The Metro comprises three lines – A (orange), B (blue) and C (green) – which operate on 60 km (37 mi) of route, serving 73 stations.

[3] In addition to the Metro, the center of Rome and its urban area are served by 8 FL lines (672 km (417.5 mi) with 131 stations) that surround Rome and the Lazio region,[5] 6 tram lines (36 km (22 mi) ) with 192 stations),[6] 3 commuter urban lines (135 km (83.8 mi) with 57 stations), as well as the Leonardo Express which connects Roma Termini, the central station of the city of Rome, to the Leonardo da Vinci Airport of Fiumicino,[7] and the Civitavecchia Express which connects the city to the main port of Rome, the Port of Civitavecchia.

[8] Network extensions are currently under construction on Line C (Porta Metronia, Colosseo-Fori Imperiali and Venezia).

Inaugurated in post-war Italy in 1955 during the reconstruction and on the verge of the Italian economic miracle, it was designed and built for the 1942 universal exhibition (Esposizione Universale Roma, which is now the current business center of Rome) desired by the fascist regime, which never took place due to the outbreak of the World War II.

Work on Line A began in 1964 in the Tuscolana area, but suffered a series of delays caused the originally planned cut and cover method of construction posed serious problems for road traffic in southeast Rome.

Work was also frequently interrupted by archaeological finds made during the excavations, particularly near Piazza della Repubblica.

When its construction was interrupted, some of the tunnels on the city-centre side of the Metro (between Termini and Piramide) had already been completed, and they were used as air raid shelters during the war.

Work restarted in 1948, together with the development of the site formerly designated for the Expo into a residential and business district under the name EUR.

The first section of the line, from Centocelle to Pantano,[14] is the furthest from the city centre and includes 15 of the planned 30 stops.

[15] After this third phase, the line will be further extended with three stations, Porta Metronia, Colosseo, and Piazza Venezia, located in the city centre.

Rome is one of the oldest cities in the world, and as such, the construction of the Metro system has encountered considerable obstacles owing to frequent archaeological discoveries.

Excavation to a depth of about 20 metres allowed the exploration of about 21 stratifications of history up to the so-called virgin soil, the one in which man's presence is absent.

The exhibition is characterized by being a real tour with libraries for the finds along the route, explanatory panels on the walls and a temporal measurement of the historical phases that follows the path of the passengers from the atrium level to the platforms' level: The various archaeological finds and exhibits include small items such as gold jewelry, coins, crockery, shells, large amphorae and elements of ancient columns and also large finds, such as the large pool, the largest reservoir ever found, located inside a farm of the imperial age.

Rome's local transport provider, ATAC, operates the Metro network and the Rome-Giardinetti line.

The Roma–Lido, which connects Rome to Ostia, and the Roma–Viterbo line, used to be operated by ATAC until 1 July 2022, when it became part of the Cotral network.

Officially termed a railway, the Roma–Giardinetti line is a narrow gauge tram which connects Laziali (a smaller, local train station some 800 metres east of Termini's main concourse) with Giardinetti, just past the Grande Raccordo Anulare (GRA) – Rome's orbital motorway.

[22] The Roma–Civita Castellana–Viterbo line (also called Roma Nord railway) began life as a narrow-gauge tram running from Piazza della Libertà in Rome to Civita Castellana.

However, the next stretch of the line, to Viterbo, was built as a railway and over the years the tram section was converted into a railway as well, a process which concluded with the moving of the Roman terminus from the street-level terminus at Piazza della Libertà across the river to a new underground station in Piazzale Flaminio, beside the subsequently constructed Line A station, after World War II.