[CaptainDecisive]

I'm also not convinced on the OP's idea, although I found it very interesting how the street cross section diagrams highlighted just how much space is consumed by streets. By it's also very interesting to see how public opinion goes in circles by comparing the 1850 Paris example. Some of the examples of slums that were demolished (eg http://en.wikipedia.org/wiki/Haussmann%27s_renovation_of_Par...) were obviously very run down, but are precisely the sort of places that have been gentrified and are now worth crazy money and considered very desirable places to live.