If the ruling gradient on a highway is 5%, what will be the compensated gradient for a curve radius of 60 m?

Given that the safe distance between overtaking and overtaken vehicles, both before and after overtaking, is 30 m, and the acceleration capacity of the vehicle is 1.3 m/s2, what is the overtaking time?

A road bend deflecting by 80° is to be designed for a maximum speed of 2 km/min (120 km/h), maximum centrifugal ratio of 0.25, and a rate of change of radial acceleration of 300 mm/s3 (0.3 m/s3). If the circular arc is combined with two cubic spirals, what is the approximate radius of the circular arc?