Abstract. The article is devoted to the study of the factors determining the ability of a railway carrier to maintain the reliability, continuity and safety of the transportation process with an increase in the volume of transport work. The relevance of the study is due to an increase in traffic volumes, an increase in cargo turnover, an extension of the average range of transportation and an increase in transit load, which leads to an increased impact on infrastructure, rolling stock, dispatch control, repair facilities and the traffic safety system. In these conditions, the sustainability of the railway carrier’s activities should be considered as the ability to ensure stable transportation under the influence of technical, infrastructural, organizational, personnel, financial, digital and external economic factors. At the same time, the paper proves that the stability of a railway carrier cannot be assessed solely by operational or economic indicators, since an increase in transport work must be accompanied by maintaining manageability and an acceptable level of risks. As a methodological basis, a computational and analytical approach is proposed, including an assessment of the dynamics of cargo flows, the calculation of the average range of transportation, the determination of the operational load index, the assessment of the transit component, as well as the calculation of the required reduction in the specific risk of traffic safety. The final result of the assessment is the determination of an integral stability index, the value of which allows us to develop a number of measures to ensure traffic safety. Special attention is paid to the traffic safety coefficient, which is considered as a limiting parameter of the carrier’s integral stability. The practical significance of the methodology lies in the possibility of using calculated indicators to make management decisions aimed at improving the reliability of transportation, preventing traffic safety violations and ensuring the sustainable development of railway carriers in modern conditions.

Keywords: railway carrier, stability, cargo flows, traffic safety, operational load, specific risk.