What does a coffee cup symbol on the car dashboard mean?

Statistics helped create demand for in-car devices that help ensure that drivers stay awake. Many automakers, including BMW, Mercedes-Benz, Audi, Cadillac and Buick, offer lane departure warnings. Mercedes's Attention Assist system, standard on some models, creates an individual driver profile and compares that to data from the car's sensors to measure the state of alertness. Mercedes' visual warning is a coffee cup icon appearing on the dashboard.