Comparative Application of Methods for the Combined Lines-Nodes Capacity Assessment

Nowadays, a considerable percentage of trains mature delays due to nodes and stations congestion. They are normally a combination of effects of routes conflicts in stations on lines and propagation in stations of delays suffered along the lines. It is a consequence of the variable values of capacity within the railway system caused by a combination of parameters, more relevant when short line sections separate nearby stations. Goal of the research is to compare some literature methods for the assessment of nodes and lines capacity to identify their reciprocal effects and innovative approaches. The work is included in a research framework with the final goal of traffic optimization and minimization of delays. In order to tackle the purpose, the paper introduces synthetically the methods and applies them systematically to a complex text network, including single and double track lines and various typologies of stations. The results of the methods applications are compared each other and with the outputs of a simulation approach. This analysis highlights the most appropriate application fields of single methods and the need of their integration and combination in terms of inputs, intermediate and final results. The review of single and coordinated use of these methods will move towards the definition of a comprehensive new methodological approach for combined lines-nodes capacity calculation. It will represent a powerful instrument to facilitate decision making on operational and infrastructural improvements of complex railway networks.