The 1.5km line will branch off Line 5/14 at Piazza Vittorio Emanuele near Termini station and run west to Largo Corrado Ricci near the Colosseum.

Services will operate at eight-minute headways and the four-station line is forecast to carry 30,000 passengers per day.

Construction is due to begin in May 2019 and the line is expected to open in 2020.

The Municipality of Rome is contributing €5m towards the €20m project, with the Ministry of Infrastructure and Transport expected to provide the remaining €15m.

The project is part of the city’s Urban Plan for Sustainable Mobility (Pums) and Raggi says the line represents an opportunity to redevelop the Vittorio-Lanza-Cavour corridor.

A feasibility study is already underway for a second phase which would extend the line beyond Largo Corrado Ricci to Piazza Venezia.