2013 Forest Service Outdoor Recreation Accessibility Guidelines (FSORAG)

3.1.3 Slope of Vehicle Parking Spurs.

The slope of parking spurs shall comply with applicable provisions of section 3.1.3. 

3.1.3.1 Slope of Vehicle Parking Areas.

The slope of vehicle parking areas shall not exceed 1:48 (2 percent) in any direction.

Exception. When the surface is not paved, slopes not steeper than 1:33 (3 percent) shall be permitted where necessary for drainage. 

3.1.3.2 Running Slope (Grade) of Driveways.

The running slope of driveways shall be no more than 1:12 (8.33 percent) for no more than 50 feet (15 m).

Exception 1. A running slope of up to 1:10 (10 percent) for driveways is permitted for up to 30 feet (9 m).

Exception 2. For alteration only, not new construction, if exception 1 of section 3.1.3.2 cannot be met because one or more conditions for exception in section 1.1 exist, a running slope of no more than 1:10 (10 percent) is permitted for no more than 50 feet (15 m).

3.1.3.3 Cross Slope of Driveways.

The cross slope of driveways shall not exceed 1:33 (3 percent).

Exception. The cross slope of driveways may be no more than 1:20 (5 percent) where needed to ensure proper drainage or to transition from the running slope of a campground road.