The answer to both questions is … well, West End Avenue isn’t. West End Avenue does not exist at either 110th or 116th Streets, unless, that is, you accept at face value various subway maps published by New York’s Metropolitan Transportation Authority since 1978, some of which went out under my “O.K. J.T.”
Despite what those years’ worth of MTA maps might say, Broadway does not intersect and subsume West End Avenue at 110th Street, as both the 1978 prototype map and the 1979 system map and consequent maps had it, as you see in the first two snippets from those maps, nor does Broadway intersect and subsume West End Avenue even further north at 116th Street at the Columbia station, as today’s MTA map shows it.
West End Avenue, the gussied-up name for the northern end of Eleventh Avenue, runs from 59th Street to 107th Street, where it encounters and is indeed subsumed by Broadway, which raises its pesky cartographic head on MTA subway maps again. (The whereabouts of Broadway at 66th and 72nd Streets on MTA system maps has been wrong from the 1978 prototype ‘til today.)
Broadway runs a straight course between Amsterdam and West End Avenues from about 86th to 102nd Streets. From that point, Broadway follows a northwesterly path to 107th Street, where Broadway does indeed subsume West End Avenue, taking it over and proceeding north. Just as Dorothy knew she wasn’t in Kansas any more, so you know that you are not on West End any more when you are walking north and cross 107th Street. West End Avenue is 100 feet wide, and Broadway is half again as wide. It’s the Boulevard.
The early maps whose accuracy I was responsible for are bad enough, and you would think that I would have known better, since I have lived on the Upper West Side for most of my life. I can find some consolation in knowing that at least those maps showed Broadway where it ought to be at 110th Street. The problem with the original maps is that the bend between 103rd and 110th Streets is angled too gently. It does not show Broadway’s intersection with West End Avenue at 107th Street. Consequently, West End Avenue flows right into Broadway at 110th Street. That’s bad enough.
Worse is the presentation today, as you see in the third snippet, here on the left. The 2012 MTA subway map has Broadway going straight from 72nd Street to 110th Street, with West End Avenue shown west of Broadway at 110th Street. Broadway is then depicted as turning on a northwesterly angle to 116th Street and merging at that point with West End Avenue, taking West End Avenue nine blocks further north from its terminal point at 107th Street.
It means getting out of the subway on Broadway and 116th Street at Columbia and expecting the intersection of Broadway and West End Avenue. Or getting out of the subway at Broadway and 110th Street and walking west, expecting to find West End Avenue, only to find Riverside Drive and no West End. To find West End Avenue you’d have to walk three blocks south on Broadway, but who would know, based on any of these maps.
It’s a “mea culpa” and an “oy vay” all over again, at least for the original 110th Street SNAFU.
N.B. As a true New Yorker, my skewed perception of north is uptown on the numbered avenues. I know that true north is angled about 28.8 degrees to the left of our perception of north, but let’s keep this geography lesson in bounds. North is straight up the numbered avenues, just as these tilted maps depict. Ergo, northwest is at an obtuse angle that leads off to the left.