Introduction

Changing trains is a crucial part of many rail journeys. It is essential for reaching all destinations, but it takes time and is often stressful, especially when the arriving train is delayed. In models for cost-benefit analyses, interchange time for the railway is typically considered 2-3 times more expensive than in-vehicle time, see, e.g., ASEK (Trafikverket, 2020). Designing and operating railway stations in a way that could minimise the required interchange time is therefore vital for making rail travel attractive.

This study addresses the problem of using the platform tracks in the best way, balancing crossing train paths with easy interchanges across the same platform. Primarily, we look at the problem on a tactical level, i.e., timetable planning, but the insights are also useful on a strategic level for designing and re-designing railway stations, and on an operational level, doing the dispatching. This work is inspired by Johansson and Nilsson (2021), who have made an initial simulation study of various platform allocation strategies using the Arena Simulation Software.

Method

This study explores principal differences when prioritising a few crossing train paths versus fast interchanges, using simple, ideal principles for allocating trains to platform tracks in RailSys. These principles are using the track allocation from a given timetable, using the lowest numbered track that is free, and maximising train changes at the same platform.

The analysis is performed for Norrköping station using the timetable of a normal Thursday in autumn 201 and counting the number of possible connections between trains, here defined as a minimum of 5 and a maximum of 30 minutes between the arrival time of a train and the departure time of another train. To investigate the effects of the track allocation principles, the number of connections at the same platform and the number of connections with crossing train paths, i.e. to some extent use the same station infrastructure, have been counted. Furthermore, the resulting capacity utilisation in per cent has been calculated with the method introduced by Weik et al. (2020). 

Results

205 passenger trains with 1,033 possible connections were identified. Results show that capacity utilisation and the number of crossing train paths increase when the number of connections from the same platform is increased.

Conclusion

Increasing the number of connections from the same platform increases crossing train paths and capacity utilisation. Future work should model connections more accurately, perform RailSys simulation of each track allocation to assess the spread of delays, and apply cost-benefit analysis to find the best balance between the conflicting goals of having few crossing train paths and many connections at the same platform.

References

Johansson, E., Nilsson, H., 2021. Station capacity and platform allocation – a test case at Linköping central station (Master’s thesis). Linköping University.

Trafikverket, 2020. Analysmetod och samhällsekonomiska kalkylvärden för transportsektorn: ASEK 7.0 (Report).

Weik, N., Warg, J., Johansson, I., Bohlin, M., Nießen, N., 2020. Extending UIC 406-based capacity analysis – New approaches for railway nodes and network effects. J. Rail Transp. Plan. Manag. 15. https://doi.org/10.1016/j.jrtpm.2020.100199