Purpose: to improve the safety of railway rolling stock in curves and on mountain-pass sections of the track. Methods: the methods of investigating emergency situations during the transportation of railway goods, as well as the main characteristics affecting the rolling stock, are given. An essential role in ensuring traffic safety is played by identifying the causes of emergency situations, which are based n data obtained during site surveys using special laboratories. After receiving the data, an appropriate analysis of the locomotive-wagon-track system is carried out in each class of this system and the ratio of deviations in these classes to the fact of a derailment or other emergency situations is calculated. Results: when examining the scene of the accident, the commission for the investigation of emergency situations must establish the fact of the descent. Establishing the fact of a derailment during an investigation by an expert commission may include several tasks: investigation of damage to the car and track, the extent of these damages, analysis of violations of operating rules, study of standard fractures, etc. To determine this derailment, it is necessary to collect a large statistical database and divide it into the main deviations in different classes of the entire locomotive-wagon system the way”. Practical importance: the computational and empirical assessment and classification of the danger of various deviations in the characteristics of the system state, as well as the development of mathematical models of these processes and situations, are essential for ensuring traffic safety. This makes it possible to increase the accuracy of determining the degree of involvement of the car in the occurrence of an emergency situation in curves and in mountain-pass sections.