2013 Forest Service Outdoor Recreation Accessibility Guidelines (FSORAG)

2.3 Clear Tread Width.

The clear tread width of an ORAR shall be at least 36 inches (915 mm). 

Figure 1—The clear tread width is the unobstructed width of the traveling surface.

• Exception 1. Where a condition for an exception in section 1.1 prevents achieving the required width, the clear tread width may be reduced to 32 inches (815 mm) minimum. If the condition for an exception prevents achieving the reduced width of 32 inches, comply to the extent practicable.

• Exception 2. Where an ORAR is provided within a vehicular way, clear passage of 32” is required around or through speed restriction devices, gates, and other barriers on the roadway.