Widening on Curves:
Pavements have to be widened on curves because of the fact that :
(a) the vehicle has a wheel base and overhang on the front and rear, and the vehicle path of the front wheel and rear wheels are different.
(b) the drivers have difficulty in steering their vehicles exactly on the centre line and have a psychological shyness to drive close to the edges of the pavement on curves.
Widening upto 1.5 m is provided on two-lane roads upto a radius of 300 m, beyond which no widening is needed.