Zero crossing (cross slope)
The zero crossing is a special form of cross slope in road and path construction. It describes the cross profile in the area of a twist from a one-sided slope to the opposite slope, where the cross slope is absolutely horizontal and is therefore zero. The zero crossing should be avoided outside of twisting areas, since in the worst case there is no runoff of the surface water at this point and thus aquaplaning can occur. A twisting area with zero crossing may therefore only be created if the surface water can flow away in some other way (usually the presence of a sufficient longitudinal slope ).