Designing for Individuals who are visually impaired or blind · 2012-10-31 · Accessible Design...
Transcript of Designing for Individuals who are visually impaired or blind · 2012-10-31 · Accessible Design...
Designing for Individuals
who are visually impaired or blind
Janet M. Barlow
Accessible Design for the Blind
NACTO Designing Cities Conference
October 25, 2012
What do we mean by visually
impaired or blind?
Accessible Design for the Blind, 10/25/2012, Slide 2
Intersection as seen by someone
with “normal” vision
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Central vision loss
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Peripheral Vision Loss
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Overall acuity loss
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Totally blind
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Pedestrians with low vision (many of
our growing elderly population)
May have difficulty with depth
perception
Problems in judging location of vehicles
Problems in judging approach speed of
vehicles
May have reduced contrast sensitivity
Difficulty reading signs and signals
8Accessible Design for the Blind, 10/25/2012, Slide
How do pedestrians who are blind
or visually impaired get around?
Accessible Design for the Blind, 10/25/2012, Slide 9
Yes! people who are blind do travel
independently to new places
Travel to unfamiliar destinations for shopping, errands, visiting friends, children’s activities, work, or other purposes, just like those who are fully sighted
May have to figure out intersections and intersection crossings when they arrive at them
May be unaware of changes and may make dangerous decisions when familiar intersections have been changed
Accessible Design for the Blind, 10/25/2012, Slide 10
Techniques and aids used by individuals
who are blind or visually impaired
Sighted (human) guide
White cane
Dog guide
Telescope or other low
vision aids
No aid
Accessible Design for the Blind, 10/25/2012, Slide 11
Aids and techniques for obstacle
and curb detection
Long white
cane - used
as a probe of
the walking
surface,
identification
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Aids and techniques for obstacle
and curb detection
Dog guide
Guides around obstacles
Stops at curbs or drop-offs
Low vision aid, such as telescope
Used only for specific tasks, ie reading sign
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Orientation and alignment cues
Slight slopes and changes in surface textures
Specific textures that are detectable
Sidewalk and/or grass line or building line
Traffic – both parallel to travel path and perpendicular to travel path
Accessible pedestrian signals
Other pedestrians, sun, other cues
Awareness of intersecting streets and general layout of area
Accessible Design for the Blind, 10/25/2012, Slide 14
Street crossing tasks
Locate edge of the street
Determine where to begin crossing (locate crosswalk)
Establish crossing direction and alignment
Determine traffic control and use pushbutton, if necessary
Decide when to begin crossing
Maintain alignment during crossing
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Traditional street crossing strategies
Walk up to corner
Maintain travel direction
Listen through a signal cycle
Cross with the surge of traffic traveling
parallel to crosswalk
Maintain direction by listening to vehicles
and other cues
Accessible Design for the Blind, 10/25/2012, Slide 16
Designs that make travel safer
Additional care is needed make streets
and sidewalks accessible to individuals
who are visually impaired
Sidewalk design features
Street crossings and access to information
about signals
Accessible Design for the Blind, 10/25/2012, Slide 17
Sidewalks
Accessible Design for the Blind, 10/25/2012, Slide 18
Would this sidewalk design be a problem
for someone who’s visually impaired?
Accessible Design for the Blind, 10/25/2012, Slide 19
How about this sidewalk for someone
who’s blind?
Accessible Design for the Blind, 10/25/2012, Slide 20
Clear straight sidewalk path with
grouping of furniture
Accessible Design for the Blind, 10/25/2012, Slide 21
Avoid obstacles (protruding objects)
that cannot be detected by cane
Accessible Design for the Blind, 10/25/2012, Slide 22
Tree maintenance needs attention
Accessible Design for the Blind, 10/25/2012, Slide 23
Barrier where crossing is closed
Accessible Design for the Blind, 10/25/2012, Slide 24
Street crossings
Accessible Design for the Blind, 10/25/2012, Slide 25
Blended transitions – can’t tell where
the plaza ends and the street begins
Accessible Design for the Blind, 10/25/2012, Slide 26
Add detectable warnings (truncated
domes) to indicate location of street
Accessible Design for the Blind, 10/25/2012, Slide 27
NOT detectable warnings
Accessible Design for the Blind, 10/25/2012, Slide 28
Detectable warning = truncated domes
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Crosswalk offset from corner can be
problematic
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Provide guidance to crosswalk
Accessible Design for the Blind, 10/25/2012, Slide 31
Crosswalk in line with sidewalk
Accessible Design for the Blind, 10/25/2012, Slide 32
Potential treatments – wayfinding
Design of
sidewalk
Tactile
features or
fences
Sound cues
from audible
signals
Accessible Design for the Blind, 10/25/2012, Slide 33
Signal features intended to help
pedestrians may not be usable without
accessible pedestrian signals
LPI
Exclusive pedestrian phases, including at
midblock crossings
Protected left turns
Pedestrian pushbuttons
Accessible Design for the Blind, 10/25/2012, Slide 34
Traffic cues may not be available or
usable where there are:
Low volumes of traffic parallel to
crosswalk
Crossing major street
T intersections (crossing top of T)
Exclusive pedestrian phases
Leading pedestrian intervals
Heavy turning traffic volumes
Masking sounds
Accessible Design for the Blind, 10/25/2012, Slide 35
Pedestrian Pushbuttons
Is there a
pushbutton?
Where is it?
Have I found
the
pushbutton
for the street
I’m crossing?
Accessible Design for the Blind, 10/25/2012, Slide 36
Access may be provided by Accessible
Pedestrian Signals (APS)
Features of new APS
Speakers at the pushbutton
Pushbutton Locator tone
Audible and Vibrotactile Walk indications
Tactile arrow
Automatic volume adjustment
Accessible Design for the Blind, 10/25/2012, Slide 37
Pushbutton-integrated APS
Pushbutton locator
tone during FDW
and DW
Rapid tick WALK
indication
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Pushbutton-integrated
APS
Pushbutton locator
tone during FDW
and DW
Speech WALK
indication
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APS Location is critical
Provide information
to the user through
proximity to the
departure point
Signal can be quieter
due to proximity
Accessible Design for the Blind, 10/25/2012, SlideSlide 40
Installation recommendations
Crosswalk B
Crosswalk A Pushbutton pole may
be a stub pole, or may
also support pedhead
10 ft min.
placement
Beside the landing of the curb ramp
Separated by more than 10 feet from other APS on corner
Nearest the crosswalk line furthest from the center of the intersection
Accessible Design for the Blind, 10/25/2012, Slide 41
Installation example - APS aligned
with crosswalk lines
Accessible Design for the Blind, 10/25/2012, SlideSlide 42
Reachable from level landing, within 10 ft
of curb, within 5 feet of crosswalk lines
Modifications that make programs and
facilities accessible to pedestrians who
are blind or who have low vision are
helpful to ALL pedestrians
Accessible Design for the Blind, 10/25/2012, Slide 43
Questions??
For more information, contact:
Janet M. Barlow
Accessible Design for the Blind
770-317-0611