|
|
|
 |
 |
Need for detailed engineering drawings and specifications Engineering drawings for installations should include location of pushbuttons, tactile arrows, vibrating surfaces, and signs of the APS devices. The location of these features affects the safety and usability of the devices. Height of pushbuttons The pushbutton must be within accessible reach range of a level landing for use from a wheelchair and no higher than 42 inches measured from the landing. Without detailed specifications, pushbuttons may be installed in locations that are 'convenient' to the installer, but not usable by pedestrians.
Vibrating surfaces Vibration-only devices are not recommended. However, many APS have vibrating surfaces that can be useful in confirming the audible WALK indication and in providing WALK signal information to pedestrians with visual impairment plus hearing loss. If used, designers/engineers and installers must remember that the vibrating surface will be usable only if they are installed within the width of the crosswalk or very near the crosswalk, and near the curb line. Pedestrians must be able to wait to cross while keeping a hand on the vibrating surface. Location of the tactile arrow If poles are located too far away from the center of the intersection, outside the extension of the crosswalk lines, the pedestrian who is blind may attempt to cross at a location that is not within the crosswalk area. Pedestrians may align with the tactile arrow and proceed to the curb from that location. The installation shown below is more than five feet from the crosswalk lines extended. While the arrow does clarify which street the device controls, it provides misleading information as well. Stub poles or other solutions should be evaluated to position the arrow more appropriately. If the pole location cannot be adjusted, moving the speaker for the WALK indication to a location closer to the crosswalk, by use of a mast arm, might help the pedestrian who is blind recognize the appropriate crossing location.
Orientation of tactile arrow The tactile arrow must be oriented parallel to the direction of the crosswalk controlled by the pushbutton. Arrows on several manufacturers' devices are positioned by the installer. However, with some devices, the direction of arrow is specified when ordering the units. Pole location in relation to the crosswalk can affect the arrow direction.
Shape and type of mounting pole US municipalities use a great variety of poles for mounting pedheads and pushbuttons. When the tactile arrow is part of the pushbutton and located on the face of the pushbutton integrated device, the orientation of the device on the pole determines whether the tactile arrow is aligned with the crosswalk. Most pushbutton integrated devices are designed to be installed on round poles. Poles that are not round may require a special mounting bracket or shim to orient the arrow correctly. Additional information on installation is included in the Field Adjustments section.
Wooden poles In areas where pushbuttons are installed on wooden poles, the wiring usually runs on the outside of the pole. A mounting bracket is needed on some devices for wiring the pushbutton. The bracket needs to be ordered with the APS.
Pedestrians who are blind in Charlotte, NC have expressed concerns about nails and staples that are common in wooden poles and the hazard in having to use their hands to locate the button. There has been some investigation there into designing a shield for the pole area near the pushbutton to solve that problem.
Stub poles The use of stub poles for mounting pedestrian pushbuttons is common in some areas of the US. This provides an opportunity to site the pushbutton where it is most usable to pedestrians and may improve pedestrian compliance with pushbutton use.
Braille labels and signs
top 
|
| << previous page | next page >> |
 |
This site
was developed under the sponsorship of the National
Cooperative Highway Research Program. |
