Subways have human operators for difference reasons not because trains cannot be fully automated. Some are partially automated because they run on old infrastru

Subways have human operators for difference reasons not because trains cannot be fully automated. Some are partially automated because they run on old infrastructure which is difficult and expensive to revamp. Others are fully automated but regulations prohibit full autonomy, or labor is unionized and operators are guaranteed work. Automation is not AI anyway, automation today is done through control systems, that is sensors, some type of control like a PID loop (or more advanced Level 2 models) and devices that allow for controlled movement/positioning. There's no artificial intelligence there.