[hinata08]

I would suggest to add some Train protection system (or even ETCS if you're motivated) on your Lego railway https://en.wikipedia.org/wiki/Train_protection_system

You can see that in some railway engineering firms.

There have been train protection systems for decades, to stop trains when something is unusual (over-speed, incapacitated driver, running a red light,...), when railways aren't fully automated yet.

You can also encode information next to the tracks, and pick it up with the train ! This kind of system was a prerequisite for high speed trains. Drivers can't read signs at cruise speed, so they are replicated on their dashboard. A fun but edgy automation would be to encode cards against humanity near the tracks, and to randomly route the train, to generate text.