A driver alert system for the steering wheel of a motor vehicle. The system comprises an electric motor, an eccentric mass connected to the electric motor, and a control circuit for providing electric supply to the electric motor in response to an alert activation signal The motor is controlled by the control circuit to an operation level of voltage during a portion of a vibration period with a non-vibration period following the vibration period, and the motor is over or under-controlled with respect to the operation range at the beginning or end of said vibration period.