Evaluation of punctuality on a heavily utilised railway line with mixed traffic

The Western Main Line (450 km) between Stockholm and Gothenburg is heavily utilised for mixed rail traffic. High speed trains are mixed with regional, local and freight trains and the congestion clearly affects the overall punctuality. In order to evaluate the possible total effects of reduced primary delays, the high speed operator, SJ AB, took the initiative to perform an extensive simulation study in RailSys, which was carried out by the Royal Institute of Technology. As preparation for this simulation study delay data was compiled for all trains using the line. This paper briefly discusses the ideas of stochastic disturbances in the simulation of rail operation and also the compilation methods for primary delay distributions. The resulting distributions from the Western Main Line were then analysed. It was clearly shown that the primary delays are extensive and have a high degree of variability. The paper ends with a discussion about the validation of the simulation model and possibilities to develop methods for more accurate stochastic modelling.