alt Hacker NewsI think subway rail systems do have "real live location", but whether that information is consistently provided to public distribution for use through apps is a question mark.
I suspect most systems are a mix of your platinum, gold and silver (and kidding me).
Lots of systems have some sort of real location data, but it can be... shaky.
In Dublin, train 'realtime location' is, AIUI, based on arrival at stations plus time-based estimate. This _usually_ works okay. Buses have transponders which register when they pass a stop. Or, ah, well, buses usually have transponders, and those transponders sometimes work. New buses sometimes lack them, as do very old buses used for covering capacity problems. If a bus without a transponder is used, they seem to just estimate where it is based on the schedule, which is useless. If a bus without a transponder is inserted out of schedule (they sometimes do this at peak time) it's totally invisible to the realtime system. Sometimes, the transponder isn't picked up, and then the bus will appear to hang around for a while and then abruptly teleport a few stops forward. Sometimes, a bus's transponder doesn't seem to start working when the bus starts up for the first few stops.
Still, it's better than when I was a kid, when you really just had the printed schedule, assuming the rain hadn't gotten to it.