The aim of the project is to modernise the railway infrastructure on the Elin Pelin-Kostenets section, as required by the TSI and Regulation (EU) No 1315/2013 for the core network of rail transport infrastructure corridors. The implementation of the project will contribute to the development of Corridor Orient/Eastern-Mediterranean, passing through Bulgaria, part of which is the railway line Sofia — Elin Pelin — Kostenets — Septemvri — Plovdiv. The starting and end points of the railway section are respectively: km 22+ 554 to km 73+ 598. The project includes the following main components:- Modernisation of about 51.044 km double railway line for speed 160 km/h for passenger trains and 120 km/h for freight trains, in full compliance with the requirements of the TSI, including:- Renewal of 14.544 km double railway line;- Construction of 36.5 km double railway line;- Extension of platforms in stations and construction of pedestrian overpasses; including providing an accessible environment for people with disabilities;- Reconstruction of reception facilities Elin Pelin and Ihtiman;- Construction of new stops Pobit stone, Vakarel South and Verinsko;- Reconstruction of platforms on 2 existing stops — Stambolovo and Nemirovo;- Closing 4 existing level crossings and replacing them with road overpasses; refurbishment and new construction of 24 bridges and viaducts;- Construction of one-way (two-pipe) tunnels with a total length of 15.4 km;- Construction of 8 two-way tunnels with a total length of 5.48 km;- Construction of new overhead contact line 50 Hz, 25 kV;- Construction of 2 new traction substations and 2 new separate posts;- Installation of 3 new route-computer centralisations at Elin Pelin, Vakarel South and Ihtiman Station.