The topics related to traffic safety are peculiar in many respects: They embrace quite a considerable number of safety-factors which, ultimately, would have to be connected with a considerable number of scientific disciplines, as communication theory, sociology, social psychology, the psychology and biology of perception, drug medicine, economics, traffic law, car and road construction technology, electronics and, of course, the methodology of data gathering, observation and statistical analysis. The papers of this volume give a feeling of the multitude of aspects and points of departure for studying traffic safety. But there is another peculiarity of the traffic-safety--area: It relates to a type of human communication which exists for a relatively short time in view of the centuries of history of civilisation, namely to the communication between persons driving with eventually high speed and with short distances between each other. To observe the other car's speed and movements and to expect reactions of the others to one's own speed and movements is a relatively new form of interaction, at least involving the high speeds as they are used on roads.