Below: some snippets captured (and out on http://www.overheardinnewyork.com/) from trains running in and around New York City. If you want to see some really unbelievable quotes go to the above site, it's hysterical.
Wednesday One-Liners, the Shepherds of New York
Conductor: This is the last stop -- Brooklyn Bridge, City Hall. Y'all have a nice day and be good, now... But if you can't be good, be baaad.
Overheard by: Paul Schroeder
Conductor: Good morning, everybody. This is your 7:15 New Haven train, express to Greenwich. To infinity, and beyond!
--Connecticut-bound Metro-North train
MTA worker: This station is now closed. No train is coming here. You all have to get out of here!
--8th St N/Q/R/W station
Overheard by: bKSquared+AV
Conductor: Ladies and gentlemen, please remember that every car of this train has four doors, so 27 people in front of one door -- well, it is not scholarship material. Let's use our brains, people. Then you won't have to bump your guns and complain that the A is never on time.
--A train, 96th St
Overheard by: Emily B.
Conductor: Attention passengers, the last two cars will not platform at Bellerose, either. That means if the doors didn't open for you at the last station, they won't open at Bellerose, either, so stop standing looking confused, and walk forward!
Overheard by: Nathalie
Conductor: For those of you standing in the first five cars, the back three cars are almost empty. Come sit down! I'm lonely back here.
Conductor: And now... the mass exodus!
Overheard by: da sarkastik ninja.
via Overheard in New York, Jan 9, 2008