How to improve trains' circulation

Railways nodes are considered as a combination of heterogeneous elements such as medium-large passenger stations, service stations, and lines for their interconnection. Their management is important to make more efficient rail transport and to promote a new urban mobility. This paper analyzes the critical features of railways existing nodes, looking mainly at the notion of railways capacity. Railway capacity is a dynamical concept strictly related to railways system's components. Those components are unpredictable; it means that the capacity varies according to train types, timetables, infrastructure layout and real operation conditions. The analysis takes into account all those factors with particular regard to infrastructures (paths of the lines, topological configurations of the stations, etc.), technology (signalling systems, conduct, etc.), and management (traffic regulations, operating models, etc.). Finally, some solutions are suggested to solve the problems connected to railways nodes. The increase of commercial speed, the reduction of propagation delay, the improvement of services' quality and the creation of new high-speed lines can be useful actions to increase efficiency and quality in railways sector.