14 A SUMMARY OFACCESSIBILITY STANDARDS FOR OUTDOOR DEVELOPEDAREAS accessibility standards for Federal outdoor developed areas Technical Requirements  The technical requirements for trails include specific provisions for the sur- face, clear tread width, passing spaces, tread obstacles, openings, running slope, cross slope, resting intervals, protruding objects, and trailhead signs. Using the Trail Exceptions [10171, Exceptions 1 and 2] When a condition for exceptions does not permit full compliance with a spe- cific provision in the technical requirements on a portion of a trail, that portion of the trail must comply with the specific provision to the extent practicable. When extreme or numerous conditions for exceptions make it impracticable to construct a trail that complies with the technical requirements, the entire trail can be exempted from complying with the technical requirements. An entire trail can be exempted from the technical requirements only after apply- ing the conditions for exceptions to portions of the trail. When determining whether to exempt an entire trail from the technical requirements, consider the portions of the trail or beach access route that can and cannot comply with the specific provisions in the technical requirements and the extent of compliance where full compliance cannot be achieved. Additional information on the conditions for exceptions, including docu- menting use of the exceptions on portions of a trail and notifying the Access Board when an entire trail is exempted from the technical requirements, is provided in the section of this guide on the conditions for exceptions.