Conference article

The current Blue metro line in Stockholm will be extended and connected to a branch on today’s Green line in the future. This paper presents a timetable simulation study which was part of a larger study regarding traffic analyses and design of the future Blue and Yellow line metro conducted in 2015–2016. Two timetable cases were considered, the first one gives 4-minute intervals on the branch lines and the second one 5-minute intervals (peak hours). At that time there was a discussion whether to design a new branch station (Sofia) with two or three tracks. The simulation model could not be set up to model all the features of the signaling system that is used today and is planned to be used when the new extensions open. Therefore, a separate model was developed to study the effects of two or three tracks at the branch station on a more detailed level. The results from this study shows that the 4-minute timetable case is clearly more sensitive to delays. Although the effects of having two or three tracks on the branch station where northbound trains will merge can be seen locally on that and subsequent stations, there is no significant difference further along the line. There exist other operational benefits of having a 3-track design at a branch station and these were also considered, although not discussed in this paper. Later it was decided that the branch station will be designed with two tracks, mainly due to the significantly higher cost for a 3-track design.

Metro operation, Timetable, Simulation, Delay, Buffer time