An driving assist control unit controls actuators such as a front wheel steering device, an accelerator pedal mechanism, an alarm lamp. The control units estimates permissible tire-force being capable of acting on the vehicle tire on the basis of road-surface friction coefficient and ground load of the tire, and then calculates tire-force margin by subtracting current tire-force currently acting on the tire, such as total driving force and lateral force, from the permissible tire-force. The control unit then controls steering reaction force of the front wheel steering device, reaction force of the accelerator pedal, and flashing frequency of the alarm lamp in accordance with the magnitude of the tire-force margin, respectively.