APPENDIX TO PART 1192-ADVISORY GUIDANCE

This appendix contains materials of an advisory nature and provides additional information that should help the reader to understand the minimum requirements of the guidelines or to design vehicles for greater accessibility. Each entry is applicable to all subparts of this part except where noted. Nothing in this appendix shall in any way obviate any obligation to comply with the requirements of the guidelines themselves.

I. SLIP RESISTANT SURFACES-AISLES, STEPS, FLOOR AREAS WHERE PEOPLE WALK, FLOOR AREAS IN SECUREMENT LOCATIONS, LIFT PLATFORMS, RAMPS

Slip resistance is based on the frictional force necessary to keep a shoe heel or crutch tip from slipping on a walking surface under conditions likely to be found on the surface. While the dynamic coefficient of friction during walking varies in a complex and non-uniform way, the static coefficient of friction, which can be measured in several ways, provides a close approximation of the slip resistance of a surface. Contrary to popular belief, some slippage is necessary to walking, especially for persons with restricted gaits; a truly "non-slip" surface could not be negotiated.

The Occupational Safety and Health Administration recommends that walking surfaces have a static coefficient of friction of 0.5. A research project sponsored by the Architectural and Transportation Barriers Compliance Board (Access Board) conducted tests with persons with disabilities and concluded that a higher coefficient of friction was needed by such persons. A static coefficient of friction of 0.6 is recommended for steps, floors, and lift platforms and 0.8 for ramps.

The coefficient of friction varies considerably due to the presence of contaminants, water, floor finishes, and other factors not under the control of transit providers and may be difficult to measure. Nevertheless, many common materials suitable for flooring are now labeled with information on the static coefficient of friction. While it may not be possible to compare one product directly with another, or to guarantee a constant measure, transit operators or vehicle designers and manufacturers are encouraged to specify materials with appropriate values. As more products include information on slip resistance, improved uniformity in measurement and specification is likely. The Access Board's advisory guidelines on Slip Resistant Surfaces provides additional information on this subject.

II. COLOR CONTRAST-STEP EDGES, LIFT
PLATFORM EDGES

The material used to provide contras should contrast by at least 70%. Contrast percent is determined by:

Contrast = [(B1 - B2)/B1]×100

where B1 = light reflectance value (LRV) the lighter area

and B-light reflectance value (LRV) of the darker area.

Note that in any application both white and black are never absolute; thus, B, never. equals 100 and B is always greater than (

III. HANDRAILS AND STANCHIONS

In addition to the requirements for hand! rails and stanchions for rapid, light, and commuter rail vehicles, consideration should be given to the proximity of hand rails or stanchions to the area in which wheelchair or mobility aid users may posi tion themselves. When identifying the clear floor space where a wheelchair or mobility aid user can be accommodated, it is suggest ! ed that at least one such area be adjacent or in close proximity to a handrail or stanchion. Of course, such a handrail or stanchion cannot encroach upon the required 32 inch width required for the doorway or the route leading to the clear floor space which must be at least 30 by 48 inches in size.

IV. PRIORITY SEATING SIGNS AND OTHER
SIGNAGE

A. Finish and Contrast

The characters and background of signs should be eggshell, matte, or other nonglare finish. An eggshell finish (11 to 19 degree gloss on 60 degree glossimeter) is recommended. Characters and symbols should contrast with their background-either light characters on a dark background or dark characters on a light background. Research: indicates that signs are more legible for persons with low vision when characters con trast with their background by at least 70 percent. Contrast in percent is determined by:

Contrast = [(B1 - B2)/B1]X100

where B1 = light reflectance value (LRV) of the lighter area

and B2 = light reflectance value (LRV) of the darker area.

Note that in any application both white and black are never absolute; thus, B1 never equals 100 and B2 is always greater than 0.

The greatest readability is usually achieved through the use of light-colored characters or symbols on a dark background.