Correct option is D
Transition curve is used to introduce a circular curve to a strength line by smoothly varying the radius of the curve from infinity (straight line) to radius (circular curve).
A transition curve is a type of curve with a varying radius that is introduced between a straight path and a curve or between two curves with different radii. The purpose of a transition curve is to provide a gradual change in curvature, which helps in avoiding sudden changes in direction or speed, ensuring a smoother and safer transition.
Key Points:
Transition Curve: It is typically used in road and railway design to connect a straight section with a curved section or to connect two curves with different radii. The radius of the transition curve changes gradually from infinity (straight line) to the radius of the main curve, or from one curve radius to another.
Application: The use of a transition curve helps in reducing lateral acceleration and discomfort for vehicles or trains moving through the curve. It also reduces the risk of derailment or skidding by providing a more gradual change in direction.
