Back-drivable steer-by-wire system with positive scrub radius

In an embodiment of the present invention, an apparatus for steering a vehicle is disclosed. The apparatus includes a back-drivable steer-by-wire system including a road wheel actuator assembly (300) coupled to a wheel of the vehicle The road wheel actuator assembly (300) defines a steering axis (303,305) and the steering axis (303,305) is off-set from a longitudinal axis (410,510) of the wheel by a positive scrub radius (SRp). In an embodiment for a method in accordance with the present invention, a method to steer a vehicle after failure of a road wheel actuator assembly (300) in a back-drivable steer-by-wire steering system is disclosed. The method includes the acts of applying a braking force to the wheel and generating a torque on the road wheel actuator assembly by the applied braking force acting through a positive scrub radius.