For almost a century commitments to autos and cheap oil prevented us from doing this. Now, losing cheap oil makes it both necessary and possible to build regions and cities much better than we have been. We can no longer build sprawl. And we must and now can organize them into communities and neighborhoods anchored by mixed use cores.¹ These cores should:

These qualities still exist in many downtowns and centers around the country. Unfortunately, They were often neglected and lost as industry and auto use came to dominate and were not replaced or extended in new development. Now the loss of cheap oil will both require and stimulate us to reestablish or include them in both existing areas and new.

From the earliest settlements of civilization these qualities have been sought in towns and cities and largely achieved . We love to visit them in areas where they can still be found. Only defense was considered more important than these qualities by Greeks seeking sites for colonies or new towns around the Mediterranean or by early immigrants to America and settlers to the West. The principles have been reaffirmed many times since, often with well supported evidence. Some of the best examples of this include:

Lewis Mumford, perhaps the world’s most acute student of urban life.

Margaret Mead, one of the world’s most perceptive observer of relationships between of humans and their environment.

Victor Gruen, the "father" of the shopping center, a sharp critic of its failures and most eloquent supporter of true mixed use. 

Architects Clarence Stein and Henry Wright who, in 1929, combined ideas about mixed use with Ebenezer Howard’s Garden Cities ideas to create Radburn, N.J. Mumford considered it "the first major advance in city planning since Venice". Although the crash in1929 prevented its completion, its concepts were subsequently reflected in a few new communities in the U. S., and many in England, Sweden, Japan and other countries around the world. 

Visionary developer, J. C. Nichols, builder of the Country Club Plaza in Kansas City, in the 1920's. This is one of the earliest and most successful, still thriving, early centers combining housing, office, retail, hotel and other uses in  any American city.

Despite these strong beginnings and even later efforts by Victor Gruen to apply mixed use principles, the depression, war, and growing dominance of the auto and cheap oil prevented the idea from being widely applied in the U. S. In the absence of strong pressure from any source it was far easier for developers and communities to simply ignore the lessons of mixed use and its related principles.

Revived Interest and First Principles

After World War II cities awakened to concerns about their downtowns². In the 1950's relatively comprehensive planning efforts were initiated in such cities as Seattle, Cincinnati, Chicago and Vancouver, each with its own approach. Even without benefit of guidelines all still achieved success. However, in his work for Chicago, Ted Aschman , as consultant to Chicago Central Area Committee, identified the six basic qualities defining a good downtown. These are listed above. Today I would add a seventh: "good management."

Unfortunately, although Ted’s firm,  Barton Aschman Associates applied them widely in over fifty downtowns, they were circulated by the Chicago Central Area and reported by the American Society of Planning Officials (now APA), they did not become widely known. They are not even  mentioned  in downtown planning "manuals" eventually prepared by the American Planning Association (APA) and the Urban Land Institute (ULI). The principles and were and remain the foundation of the plan for Chicago and, in 1957, were applied in downtown Minneapolis and have been reiterated at every revision of it’s plan.

Publicizing Principles and Benefits

Finally, successes in some of the nation’s best central cities (Vancouver, Seattle, Minneapolis, Portland, etc.) as well as in some new suburban areas started generating attention to the values these principles create when applied and to failures when they are not. The work of Joel Kotkin, Richard Florida and the Urban Land Institute, in particular, has been very effective.

Several years ago, several planners and architects developed the concept of "new urbanism," established an organization using that name  (Congress for the New Urbanism. CNU) and proposed a set of principles to be applied to new development. Likewise, the ULI initiated a  program to overcome problems of many failing shopping centers using a set of principles they developed for this purpose. 

The rules developed by these organizations are consistent with those developed by Ted Aschman. And, both the CNU and ULI continue to advocate and offer assistance in their application. And both organizations are calling attention to mixed use,  and its principles for development and stimulating both developers and communities to accept and use them as a model.

Many claims are made for the value of mixed use. The benefit of mixed use principles is largely self evident. For example, the need for access and internal circulation cannot be denied. Yet, adequate transit and pedestrian facilities are often overlooked. No one argues against the value of compactness, amenities, real mixed use and support. Still, these are often short changed.  And little hard evidence exists for claims that mixed use can reduce travel, provide more workers with convenient access to affordable housing or create stronger community identity and citizen involvement. Yet, logic tells us that these things are and can be true.

The claim which is most important in relation to the loss of cheap oil is that mixed use  can be one of the most valuable ways to reduce the consumption of energy and especially oil. Research here needs to explore the degree to which mixed use can reduce the need for auto travel and fuel consumption. The theory is that mixed use will allow more people to live closer to most of the destinations that they have in their lives each day: work, play, school, shopping, education, health, etc. and that it provides an environment which generates better energy saving options for travel such as walking and transit.

The corollary question: is there some equally effective or cheaper way to accomplish such reductions, such as rationing or other types of control. However, I would argue that this is a moot question: the need for reduction is so great that we need to use every means we have.

• One of these by Kyles, Sanborn and Carroll of the Brookhaven National Laboratory showed reductions in transportation energy use for the “growth center” (vs sprawl alternative) of 32%.
• A second, by Peskin and Schofer of Northwestern University, compared three diagrammatic forms, two single-centered, "Concentric” and  “One-Sided,” and one including four major “centers,” a downtown and three outlying centers. Reductions in gasoline use for the latter were 57% less for passenger travel in the Concentric option and 44% less than the One-Sided option.
• A third, by Professor Ronald Rice examined six forms: central, homogeneous, multi-centered, radial corridor, linear and satellite. The multi-centered form was 23% better in person-hours ofwork trip travel and 22% better in average trip length. The greatest benefit would probablycome from non work trip travel which was not included. 
• The Costs of Sprawl, in 1974 (Real Estate Research Corporation) reviewed alternate patterns of residential development and concluded that huge savings in transportation infrastructure costs could result from building at higher densities, with an option of a “planned mix” with the lowestcost of any option except for “high density.” Several additional studies, such as the Costs of Sprawl, of this subject have been made since. None specifically include the element of “mixed use.” However, most continue to show  substantial reductions in transportation and other costs solely from  the factor of higher densities. Because the concept of mixed use discussed here requires a planned mix of uses and a higher jobs-retail-housing  balance it could be expected that its widespread use would greatly increase savings beyond those generated solely by increased densities. 
• Work by Robert Cervero, especially his work with Robert Duncan reported in the Autumn 2006 Journal of the American Institute of Planners titled Which Reduces Vehicle Travel More: Jobs-Housing Balance or Retail-Housing Mixing? which concludes: “....Linking jobs and housing holds significant potential to reduce VMT (vehicle miles traveled) and VHT (vehicle hours traveled).”

The multi-center options analyzed in these studies only very roughly approximate the kind of pattern of mixed use centers contemplated by this analysis. Of course, for a large region there would not only be a number of large centers but also hundreds of smaller centers, each as self sufficient as possible in matching housing with job and other destinations. One could never expect universal matching of uses. But, I would expect only partial implementation in the manner proposed here to produce savings beyond those identified in the studies noted above.

In 1994, before recent rising concerns about the loss of cheap oil, Anthony Downs’ book, New Visions for Metropolitan America, emphasized five problems which he says we must solve: congestion, air pollution, loss of open space, growing infrastructure costs and affordable housing and evaluated four options to continued sprawl. He said that “if these problems are not addressed vigorously, they will gravely impair the political unity, productivity, and economic efficiency of American society and the personal security of everyone.” His concerns then are now multiplied by the loss of cheap oil. He identified and evaluated three broad options for future growth:

1. unlimited low-density development
2. limited-spread, mixed density growth
3. new communities and green belts
4. bounded, high density growth