Lane departure warning technique

A lane departure warning technique that reduces false warnings in the case of intended lane departures is described. In a first step, a first parameter indicative of lane boundary position (130) and a second parameter indicative of a level of vehicle driver alertness are determined. Then, a virtual lane boundary (150) is determined based on the first and second parameters. In a next step the position of the vehicle (100) relative to the virtual lane boundary is determined. An alarm signal is generated in case of an actual or forthcoming crossing of the virtual lane boundary. As the position of the virtual lane boundary is based on the alertness level of the vehicle driver false warnings of attentive drivers can be prevented by intentionally allowing an attentive driver to cross the actual lane boundary.