London's Victoria Line has been driverless for decades. It's not a hard problem. You solve it by putting linked activators along the track to control the train

London's Victoria Line has been driverless for decades. It's not a hard problem. You solve it by putting linked activators along the track to control the train speed and acceleration. RMT has backup sensors for train position and radio control for emergencies. It's plain old engineering. No AI required. It's a completely different problem to automating a mixed use national high speed rail network which has to deal with a huge range of contingencies.