Outdoor Developed Areas: A Summary of Accessibility Standards for Federal Outdoor Developed Areas

Running Slope [1017.7.1]

Running slope, also referred to as grade, is the lengthwise slope of a trail, parallel to the direction of travel. Trails or trail segments of any length may be constructed with running slopes up to 1:20 (5 percent). To accommodate steep terrain, trails may be designed with shorter segments that have a running slope and length, as shown in table 2, with resting intervals at the top and bottom of each segment.

To ensure that a trail is not designed as a series of steep segments, no more than 30 percent of the total length of the trail may have a running slope exceeding 1:12 (8.33 percent). The running slope must never exceed 1:8 (12 percent). Resting intervals must be provided more frequently as the running slope increases (figure 8).

Figure 8—The running slope is measured along a trail’s length; the cross slope is measured across its width.

 CONSTRUCTION TIP—How is running slope measured?

Running slope is often described as a ratio of vertical distance to horizontal distance, or rise to run (figure 9). For example, a running slope of 1:20 (5 percent) means that for every foot of vertical rise, there are 20 feet of horizontal distance. The technical requirements specify running slope as both a ratio and percentage.

Figure 9—Determining the slope ratio.