Superelevation is the angle or bank of a road surface. For example, superelevation of 0.01 is a 1% slope, which rises 1 unit for every 100 units of horizontal distance. The sign convention for superelevation depends on whether superelevation is affecting the turn positively or negatively, i.e. whether or not the slope of the ground is in favor of the turn. If a vehicle is turning right, and the ground is sloped down to the right, superelevation will be affecting the turn positively, and its value will be positive.

Leg Superelevation

Based on the AASHTO values, the approach leg superelevation is usually assumed to be 2% (+0.02), and the circulatory superelevation -2% (-0.02). The superelevation parameters can be set under Superelevation in the Design Guidelines' Fastest Path Category dialog box.