Transcript Accessible Pedestrian Signal (APS) What is an APS

Accessible Pedestrian Signal
(APS)
Formerly Audible Pedestrian Signals
What is an APS?
• Accessible Pedestrian Signal - a device
that communicates information about
pedestrian timing in nonvisual format such as
audible tones, verbal messages, and/or
vibrating surfaces. (US-MUTCD 2000,
Section 4A.01)
[I acknowledge www.walkinginfo.org for some data
provided:
www.mwcs.mb.ca~morganj/apssounds.html for
new sounds]
Other terms
• APS are known by different names in
different countries:
Acoustic signals
Audio-tactile signals
Audible pedestrian signals
Audible pedestrian traffic signals
Audible traffic signals
Audible crossing indicators
Major functions of APS
• APS can provide information to
pedestrians about:
– Existence of and location of the pushbutton
– Existence of the Walk [and DW] intervals
– Direction of the crosswalk and location of the destination
curb
– Intersection geometry through maps, diagrams, or speech
– Intersection street names in Braille, raised print, or speech
– Intersection signalization
Visual impairment
• Normal Vision - Vision correctable to 20/20
with at least 180-degree field is considered
'normal vision’
Visual impairment
• A functional limitation in seeing, including
those with:
– "non-severe limitation" ("difficulty seeing words and
letters") and those with "severe limitation" ("unable to
see words and letters")
– Legal blindness: a level of visual impairment that has
been defined by law to determine eligibility for benefits
Visual impairment
• A person who is legally blind sees at
approximately 20 feet what a person with
20/20 vision sees at 200 feet
• Or is able to see no more than a 20-degree
field without scanning
Reduced acuity
Central field loss
Peripheral field loss
Decrease in attentional field
• Research by Brabyn, Haegerstr�m-Portnoy,
Schneck, and Lott (2000) demonstrated that over
age 60-65 the prevalence of problems detecting
objects in the peripheral visual field increases
dramatically. This is known as a decrease in
attentional field, and it may be present with or
without other types of visual impairment
Decrease in attentional field
• By age 90, 40% of people have an attentional field
of less than 10 degrees left and right. Thus, if they
are looking at a ped head, they are unlikely to be
visually aware of vehicles that may be disobeying
the signal, or turning across their path of travel,
until it is too late to take appropriate action
Total blindness or light perception
• Individuals who are considered totally blind
usually cannot see any difference in light and dark
• Individuals who have light perception may be able
to tell if it is dark or light and the direction of a
bright light source, but do not have vision that is
useable for discerning objects or the travel path
Prevalence of blindness
• Some degree of vision impairment affects 8.3 million
(3.1%) Americans of all ages (Adams, Hendershot, &
Marano, 1999)
• Approximately 3% of individuals age 6 and older,
representing 7.9 million people, have difficulty seeing
words and letters in ordinary newspaper print even when
wearing glasses or contact lenses. This number increases
to 12% among persons age 65 and older (3.9 million)
(McNeil, 2001). Approximately 1.3 million Americans are
legally blind
Prevalence of blindness
• By 2010, projections are that there will be 20
million visually impaired persons over 45
Area of residence
• Most persons who have a vision impairment live in
metropolitan areas (70%)
• 33% live in cities, 37% live in suburbs, 28% live in nonmetropolitan areas (e.g., small towns) and 1% live in farm
areas (Schmeidler & Halfmann, 1998b)
• In comparison to the general population, persons who are
visually impaired are over-represented in cities and nonmetropolitan areas and somewhat under-represented in the
suburbs (i.e., 48% of general population live in suburbs)
(Schmeidler & Halfmann, 1998b)
What can be done?
?
Intersection design
• Wider streets require more precise alignment
• Wide radius turns make alignment more difficult
and increase crosswalk length
• Curb ramps and depressed corners make street
detection and alignment difficult
• Medians and islands complicate wayfinding and
alignment
Intersection design
• Slip lanes and splitter islands require crossing in
gaps in traffic even at signalized intersections
• Crosswalk alignment is not consistent
• Curb extensions, also called bulb-outs or
intersection chokers, sometimes complicate
wayfinding
Intersection design
• Raised crosswalks may obliterate the
sidewalk/street boundary
• Tabled intersections may also obliterate the
sidewalk/street boundary
• Intersection signalization has become more
complex
Driver behavior& auto technology
• Aggressive drivers are moving faster and less
likely to stop for pedestrians
• The technology of cars, including electric cars,
has become quieter, making them harder for
pedestrians who are visually impaired to hear
• In many areas there is less pedestrian traffic and
less awareness of pedestrians by drivers
Control Issues
• The techniques which worked at pretimed lights
controlled by mechanical controllers are not
adequate for intersections which change minute by
minute in response to vehicular and pedestrian
actuation. These changes affect the ability of
pedestrians who are blind or visually impaired to
recognize the pedestrian phase
Proposed CNIB Standard
• Draft Accessible Pedestrian Signal recommendations {to
TAC last fall} reflect the latest research and technology
and the expertise of the members of a national Committee,
which was formed by the Canadian National Institute for
the Blind to advise on this matter
• The Committee has representatives from across Canada
and includes people who are blind, visually impaired and
deafblind, orientation and mobility specialists, traffic
engineers and consumer advocates
Proposed CNIB Standard
• The proposed standard has two levels of operation. Level 1
is a low-level tone for location, audible within 3m.
Generally meant for fixed time operation - no ped calls.
• Level 2, if you hold the ped button in for 3 or more
seconds, you will get the high level tones for Walk and Ped
Clearance.
Report Contents
•
Introduction
1. Framework
- The creation of the Committee
- Principles
- Mandate
- Approach to the task
2. Navigating intersections: the skills used by
pedestrians who are blind, visually impaired or
deafblind
3. An implementation strategy
•
II – Definitions of Words and Terms
III -- Features of an Accessible Pedestrian Signal
•
1. Required features of an APS
1.1 Operating period
1.2 Locator tones
1.3 WALK indication
1.4 Clearance indication tone
1.5 Activation
1.6 Volume
•
2. Pushbutton
2.1 Size
2.2 Surface
2.3 Operating force
2.4 Visual contrast
2.5 Location
2.6 Locator tone
2.7 Activation indicator
2.8 Voltage
•
3. Pushbutton Pole location
3.1 Visual contrast
3.2 Mounting height
3.3 Location
- Adjacent to landing
- Proximity to approach
- Close to sidewalk
- Proximity to curb or transition ramp
- Separation
3.4 Location exception
3.5 Maximum distance
3.6 Crossing time
Report Contents
•
•
4. Pushbutton signage
4.1 Signage location
4.2 Tactile arrow
4.3 Universal symbol
4.4 Street name
4.5 Characters
- Braille
- Tactile characters
- Stroke thickness and cross-section
- Lettering
4.6 Indication of number of lanes
5. Locator tone
5.1 Volume
5.2 Repetition rate
5.3 Vibrotactile element
5.4 Availability
5.5 Single pole exception
5.6 Frequency range of pole locator tone
5.7 Location of locator tone speaker
•
6. Operational modes
6.1 Two-phase operation without pushbutton
6.2 Two-phase operation with pushbutton
6.3 Multi-phase operation
6.4 Rest in Walk operation
•
7. APS deactivation
7.1 Operation period
7.2 Suspended operations
•
8. Audible walk and clearance sounds
8.1 Tones
8.2 Recommended tones
•
9. Augmented features
9.1 Activation
9.2 Augmented features
9.3 Augmented optional features
•
10. Other requirements
10.1 APS support elements
Proposed Features
•
•
•
1.1 Operating period
An APS must be operational at all times
and not limited in operation by time of
day or day of week
1.2 Locator tones
Where an APS is controlled by a
pushbutton, a locator tone must be used.
1.3 WALK indication
When indicating the WALK interval,
the APS must deliver the indication in
audible and vibrotactile format. It is not
sufficient for signals to provide
accessible information only in
vibrotactile format.
•
•
•
1.4 Clearance indication tone
The APS must have a specific audible
indication (tone / message) for the
Clearance interval.
1.5 Activation
The two parallel legs of the crosswalk
must be activated at the same time
when a pushbutton is pressed.
1.6 Volume
The volume of the audible signals must
rise and fall in relation to the ambient
sound. See the definition of "2 dB and
no more than 5 dB greater".
Augmented optional features
9.3.1 Voice announcements to indicate
the street to be crossed
9.3.2 An extended WALK period may
be provided to accommodate the
needs of pedestrians at a particular
intersection.
9.3.3 An extended WALK time should
be considered when the following
conditions are present:
a. the running grade of the
crosswalk is greater than 1:20
b. the cross slope of the crosswalk
is greater than 1:48
c. the crosswalk length is greater
than 15.24 meters (50 feet) with no
intermediate pedestrian refuges.
9.3.4 The total crosswalk distance used
in calculating pedestrian signal
timing must include the entire
length of the crosswalk plus the
length of one curb ramp. When the
crosswalk has an APS signal, the
starting point of the overall
crosswalk length used must extend
to the vibrotactile signal path or to
the top of the curb ramp, which
ever results in the longer distance.
Proposed Sound Changes
Locator
Cuckoo Wk
Chirp
Cuckoo DW Melody Wk
Montreal Sound
Melody DW
Other Proposed Changes
• Lower speakers nearer to ground
In Ontario ..
• Ontario Disabilities Act. “The Ontarians with Disabilities Act, the
final sections of which were proclaimed into law in October
[2002], spells out accessibility requirements for government
offices and other public sector organizations such as public
transit, school boards, hospitals, colleges and universities. The
law also requires municipalities with 10,000 or more people to
establish municipal accessibility advisory committees that will
develop annual accessibility plans.”
USA Situation
• Access Board
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–
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a new Federal Agency
mandated to provide accessibility
mandated to write legislation
working with CNIB
Status
• CNIB is approaching traffic depts with new
spec in hand
• New spec at TAC - committee meets this
week!