A presupposition for the engagement of effective measures for motor cars with the aim of reducing the trauma of traffic participants are findings of the Traffic Accident Research about the influence of vehicle-, traffic participant- as well as accident- parameter on trauma. Contrary to dummy tests, the correlation dummy - human body, vital - postmortem tissue is eliminated in the analysis of real accidents. It is however, supplemented by the age parameter. Besides assessing the trauma of single body regions, it is also possible to evaluate the overall trauma of the body.From the traffic accident development of the FRG it is evident that the relative danger for child passenger car-occupants as well as for pedestrians, compared with other groups of traffic participants is increasing.Based on 130 medically and technically thoroughly worked out single-case analyses of real accidents involving child car-occupants the importance of supposed major influencing parameters on trauma, such as impact direction, seating position as well as age, have been investigated. For the comparison of groups and as a measure of the dynamic load to the vehicle during the crash phase, the vector of resultant speed changing of the center of gravity of car is calculated. For the valuation of the trauma, costs arising as injury sequence - assessed separately for children and other people - are applied under consideration of injury frequency and average ▵v of groups to draw comparisons.For improvement measures, the injury causes are analysed by their costs. Finally the use-value and - as an example - the use/cost-value for restraint devices used by children, and for types of restraint-system disfunctions are calculated in line of order with their costs as sequence of their suffered injuries.Regarding the pedestrian accident, an optimisation of the vehicle exterior is only reasonable as far as their main groups are concerned. Based on 310 thoroughly worked out single-case analyses of real pedestrian accidents involving 170 children, the aggressivity of the vehicle, measured by the costs arising from injuries received, are analysed for vehicle frontal impacts regarding different front shapes and their elements, in order to establish priority in line of order with their cost-causing aggressiveness. For the layout of vehicle elements producing highest costs the body region strongest traumatised by them, combinations of the latter with vehicle elements are analysed in regard to their costs as consequence of caused injuries. In conclusion, measures regarding the vehicle exterior are proposed. As an also important result elements of requirements for test conditions resembling real accident occurences, are as relevant parameters methodically described in accordance with their occurances1.