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

1015.2 Clear Ground Space

This section requires a clear ground space 36 inches minimum by 48 inches minimum positioned for either a forward or parallel approach to be provided at each distinct viewing location, and one full unobstructed side of the clear ground space to adjoin or overlap an outdoor recreation access route or trail, as applicable, or another clear ground space.