train separation, automatic block system, ABTC-MSh system, moving block, interlocking, automatic cab signalling, train control system The article discusses the development of automatic block systems, which form the basis of separation systems. It also highlights the key factors limiting the capacity on open lines, and ways to solve them. A brief overview of the foreign experience of the organization of train separation using automatic block system based on track circuits is given. The article shows the capabilities and role of the computerbased automatic block signalling system with a centralized placement of equipment, audio frequency track circuits and duplicating information transmission channels as an important element of the train traffic management at the sections of Moscow Central Diameters. The significance of the implemented non-stop passage of trains along the main station tracks providing substantial section capacity increase is demonstrated. The necessity of building a digital system for train spacing is shown, which makes it possible to implement the moving block technology with-in the station ensuring the movement of trains on open lines and at stations with the same headway. The advantages of a new type of the computer-based automatic block signalling system as a basic element of a promising Russian train traffic control system and the positive effects of its implementation on the Russian railway network are indicated. The direction of development of train separation systems is outlined within the framework of further digitalization.