The forward-looking camera constantly monitors the vehicle position in the driving lane and checks for sudden and exaggerated corrections, which are characteristics of drowsy or inattentive driving. Based on this information and the history of the calculated vigilance level, the system issues two levels of warning – a soft-, or hard-warning. The soft-warning consists of an audible chime to alert the driver to the message in the cluster screen. This chimes for 10 seconds and if the driving behaviour does not change then the hard-warning occurs. The hard-warning is triggered if the vigilance level calculated by the system remains below a certain level. It also comes along with an audible chime to alert the driver, but it is now more intrusive to urge the driver to take a rest.