Pushbutton locator tone
Locator tone 1
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Locator tone 2
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Locator tone 3
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Description
A pushbutton locator tone is "A repeating sound that informs approaching pedestrians that they are required to push a button to actuate pedestrian timing and that enables pedestrians who have visual disabilities to locate the pushbutton." (MUTCD 2003, 4E.09)
The pushbutton locator tone is referred to by different names in manufacturer's brochures, including:
- pole locator
- locator signal
- locator tone
- locating tone
- locator audible
Additional information
Pushbutton locator tones typically sound from the pushbutton during the flashing and steady DONT WALK intervals. The locator tone informs pedestrians of the need to push a button and provides an audible cue to the location of the pushbutton. During the street crossing the locator tone may be audible in the last lane and provide a cue to the direction of the destination.
In available products, the pushbutton locator tone varies from a click sound to a beep tone. Repetition rate and length of tone are standardized by language in the MUTCD: "…pushbutton locator tones shall be easily locatable, shall have a duration of 0.15 seconds or less, and shall repeat at 1-second intervals." (4E.09)
Volume of this slowly repeating tone should be adjusted to be heard no more than 6 to 12 feet (2 to 4 meters) from the push button or at the building line, whichever is less (MUTCD 4E.09). Draft PROWAG states that the volume of the pushbutton locator tone is to be adjusted to between 2dB and 5dB above ambient sound levels in standard operation. (R306.3.2) These requirements may appear to be in conflict, however both can generally be met. Perceived loudness can vary, depending on the environment near the sound source.
Both MUTCD and Draft PROWAG allow an increased volume of the locator tone to provide audible beaconing in response to a request (see sections on extended button press and audible beaconing).
The pushbutton locator tone typically has automatic volume control. A microphone or sensing device is installed in the APS device or in the pedestrian signal head to monitor intersection sound levels and adjust the volume of the locator tone. This technology is also used to adjust the volume of the WALK indication. The web page at www.walkinginfo.org/aps includes sample locator tones.
When to use
The pushbutton locator tone can be useful whenever there is a pushbutton that a pedestrian should use.
References
Draft PROWAG requires a pushbutton locator tone wherever there is a pushbutton (R306.3.2).
MUTCD states that pushbutton locator tones may be used. (4E.09).
Draft PROWAG and MUTCD have additional information regarding pushbutton locator tone volume, as discussed above.
How used by pedestrians who are blind or who have low vision
Pedestrians who are unfamiliar with an intersection will approach the intersection:
- Upon hearing the locator tone, or two locator tones if there are two pushbuttons, will realize that there is a pushbutton for the crossing,
- Will probably continue to the curb or curb ramp location, in order to become familiar with the corner, determine proper alignment, and become familiar with the intersection layout and sounds by listening to traffic,
- Return to the pushbutton locator tone that is believed to be the correct pushbutton for the crossing, if it is not within reach, and check that the tactile arrow alignment is parallel to the desired crosswalk,
- Push the button and return to the curb to realign to cross the intersection, if necessary,
- May repeat this process if the pedestrian phase begins before they are properly aligned to cross.
- While crossing the street, the pushbutton locator tone for the APS on the opposite side of the street may be audible, allowing them to home in on the sound.