Prevalence Common in Europe and Australia, now available in US; many recent
installations are of this type
Function
Pushbutton integrated APS systems have a speaker integrated into the pushbutton housing.
Sound comes from the pedestrian pushbutton housing, rather than a speaker mounted at the pedhead.
Provide a locator tone, a Walk interval tone or speech message, and
a raised arrow, which should be oriented parallel to direction of travel
on the crosswalk
Sound is directly audible, that is, it is heard by everyone in the vicinity; users do not require receivers to hear the sound
Include automatic volume adjustment
WALK indication
The WALK indication may be a different tone, a rapid repetition of the locator tone, or a speech message.
Vibrotactile information
Vibrotactile information
Is typically provided in this type of signal by a button or arrow that vibrates to indicate the WALK signal
Is useful for confirmation of which signal is sounding at a particularly noisy intersection
Makes WALK signal information accessible to persons who have hearing loss in addition to visual impairment.
Locator tone
The locator tone is a quiet, repeating tone that:
Notifies pedestrians with visual impairments that it is necessary to push a button to actuate a pedestrian phase,
Aids in location of the pushbutton, and
Aids in homing in on the opposite corner when crossing the street.
Tones used in the US vary, however the repetition rate is standardized at once per second. The duration of the tone is 0.15 sec maximum, so that it is not mistakable for a vehicle back-up tone that usually sounds during approximately half of its cycle length.
Installation
When pushbutton-integrated APS are consistently mounted on poles at the ends of crosswalks, and near the crosswalk line furthest from the center of the intersection, they provide unambiguous information about which crosswalk has the Walk interval.
Pushbutton-integrated APS must be oriented on poles very precisely so the arrow is aligned in the same direction as the crosswalk whose signal is actuated by that pushbutton.
Pedhead speakers may be aimed in various directions; some cities in California
have experimented with aiming the speaker down toward the waiting location
and reducing the volume.
Installation examples
Two examples of Pushbutton-integrated
APS with audible and vibrotactile output. Both have locator tones
as well as Walk indications.
Tone volume
These signals, in their typical mode of operation and installation, are intended to be loud enough to be heard only at the beginning of the crosswalk, although the locator tone on the opposite curb becomes audible as the pedestrian approaches it.
Options
Additional options include:
Pushbutton information message with street name, geometry, and signalization information
Braille labels
Tactile map of the crosswalk
'Alert tone' at the onset of the Walk interval
Actuation tone and light
Audible beaconing
Limitations
Potential limitations include:
Extra wiring needed in order to install to the pushbutton
Poles on which to locate the device should be close to the crosswalk location lines extended and the curb (or curb ramp)
