A target vehicle speed is switched between a target slip vehicle speed and a target torque vehicle speed on the basis of a result of a determination regarding whether or not a vehicle is insufficiently accelerated. More specifically, if traction control is not performed, the target slip vehicle speed is set as the target vehicle speed. If it is determined that the vehicle is sufficiently accelerated during traction control, a value obtained by subtracting a maximum permissible value from a value set last time as the target vehicle speed is compared with the target slip vehicle speed, and the larger one of them is set as the target vehicle speed this time. If it is determined that the vehicle is insufficiently accelerated during traction control, the larger one of the target slip vehicle speed and the target torque vehicle speed is compared with a value obtained by adding a maximum permissible value to a value set last time as the target vehicle speed, and the smaller one of them is set as the target vehicle speed this time.