Dimensional Tolerances in Construction and for Surface Accessibility

1.1.3 Walk running slope. Measure for overall running slope (the primary direction of travel) by determining elevations at the ends of the walk, noticeable changes in slope, or at a maximum of 20 ft (6 m) intervals beginning at one end of the walking surface. Elevations should be measured at the midpoint of the width of the walking surface. Calculate the slope using the horizontal distance between elevation points and the difference between the elevations at those points (i.e. the rise over the run).