Highway Curves and Driver Safety

Highway curves are designed so that safety and comfort of the driver is maintained. There is a gradual change from a tangent to the start of a circular curve.

The outer edge is raised first until the outer half of the cross section is level with the crown (point B). Then, the outer edge is raised farther until the cross section is straight (point C). From there on, the entire cross section is rotated until the full super- elevation is attained (point E).

Superelevated roads are typically employed on curves of rural highways and urban freeways. Rarely you will see them on local streets in residential, commercial, or industrial areas.