Passante Ferroviario di Napoli
The Passante Ferroviario di Napoli (also called Villa Literno–Napoli Gianturco railway) is a 16 km-long double track transit line which connects the line to Rome via Formia with the line to Salerno near Napoli Gianturco station through Naples and its north-western suburbs. This line is used by the suburban trains named as line 2.
Source: Wikipedia — Passante Ferroviario di Napoli (CC BY-SA 4.0)