accessibility standards for Federal outdoor developed areas 41 Openings [1016 6] Openings are gaps in the surface of an ORAR. Gaps, includ- ing spaces between the planks on a boardwalk or slots in a drainage grate, that are big enough for wheels, cane, or crutch tips to drop through or become trapped in are potential hazards (figure 13). Where possible, drainage grates should be located outside the minimum clear width of the ORAR. Openings in the surface of ORARs, passing spaces, and resting intervals must be small enough so that a sphere more than one-half inch in diameter cannot pass through. Where possible, elongated openings should be placed perpendicular, or as close to perpendicular as possible, to the dominant direction of travel. Figure 13—Whenever possible, elongated openings in outdoor recreation access routes should be placed perpendicular to the dominant direction of travel to avoid creating potential problems.