The project for Lot 1 of Bucharest Subway Line 5 (Raul Doamnei Station-Pozzo PS Opera) involved the design and construction of 2 single-track tunnels of 4.2 km in length each, in the section running completely underground between Raul Doamnei and Eroilor (PS Opera) stations. 

The work, carried out by a joint venture of companies led by the Webuild Group, resulted in the overall excavation of just over 8 linear kilometres of tunnels, constructed using TBMs (Tunnel Boring Machines), large mechanical cutters that in the case of Line 5 are of the EPB (Earth Pressure Balance) type, with characteristics particularly suitable for excavating subsoils that pass under urbanized areas. There is also a plan to build 9 new stations. 

Metro stations are located at major local roads served by surface public transportation, to allow easy transfer between underground and surface transportation. At the Eroilor station, a connection to the rest of the subway network is provided by a pedestrian underpass that gives Line 5 passengers direct access to Metro Lines 1 and 3.