Big Ideas that are working in Small and Big Towns

This is a continuation of my discussion of reducing vehicular traffic and increasing pedestrian and non-motorized activity.   Atlantic Cities www.atlanticcities.com has an article on  Mexico City's Centro Historico where they increased night time pedestrian traffic and reduced crime by closing some the streets to vehicular traffic.
Hopeful Footsteps in Mexico City's Centro Historico  

Combine this with my previous video post of How the Dutch got their cycle paths, and perhaps one can start to believe the new planners and their claims that more and more cars does not guarantee long term success.  The number of failing car cities in Michigan would seem to be proof enough if it were not for the ongoing stories demanding more roads while the funding for any type of mass transit is eliminated.

Why can't these type of ideas be refined in Small Towns where the cost and complexity is far less than in a major urban area?  Both may need Big Ideas to survive but it seems Small Towns should be closer to the ideals already and have far fewer people and bureaucratic agencies to convince.