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Comments on the Draft Guidelines for Accessible Public Rights-of-Way |
Scott, I wanted to extend my appreciation for your efforts at the public forum in Portland. The meeting was well organized and provided an excellent opportunity for people to have their voices heard – well done!
Please accept the following comments pertaining to the Draft Guidelines for Accessible Public Rights-of-Way. If any clarification or other information is needed, I can be reached at the following:
Darren Kaihlanen, ADA Coordinator
Montana Department of Transportation
General Comments:
- Consistency. The consistency
throughout the previous versions of the ADAAG and public right-of-way design
guide are poor. For example, the ADAAG references 1:48 to be a 2% slope;
however, the design guide references a 2% slope using both 1:48 and 1:50. I
recommend using 1:50 as a standard for 2%.
- While the discussion of the General Scoping requirements is extremely helpful, it is not practical. The only precedent to determine when an “alteration to an existing facility” exists is the Kinney v. Yerusalem case from 1993.
In that case it states, “The Department takes the position, sustained by the district court here, that resurfacing of a street is an alteration that triggers the obligation to install curb ramps. The reasonableness of the Department’s conclusion is supported by the evidence introduced by the plaintiffs on summary judgment concerning the City of Philadelphia. As the district court found, resurfacing ‘entails more than minor repair work or maintenance’.”
Since the final guidelines are intended for use within the public rights-of-way, an explicit description of when an alteration is triggered should be included so that there is no question when the installation of curb ramps and other accessible appurtenances are required.
Pedestrian Crossings (1102.8,1105)
The width of crosswalks should match the Manual of Uniform Traffic Control Devices (MUTCD). By increasing the width, other factors such as sight triangle/distance, stop bar placement, geometric and hydraulics will be affected. If it is the desire to have a wider crosswalk, that should be a threshold determination based on the number of pedestrian movements in a pedestrian access route.
Detectable Warnings (1104.3.2)
Detection techniques depend on the travel aids used by people who are blind, such as long canes or dog guides, and their amount of vision.
- People who are blind and use a long cane for travel aid detect a curb, or any other drop-off such as stairs or a platform edge, by a change in the angle of the wrist and the failure of the cane to contact the sidewalk at the expected level.
- People who use dog guides are alerted to the presence of a curb or other drop-off when their dogs stop. They then confirm the presence of the drop-off with a foot.
- People who have low vision, and do not use either a long cane or dog guide, rely on differences in color or shading of the walking surface. The sidewalk and street may have visual contrast, or the curb material may contrast with the sidewalk or street.
There are a number of other sources of information about the location of the curb indicating the end of the sidewalk (and the beginning of the street) which may be used by any person having a visual impairment, regardless of their travel aid or amount of low vision. These include traffic sounds, the slope of the sidewalk, the end of a building line, and changes in the sun or wind. These are all simply clues to the sidewalk/street boundary. None is a definitive cue.[1]
In the absence of a definitive cue – the curbed sidewalk – at the sidewalk/street boundary, it has become much more difficult for pedestrians who are blind to detect streets. When blind pedestrians do not detect a curb at the end of a block, they must rely on multiple clues which, taken together, indicate the high probability that they have come to a street.[2]
Based on the information gathered during research of the detectable warnings, it appears that vision impaired/low vision/blind pedestrian rely on multiple cues to determine their location at a street or crosswalk. The absence of multiple cues, should trigger the application of truncated domes/detectable warnings rather than a blanket application.
Pedestrian Overpasses and Underpasses (1105.5)
ADAAG 4.8.2 states, “The least possible slope shall be used for any ramp. The maximum slope of a ramp in new construction shall be 1:12. The maximum rise for any run shall be 30 in (760mm)(see figure below).”
The elevator requirement proposed in this section is cost prohibitive, unreasonable and not appropriate in most cases. Depending on the type of overpass/underpass, the elevation can easily be mitigated with a switchback type of ramp as shown in the following pictures:
[1] Detectable Warnings: Synthesis of U.S. and International Practice, 12 May 2000, page 14.
[2] Ibid, page 15.
