36 C.F.R. § 1192.79 Floors, steps and thresholds.
Title 36 - Parks, Forests, and Public Property
(a) Floor surfaces on aisles, step treads, places for standees, and areas where wheelchair and mobility aid users are to be accommodated shall be slip-resistant. (b) All thresholds and step edges shall have a band of color(s) running the full width of the step or threshold which contrasts from the step tread and riser or adjacent floor, either light-on-dark or dark-on-light.
Title 36: Parks, Forests, and Public Property
PART 1192—AMERICANS WITH DISABILITIES ACT (ADA) ACCESSIBILITY GUIDELINES FOR TRANSPORTATION VEHICLES
Subpart D—Light Rail Vehicles and Systems
§ 1192.79 Floors, steps and thresholds.

