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

13Accessible Design for the Blind, 10/25/2012, Slide

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

jmbarlow@accessforblind.org