GoA 4 is total automation.
At this level, the transformation is complete and the system has taken over the train, wayside and the platforms. Involvement from the operator has been reduced if not eliminated. The operator’s role is to only monitor the system and get involved if there is a failure the automated system cannot handle.
GoA 4 has also extended its reach into the yard which means human intervention is no longer required to bring a train from the storage tracks to the mainline. GoA 4 will “wakeup” the train, perform self-tests, launch the train into the mainline, route the train to the yard at the end of service, park the train in the storage track, command the train to “sleep” and repeat the process the next day.
The involvement of a human operator has been reduced to monitoring the system and perform maintenance functions when required.
A good example of a GoA 4 system is one of the first CBTC based metros deployed in the world, Vancouver Skytrain which implements most if not all GoA 4 functions.
The following video provides more details of the functions that define a GoA 4 based system.