TRAVEL CONTROL DEVICE AND TRAVEL CONTROL METHOD

A travel control device includes ultrasonic obstacle detection sensors detecting an obstacle entering a rear side of a vehicle and a distance to the obstacle, and an image obstacle detection unit detecting the obstacle entering the rear side of the vehicle by using an image of the rear side. If a distance to the obstacle detected by the sensors is equal to or less than an activation threshold for warning, the travel control device issues a warning, and sets the activation threshold larger as the vehicle speed of the vehicle becomes high. If the vehicle is detected preparing to move rearward and the image obstacle detection unit detects the obstacle, the travel control device sets the activation threshold to a constant value regardless of the vehicle speed.