Every city and town are formed by its neighborhoods, districts, corridors, and its downtown. Each of these place types range from a more urban extreme, such as downtown, towards its more suburban, rural, or natural boundaries. And, each of these include a broad spectrum of public and private functions and places.

Looking in more detail, each neighborhood has its own set of more urban centers, general areas, suburban, and rural edges. For example, in my San Diego neighborhood, our center is the 100% shopping corner with coffee shops, boutiques, bars, mixed-use buildings and bus stops. And, my neighborhood boundary is formed by canyons and Balboa Park. In between are a variety of housing types ranging from garden apartments, bungalow courts, and small lot homes nearer the center to large lot homes along the canyon edges.

Single-use districts are places of industry, education, and regional institutions. These include airports, hospitals, and military basis. I tend to put suburban sprawl in…