In the process of writing my column on transit system maps, I got distracted by a Wikipedia clickfest, and discovered the answer to a longstanding question I’ve had. The Q can indeed go further north than 57th St.—to 63rd and Lexington Avenue, as it happens, where it would one day be able to hand off passengers to the mythical and deadly T train (the always-not-quite-here-yet Second Avenue line). When that happens, I’d expect traffic on the Q to skyrocket.