Applying the Forest Service Outdoor Recreation Accessibility Guidelines (Continued)
Getting from Here to There—Outdoor Recreation Access Routes (Continued)
Clear Tread Width and Passing Spaces for ORARs
Clear tread width means the width of the traveled surface on the ground and also above the ground between obstacles (figure 32). The minimum clear tread width of an ORAR is 36 inches (915 millimeters), which is wide enough to allow unobstructed passage by a wheelchair. Where a condition for departure exists, such as when an ORAR must be routed between two large boulders that can't be removed, then the clear tread width may be reduced to not less than 32 inches (815 millimeters) for a maximum distance of 24 inches (610 millimeters).
Figure 32—The clear tread width is the width
of the unobstructed traveling surface.
DESIGN TIP—How Wide Should the Access Route Be?
The 36-inch (915-millimeter) minimum clear tread width is just that—a minimum. To determine how wide the ORARs in a project should be, look at the level of development of the site and how it will be used. In a more highly developed area, a 48- or 60-inch- (1,220- or 1,525-millimeter-) wide ORAR may be appropriate, while a 36-inch- (915-millimeter-) wide tread may be a better fit in a less developed site.
All ORARs in a recreation site don't necessarily have to be the same width. It may make sense to vary the width, depending on the location of the ORAR. For example, a designer may decide to make the main ORAR 60 inches (1,525 millimeters) wide if it connects campsites to important constructed features, such as a rustic outdoor amphitheater, toilet buildings, or water hydrants.
Secondary ORARs, such as a spur from the main ORAR to a quiet, intimate path along a stream, may be only 36 inches (915 millimeters) wide. Consider how many people will likely be using the ORAR at the same time and how they will want to use it—single file or walking and talking side by side—and design accordingly.
Two wheelchairs need 60-inch- (1,525-millimeter-) clear tread width to pass comfortably and safely on an ORAR. However, this width isn't always appropriate or required. Where the clear tread width of an ORAR is less than 60 inches (1,525 millimeters), passing spaces are required at least every 200 feet (60 meters). If this isn't possible because of a condition for departure, an exception is provided that permits passing spaces to be 300 feet (90 meters) apart. Passing spaces must be at least 60 inches (1,525 millimeters) wide (including the ORAR width) by 60 inches (1,525 millimeters) long (figure 33).
Figure 33—A passing space for an
ORAR or a beach access route.
Another option allows a T-intersection of two ORARs or other walking surfaces to be a passing space (figure 34), provided that the arms and stem of the T-shaped space extend at least 48 inches (1,220 millimeters) beyond the intersection. Either configuration would provide enough room for someone to move to the side and let an oncoming person pass along the ORAR. The cross slope of a passing space shouldn't exceed 3 percent.
Figure 34—A “T” Intersection for passing
on an ORAR or a beach access route.
Tread Obstacles on ORARs
A tread obstacle is anything that interrupts the evenness of the tread surface. On ORARs, an obstacle may occur where a tree root or rock protrudes above the surface or where two different surfaces abut, such as when a concrete path joins an asphalt path. If they are pronounced, tread obstacles can pose a serious tripping hazard. Where tread obstacles exist along an ORAR, they can't be more than 1 inch (25 millimeters) high. If compliance with this provision isn't possible because of a condition for departure, an exception permits obstacles up to 2 inches (50 millimeters) high, provided that the obstacle is beveled with a maximum 1:2 slope.
Protruding Objects and ORARs
Protruding objects extend into the clear width area of an ORAR from beside or above the ORAR. Leaning tree trunks, rock ledges, and branches are common protruding objects. The ORAR must provide at least 80 inches (2,030 millimeters) of clear headroom (figure 35), which is the same requirement as ABAAS section 307. Where the vertical clearance of an ORAR is reduced to less than 80 inches (2,030 millimeters) because of a condition for departure, a barrier to warn blind and visually impaired persons must be provided. This exception allows an ORAR to pass under ledges or other naturally constricted areas.
Figure 35—A warning barrier is required wherever
vertical clearance is insufficient.
Openings in ORAR Surfaces
Openings are gaps in the surface of an ORAR. Gaps include spaces between the planks on a boardwalk or in a drainage grate. Openings that are big enough for wheels, cane or crutch tips, or shoe heels to drop through are hazards that shouldn't be designed in pedestrian routes (figure 36). Openings up to ½ inch (13 millimeters) wide are permitted. Elongated openings must be placed so that the long dimension runs perpendicular or diagonal to the primary direction of travel (figure 37). Openings narrower than ¼ inch (6.4 millimeters) are allowed parallel to the dominant direction of travel.
Figure 36—Big openings in ORAR
surfaces are a bad idea.
Figure 37—Elongated openings must be
perpendicular to the direction of travel.
Edge Protection for ORARs
Edge protection is a raised curb, wall, railing, or other structure that defines the edge of a travel surface and helps keep people and assistive devices from accidentally falling off the edge. Edge protection is not required for accessibility on ORARs. However, where designers and managers have determined that edge protection is required for safety or other reasons, the FSORAG requires curbs to be at least 3 inches (76 millimeters) high (figure 38). This is higher than required by the ABAAS because objects less than 3 inches (75 millimeters) high aren't easy to see or detect outdoors and could become a tripping hazard.
Figure 38—Edge protection is optional on an ORAR, but if present,
edge protection must be at least 3 inches high.
