Oh, I see how you could think that, without context. That's in fact not what I wanted to say. I meant that pretty literally. The infrastructure of course knows where the train is.

> Trains are still not able to assess properly where they are, even using satellites and inside train sensors. Of course there is research on that, but it's still an unsolved problem.

*Trains* on there own! This IS a hard problem, how to do that with any other infrastructure. It IS current research and not yet solved. That is for example relevant, if you want to be able to run trains at full speed <1m tolerance, so that you can have more than one train stopping at a station <60s. All while still not paying for infrastructure and maintaining backward compatibility with a century old trains. (I mean in the future you could use the same to also couple trains at full speed, but that's still sci-fi.)

> That is for example relevant, if you want to be able to run trains at full speed <1m tolerance, so that you can have more than one train stopping at a station <60s.

...is that something you'd ever want? In general, it is, but the way it's handled is by having those trains stop on separate tracks.

Running multiple trains through the same station track in under 60 seconds means that all passengers must embark and disembark in under 30 seconds. That's very tight. I would venture to say it's too tight and meeting this goal would make the trains worse.

(And if passengers aren't getting on or off the train, then the train isn't stopping at a station.)