The project Kalotina-Sofia Motorway, Lot 1 “Western arc of Sofia Ring Road (SOP)” covers the existing route of the Sofia Ring Road (SOP) and provides for the reconstruction of the road section from the connection with the Lyulin Motorway to the connection with the North Speed Tangent (FTA). According to the feasibility studies, the route includes:- Division 1 — from km 59+ 400 (Lulin road) to km 61+ 629 (=0+ 000 — Slivnitsa) and from km 0+ 000 to km 0+ 780. The implementation of Part 1 is financed under OP “Transport” and is under implementation, and- Section 2 — from km 0+ 780 (p. Coach) to km 6+ 308 (link to FTA).The implementation of the project is divided into two phases — Phase 1 (financed under OPT 2007-2013), including Part 1 and part of Section 2, which includes partial implementation of a bridge facility from km 1+ 290. 46 to km 1+ 634,46, part of Stefanson Blvd. at km 1+ 320 — left lane and construction of 678 m road part, right lane from km 4+ 430 to km. 4+ 900 and from km 6+ 100 to km 6+ 308.17/to the level of laying a layer of loose asphalt-concrete/.Phase 2 for funding under OPTTI 2014-2020 includes the rest of Section 2, namely: complete completion of the route of section 2 with a total length of 4 506 m full design gauge, 344 m right lane from km 1+ 290.46 to km 1+ 634.46 and 678 m left lane on the motorway from km 4+ 430 to km 4+ 900 and km 6+ 100 to km 6+ 308.17. The new construction mainly includes: The right road lane from “Sthanson blvd” at km 1+ 320; Road junction at Lomsko Shose Blvd. at km 3+ 180. Road junction at the FTA and the direction “Kalotina-Kapitan Andreevo” Road connection for the Voluyak railway station at km 1+ 620 Road connection to the village of Maramor at km 4+ 000Transsections of the railway route per km 1+ 380 and km 1+ 560. Currently, the western part of the Sofia Ring Road has a gauge of 10.50 m, and after the extension the road gauge is expected to be 26.50 m, including 3 active traffic lanes (3 m wide each), dividing strip — 3.00 m and banquet — 1.25 m for each direction.