A drowsiness alarm system for a vehicle detects and signals that the vehicle driver is drowsy on the basis of the duration during which no steering adjustments are made and the magnitude and speed of abrupt steering adjustments immediately following the non-steering period. Parameters compared to the magnitude and speed of the abrupt steering adjustments in order to recognize steering behavior reflecting drowsiness are adjusted in accordance with the duration of the non-steering period.
Method and system for detection of driver drowsiness by an abrupt steering change following no steering movement