This paper presents functional connecting of the railway bypass around Niš and the railway junction Niš. Railway infrastructure in the city of Niš consists of two main railway lines Belgrade – Niš – Preševo – state border (E-85 and E-70) and Niš – Dimitrovgrad – state border (E-70) and one regional railway line (Niš) – Crveni Krst – Zaječar – Prahovo Pristanište. Within the junction, connections are made by railway lines which are the parts of main directions E-85 and E-70: Crveni Krst – Niš Marshalling, (Crveni Krst) – (Ćele Kula), Trupale – Niš Marshalling – Medjurovo, Niš – (Niš Marshalling). The traffic issue is for the city of Niš on one hand – the limiting factor, and on the other hand – stimulating factor of development. Functionality of railway traffic in the city, in addition its’ basic function, need to have a positive effect to meet the needs of citizens’ mobility. Reduction of collision points “city – railways” should correspond to the strategy of the city development, previously planned and defined. In the city centre, a huge problem of level crossings exists. In the present situation, running of freight trains through the central zone of the city produces increased levels of pollution and noise, and increases risk of environmental pollution, due to the passing of dangerous goods through the town. Construction of the railway bypass is one of the phases of solving traffic problems in Nis, and by its construction following will be achieved:
• The separation of the railway line and roads in the city area, the separation of passenger and freight traffic in the urban area and the separation of transit from local traffic;
• Harmonization of transport infrastructure development with city’s development and development of the airport “Constantine the Great” in Niš;
• Development of railway facilities without disruption of transit traffic on Corridor X by local works.

railway junction; traffic organization; functionality of the station; traffic flows; technological effects