Signalling of the Milan Metro


The Milan Metro subway system is managed by a single ATM control centre, built in 2013 by Alstom.

Lines 1 and 2

Line 2 uses a speed signaling system. Trains are directed using a semaphore system, which has five states:
Before 2011, Line 1 used this same system, but now uses a new signaling apparatus. The signaling apparatus permits a 90-second frequency on the line, similar to the one used on the M3 line. The speed of the train is decided by an ATC system and a two-color semaphore system.
The two-color semaphore system has three possible states:
Line 3 has an ATO/ATP system, so the driver must only check the doors and give consent to the electronic system to start the train.

Line 5

Line 5 uses AnsaldoBreda Driverless Metro, consequently the line does not have classical light signaling. Automatic signaling permits a frequency of a train every 75 seconds, but today only a 90-second frequency is used.