Description: The inspection of the accident scene and the vehicles, the study of different traces and findings, the determination of the dynamic parameters of the movement, the choice of different methods, quantities and dependencies are the main tasks of the expert. Measurement of vehicle deformations is an important point in the expert study of road accidents. In expert practice, it is very important for experts to know the influence of different input parameters on outputs. Knowledge of this can improve the analysis of the accident and the quality of the expertise. This paper presents a study of the effect of the depth of deformation and mass of the vehicle on the speed of a real accident.