ABA Accessibility Standard for GSA Facilities Pocket Guide

302.3 Openings.

Openings in floor or ground surfaces shall not allow passage of a sphere more than ½ inch (13 mm) diameter except as allowed in 407.4.3, 409.4.3, 410.4, 810.5.3 and 810.10. Elongated openings shall be placed so that the long dimension is perpendicular to the dominant direction of travel.

Figure 302.3 Elongated Openings in Floor or Ground Surfaces