A road bend deflecting by 80° is to be designed. The maximum speed is to be 2 km/min, maximum centrifugal ratio 0.25 and rate of change of radial acceleration of 300 mm/sec3. The circular arc is combined with two cubic spirals. The radius of the circular arc will be about
1
272.42 m
2
905 m
3
360.15 m
4
453 m