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

1018.6 Openings

This section requires openings in the surface of beach access routes and resting intervals such as spaces between boards to not allow passage of a sphere more than 1/2 inch in diameter. Elongated openings should be placed so that the long dimension is perpendicular, or as close to perpendicular as possible, to the dominant direction of travel.