It operates as a combined suburban railway system that connects the city-centre and the outskirts of the city via a commuter rail line.

[2] The FL network, initially made up of two lines and called FM lines (Metropolitan Railways), was formally inaugurated in 1994, following the signing of an agreement between the Lazio Region, the Municipality of Rome, the Province of Rome and Ferrovie dello Stato Italiane, aimed at implementing a new integrated transport structure in the Roman metropolitan and regional area.

The fleet of convoys operating on the network is made up of 388 trains on the entire Lazio railway network,[1] distinguished according to service needs: Following the upgrading of the Rome railway hub by RFI, new FL stops will be built such as Roma Pigneto, in correspondence with the Pigneto station of the metro, which will be the third busiest railway hub in Rome after Roma Termini and Roma Tiburtina,[6] and track doubling and quadrupling will be implemented on the existing sections as well as technological upgrades for the safety and control of train movement (the implementation of the European Rail Traffic Management System (ERTMS) in the Rome hub is expected by 2024[7]).

In June 2022, 32 years after the 1990 FIFA World Cup, the Valle Aurelia - Vigna Clara route was reactivated with the related Vigna Clara stop, which will be a fundamental part of the so-called "Cintura-Nord" (Northern Belt), whose closure, expected for years, will to complete the Rome railway ring.

[8][9] A year later, in June 2023, the Val d'Ala station was reopened, which is served by some trains of the FL2 line that leave and return from the "Roma Smistamento" depot.