Working with Accessible Pedestrian Signals

Lisa Martellaro-PalmerTransportation Engineering Associate

City of Los Angeles, Department of Transportation (LADOT)

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

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

The 2012 MUTCDThe 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

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

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.

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

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.

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.

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

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

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: