January 20, 2009
Thank you for the opportunity to comment on the Draft Revisions to the ADA Accessibility Guidelines for Buses and Vans, as issued by the U.S. Access Board on November 19, 2008.
Because of time constraints, I will only address what many would regard as a relatively minor issue—the technical requirements for stop request systems (T706.2 and 805), to which I strongly (albeit very belatedly) object because of both their format and their substance.
First, I am greatly dismayed that the Board has adopted the ANSI 117 standard and ADAAG’s (to my mind profoundly misguided) practice of a) specifying a single permissible range for (in this case) unobstructed side reach in section 308, and b) saying that just about any operable part must comply with Sec. 308. The reasoning behind this change was that it would streamline the standard by reducing repetitive language. But it means that users of the standard now have to look in two (or even three!) places to ascertain the requirements for a particular element. This makes the standard harder to use. The draft is even more problematic in this respect: the horizontal placement of the stop request system is specified in T706.2, but the user has to go to T805 for other requirements.
I recommend that T805 be deleted and that all the technical requirements for stop request systems be incorporated into T706.2, as was the practice in the 1991 guidelines.
An even bigger problem with ADAAG/ANSI 309 (from which T805 is lifted) is that none of its provisions is appropriate to stop request systems.
1. Bear in mind how the l5-48 inch range came to be. The ANSI 117 committee (on which I serve) arrived at the one-size-fits-all side and forward reach ranges simply by incorporating all the height ranges that previous editions of the standard had set for various individual elements. Specifically, the lower end of the range was set at 15 inches (380 mm), as I recall, because that had been specified as the minimum height for electrical outlets.
At least one commenter in the last round, Douglas J. Cross, addressed this issue, saying, “the specification for this control to be located anywhere from 15 to 48 inches above the floor is too broad of a range, as it puts the typical small control out of reach of mobility device users that may have limited arm motion.”
Indeed, recent research (see attachment) conducted by Dr. Edward Steinfeld at SUNY Buffalo (the country's leading authority on disability ergonomics) found that 99% of wheelchair users are unable to reach as low as 15 inches.
Since Dr. Steinfeld's charts indicate that "reachability" improves rapidly as height increases to 700 mm (25.6 inches), but does not improve significantly above that height, I recommend that T706 specify 700 mm as the minimum height for stop request controls.
2. Even if someone is able to reach the stop request control, this does not mean they will be able to actually activate it; the force required may be beyond their capabilities. It is clear to me (although I cannot cite research on this issue; perhaps the Board knows of such research) that many people with disabilities will be unable to exert 22.2 N of force on a stop request control.
In preparing these comments I pushed on a postal scale with my headstick to see how much force I could exert and found that I could, with great effort, barely reach two lbf. Now I know full well that one person’s experience cannot be taken as definitive, but it is somewhat indicative, I submit, particularly given that I am able to exert only 40% of the force that the draft would permit. It should also be borne in mind that musculature weaker than mine is an element of many disabilities.
I also reiterate my objection to using a one-size-fits-all requirement—in this case, one that is the same for elements as disparate as doors and elevator call buttons—rather than one tailored to the element involved.
I recommend that the force required to activate stop request controls be limited to 4.4 N (1 lbf).
3. Have stop request controls ever required “tight grasping, pinching, or twisting of the wrist.“? 1`I doubt it. I think this prohibition is superfluous.
Unless I am missing something, the only other element subject to T805 is fare collection devices. It is not clear to me how cash slots and ticket and card readers can be considered “operable parts,” but even if they can be, do they ever require any force or “tight grasping, pinching, or twisting of the wrist.“? I think not. So two of the three requirements in T805 are superfluous, and the other (the height range) is inappropriate to the element, for the reasons stated above.
Thank you very much for considering my criticisms.
Chair, ATBCB Transportation Committee, 1980-83
Click here to see the attached file.