The project will improve the connection, efficiency and safety of the metro lines. It will better link Lisbon's busy Yellow line, which serves the area with the highest employment density, with the Green line, making it circular.

Once completed, the improved metro network will reduce bottlenecks and travel times in the Portuguese capital's metropolitan area.

Commissioner for Cohesion and Reforms, Elisa Ferreira, commented: “This project will bring lots of benefits to the Lisbon metropolitan area: smoother connections among all forms of public transports, shorter travel times, reduced CO2 emissions and better access to these services, including for people with reduced mobility.”

The project will also ensure a better connection between the city's urban centre and its outlying area, especially for people who travel from the municipalities of Oeiras, Cascais, Almada, Seixal and Montijo to Cais do Sodré. Furthermore, public transport use should significantly increase after the project's completion, expected in 2024.

Car transport should decline by about 25 million passengers per kilometre. This will reduce energy consumption and CO2 emissions by about 5,000 tonnes per year.

Overall, the improved connections will contribute to job creation in the area, as it will make Lisbon more attractive for business and investments.