A vehicle has a rear wheel drive device for driving rear wheels independently of a front wheel drive device. A drive mode control unit performs at least one of a first switching operation for switching between a front-wheel-only-drive mode and a rear-wheel-only-drive mode, a second switching operation for switching between a composite drive mode and the rear-wheel-only-drive mode, and a third switching operation for switching between the composite drive mode and the front-wheel-only-drive mode. When the drive mode control unit performs any one of the first switching operation, the second switching operation, and the third switching operation, an assistive force controller of the steering apparatus changes a control process for controlling a steering assistive force.