Comment by renehsz

LZB does cab-signalling and continuously supervises speed and braking curves. Combined with AFB it can accelerate and brake automatically to LZB targets. So regular operations are already partly automated (and have been for a long time). The system already doesn't rely on perfect driver attentiveness for safety. The driver should still watch the track ahead, but trains usually can't stop within line of sight anyway, so for separation we have to rely on the signalling system.

Drivers are absolutely still needed for other parts of the operation though, like working stations, shunting, and perhaps most importantly handling irregularities. Faults can happen and you don't want the train to be stuck out on the track for hours. Instead, it makes so much more sense to either fall back to lineside signals (often accompanied with a point-based train protection system) or driving within line of sight.