This is a video of the "highway" (it just looks like a road to me) built on top of a five-story apartment building in China (although I only counted four stories). How about that! They build pools on apartment building roofs, why not a road? Of course this really isn't news to me -- my place has had roads built on top of it for decades. "Is this the part where you try to convince us you live with the Ninja Turtles?" Why doesn't anybody believe me?!
Keep going for the video.
Thanks to hairless, who agrees a go-cart track on top of your apartment building would be a pretty sweet amenity. Same goes for a clothing-optional beach.