Common Problems Arising in the Installation of Accessible Pedestrian Signals

Issue 11: Good vibrations (vibrotactile indications)

APS device usability is compromised if the vibrotactile indicator doesn’t vibrate during the WALK. The vibrotactile indication provides WALK signal information for pedestrians who are both visually and hearing impaired and also may be used by pedestrians who are visually impaired (with normal hearing) to clarify or confirm which street’s audible WALK is sounding. 

Where mounting two APS on one pole can’t be avoided, take care to ensure that the activation of the vibration of one device doesn’t cause vibration of the device for the perpendicular crossing.

Remedy: The functioning of the vibrotactile indication needs to be carefully checked before installation is considered complete and should be a part of regular maintenance checks. 

Troubleshooting: If the arrow does not vibrate during WALK, there are several potential areas to check:

• the basic settings of the device;
• wiring to the vibrotactile feature; and
• attachment of the arrow to the device. 

The vibrotactile indication can be turned off in some devices by a setting either on the control board or within the PDA device. Check settings to be sure vibration is on. Vibrotactile indications may have separate wires to attach in order to enable the feature. If those wires are not attached properly, or are attached to the wrong places, or are pinched when reclosing the device, the arrow may not vibrate properly. 

If the plate holding the arrow is screwed in, over-tightening the screws can prevent the vibration. If the arrow is attached with glue, as found on some manufacturers’ APS, too much glue under the arrow can prevent the vibration of the arrow. The arrow needs to be glued down, but it also needs to contact the vibrating plate. It seems to work best to put a thin layer of glue around the outside edges of the recess, then insert the arrow and align it with the direction of travel on the crossing the device indicates. 

If the arrow seems to be vibrating during flashing or steady don’t walk and there are two devices on the same pole, the devices are probably touching each other and causing vibrations. Installing insulation between the pole and the APS and between the two APS will probably remedy the problem.