Abstract: A steering apparatus for a steerable vehicle includes a steering unit, an operating unit, a backup unit, and a control unit. The backup unit selectively connects/disconnects the steering unit and the operating unit. The control unit is operable in two control modes including an SBW mode and a PS mode. In the SBW mode, the control unit separates the steering unit from the operating unit; controls a steer angle of the vehicle in accordance with a manual steering effort; and switches the control mode from the SBW mode to the PS mode when an SBW-to-PS mode switch condition is satisfied, the SBW-to-PS mode switch condition including a condition that the steer angle is larger than or equal to a first threshold angle. In the PS mode, the control unit connects the steering unit and the operating unit; controls an assist steering effort to boost the manual steering effort.