Images: Car tech for the masses

Lane-departure-warning or lane-assist systems use cameras to detect lane markings on the road and warn drivers when they drift out of lane. (They don't go off if the driver has put the turn signal on.) Some manufacturers use a beep as a warning. Others, such as Audi and BMW, vibrate the steering wheel. The vibration method is meant to simulate a feeling drivers are already used to when they drift off-road and are met with a rumble strip," BMW's Plucinsky said.

For more on the technology, check out this CNET video.

Photo by Audi