High Quality Content by WIKIPEDIA articles! Automatic Train Control (ATC) is a train protection system for railways, ensuring the safe and smooth operation of trains on ATC-enabled lines. Its main advantages include making possible the use of cab signalling instead of track-side signals and the use of smooth deceleration patterns in lieu of the rigid stops encountered with the older ATS technology. ATC can also be used with Automatic Train Operation (ATO). There are several implementations and versions of ATC and each is different.