Construction of the line began in 1994. Between 2004 and 2005 a series of tests was carried out prior to the line being opened for commercial operations, to obtain approval for the line to be regularly operated at up to. During these tests an ETR 500 train achieved a speed of. These speeds were made possible by the line's 25 kV AC railway electrification system, and the new signaling, control and train protection system provided by the European Rail Traffic Management System/European Train Control System. It was the first railway line in Italy to be electrified at 25 kV AC at 50 Hz and the first in the world to use ETCS Level 2 in normal rail operations. The first of the line was brought into service on 19 December 2005. The new line begins near Roma Prenestina station and ends at Gricignano di Aversa, where a connecting line leads to the Rome-Naples via Formia line, which is used for the last to reach Napoli Centrale station. The line features three other interconnections that link with the historical Rome-Naples via Cassino line, near Anagni, Cassino and Caserta. On 13 December 2009, work was completed on the last 18 km line of the line between Gricignano and Napoli Centrale. This includes the Napoli Afragola station, which was due to be open in 2009 when the construction contract was first awarded, but tenders had to be called again and construction was put on hold. Construction was delayed on several occasions and did not get fully underway until 2015. It was opened on 6 June 2017, with regular traffic for passengers starting from 11 June 2017. The station is planned to provide interchange at Afragola station with the Circumvesuviana line in 2022, once that line has been reconstructed. The Naples–Salerno high-speed railway was completed in June 2008 to allow high-speed trains to and from Salerno and the south to bypass Napoli Centrale station. When the Rome–Naples high-speed line is fully open the length of the high-speed section will be about. The connecting line to Gricignano di Aversa is now not used for normal operations. The longest tunnel on the line through the Alban Hills is long. The minimum radius of curves is and the centres of the running lines are apart. The maximum gradient of the line is 21 per thousand.
