Alan Fisher posted a video today on Brightline West's waiver to use Euro parts on its signal system encouraging people to comment.
While I disagree with him on so many things, I still tend to watch his videos. This video had me pause for a moment because I realized how little I understood about signal systems.
My question is what exactly does ERTMS use to determine signaling (is it wireless at all, does it use RFID signals imbedded in rail-ties, why is it so much better than PTC or whatever system used in the NEC (and Brightline Florida), how does CBTC used in the NYC Subway system differ (and why isn't that the standard for all passenger rail based on the level of accuracy claimed), and lastly what does Japan use (given their system has to be fantastic and reliable based on their on time performance and lack of accidents)?
Anyone who knows anything on this would be a great benefit--I spend so much time complaining about signal systems but don't have a clue how they really work and how to solve them.