Now this is truly meta.  A subway map visualization of all the Subways of North America from Randall Monroe of xkcd.com.

For the pedantic rail enthusiasts, the definition of a subway used here is, with some caveats, “a network containing high capacity grade-separated passenger rail transit lines which run frequently, serve an urban core, and are underground or elevated for at least part of their downtown route.” For the rest of you, the definition is “an underground train in a city.”

About one in three subways stops in North America are in NYC

Another great design from Randall!