Which of the following conditions is to be satisfied by a transition curve?

Its curvature at its junction with the circular curve should be zero.

At the junction of transition and circular curves, the angle between their respective tangents should be 90°.

At the junction of transition and circular curves, the angle between their respective tangents should be zero.

The radius of the transition curve at its junction with the straight is infinity.

Solution

Correct option is C

• A transition curve is introduced between the straight and a circular curve which helps in gradually introducing the designed super elevation and the extra widening necessary.
• Overturning of vehicles on a curve can be avoided by using transition curve which gradually reduces the effect of centrifugal acceleration.
• IRC (Indian Roads Congress) recommended spiral nature transition curve for horizontal alignment and cubic parabola transition curve for vertical alignment (Valley curve).