locator tone
followed with
speech walk
indication
Sounds attached; click on
photo to hear sounds
4/4/2008
Accessible Design for the Blind
Slide 7
Features

Following slides explain each feature
 Speaker at the pushbutton
 Pushbutton locator tone
 Tactile arrow
 Audible and vibrotactile walk indications
 Locator tone and walk indication volume
adjusts in response to ambient noise
levels
 Audible beaconing on “request” (by
holding pushbutton for over 1 second)
4/4/2008
Accessible Design for the Blind
Slide 8
Speakers at the pushbutton
4/4/2008
Accessible Design for the Blind
Slide 9
Pushbutton Locator Tone





Sound comes from the pushbutton
Provides information about pushbutton
presence and location
1 tone per second, each tone less than
0.15 seconds in duration
Volume set to be heard within 6 – 12 feet,
or at the building line, whichever is less
Different sounds acceptable (click, beep,
etc)
4/4/2008
Accessible Design for the Blind
Slide 10
Tactile arrow
Raised arrow aligned with
direction of travel on the
crosswalk controlled by
the pushbutton
 Arrow may be on the
pushbutton or on part of
the device or sign above
the pushbutton

4/4/2008
Accessible Design for the Blind
Slide 11
Tactile Arrow – examples
4/4/2008
Accessible Design for the Blind
Slide 12
Recommended WALK indications

A rapid tick WALK indication (sound
on slide 6) at locations where the
speakers for APS for two different
crosswalks are separated by at least
10 feet

Vibrotactile WALK indication - arrow
(or other surface on pushbutton unit)
that vibrates during WALK
4/4/2008
Accessible Design for the Blind
Slide 13
Volume adjustment
Relatively quiet unless audible
beaconing is called
 Volume only 2-5dB over ambient
noise level
 Audible within 6 - 12 feet of the
pushbutton, or the building line,
whichever is closer

4/4/2008
Accessible Design for the Blind
Slide 14
Automatic volume adjustment

Volume of pushbutton locator tone and
audible walk indications adjusts in
response to ambient sound
 Louder when traffic is loud or there is
other noise at the intersection
 Quiet when traffic or other sounds are
quieter (night)
4/4/2008
Accessible Design for the Blind
Slide 15
APS Location is critical
Provide information to the user through
proximity to the departure point
 Impose less of a cognitive load on
pedestrians who are visually impaired
 ‘I have pushed the button on my right’
 ‘The WALK indication is coming from
my right’
 ‘That sound is for my crosswalk’
 Signal can be quieter due to proximity

4/4/2008
Accessible Design for the Blind
Slide 16
Ideal
placement
Installation
recommendations
Crosswalk B
Crosswalk A
4/4/2008
10
.
in
m
ft
Beside the landing
of the curb ramp
 Separated by more
than 10 feet from
other APS on corner
 MUTCD says within
5 feet
of crosswalk
Pushbutton
pole may
be a stub
pole,and
or maywithin 10
line
also support pedhead
feet of the curb

Symbol Key
Accessible
Design
the Blind speaker
Sound
fromfor
pushbutton
Slide 17
Installation Example




Near
departure
point
Poles
separated by
more than 10
feet
Low sound
intensities
Vibrotactile
available
4/4/2008
Accessible Design for the Blind
Slide 18
Pushbutton within five feet of
crosswalk line extended
< 5 feet
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Accessible Design for the Blind
Slide 19
Pushbutton within 10 feet of
the curb
< 10 feet
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Accessible Design for the Blind
Slide 20
Installation example - APS
separated by 10 feet (3m)
Reachable from level landing, within 10 ft
of curb, within 5 feet of crosswalk lines
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Accessible Design for the Blind
Slide 21
Installation example - APS
aligned with crosswalk lines
4/4/2008
Accessible Design for the Blind
Slide 22
IF it’s impossible to install two poles
10 feet apart (in alterations, not new
construction)
Two APS may be placed on same pole,
or closer than 10 feet, BUT additional
features are required
 Use speech message WALK indication,
and, to clarify message,
 Pushbutton information message
 Tactile arrow

4/4/2008
Accessible Design for the Blind
Slide 23
Pushbutton information message
Pushbutton
message to provide
intersection
information
 Plays when
pushbutton is
pressed for 1
second or more

Click on photo to hear message
4/4/2008
Accessible Design for the Blind
Slide 24
Pushbutton information message
and speech walk message example
4/4/2008
Accessible Design for the Blind
Slide 25
Audible beaconing

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Sound from the opposite side of the street
is used to provide directional guidance
during street crossing
Provided after pedestrian holds the
pushbutton in for over one second to call
the audible beaconing
Walk tone and the subsequent locator tone
increased in volume during the next signal
cycle
4/4/2008
Accessible Design for the Blind
Slide 26
Additional possible feature:
Crosswalk Map
Tactile map of
crosswalk

4/4/2008
Symbols (from
bottom of picture) for:
 down curb,
 bike lane
 2 lanes of cars
from left
 Island
 rail line
 2 lanes of cars
from right
 up curb
Accessible Design for the Blind
Slide 27
Thanks to:

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Lukas Franck of The Seeing Eye, and
Billie Louise Bentzen of Accessible Design
for the Blind for photos and assistance in
development
John McGaffey from Polara Engineering,
Roger Peterson from Prismatek, Doug
Gubbe from Novax, for photos and sounds
Doug Barlow for technical help
Lois Thibault, US Access Board, for
feedback and suggestions
4/4/2008
Accessible Design for the Blind
Slide 28
For more information,
contact:
Janet M. Barlow
Accessible Design for the Blind
3 Manila Street
Asheville, NC 28806
770-317-0611
[email protected]