Among all the various kinds of buildings (old or new) in a city, some kinds are always less efficient than others in adding dwellings to the land. A three-story building will get fewer dwellings onto a given number of square feet of land than a five-story building; a five-story building, fewer than a ten-story building. If you want to go up far

Mazes of coordination, conference and liaison tenuously connect these sprawling and randomly fractionated empires with one another. The mazes are too labyrinthine even to be kept mapped and open, let alone to serve as reliable and sensitive channels of interdepartmental understanding, or channels of pooled information about specific places, or

The exact reasons for scantness of use at a border vary. Some borders damp down use by making travel across them a one-way affair. Housing projects are examples of this. The project people cross back and forth across the border (usually, in any appreciable numbers, at only one side of the project or at most two sides). The adjoining people, for the

And here we come to the third kind of city neighborhood that is useful for self-government: the district. This, I think, is where we are typically most weak and fail most disastrously. We have plenty of city districts in name. We have few that function. The chief function of a successful district is to mediate between the indispensable, but

If the only kinds of city neighborhoods that demonstrate useful functions in real-life self-government are the city as a whole, streets, and districts, then effective neighborhood physical planning for cities should aim at these purposes: First, to foster lively and interesting streets. Second, to make the fabric of these streets as continuous a

His remarks sum up, in an oblique way, virtually the intellectual history of city planning. Dr. Weaver lists three stages of development in the history of scientific thought: (1) ability to deal with problems of simplicity; (2) ability to deal with problems of disorganized complexity; and (3) ability to deal with problems of organized complexity.

If secondary diversity flourishes sufficiently and contains enough that is unusual or unique, it seemingly can and does become, in its accumulation, a primary use itself. People come specifically for it. This is what happens in good shopping districts or even, to a humble extent, on Hudson Street. I do not wish to minimize this occurrence; it is

Attrition of automobiles operates by making conditions less convenient for cars. Attrition as a steady, gradual process (something that does not now exist) would steadily decrease the numbers of persons using private automobiles in a city. If properly carried out—as one aspect of stimulating diversity and intensifying city use—attrition would

Secondary diversity is a name for the enterprises that grow in response to the presence of primary uses, to serve the people the primary uses draw. If this secondary diversity serves single primary uses, no matter what the type of use, it is innately inefficient. Serving mixed primary uses, it can be innately efficient and—if the other three