What Is An APS?
Accessible Pedestrian Signals (APS) are devices that communicate information about the WALK and DON’T WALK intervals at signalized intersections, in non-visual formats, to pedestrians who are blind or have low vision.
APS' have also proven to provide benefit to all pedestrians and especially children by alerting them to the instant when the walk sign turns on and the status of the walk cycle.
An APS that meets the current requirements in the Manual on Uniform Traffic Control Devices would have the following features and operate in the following manner.
When you approach an intersection where an APS is installed the first thing you will notice when you come within 6-12 feet of a push button, is a beeping sound emanating from the push button. This sound is called the “Locate Tone” and sounds once per second. It is intended to direct a visually impaired pedestrian to the push button. The volume of this should typically be low and only heard within 6-12 feet from the pole so it does not disturb the surrounding public.
On the button is a raised tactile arrow pointing in the direction of the crosswalk. This helps a visually impaired pedestrian to orient themself in the direction of the crosswalk. Each time the button is pushed one should hear the word “wait”.
An APS can be programmed with custom messages giving the street names and the street being crossed. If the button is pushed and held until a click is heard, this indicates there is no special message. Depending on the extended push time which can be from 1 to 6 seconds, when the button is pushed and held until the extended push time is met, if the unit is programmed with a custom message, instead of the click sound the custom message will play. The direction of travel can also be added to the custom message. Braille can be added to the sign giving the name of the street being crossed.
When the pedestrian walk signal turns on the button vibrates and either a rapid tick sound or a custom walk message will be heard during the walk phase. The walk sound typically plays for the entire time the walk light is on. However, if the walk period is exceptionally long, or set to rest in walk, the walk sound can be limited for how long it plays.
When the walk message turns off and the Clearance phase (flashing don’t walk) turns on, the button can be set to play the Locate Tone, or a different sound, or an audible countdown of how many seconds are left in the clearance phase. Once the clearance phase ends the button will play the Locate Tone.
Most APS buttons have a built in microphone that measures ambient sound and increases the volume level played by the button as needed to be heard over traffic noise.
Some APS buttons have the capability to boost the volume for one walk cycle if the button receives an extended push. This way when a blind person uses the button the volume is a bit louder for their crossing, but quiet all other times. Some systems can also mute all sounds except for the crosswalk in which the button was pushed. Some APS buttons/systems can be programmed to reduce volumes during certain times/days. Some APS systems can be programmed to give warning messages when emergency vehicles or trains are approaching.
APS’ are helping to revolutionize how pedestrians cross the street! Typical APS features include:
- Vibrating button during walk
- Confirmation of button push via latching LED, sound, and tactile bounce
- Direction of travel (with extended button push)
- Standard locating tone during Don’t Walk (and Clearance if desired)
- Cuckoo, Chirp, Rapid Tick, Verbal, or user customized voice messages during walk. A total of 14 walk sound options are available, 3 are for custom voice messages/walk sounds
- Choice of 4 locate tone options
- Choice of 7 PED clearance. sound options
- All sounds automatically adjust to ambient
- Most sounds have a minimum and maximum volume setting option
- An extended button push can turn on, or boost volumes.
- Independent ambient adjustment setting for the locate tone which allows fine adjustments for low ambient conditions.
- False Walk Detection: Built-in
- Program Selection Options: Time of Day, Week, Month, Holidays & Daylight Savings Time
- Programs (Configurations): 1 Default plus 3 Alternate programs
- Multiple Languages: Messages in a second Language can be provided
- APS Connectivity Accessibility, and Confidence with Independent Lab Testing: NEMA TS2, Temperature, Humidity, Mechanical-Shock-Vibration, Transient Surge