Improvement of suburban railway services by infrastructure and timetable modifications based on simulation modelling

As part of this research, a computer model of the existing bidirectional single-track railway line section between Zagreb Glavni and Turopolje railway stations has been developed, and it has been modified with the aim of developing a new model of the double-track line on this line section, and which in relation to the existing conditions also includes additionally the new stop Donja Lomnica. The purpose of developing the new model of the double-track line is to study the possibility of introducing a new plan of cyclic timetable of the suburban and regional trains that would significantly improve the quality of existing service in railway suburban traffic of the city of Zagreb. The procedure of single-track line model modification has been performed based on simulation of railway operations in the station areas with the aim of improvement of line capacity necessary for introduction of new solution of the cyclic timetable. Within this approach, the solutions for modification of railway infrastructure in stations have been selected which have proven to be the best regarding the achievement of the mentioned purpose. As part of this work, a new solution of cyclic timetable of suburban and regional trains on the new model of the double-track railway line has been proposed by taking into consideration the existing characteristics of traffic of other trains on the observed railway line section, as in Zagreb Glavni railway station which represents the main node in the network. Stability of this cyclic timetable has been tested by the application of three different simulation scenarios. The results of this research have proven that the introduction of the new model of double-track line can enable stable application of the proposed cyclic timetable.