Ever wonder how much road space NYC would need to replace its subway system? Or how much of Manhattan we would need to block off to provide parking to all those commuters? Here's some awesome and interesting math from the blog Frumination. My favorite statistic:
At best, it would take 167 inbound lanes, or 84 copies of the Queens Midtown Tunnel, to carry what the NYC Subway carries over 22 inbound tracks through 12 tunnels and 2 (partial) bridges. At worst, 200 new copies of 5th Avenue. Somewhere in the middle would be 67 West Side Highways or 76 Brooklyn Bridges. And this neglects the Long Island Railroad, Metro North, NJ Transit, and PATH systems entirely.
Here's the map Frumin provides -- the blacked out spaces south of 57th are parking lots. The other black swatch are the roads, bridges and tunnel space that would be needed to move cars. Who likes the East River, anyway?