36 CFR Part 1191 ABA Accessibility Guidelines, Outdoor Developed Areas - Preamble

Surface Slopes

The proposed rule would have required clear ground spaces to have slopes not steeper than 1:50 in any direction, and would have permitted slopes not steeper than 1:33 when necessary for drainage. The final rule requires clear ground spaces to have slopes not steeper than 1:48 in any direction and, where the surface is other than concrete, asphalt, or boards, permits slopes not steeper than 1:20 when necessary for drainage. The final rule defines the term boards to include wood, plastic, metal, and composite products.

The proposed rule would have required outdoor recreation access routes and beach access routes to have cross slopes not steeper than 1:33, and would have permitted cross slopes not steeper than 1:20 when necessary for drainage. The proposed rule would have required trails to have cross slopes not steeper than 1:20. The final rule requires outdoor recreation access routes, trails, and beach access routes to have cross slopes not steeper than 1:48 and, where the surface is other than concrete, asphalt, or boards, permits cross slopes not steeper than 1:20 when necessary for drainage.