Horizontal Curve Radius

 

Minimum horizontal curve radius is calculated based on the following formula :

 

 

                Where,

                        = 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.