I remember the huge article a few years ago on why train counters/timers were not possible in the NYC subway because of the lack of ATC/PTC, and the entire syst

I remember the huge article a few years ago on why train counters/timers were not possible in the NYC subway because of the lack of ATC/PTC, and the entire system was still pretty much mechanical relay switched and zoned occupancy. [1] Has something changed? Do trains now have transponders or something? [1] https://www.theatlantic.com/technology/archive/2015/11/why-dont-we-know-where-all-the-trains-are/415152/ https://www.theatlantic.com/technology/archive/2015/11/why-d...