I guess I used "train control" to mean separating trains for safety. While RT's signals will do that (holding a train in a station until a very late previous train has cleared the next one), they rarely have to and work more to ensure that upcoming grade crossings are safe for trains to proceed through before release from a station. There are few signals between stations other than at crossovers and junctions, and as long as trains are running somewhere near schedule (up to 10 minutes late doesn't usually bother things much with 15-minute headways) separation of trains requiring attention to signals for that purpose is seldom an issue outside of downtown.

I think there are basic track circuits at the grade crossings as backup, based on being on trains that had to stop or proceed very slowly approaching crossings where gates were malfunctioning - often the would finally go down only when a train got close. No need for predictors in normal operation because the signal-triggered progression takes care of that. Other crossing problems would also require restricted speed, like loss of communication with the train signals or the traffic signals (interconnected along certain streets) even if the gates were closing.