Originally Posted by
sbm12
There are actually two stations where you can do a subway-to-subway transfer leaving the system and going back in, though generally it is not permitted. A transfer between the 63rd & Lex station on the F line to the 59th & Lex station on the 4/5/6/N/R/W lines is permitted.
How does that work? You don't swipe your card going out. So, if you get on the system in, say, Brooklyn and get off at 63 and Lex, how does it know not to charge you when you go in again at 59th and Lex? All your card shows is an entry in Brooklyn and another entry at 59th and Lex.