Magistrala 4 de metrou București (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

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

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