Minimum horizontal curve radius is calculated based on the following formula :
= radius defined to the vehicle’s travel path in ft (m),
= coefficient of side friction, typical 0.13
V = vehicle speed in ft/s (m/s),
g is the gravitational constant, 32.3 ft/s/s (9.807 m/s/s), and
e = number of vertical ft (m) of rise per 100 ft (m) of horizontal distance.