Which of the following is/are correct?
1
Transition curve is provided to gradually increase the radius of curvature of the pavement.
2
Psychological widening will be zero for a single-lane road.
3
In the case of equilibrium superelevation, transverse friction is zero and the reaction on the tyre towards the outer edge will be more than the tyre towards the inner edge of the pavement.
4
As per IRC, the ruling design speed for the national highway in rolling terrain is 80 kmph.