The high level of protection afforded by the safety belt has been proved in the past beyond doubt. The results of national and international studies of its effectiveness are given. The possible relative reduction of the frequency of injuries to different parts of the body is pointed out. These reduction quotas are derived by means of direct comparison from equivalent real-life accidents. The effects of a 100% and 85% belt-wearing rate is described for the traffic accident incidence in the Federal Republic of Germany.On the basis of selected study material comprising 200 belted car drivers who were involved in head-on collisions, the injuries to the different parts of the body are presented in relation to the accident severity. In the light of these injuries, technical measures to the car and the belt system are proposed which might effect a further reduction of injuries.