Sofia – Plovdiv railway modernisation

Double-track electrified line of about 23 km through Poduyane, Iskar and Kazichene stations (Sofia and Elin Pelin stations are outside the 2023 contract), part of the Sofia – Plovdiv modernisation. The 2023 contract (up to 24 months, BGN 63,336,032.24 excluding VAT) covers only the Sofia – Iskar finishing works. Double-track running was suspended in 2018 during the works; NRIC restored it on the 13 km Iskar – Elin Pelin stretch with its own forces on 9 May 2025. The drawn geometry follows the OpenStreetMap line, 22.55 km from Sofia Central Station to the start of the Elin Pelin – Kostenets project at km 22+554. Contractor in Cyrillic: Транспортно строителство и възстановяване ЕАД (ТСВ ЕАД).

Km 22+554 to 42+200 (length from the chainage), the hardest stretch of the Sofia – Plovdiv line. It includes Bulgaria's longest railway tunnel at 6.8 km, the first of its kind since the Koznitsa tunnel of 1949–1951, a new Elin Pelin station, Pobit Kamak halt and Vakarel passing loop, two twin-bore tunnels of about 1.5 km in total, and 8 bridges and trestles. Construction supervision: Zhp Trans DZZD. The 51.044 km project (14.544 km renewed, 36.5 km new double track) is designed for 160 km/h passenger and 120 km/h freight traffic. NRIC gives the total as BGN 1.310 billion and says works started with considerable delay after appeals against detailed plans, slow land expropriation and COVID-19, so the project was split into two funding phases.

Km 42+200 to 62+400 (length from the chainage). Includes Verinsko halt, Ihtiman station and Stambolovo halt, 4 overpasses, 3 bridges and 39 culverts. Construction supervision: Zhp Trans DZZD. The 51.044 km project (14.544 km renewed, 36.5 km new double track) is designed for 160 km/h passenger and 120 km/h freight traffic. NRIC gives the total as BGN 1.310 billion and says works started with considerable delay after appeals against detailed plans, slow land expropriation and COVID-19, so the project was split into two funding phases.

Km 62+400 to 73+598 (length from the chainage). Includes 8 single-bore tunnels for double track of about 5,478 m in total, 2 viaducts of about 1,005 m and 11 bridges of about 777.70 m, and Nemirovo halt. Construction supervision: Zhp Trans DZZD. The 51.044 km project (14.544 km renewed, 36.5 km new double track) is designed for 160 km/h passenger and 120 km/h freight traffic. NRIC gives the total as BGN 1.310 billion and says works started with considerable delay after appeals against detailed plans, slow land expropriation and COVID-19, so the project was split into two funding phases.

About 24.5 km of double electrified line: 3 tunnels of 4.6 km in total, 23 bridges and viaducts of 2.49 km, a new Kostenets station and reconstruction of Belovo station. NRIC gives the total project value as BGN 300,251,198 excluding VAT. In August 2025 the deputy prime minister said the 2.5 km tunnel had broken through and that, despite delays, the line would be built for 160 km/h by 2029. Construction supervision: Iver DZZD. The drawn geometry is 25.3 km from OpenStreetMap, cut at the end of the Elin Pelin – Kostenets lot 3 and at Septemvri station.

Track for 160 km/h passenger trains (200 km/h tilting stock) and 120 km/h freight, catenary, signalling with ETCS level 1, in three positions: Septemvri – Pazardzhik (BGN 57.08 million, Svitelski-RVP Kyone), Pazardzhik – Stamboliyski (BGN 49.84 million, Ay Dzhi Ey – Zhp Infrastruktura) and Stamboliyski – Plovdiv (BGN 50.93 million, Porr Bau), plus a BGN 69.25 million signalling and telecommunications contract (TKB Sofia-Plovdiv), all excluding VAT. NRIC records all four as commissioned in March 2017. Total project value BGN 630,626,259.28. BTA reported on 24 September 2026 that a demonstration run covered the 53.5 km at 160 km/h in 25 minutes, against 40 minutes at 80 km/h with older stock. NRIC chainage runs from km 102+014 to km 154+606 (52.6 km). The drawn geometry is 52.3 km from OpenStreetMap.