The B84 and M12 come to mind as routes that should probably be axed. From what I seen, most of the M12 ridership is along 57 street for when the M31 or M57 dont show up in a certain time (606 w57 residents and the like in that pocket of manhattan coming from/going to columbus circle). The B84 is basically an express B83 to New Lots from/to Gateway center.