Bogota Mayor Enrique Penalosa's exquisite dissertation and disposition toward parkspace was inspiring. My home is Portland Oregon, reknown for its public spaces. When my work takes me to other cities, I seek out the public space and judge critically when there is too often sadly, a lack thereof.
I'm not a real fan of the gigantic parkspace - NY Central Park, Golden Gate Park San Francisco, the Mall of Washington DC, etc. They're great for large gatherings and events, (often commercialized), but do not replace the need for smaller community parks. The large park has a transportation demand that is hard to meet and this makes them exclusive. A large number of small parks, carefully sited to serve surrounding neighborhoods, is more accessable than the same area devoted to a single large park. If we had to choose between setting aside a certain amount of land for the construction of one park type over the other, the better choice is the numerous smaller parks.
Parks and public spaces are certainly a humanizing factor, as Mayor Penalosa so ably presents. Parks are also an economic factor. The built environment cannot live up to its greatest potential without a quantifiable amount of unbuilt environment, or public spaces in the form of plazas, greenbelts, pedestrian and bicyle corridors, wide sidewalks with street trees and furniture, grand and modest parks, playgrounds, fountains & art. Unless pedestrians are conveniently and comfortably able to travel between workplace, home, recreation sites, retail outlets, supply stores, educational and instutitional facilities, the cost of more complicated transport increases, and the ability to accomplish daily goals decreases as more time is wasted in travel. Thus, public spaces must also include a critical transportation element to serve the non-motorized traveller to achieve the economic goals of development.