System and method for monitoring the physiological behavior of a driver that includes measuring a physiological variable of a driver, assessing a driver's behavioral parameter on the basis of at least said measured physiological variable, and informing the driver of the assessed driver's behavioral parameter. The measurement of the physiological variable can include measuring a driver's eye movement, measuring a driver's eye-gaze direction, measuring a driver's eye-closure amount, measuring a driver's blinking movement, measuring a driver's head movement, measuring a driver's head position, measuring a driver's head orientation, measuring driver's movable facial features, and measuring a driver's facial temperature image.