If the rate of change of grade permitted along a vertical curve is r and total change of grade is g%, the length L of the curve to be provided, is

Highway engineering (also known as roadway engineering and street engineering) is a professional engineering discipline branching from the civil engineering subdiscipline of transportation engineering that involves the planning, design, construction, operation, and maintenance of roads, highways, streets, bridges, and tunnels to ensure safe and effective transportation of people and goods. (Source: Wikipedia)