Italian railway signalling

The Italian railway signalling currently in use, employed on the Italian national railway network, is regulated by the "Regulation on signals" (Regolamento sui segnali), issued by the Italian railway infrastructure manager, RFI (Rete Ferroviaria Italiana, part of the FSI Group). Signals have historically been derived from early British semaphore signals, along with the practice of running on the left side on double track main lines.

Source: Wikipedia — Italian railway signalling (CC BY-SA 4.0)