Abstract: A steering assistance controller for the generation of a compensating torque which assists the driver in overcoming the tendency of a vehicle to oversteer by encouraging the driver to steer the vehicle back to a non-steering condition through the application of said compensating torque which is based substantially upon an estimate of magnitude of oversteer.

Abstract: An electric assisted steering system for a motor driven road vehicle, having assist torque signal generating means which generates an assist torque signal for the steering system in response to the driver's applied torque and sensed vehicle speed to reduce the driver's steering effort. A yaw rate haptic torque is generated which is based upon vehicle rate error and is arranged to be added to the torque assist signal such that, when the yaw rate error builds up corresponding to increasing steering instability (e.g. understeer or oversteer) of the vehicle, the haptic torque added to the torque assist signal reduces the effective road reaction feedback sensed by the driver in advance of any actual vehicle stability loss whereby to allow the driver to correct appropriately in good time before terminal steering instability is reached.