Ideal vertical curve is circular if sight distance available throughout the length of curve is constant it possible only in case of Joining one Gradient. In this case, two gradient are Joint by curve therefore sight distance is not constant throughout the length of curve so we provide Simple Parabolic curve.

Vertical Curve in Highway Engineering

A vertical curve is a curve that is used to connect two different grades on a roadway. It is an essential element in highway engineering that helps to ensure the safety and comfort of drivers. The main purpose of a vertical curve is to provide a smooth transition between two different grades, which can be either uphill or downhill.

Types of Vertical Curves

There are four types of vertical curves that are commonly used in highway engineering:

1. Circular Curve
2. Parabolic Curve
3. Elliptical Curve
4. Reverse Curve

Among these four types, the parabolic curve is considered the most ideal for joining two gradients. Here are some reasons why:

Parabolic Curve

1. Smooth Transition: A parabolic curve provides a smooth transition between two different grades, which helps to ensure the safety and comfort of drivers. This is because the curve has a constant rate of change of slope, which means that the slope changes gradually over the length of the curve.

2. Easy to Design: A parabolic curve is easy to design using simple mathematical equations, which makes it a popular choice among highway engineers.

3. Low Construction Cost: A parabolic curve requires less earthwork than other types of curves, which makes it more cost-effective to construct.

4. Less Maintenance: A parabolic curve requires less maintenance than other types of curves because it has a smooth surface that is less prone to wear and tear.

Conclusion

In conclusion, a parabolic curve is the most ideal type of vertical curve to join two gradients in highway engineering. It provides a smooth transition between two different grades, is easy to design, has a low construction cost, and requires less maintenance.