A method is presented which correlates injuries in real accidents with Dummy Loadings. This procedure was applied to frontal car/car collisions with 318 occupants wearing safety belts. Dummy Loadings on head, chest and pelvis are confronted with real injury severity in the sub-critical injury level and maximum tolerance limits are deduced. The Dummy Loading curves are worked out by means of a comprehensive calculating simulation. The calculation programs applied were calibrated with crash tests and sled runs. The connection between simulation and real accidents is formed by an Equivalent Accident Characteristic for the defining of the accident severity; the velocity change ▵v has proved to be practicable and reliable for the frontal collisions analysed here. Both results of simulation and accident analysis are related to the reference factor “▵v”. By elimination of the accident characteristic ▵v direct relation between real injury and Dummy Loading was established. Corresponding Dummy Loadings for subcritical AIS-values are given. The tolerance limit for fatal head injuries was found at about HIC = 1 600 and therefore is higher than it is assumed up to the present time. The tolerance limit of the chest of SI = 1 000 has been confirmed. For pelvis/abdominal injuries the tolerance limit resulted in a value of 74 g. Possibilities for further research works are indicated. The method will be modified also for side collisions and total Dummy Load index in the subcritical area in later reports.