Bucharest Metro Line M4 (Gara de Nord 2 – Străulești)

3.6 km and 4 stations, the first line begun under the communist government and finished after it. Tunnelling reached as far as today's Parc Bazilescu before works were abandoned and restarted in the 1990s. Basarab 2 is a four-track station with the M1 tracks between the M4 tracks. Ziarul Financiar reported the investment at €220 million; no price year is published for a spend running from 1989 to 2000, so no cost is recorded. Line M6 will share this section

2.62 km and 2 stations, Jiului and Parc Bazilescu. Parc Bazilescu was not in the original plan and was built to bring the section into service sooner. România liberă put the cost of the two stations at 300 million lei (about US$100 million), 200 million of it spent between 1990 and 2010 and the rest in the two years before opening. The sums are nominal across the 2005 redenomination, so no cost is recorded. Works on Racordul 2 (Gara de Nord – Laromet, 6.1 km, including Pajura, today's Jiului, and Bazilescu) began under Decree 303 of 7 December 1989, per Metrorex; România liberă gives 1988. The association of SOMET, Schindler and TIAB carried out the 2010–2011 completion works on Jiului, Parc Bazilescu and the interstation, with Metroul as general designer; the contractor for the structural works begun in 1989 is not named. On 20 August 2010 Metrorex signed a 21.9 million lei contract with TIAB, funded from the state budget, for general installations and finishes of the technical spaces on 1 Mai – Parc Bazilescu, with a six-month execution period.

2.1 km and 2 stations, Laminorului and Străulești, together with the Străulești depot and an interchange with the surface network. Works started in 2013, tunnelling was finished on 3 September 2015 and the stations opened on 31 March 2017. The English article gives this section as 1.89 km and the M4 article as 1.6 km. Works contract signed on 12 July 2012 with a consortium led by Astaldi (with SOMET, TIAB and UTI), covering the tunnel, both stations, the Străulești depot, the multimodal terminal and park and ride. Economica.net gave the total project value as 1,115 million lei (€252.4 million), covering stations, tunnel, depot, intermodal terminal and park and ride, with no price year or VAT basis. At the opening the transport minister gave the project value as €241 million.

About 11 km and 14 new stations south from Gara de Nord along Berzei, Vasile Pârvan, Hașdeu, Izvor, 13 Septembrie, Tudor Vladimirescu, Șoseaua Viilor and Șoseaua Giurgiului to Gara Progresul, where a depot is planned. Route from the revised feasibility study presented in November 2020; the tender was launched on 26 April 2024. The English article gives the planned length as 10.6 km. The alignment drawn here follows those streets and is indicative. Contracting authority: Sector 4 City Hall. Both design-and-build contracts were awarded in August 2025: Section I (Gara de Nord – Eroii Revoluției) to a consortium led by Dogus, Section II (Eroii Revoluției – Gara Progresul) to one led by Construcții Erbașu. The Section I contract was signed at the end of 2025 and its start order for design and execution was issued on 4 December 2025; physical works follow the design phase. Each contract runs 60 months, starting with a design phase given as 8 or 10 months depending on the release. By December 2025 Sector 4 gave the investment value as €3.5 billion (over 17 billion lei) of non-reimbursable EU funds. The EU award notice gives 4,691.4 million lei for Section I (signed 2 December 2025) and 4,383.0 million lei for Section II (signed 26 January 2026), 9,074.5 million lei in all, against a tender estimate of 11,395.1 million lei, all excluding VAT. The two contracts are recorded separately, so no single contract value is given.