The Public Rights-of-Way Access Advisory Committee (PROWAAC) released its recommendations to the U.S. Access Board in January 2001. Part III, Section X02.5 addresses pedestrian street crossings. Sections X02.5.1 and X02.5.2 specifically address pedestrian signal push buttons and accessible pedestrian signals, respectively. Both sections are reproduced below.
X02.5.1.1 General. Where new traffic signals with pedestrian controls are installed, they shall comply with this section.
X02.5.1.2 Features. Push buttons shall have the following features.
(A) Size. Push buttons shall be a minimum of 2 inches (51mm) across in at least one dimension.
(B) Maximum force. The force required to activate push buttons shall be no greater than 3.5 pounds (15.5N).
(C) Operation. Push buttons shall be operable with a closed fist.
(D) Locator tone. There shall be a locator tone complying with X02.5.1.5.
(E) Visual contrast. Push buttons shall have a visual contrast with the body background of at least 70 percent.
(F) Indicator. There shall be a visible and audible indicator that the button press has occurred.
Advisory: A long button press (e.g., 3 seconds) may bring up the accessible features or additional accessibility features of the individual device. An additional button should not be used to bring up additional accessibility features. All accessible features available are to be actuated in the same way. Thus, for a given signal, a long button press could request more than one additional feature. Possible additional features include: 1) sound beaconing by increasing the volume of the WALK tone and the associated locator tone for one signal cycle, so a blind pedestrian might be able to use the sound from the opposite side of the street to provide alignment information; 2) sound beaconing by alternating the audible WALK signal back and forth from one end of the crosswalk to the other; 3) providing extended crossing time; and 4) providing a voice message with the street names at the intersection.
(G) Signage. Signage accompanying push buttons shall comply with Section X02.5.1.4.
Discussion: These specifications are intended to make pedestrian push buttons accessible. The recommended change to a reduced maximum operating force is based in part, on the preamble to proposed ADAAG309 Operable Parts (p 62262, 2nd col): “Information indicates that most control buttons of keys can meet a 3.5 maximum pounds of force and a maximum stroke depth of 1/10 inches.” The closed fist requirement is based on the Access Board’s design guidelines: “Devices that can be operated by a closed fist acting on any point on the surface will be most usable by pedestrians who have mobility impairments.” The provision of visual contrast and a locator tone enable blind or visually impaired pedestrians to locate the push button. The visible and audible indicator informs both visually impaired and sighted individuals that the request for a walk signal has been received.
X02.5.1.3 Push button location. The location of push buttons shall be in accordance with the following minimum requirements.
(A) Adjacent to landing. The push button shall be mounted adjacent to a clear ground space or a landing on the pedestrian access route leading to the crosswalk. The clear ground space shall be at least 32 inches by 54 inches (815 by 1370mm), shall slope no more than 1:48 in any direction, and shall be provided with a stable, firm and slip resistant surface from which to operate controls. This clear ground space may overlap entirely with the pedestrian access route.
(B) Proximity to approach. Where a parallel approach to the push button is provided, controls shall be within 10 inches (255 mm) of the clear ground space, measured horizontally, and centered on it. Where a forward approach is provided, controls shall abut and be centered on the clear ground space.
(C) Direction of control face. The control face of the push button shall be parallel to the direction of the crosswalk controlled by the push button, and no closer than 30 inches (760mm) to the curb line.
(D) Mounting height. The centerline of the push button shall be mounted 42 inches (1070mm) above the clear ground space for approach.
(E) Close to crosswalk. The push button shall be mounted no further than 5 feet (1.5m) from the extension of the crosswalk lines, and within 10 feet (3m) of the curb line, unless the curb ramp is longer than 10 feet (3m).
(F) Proximity to curb or transition ramp. When located at a curb ramp, the push button shall be placed within 24 inches (610mm) of the top corner of the curb ramp, on the side furthest from the center of the intersection of the roadway. When located at a transition ramp, the push button shall be placed adjacent to the lower landing.
Advisory: It should be noted that for information in vibrotactile format to be useable, the pole must be located so the user is able to keep a hand on the button while aligned at the top of the curb ramp or at the crosswalk. Note: vibrotactile information alone is not allowed.
(G) Separation. Where there are two accessible pedestrian signals on the same corner, the push buttons shall be mounted on poles separated by at least 10 feet (3 meters).
EXCEPTION: If the requirement for separation cannot be met due to location requirements (A) through (G), two accessible pedestrian signal-related push buttons may be installed on a single pole. If installed on the same pole, the APS must be equipped to provide speech-transmitted data or other technology that delivers an unambiguous message about which crosswalk has the walk signal indication.
Discussion: Requirements for push button location were discussed in detail by the subcommittee and are essentially the same as requirements proposed by FHWA for inclusion in the Manual on Uniform Traffic Control Devices (MUTCD) in December 1999. The committee’s intent is to standardize some elements of pedestrian push button location to make the push button more accessible to pedestrians who are blind or who have vision impairments. Locating the pedestrian push buttons at some distance from the crosswalk, which is common now, makes it difficult for a pedestrian, particularly a blind pedestrian or a pedestrian using a mobility aid, to push the button and return to the crosswalk location in time for the walk phase. Users of wheelchairs and mobility aids need to be able to push the button from a level surface. The control face of the push button or the push button housing will include a tactile arrow to inform a blind pedestrian about the direction of the crosswalk, so the location and direction of the control must be aligned with the crosswalk. Since the APS will provide an audible indication of the walk interval from the pedestrian push button, the blind pedestrian must be able to discern which signal is sounding at each phase. This is much harder if both APS are on the same pole, since using only different tones to distinguish the directions is prohibited in Section X02.5.2.2 (A). The separation is intended to allow the blind pedestrian to determine which APS is sounding through sound localization while standing at the curb preparing to cross the street. While the separation is not required for call buttons that are not associated with an APS or locator tone, routinely separating the call buttons will result in a more uniform and predictable location, and will facilitate future APS and/or locator tone installation.
X02.5.1.4 Push Button Signage.
(A) Tactile arrow. Where there is a push button, there shall be a tactile arrow pointing in the direction of pedestrian travel controlled by the button. The arrow shall be raised at least 1/32 inch (0.8 mm), 1 1/2 inches (38mm) in length. Stroke width shall be between 10 percent minimum and 15 percent maximum the length of the arrow. The arrowhead shall be open and at 45 degrees to the shaft. The arrowhead shall be no more than 33 percent of the length of the arrow shaft.
Advisory: If the curb ramp is not aligned with the crosswalk, the arrow will point in the direction of travel, not in the direction of the curb ramp orientation.
(B) Universal symbol. Controls are to include a universal tactile and visual symbol (if established by the Access Board) that will go on or at the push button indicating the presence or absence of an accessible pedestrian signal at a crosswalk.
Discussion: For the universal tactile and visual symbol, the committee suggests application of three dots in a triangle on the button as close to the center as practicable.
(C) Street name. Street name information shall be provided at pedestrian push buttons. The accessible street name information provided at a pedestrian push button shall include the street name (or a reasonable abbreviation) in grade 2 Braille and in tactile raised letters complying with Section X02.3 and Section X02.5.1.4. The sign shall be located immediately above the push button mechanism and parallel to the crosswalk controlled by the button. The street name shall be the name of the street whose crosswalk is controlled by the push button.
Advisory: While this is in contrast to the convention in visual street naming, where the street name is parallel to the street itself in order to be visible to drivers and pedestrians, it is not in contrast to visual signs adjacent to pedestrian push buttons which indicate which street is controlled by the push button.
Audible signage may be provided in addition to Braille and tactile signage. Audible signage can provide auxiliary information about the intersection, which can be of great value to persons with visual impairments and to persons benefiting from redundancies.
Discussion: The arrow and street name information at the push button will provide information accessible to blind pedestrians, now typically provided to sighted pedestrians by signage, to clearly indicate which crosswalk is controlled by the push button. The arrow must be oriented parallel to the crosswalk to give this information clearly; the specifications of the arrow are to make it more easily distinguishable by touch.
(D) Crosswalk mapping. Where a map of a crosswalk is associated with a push button, the map shall be visual and tactile. Maps shall have at least 70 percent visual contrast, light-on-dark or dark-on-light. The characters and/or symbols shall be raised 1/32 inch (0.8mm) minimum. The crosswalk shall be represented by a vertical line, with the departure end of the crosswalk at the bottom of the map. The map shall be on the side of the push button housing that is furthest from the street to be crossed.
Advisory: The above elements should be arranged at a push button as follows : symbol on the push button, arrow on or immediately above the push button, and signage above the arrow.
X02.5.1.5 Locator tone. Where provided, locator tones shall meet the following requirements.
(A) Volume. Volume of the locator tone shall be at least 2 dB and no more than 5 dB greater than the ambient noise level and shall be responsive to level changes. At installation, signal system is to be adjusted to be audible at no more than 5 to 12 feet (1.5 - 3.7m) from the system or at building line, whichever is closer.
EXCEPTION: At locations with audible beaconing, in response to a long button press, the locator tone loudness may increase during the pedestrian clearance interval to allow the user to hear the tone on the opposite side of the intersection (see Section X02.5.2.3 (B)).
(B) Repetition. The locator tone shall be 0.15 seconds maximum in duration and repeat at one second intervals. Sound shall operate during the DON'T WALK and flashing DON'T WALK pedestrian clearance interval of the signal.
(C) Availability. The locator tone shall be audible whenever people are in the vicinity.
Advisory: The locator tone may be initiated by a passive detector such as an infrared detector, and therefore sound only when pedestrian presence triggers the device.
(D) Deactivation. The locator tone shall be deactivated during periods in which the pedestrian signal system is inactive.
Discussion: A locator tone notifies pedestrians who are blind or visually impaired of the need to push a button to request a WALK signal. It also indicates the location of the push button. These specifications are the same as the specifications in the proposed MUTCD for the locator tone.
Research need: A variety of tones are currently utilized as locator tones. The above specifications describe the repetition rate of the tone, however the exact nature of the tone is not specified. Research is recommended to determine the most localizable tone in the presence of traffic sounds.top
X02.5.2.1 General. Where new traffic signals are installed, accessible pedestrian signals (APS) shall be provided when any of the following conditions are present:
(A) Actuation. An accessible pedestrian signal shall be provided where the timing of pedestrian phases is affected by push button actuation.
(B) Lead pedestrian interval. An accessible pedestrian signal shall be provided where the signal includes a leading pedestrian interval (LPI).
Advisory: Without an accessible pedestrian signal, a blind pedestrian listening for a parallel traffic surge at a crosswalk with LPI may miss the walk interval and enter the crosswalk without enough time to complete the crossing before the signal changes.
(C) Pretimed signal. An accessible pedestrian signal that is available at the option of the user shall be provided where there is a pretimed traffic signal that presents pedestrian signal indication information. In this instance, a push button shall be provided that actuates the accessible pedestrian signal.
Discussion: The primary technique that people who are blind or visually impaired have used to cross streets at signalized locations is to initiate their crossing when they hear the traffic alongside them begin to move, corresponding to the onset of the green interval. The effectiveness of this technique has been reduced by several factors including: increasingly quiet cars, the availability of right turn on red (which masks the beginning of the through phase), complex signal operations and wide streets. Further, low traffic volumes make it difficult for pedestrians who are blind or visually impaired to discern signal phase changes. The increasing use of actuated signals, at which the pedestrian must push a button and cross during the pedestrian phase, requires blind pedestrians to locate the pedestrian push button and to cross only at the proper time during that phase. These changes in signalization make it necessary to provide the pedestrian signal information in an accessible format. In responding to a request for an accessible pedestrian signal at an existing intersection, the jurisdiction may find it useful to work closely with the blind pedestrian(s) who will be using the intersection and with an orientation and mobility specialist.
X02.5.2.2 Required features. Where accessible pedestrian signals are provided, they shall comply with the following requirements.
(A) Crosswalk indication. Accessible pedestrian signals shall clearly indicate which crosswalk has the walk interval. The use of two different tones as sole indication of which crosswalk has the walk interval is not permitted.
Advisory: When walk interval information is broadcast from the push button housing, then separation of the push buttons combined with the required signage is a good means to provide crosswalk-specific information. A speech message may also be used to provide this information. The MUTCD specifies the wording of such a speech message. Remote infrared audible signs (RIAS), which are inherently directional, are another good way to clearly indicate which crosswalk has the walk interval. Additional strategies that may provide unambiguous information are an alternating audible signal or an audible signal from the far end of the crosswalk; however, this type of beaconing is not generally recommended; see X02.5.2.3 (B), Audible Beaconing.
(B) Walk indication. When indicating the walk interval, the accessible pedestrian signal shall deliver the indication in audible and in vibrotactile format. Signals providing accessible information in vibrotactile format only are not permitted.
(C) Locator tones. Where an accessible pedestrian signal is controlled by a push button, there shall be an associated locator tone.
(D) Walk interval tone. When an APS uses audible tones, it shall have a specific tone for the walk interval. If the same tone is used for the push button locator tone, the walk interval tone shall have a faster repetition rate than the associated locator tone. The two signals shall be distinguishable either by tone and/or by repetition rate. A voice message may be used for the WALK indication.
Where the APS provides signal information using tones, the tone shall consist of multiple frequencies with a large component at 880 Hz. The walk tone shall have a repetition rate of 5 Hz minimum and a duration of 0.15 seconds maximum.
Advisory: Frequencies above 1 kHz are difficult for persons with an age related hearing loss to detect. Multiple frequencies will assist a larger population group of vision and hearing impaired persons.
(E) Operating period. Under stop-and-go operation, APS shall not be limited in operation by time of day or day of week.
Advisory: Information access must not be abridged by day or time. Rather than disconnect a device for periods of time, volume should modulate in response to ambient levels.
(F) Activation. Actuating a single APS on an intersection is not intended to activate all other devices at all other crosswalks.
(G) Volume. Tones shall be at least 2dB and no more than 5dB greater than the ambient noise level and shall be sensitive to level changes. The walk tone shall be no louder than the locator tone. At installation, the signal system should be adjusted to be audible at no more than 5 to 12 feet (1.5 to 3.7m) from the system or at building line whichever is closer. If an audible tone is provided, the audible tone(s) shall be audible from the beginning of the associated crosswalk. Audible information shall be provided at the departure curb only.
EXCEPTION: Where audible beaconing is provided, the opposite beacon may be audible at the departure curb. A louder walk interval audible tone and subsequent pedestrian clearance interval tone may be provided after a long button press at intersections where audible beaconing is needed.
Advisory: The APS specifications and sound levels recommended here are intended to provide precise information about the onset of the walk interval. Using special actuation as specified below, they may also function as audible beacons, giving assistance in alignment and crossing within the crosswalk.
X02.5.2.3 Optional Features.
(A) Prolonged push button press. Additional features which may be required to make a specific intersection accessible shall be brought up by a prolonged press of the push button.
Advisory: A long button press (e.g., pushing the pushbutton for 3 seconds) may bring up the accessible features or additional accessibility features of the individual device. An additional button should not be used to bring up additional accessibility features. All accessible features available are to be actuated in the same way. Thus, for a given signal, a long button press could request more than one additional feature. Possible additional features include: 1) sound beaconing by increasing the volume of the WALK tone and the associated locator tone for one signal cycle, so a blind pedestrian might be able to use the sound from the opposite side of the street to provide alignment information; 2) sound beaconing by alternating the audible WALK signal back and forth from one end of the crosswalk to the other; 3) providing extended crossing time; and 4) providing a voice message with the street names at the intersection.
(B) Audible Beaconing. Where provided, audible beaconing signals shall be provided during the walk interval. Audible beaconing may be provided during the pedestrian clearance interval, if no conflicting traffic movements are permitted.
Advisory: Audible beaconing is usually not needed. Beaconing may be needed at intersections that are wide, have low parallel traffic volume, or have skewed crosswalks. Where beaconing is desired as an additional accessibility feature, it should be actuated by depressing the push button for a longer period of time.
Where beaconing is provided, it will be most effective if it functions only for that crosswalk where the push button was actuated. The area of definite audibility in the direction of travel should be detectable within one-third of the width of the crosswalk from the entrance to the crosswalk. Beaconing may be provided by the increase in the locator tone (see Section X02.5.1.5 (A.)).
Discussion: The technology of accessible pedestrian signals has developed in recent years. There are now four types of APS available in the United States. Overhead signals mounted on the pedestrian signal indication have been most commonly used, but problems noted include: difficulties identifying which signal is associated with which crosswalk and which signal is associated with which intersection; noise complaints from neighbors; and difficulty by blind pedestrians in hearing traffic above the loud sound of the APS.
Signals in which sound comes from the pedestrian push button and include a locator tone and vibrotactile information, are used extensively in Europe and Australia and are now available in the United States. There are also signals that are vibrotactile only, but that system is not recommended by the committee. Sound transmitted to a receiver carried by the blind pedestrian, using RIAS or Light Emitting Diode (LED) technology, has also been used to provide information about the status of the walk signal and to provide additional information about the location and the nature of the intersection. RIAS systems provide a beaconing effect by means of the directional sensitivity of the receiver units.
The features and specifications listed above are currently appropriate given the technology and research available. Future technological developments may lead to additional alternatives. The committee wished to open the door to new technologies, but was interested in clarifying some features that most members considered essential in an APS. The committee did not want travelers to be required to carry a single, function-specific receiver in order to access intersection information.
While sound beaconing is an alternative that may assist a blind pedestrian in aligning at a difficult crosswalk, the committee did not feel that the use of beaconing at all intersections is necessary. There are concerns that loud overhead APS may mask traffic sounds that are useful to the blind pedestrian, and subject residents who live near the APS to unacceptable noise levels. Nearby residents have objected to audible signals in the past where they used two different sounds in a beaconing manner to alert users. By providing tones with volume that modulates to ambient noise levels, noise intrusion beyond the intended hearing range is minimized and termination of the tone during night hours is unnecessary.
Research need: A variety of tones, speech messages, or melodies are currently utilized to indicate the walk interval. Research is recommended to determine the most localizable tone in the presence of traffic sounds. The committee felt there was enough information to provide basic specifications for the walk interval tones. Research now being conducted by the National Institutes of Health on accessible pedestrian signals will compare usability of overhead and pedestrian button mounted speakers for orientation and alignment and provide additional information regarding the use of tones, speech messages, or alternating signals for localization.top
X02.5.3.1 Other pedestrian signals and timing controls not specifically described elsewhere shall comply with the requirements of this section.
Advisory: When a dedicated phase for left-turning auto traffic precedes the through movement and the walk interval, it increases the difficulty for persons using auditory cues to accurately determine the appropriate time to start crossing. It is easier to determine the appropriate time to start when the through movement occurs first and the left-turning movement afterward.
X02.5.3.2 Mid-block crosswalks. Reserved.
X02.5.3.3 Near side pedestrian signals. Reserved.
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