Surprised that "Charlie on the MTA" hasn't been mentioned yet. In the fifties it was possible to go anywhere in the city of Boston with the creative use of 'transfers'. The MTA, in an effort to stop the loss of revenues, began locking turnstyles so that they would only turn in one direction, and began to get rid of the transfer system as well. I'm not sure, but I believe this song was written in response to the chaos that resulted.