TRAVELING CONTROL APPARATUS FOR VEHICLE AND TRAVELING CONTROL PROGRAM THEREOF

A traveling control apparatus for a vehicle that travels by transmitting force of a driving motor to tires is provided, including: a relaxation length calculation unit that calculates a relaxation length of the tires in a longitudinal direction as a moving distance required until a lateral force reaches a steady-state value when a slip angle is present in the tires; and a slip rate calculation unit that divides a deviation length of a deformation of the tires in the longitudinal direction, by the relaxation length calculated at the relaxation length calculation unit, thereby calculating a slip rate indicating a degree of slip between the tires and a road surface.