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Accessible Pedestrian Signal (APS). Formerly Audible Pedestrian Signals. What is an APS?.
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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
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
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
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 Total blindness or light perception
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
Prevalence of blindness • By 2010, projections are that there will be 20 million visually impaired persons over 45
Most persons who have a vision impairment live in metropolitan areas (70%) 33% live in cities, 37% live in suburbs, 28% live in non-metropolitan 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 non-metropolitan areas and somewhat under-represented in the suburbs (i.e., 48% of general population live in suburbs) (Schmeidler & Halfmann, 1998b) Area of residence
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
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
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 Driver behavior& auto technology
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 Control Issues
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
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.
Introduction1. Framework- The creation of the Committee- Principles- Mandate- Approach to the task2. Navigating intersections: the skills used by pedestrians who are blind, visually impaired or deafblind3. An implementation strategy II – Definitions of Words and TermsIII -- Features of an Accessible Pedestrian Signal 1. Required features of an APS1.1 Operating period1.2 Locator tones1.3 WALK indication1.4 Clearance indication tone1.5 Activation1.6 Volume 2. Pushbutton2.1 Size2.2 Surface2.3 Operating force2.4 Visual contrast2.5 Location2.6 Locator tone2.7 Activation indicator2.8 Voltage 3. Pushbutton Pole location3.1 Visual contrast3.2 Mounting height3.3 Location- Adjacent to landing- Proximity to approach- Close to sidewalk- Proximity to curb or transition ramp- Separation3.4 Location exception3.5 Maximum distance3.6 Crossing time Report Contents
4. Pushbutton signage4.1 Signage location4.2 Tactile arrow4.3 Universal symbol4.4 Street name4.5 Characters- Braille- Tactile characters- Stroke thickness and cross-section- Lettering4.6 Indication of number of lanes 5. Locator tone5.1 Volume5.2 Repetition rate5.3 Vibrotactile element5.4 Availability5.5 Single pole exception5.6 Frequency range of pole locator tone5.7 Location of locator tone speaker 6. Operational modes6.1 Two-phase operation without pushbutton6.2 Two-phase operation with pushbutton6.3 Multi-phase operation6.4 Rest in Walk operation 7. APS deactivation7.1 Operation period7.2 Suspended operations 8. Audible walk and clearance sounds8.1 Tones8.2 Recommended tones 9. Augmented features9.1 Activation9.2 Augmented features9.3 Augmented optional features 10. Other requirements10.1 APS support elements Report Contents
1.1 Operating periodAn APS must be operational at all times and not limited in operation by time of day or day of week 1.2 Locator tonesWhere an APS is controlled by a pushbutton, a locator tone must be used. 1.3 WALK indicationWhen 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 toneThe APS must have a specific audible indication (tone / message) for the Clearance interval. 1.5 ActivationThe two parallel legs of the crosswalk must be activated at the same time when a pushbutton is pressed. 1.6 VolumeThe 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". Proposed 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 1:20b. the cross slope of the crosswalk is greater than 1:48c. 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. Augmented optional features
Proposed Sound Changes Locator Chirp Montreal Sound Melody DW Cuckoo Wk Cuckoo DW Melody Wk
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 publictransit, 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 • 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!