Re: Fail-Safe
The question is whether such tracking engenders fail-safe operation of the railways.
So long as it's done right, yes. Generally speaking you need everything to fail safe when the radio craps out, and not depend on radio to propagate the fail safe network-wide.
So if an emergency stop signal for a train is delivered by radio, that won't work. The signal may not arrive.
However if the train stops automatically if the radio craps out, that's better, so long as the signalling separation gives everything else time to realise there's a problem before one train hits another.
My biggest worry over things like this is that it's putting a lot of eggs in one basket. Lose the satellite and you're left with minimal train network capacity for years.
Biting the hand that feeds IT
