When a condition in which a plurality of conditions among the aforementioned reinforcement reference conditions overlap each other is satisfied (when a vehicle is present in a high-accident frequency area at 1 p.m. and is present on a road characterized in that a warning of a driver warning system is frequently output), point-deduction standard information for the corresponding vehicle may be determined as the largest value of point-deduction standard values set in a separate reinforcement reference condition. This is because a warning is output in the case of lane departure only once to cause inconvenience of a driver when respective point-deduction standards for a plurality of reinforcement reference conditions are summed. Needless to say, on the other hand, point-deduction standard values set in the respective reinforcement reference conditions may be summed, in which case a maximum value of the point-deduction standard values applied when the conditions overlap with each other may also be set.

According to at least one embodiment of the present invention configured as described above, an abnormal driving situation may be more effectively determined.

In particular, according to the present invention, when whether to output an alert is determined, the reference point and the point-deduction standard may be set in consideration of a route, a time period, and the like, and thus a warning may be effectively output.