I can think of a couple of times when I've nodded off while driving. This feature would've come in handy. Special sensors in the steering wheels of new Mercedes E-Class cars will detect inattentiveness by the driver and sound an alarm.
Link via Geekologie
Once I became throroughly exhausted while driving. As I approached the next rest area, I suddenly saw the cars ahead of me on the road appear to shift places abruptly, as though were watching a movie from which several consecutive frames of film had been edited out at random intervals. Later, I recall awaking safely in a parking-space at the rest area, but unable to recall entering the area or parking. Scary!
My work schedule is still overtaxing. But since I've lost weight, I find it easier to stay alert while driving.
Is that for the driver of the benz who is tailgating or to warn them that they are being tailgating?