alt Hacker NewsThere are switches that move trains between tracks. Now you need every switch to report, keep a history of that. Many trains also separate and combine. Trains sometimes go backwards to be switched.
It's not impossible. But handwaving GPS placement of trains at the correct location, direction, and track deserves more than a handwave as trivial.
All of those failure modes can be accommodated. I fail to see anything here a competent engineer couldn't address. I speculate it's not a technical problem, but an operational and cultural one. This is not rocket science.