1. Working with Accessible Pedestrian Signals
Lisa Martellaro-Palmer
Transportation Engineering Associate
City of Los Angeles, Department of Transportation (LADOT)

2. Old Version: Accessible Pedestrian Signals (APS)
Cuckoo and Peep-Peep
Resembled bird’s chirp
Circuit Board set to one volume
Problem for visually impaired seniors that are hard of hearing

3. New Version: Accessible Pedestrian Signals (APS)
Rapid Tick Sound for Walk then returns to a locator tone for remainder of Walk interval.
Flashing Don’t Walk and Solid Don’t Walk only use locator tone
Adjusts to ambient noise
Vibrotactile Arrow for those persons hard of hearing

4. The 2012 MUTCD
The 2012 MUTCD has more guidelines for design and installation
APS shall be used for new installations and during maintenance
Audible tones such as a Tick Tone
Vibrotactile arrows on the pushbutton
Verbal messages

5. The 2012 MUTCD
APS shall have both audible and vibrotactile WALK indications
If two APS pushbuttons are less than 10 ft apart or on the same pole, each APS pushbutton shall be provided with the following features:
A locator tone on the pushbutton
A vibrotactile arrow
A speech WALK message symbolizing the WALK indication

6. Audible Tones
Locator Tone – a repeating sound that informs approaching pedestrians that they are required to push a button and enables visually impaired pedestrians to locate the pushbutton
WALK Tone - a Rapid Tick Tone for a maximum of 7 seconds. If walk tone is similar to locator tone, the Walk tone shall have a faster repetition rate.

7. Audible Tones
Automatic Volume Adjustment in response to ambient traffic noise should be provided up to 100 dBA (previously 89).
Automatic Volume Adjustment tones should be no more than 5 dBA louder than ambient sound
Audible WALK shall repeat at 8 to 10 ticks/sec
Audible WALK shall consist of multiple frequencies with a dominant component at 880 Hz

8. Audible Tones
Alert Tone – a very brief burst of high frequency sound at the beginning of the audible WALK indication that rapidly decays to the frequency of the WALK tone and may be used to alert pedestrians to the beginning of the WALK interval during heavy traffic conditions.

9. Audible Tones Flashing Don’t Walk and Sold Don’t Walk
During the WALK interval, the Rapid Tick lasts for a maximum of 7 seconds and then returns to the locator tone for the remainder of the WALK Interval.
The Flashing Don’t Walk and Solid Don’t Walk only use the locator tone.

10. Walk Tone and Vibrotactile require actuation on PPB
Vibrotactile Arrows
A Vibrotactile Device communicates information about ped timing through a vibrating surface by touch.
Vibrotactile Devices shall indicate that the WALK Interval is in effect and for which direction it applies through the use of a vibrating directional arrow on the pushbutton.
During the WALK Interval, the vibration on the PPB lasts for 7 seconds.
The arrows are aligned with the direction of travel on the associated crosswalk.
Walk Tone and Vibrotactile require actuation on PPB

11. Speech WALK messages may transmitted with a receiver
Verbal Messages
Verbal Messages are used to communicate the pedestrian interval and they shall provide a clear message that the WALK Interval is in effect as well as to which crossing it applies.
The verbal message that is provided at regular intervals throughout the WALK Interval shall be the term “WALK SIGN” which may be followed by the name of the street to be crossed.
A verbal message is not required at times when the WALK Interval is not timing but if provided it shall be the term “WAIT” and it does not need to be repeated while the WALK Interval is not timing.
Speech WALK messages may transmitted with a receiver

12. Reasons for Installing APS
Increasingly quiet cars
Right Turn on Red
Continuous Right Turn Movements
Complex Signal Operations
Traffic Circles
Wide Streets
Low Traffic Volumes (difficult to discern signal phase changes)
Factors that might make crossing difficult: