Question

What is the advantage of banking of roads

Answer 1

It becomes easy to take turns with high velocity.
hope it helps you out

Answer 2

Necessity of Banking: As the speed of vehicle increases, the centripetal force needed for the circular motion of vehicle also increases.

... Also, the force of friction is not always reliable because it changes when roads are oily or wet due to rains etc.

To eliminate this difficulty, the curved roads are generally banked.