As per a press release of the Governor Andrew M. Cuomo's office, the MTA will be flipping the switch at the Clark Street on the 2, 3 line in Brooklyn on Monday, and that's the last station in the project to provide subway cellular connectivity throughout NYC Metro. You are getting coverage for the top tier carriers like Verizon, AT&T, Sprint and T-Mobile, a year ahead of schedule, as well as 5000 extra hotspots for a total Wi-Fi blanket, and that's two years ahead of schedule.
Ok, by this point we are starting to wonder if the schedules haven't been overly generous, but who's counting when you will have uninterrupted stream of bits, bytes and voices to gobble on the train. The project has been funded with $300 million in private money, and, given how much time we spend commuting each day, it has to be one of the lasting legacies that Governor Cuomo will leave for New York City dwellers.
source: NY Governor Office