Transcript Dulaney Valley Rd & Fairmount Ave Towson, MD

Audible Beaconing to Help
Pedestrians Who are Blind
Cross Streets
Billie Louise (Beezy) Bentzen
Janet M. Barlow
David Guth
Alan C. Scott
TRANSED 2012
This project was supported by
Grant #5 R01 EY12894-07 from the
National Eye Institute, National
Institutes of Health. Its contents
are solely the responsibility of the
authors and do not necessarily
represent the official views of the
National Eye Institute.
Accessible Design for the Blind, 17/9/12, Slide
2
A Far-side Walk Signal Gives Good
Results at a Simulated Crosswalk
Compared simultaneous signals from
both ends of crosswalk, signals
alternating from one and to the other,
and far-side signal,
16 m long (4-lane) crosswalk simulated in a
parking lot
Accuracy of crossing significantly better with
far-side signal
Accessible Design for the Blind, 17/9/12, Slide
3
Problems with Far-side
Walk Signal Beacons
Too noisy to be tolerated in a
neighborhood
The far-side walk signal for one crosswalk
might be mistaken for the signal for
another crosswalk
The far-side signal wouldn’t work if
people on both ends of a crosswalk
pushed the button to cross during the
same cycle
Accessible Design for the Blind, 17/9/12, Slide
4
A Prototype Developed to
Avoid the Problems
Comes on only in response to a buttonpress of 1 sec or longer—seldom heard
Comes on only for the crosswalk where
the button is pushed
Unlikely to have 2 pedestrians holding
the button down for the same crosswalk
during the same cycle
Accessible Design for the Blind, 17/9/12, Slide
5
Components of APS with
Far-side Beacon
Accessible Design for the Blind, 17/9/12, Slide
6
Users’ Experience
1. Users hear locator tone from pushbutton
2. Users push and hold button for at least 1 sec
3. Users hear alignment tone--7 repetitions of
locator tone audible from far-side speaker
4. Users wait for walk signal—quiet locator tone
continues
5. Users hear walk signal from near-side APS
only, and begin crossing
6. When walk signal ends, users hear far-side
beacon (loud locator tone) during pedestrian
clearance interval, while crossing is completed
Accessible Design for the Blind, 17/9/12, Slide
7
Tested in Charlotte, North Carolina
16 participants made
total of 48 crossings
with and without farside beaconing
Beaconing resulted in
improvement in
crossing within the
crosswalk
More Intersection Testing—
Alpharetta, GA, Towson, MD, Austin, TX
Compared crossings using far-side
beacon APS, standard APS, and tactile
guidestrip
Far-side beacon and tactile guidestrip
resulted in good accuracy
Participants enthusiastic
about far-side beacon
Accessible Design for the Blind, 17/9/12, Slide
9
But is Far-side Beaconing Safe?
What if the intersection is not very wide?
What if there are reflective buildings on
the corners?
What if two people at the intersection
request a far-side beacon during the
same cycle?
Accessible Design for the Blind, 1/10/2010, Slide 10
Trying to Cause Trouble in Portland, OR
Characteristics of the intersection
Crossings were 2-5 lanes wide
Buildings on all corners
3 crossings without good parallel traffic cues
3 crossings not well aligned with direction of
approach
5 crossings
Accessible Design for the Blind, 17/9/12, Slide 11
43rdAve & Sandy Blvd
Hancock Street
43 Ave
Accessible Design for the Blind, 17/9/12, Slide 12
4 Crosswalks Used for Experiment
Hancock Street
43 Ave
Accessible Design for the Blind, 17/9/12, Slide 13
Method
22 participants who had little or no vision
made 2 round-trip crossings of each
experimental crossing
Each crossing had one of 3 beaconing
conditions
Standard APS—no beaconing
APS with far-side beaconing
APS with far-side beaconing, with experimenter
calling walk signal for another crosswalk—
“confusion trials”
Accessible Design for the Blind, 17/9/12, Slide 14
Results for Portland Experiment
Accessible Design for the Blind, 17/9/12, Slide 15
Standard APS--participants tended to veer out of the
crosswalk, and did not successfully correct their
heading; some diagonal crossings
Accessible Design for the Blind, 1/10/2010, Slide 16
APS with far-side beaconing—
participants often observed to correct their heading;
no diagonal crossings
Accessible Design for the Blind, 17/9/12, Slide 17
APS with far-side beaconing and
“confusion”
No confusion noted
Accessible Design for the Blind, 17/9/12, Slide 18
Conclusions
APS with far-side beaconing
Enable blind pedestrians to maintaining or
correct their heading so they usually cross
within the crosswalk
Accessible Design for the Blind, 17/9/12, Slide 19
Conclusions
APS with far-side beaconing
Enable blind pedestrians to maintaining or
correct their heading so they usually cross
within the crosswalk
Do not result in confusion about which
crosswalk has the walk signal even when
another person actuates beaconing for another
crosswalk
Accessible Design for the Blind, 17/9/12, Slide 20
Conclusions
APS with far-side beaconing
Enable blind pedestrians to maintaining or
correct their heading so they usually cross
within the crosswalk
Do not result in confusion about which
crosswalk has the walk signal even when
another person actuates beaconing for another
crosswalk
Can safely be used at medium-sized
intersections even where there are reflective
buildings on the corners
Accessible Design for the Blind, 17/9/12, Slide 21
Recommendations
APS with far-side beaconing may be used
to provide wayfinding information
At crossings where there is insufficient or
inconsistent directional information from
traffic, or very wide crossings
At intersections where there are reflective
buildings near the corners
Accessible Design for the Blind, 17/9/12, Slide 22
Cautions
APS with far-side beaconing
Should be actuated by an extended buttonpress
Accessible Design for the Blind, 17/9/12, Slide 23
Cautions
APS with far-side beaconing
Should be actuated by an extended buttonpress
Do not need to be programmed for all
crossings at an intersection; e.g. short
crossings or crossings with reliable parallel
traffic
Accessible Design for the Blind, 17/9/12, Slide 24
Cautions
APS with far-side beaconing
Should be actuated by an extended buttonpress
Do not need to be programmed for all
crossings at an intersection; e.g. short
crossings or crossings with reliable parallel
traffic
Should have especially careful attention to
sound-level adjustment—no louder than
necessary
Accessible Design for the Blind, 17/9/12, Slide 25
For additional information:
Contact Beezy Bentzen
[email protected]
Accessible Design for the Blind, 17/9/12, Slide 26