Question

Difference between valley curves and summit curves

Answer 1

It is a vertical curve provided when the gradient is downwards. Generally when the vehicle meets downward gradient it accelerates more and discomfort arises. So, in the design of valley curvein vertical alignment comfort is considered along with sight distance

Answer 2

The difference between valley curves and summit curves is as follows-

1. Valley curves: These curves have their convexity in the downward direction. These are also called sag curves and are of the cubic parabola shape. These are formed by the meeting of positive and negative gradients.

2. Summit curves: These curves have their gradient in the upward direction. These are also known as crest curves and their ideal shape is circular. These are formed when two positive gradients meet.