The article focuses on theoretical and practical issues of relationship between demand for rail cargo transportation and development of transit and traffic capacity of the railway network. The current situation of public railway transport in the transport system of Russia is described. The dynamics of the main volume indicators of the transport complex over several years is analyzed, the key cargo groups, which account for more than 75 % of the traffic volume, are identified in the structure of traffic volumes. An algorithm is proposed for economic evaluation of railway infrastructure development projects in conjunction with the dynamics of development of commodity markets. The relationship and nature of mutual influence of the elements of the algorithm for economic evaluation of railway network development projects are identified. Examples of currently implemented integrated investment projects of JSC Russian Railways aimed at attracting perspective cargo volumes are commented. The objective of the article is to develop methodological tools for economic evaluation of projects for developing the transit and traffic capacity of a railway network in the face of changing directions and volumes of cargo flows, considering the dynamics of development of external and internal commodity markets. In accordance with the objective, the main tasks comprise comparative assessment of the indicators used in domestic practice, used to determine the impact of market conditions as compared with indicators used by leading foreign companies for these purposes; assessment of the value of integrated investment projects for development of transit and traffic capacity (at the example of Russian railway network) under the conditions of dynamically developing external and internal commodity markets; development of an algorithm for evaluating railway infrastructure development projects to ensure a higher level of quality of transport services with the aim of assessing mutual influence of individual project parameters and their balance, depending on the dynamics of external and domestic product markets, as well as on the need to attract investment resources. Empirical and theoretical methods, such as collecting and analyzing information, deduction, modelling, comparison, technical and economic calculations, an economic and statistical method, were used to implement the goals and objectives set in the article. It is concluded that it is necessary to consider dynamically changing conditions of commodity markets when assessing the prospects for development of the railway network.