I've known about this rotting piece of infrastructure for years now. It sits alongside the current and active West Side Highway at about 72nd Street, wedged between the Hudson River Greenway and the Joe DiMaggio Highway. You can read about the full history on your own, but just quickly, all you need to know for now is that the old West Side Highway collapsed at some point in 1973 and was subsequently left abandoned until about mid to late '80s when it was dismantled entirely and re-paved as a ground-level highway.
Fun little thing to watch out for next time you drive southbound on the West Side Highway near 72nd Street.
Here's video of the old Westway before it was dismantled following a collapse.
And here it is roughly today. Or at least, what's left of it. Just a broken section of asphalt covered by planks of wood and a few broken street lamps from an era gone by.