I have received multiple requests to discuss the pros and cons of installing diagonal/radius curb ramps at intersections. This design actually requires two actions for the user: (1) step out onto the street at a forward diagonal angle, and then (2) change directions to actually cross in the direction they need to go. For wheelchair users and someone pushing a baby stroller, increased danger exists since they must extend into moving traffic much farther than a standing person. The walking pedestrian, however, can step over the curb to take a more direct approach.
First, let me be clear that even though a diagonal curb ramp is allowed by ADA guidelines, I believe that it is the worst style beyond a full blended radius curb ramp, or depressed corner, that wraps from one side of the corner to the other—which, by the way, I see as a true safety problem. (As a wheelchair user, I’ve personally experienced the dangers, but that’s a subject for my next post.) Plus, the Federal Highway Administration’s “Accessible Sidewalk and Street Crossings” booklet clearly states that this style of curb ramp is “NOT RECOMMENDED”:
Also, the Access Board’s Public Rights-of-Way (PROW) 1999 Design guide provides excellent examples that explain the problems related to diagonal curb ramps:
A suitable alternative is to install paired ramps with the radius raised up. The following graphic shows how the raised radius curb delineates the ramps so a person with vision impairments can follow the separate crosswalks:
I'm not adding other comments, since I feel these graphics with their comments speak for themselves. My next post will address full blended radius curb ramps.
Wishing you success in all you are doing to improve the world we live in,
Michele w/ Maddie in my heart forever