36 CFR Part 1192 Americans with Disabilities Act (ADA) Accessibility Guidelines for Transportation Vehicles (2016 Non-Rail Vehicle Guidelines) - Preamble

T302 Walking Surfaces

The technical requirements for walking surfaces include provisions on slip resistance, the maximum size of surface openings, and the maximum height of vertical surface discontinuities (i.e., changes in level), with and without edge treatment. Exceptions are also provided for certain openings in wheelchair securement system components affixed to walking surfaces and for manual placement and removal of ramps and bridgeplates (as, for example, on small buses or vans in cases of emergency), as well as walking surfaces on steps that are not part of onboard passenger access routes.

With respect to slip resistance, a bus manufacturer urged the Access Board to incorporate specific measures for slip resistance (i.e., maximum and minimum friction coefficients) in the final rule. The Board declines to adopt this recommendation. As with our other existing accessibility guidelines for the built environment and other areas, we do not specify in this rule any coefficients of friction because a consensus method for rating slip resistance still remains elusive. While different measurement devices and protocols have been developed over the years for use in the laboratory or the field, a widely accepted method has not yet emerged. Since rating systems are unique to the test method, specific levels of slip resistance can only be meaningfully specified according to a particular measurement protocol. Some flooring products are labeled with a slip resistance rating based on a laboratory test procedure.

Another commenter, a transportation research center, noted that the wheelchair securement systems used in many non-rail vehicles—especially small buses and vans—are floor mounted and have openings that allow wheelchair tie downs to be attached using the openings. As a consequence, this commenter observed that most securement systems would not satisfy the proposed maximum opening in walking surfaces (i.e., passage of a sphere no more than 5/8 inch or 16 mm in diameter). See 2010 NPRM, Section T802.3). To address this concern, an exception has been added to the final rule that allows a larger opening (7/8 inch width maximum) for wheelchair securement system components affixed to walking surfaces, provided that, where such openings are greater than 5/8 inch in width, they visually contrast with the rest of the walking surface. See 2016 Non-Rail Vehicle Guidelines, T302.3, Exception 1. We do not, however, adopt this commenter’s additional suggestion that wheelchair securement system components be exempted from the surface discontinuity requirements, which, in their view, was needed due to concerns about the commercial availability of products that meet this standard. We have identified several recessed or flush-mounted securement systems currently on the market that would comply with the requirements in the final rule. Accordingly, the final rule does not exempt wheelchair securement systems from compliance with the technical requirements for surface discontinuities in T302.4.