Railway nodes in an integrated timetable-based network capacity assessment model

This paper explores an approach to integrate nodes into a timetable-based network capacity model that computes residual freight capacity for a given passenger timetable for strategic planning. Since timetable-based capacity assessment suffers from fluctuating freight traffic demand, we use pre-constructed slots on net segments and nodes which are combined into freight train paths for specific demand patterns. An evaluation, using a (max,+)-approach, of resulting slots and timetables ensures their robustness against delays and an acceptable level of service. As capacity assessment relies on an accurate modelling of railway node infrastructure, a sufficient level of accuracy must be derived. We demonstrate that publicly available open data sources contains the necessary information for achieving sufficient accuracy for strategic planning. From the provided layout of railway nodes – including tracks, switches, and signals – we can deduce additional relevant information, such as turn restrictions and the number of siding tracks for freight trains. This enables the construction of feasible slots and train paths in and through railway nodes, allowing for a network-wide capacity assessment. Moreover, our approach can accommodate different signalling and train control equipment and is flexible to allow data enrichment from other sources. The integrated model is applied in a case study on a railway node and its adjacent lines in Northern Germany to evaluate its effects.