Outdoor Developed Areas: A Summary of Accessibility Standards for Federal Outdoor Developed Areas

Cross Slope [1017.7.2]

Cross slope is the side-to-side slope of a trail tread. Some cross slope is necessary to provide drainage and to keep water from ponding and damaging the trail surface, especially on unpaved or natural surfaces.

When the trail surface is constructed of concrete, asphalt, or boards, the cross slope must be no steeper than 1:48 (2 percent). When the trail surface is constructed of materials other than asphalt, concrete, or boards, cross slopes no steeper than 1:20 (5 percent) are allowed when necessary for drainage.