The aim of the study is to draw scientifically based conclusions about the most frequent objective causes of serious traffic accidents, as well as to draw conclusions based on the results of the analysis for the development of safe infrastructure and improvement of traffic safety. The focus of the study is to detail and specify the causes of serious traffic accidents and identify critical parameters in traffic infrastructure and traffic processes with the help of in-depth data analysis. The study uses both publicly available data and data obtained directly from traffic accident case holders and by conducting additional research on the site of traffic accidents. Statistical methods are used as analysis tools.