Interesting. What's odd, though, is the road layout. If you look at the interactive map, you'll see that it deletes major roads before deleting minor roads. If you go over by 23rd/11th and zoom in to the point where the transition between no-buildings and buildings occurs, you'll see the west side highway. Then, zoom out. The access roads to the indoor Chelsea Piers parking lots show up, but the the 6-lane highway disappears.

Odd. This happened the last time there was an article about make-your-own maps, too.