The General Directorate of Turkish State Railways (TCDD), Department of Railroads issued a tender for the Infrastructure Construction Works of the Ankara (Polatlı) – Afyonkarahisar Section of the Ankara-Izmir High-Speed Train Project, and the construction is carried out by Sigma – YDA – Makimsan – Burkay Partnership. The construction of the project started on 29th June 2012 and the expected date of completion is 2019. The contract covers excavations (49,000,000 m³), fillings (16,500,000 m³), 2 cut-and-cover tunnels of 460 m, 8 bored tunnels of 7,505 m, 16 viaducts of 6,236 m, 24 bridges of 980 m, 32 overpasses of 1,091 m, 73 underpasses of 2,494 m, and 182 culverts of 8,337 m en route the 161.80 km2 railroad. The rate of completion at the end of 2017 was 64%.
With 5,205 meters, the Köroğlu Tunnel is the second longest tunnel among those of all High-Speed Train Projects currently constructed in our country.