Abstract
In the man- vehicle- roadway system the driver himself is the most crucial element. For his information he largely depends on his visual system and also the primary means of transmitting information to him is by means of visual communications, e.g. traffic signs. Only recently also audio- communication is made possible by broadcasting. To discuss the capabilities and limitations of drivers in this context, drivers can be considered as information processing organisms, executing a special task, i.e. car driving. Given is a global characterization of the driving task, and some relevant knowledge about the driver and about temporary intra- individual and inter- individual variations will be discussed.