At the very opposite end of the design spectrum from neotraditionalism is the edge city. Unlike neotraditionalism, which is a very clearly articulated design philosophy, the edge city embodies no single design philosophy, nor does it have a clear spokesperson such as Andres Duany. Rather, the edge city is an evolving form of development based on a variety of economic forces and on the understandings that developers and investors have of those forces.
The term edge city was coined by journalist Joel Garreau to describe this new form of development that has been springing up all over America in the last three decades or so. Using Garreau's somewhat arbitrary definition given below, there are more than 200 edge cities in the United States. Some of those identified by Garreau include Tyson's Corner outside Washington, DC; Buckhead in Atlanta; the Schaumburg area outside Chicago; Dearborn-Fairfield Village outside Detroit; the Galleria area outside Dallas; Irvine Spectrum outside Los Angeles; the Stamford-Greenwich area in Connecticut; Mitchell Field-Garden City in Nassau County, New York; and the King of Prussia area west of Philadelphia. He defines an edge city as meeting the following five requirements:
What are the market forces that favor the development of edge cities? The peripheral location means that the developer(s) can build a large, unified design at one time and do so without having to absorb the residual value of existing structures (see Chapter 11). The large size may offer substantial economies of scale in planning, construction, and marketing.
Its position on the periphery of the metropolitan area gives employers in the edge city access to a large and suitable labor force. Retailers and providers of personal services prosper in the edge city because they are easily accessible to a large, affluent suburban population. The different activities in the edge city may provide profitable synergy. For example, workers in the office buildings will also be customers for retailers and service businesses in the mall. The edge city is an understandable adaptation to a suburbanized population with a very high rate of automobile ownership and access to high-capacity, high-speed highways. The most basic requirements for the formation of an edge city are good highway access, a large and at least moderately prosperous population within easy driving distance, and a large block of available land.
Some edge cities, such as Irvine Spectrum, are planned as a single entity. Others are planned in stages. In either case, the process is very different from traditional urban development under Euclidean zoning. The developer must assemble a sizable piece of land and present the government of the municipality or municipalities with a unified plan. Development is a complex negotiated process, rather than a matter of the developer's acquiring a single parcel and then either building what is allowed by the zoning code or petitioning for a rezoning or variance for that one parcel.
Although the edge city contains many of the same commercial elements as the traditional urban downtown, it differs radically in physical form. The edge city is much more spread out than the traditional downtown. The spread-out form is an adaptation to virtually total reliance on the automobile. Garreau notes that developers regard 600 feet as about the biggest distance that people can realistically be expected to walk without complaint. Thus the typical form of the edge city is a building or perhaps two or three buildings closely grouped and surrounded by some acres of parking space. Larger groupings are generally not done because they would stretch out walking distances beyond what an automobile-owning populace would accept.
Just as the edge city is automobile friendly, it is also pedestrian unfriendly. Irvine Spectrum in southern California, shown in the map on page 196, dwarfs the traditional downtown. Its size alone renders it essentially unwalkable. So, too, does its design. There is no continuous pattern of streets with sidewalks, nor are buildings and their surroundings laid out for walking. Rather, they are laid out for driving, and the visitor is expected to make only the trip from parking space to building on foot. To the extent that there are pedestrian facilities, they are jogging trails or scenic paths intended for recreation, not transportation. Edge cities do mix a variety of commercial uses, though generally at a coarser grain than the proponent of neotraditional design would prefer. But they separate work from residence very effectively and thus render virtually every trip to work an automobile trip—again, the antithesis of the neotraditional philosophy.
The edge city is only several decades old. Although numerous architects, planners, and others have speculated about the future of urban form, none really foresaw the edge city. In some ways, Frank Lloyd Wright, with his vision of Broad Acre City, anticipated the dispersed pattern of settlement and the overwhelming reliance on the automobile that characterize the larger environment in which the edge city has developed. But neither
FIGURE 10-2 Downtown Cincinnati and Irvine Spectrum edge city are shown at the same scale. Note that the longest dimension of Irvine Spectrum is approximately four times that of the longest dimension of the Cincinnati downtown and that the area of Irvine Spectrum is approximately nine times that of the Cincinnati downtown.
Source: Reprinted by permission of the Journal of the American Planning Association, 64, no. 3, summer 1998.
he nor any other writer anticipated the edge city itself. Joel Garreau notes that because the edge city is a new form, we cannot say what it will ultimately evolve into. Just as the nineteenth-century city that burgeoned as a result of the industrial revolution often evolved into a much cleaner and pleasanter form in the twentieth century, so too may the edge city evolve into a more gracious and subtle form in years to come. But that is only speculation.
The top picture shows the entrance to the Galleria shopping center in Tyson's Corner. Note the massive amount of parking space in front of it. It is clearly designed for almost exclusive automobile access. The bottom picture shows a designer's vision of what a much more urban and pedestrian-friendly Tyson's Corner might look like in 2050.
Tyson s Corner s super-blocks today
Future smaller, walkable blocks
The figure at top shows the route of the Metro line with its four stops, average spacing a little more than half a mile, which would form the main axis of the redeveloped Tyson's Corner. The route of the train if coming from Washington, DC enters the figure about an inch below the top right corner, then drops down toward the center of the figure and exits the left edge of the figure about a quarter of an inch below the top. Note that the intensity of development would be greatest immediately around the stops and then decline out to a distance of about half a mile. The two figures below show the existing (top) and proposed (bottom) street patterns. The area outside the dark background shows the present street pattern, primarily suburban subdivisions, outside Tyson's Corner.
Perhaps we will get our first view of what a transformed edge city might be like from Tyson's Corner, in Fairfax County, Virginia. Tyson's Corner is located just outside the Washington, DC Beltway (I-495) and just to the north of its intersection with I-66. If you think of the DC Beltway as a clock face, Tyson's Corner would be at 9 o'clock. For the relationship of the city to the Beltway and I-66, see the map on page 198. Tyson's Corner is not a separate municipality, but rather a Census Designated Place (CDP) occupying 4.9 square miles and with a year 2000 resident population of 18,450. These may sound like the statistics for any number of towns in America, but Tyson's Corner is very different from an ordinary town. On a typical weekday its daytime population is probably seven or eight times its resident population, since an estimated 117,000 people work there. Add to that numerous shoppers, and the weekday daytime population exceeds 150,000. Tyson's Corner contains an estimated 167,000 parking spaces and 46 million square feet (1.65 square miles) of commercial floor space (primarily office and retailing). It is considerably more densely developed than Irvine Spectrum, shown on page 196. Like the typical edge city, it is almost entirely designed for the automobile. There is not a continuous grid of streets and sidewalks as there is in the ordinary city or town, and wide, curved intersections designed to speed auto traffic further discourage foot travel. It is definitely not pedestrian friendly.
But plans to change Tyson's Corner into something more typically urban are underway. One central element in the plan is to connect Tyson's Corner to the Washington, DC Metro system. An extension to the existing system will have four stops spaced about half a mile apart in Tyson's Corner and will continue westward to several other municipalities and then to Dulles Airport. At this writing the rail work in Tyson's Corner is well underway and the financing for the extension out to Dulles Airport is being worked out.12 The Metro link between Tyson's Corner and Washington, DC, with its mass of employment, will greatly increase Tyson's Corner's attractiveness as a residential location.
Additional housing will be multi-family, and a substantial share of it will have to be at least moderately high-rise, for there simply is not the space for a significant amount of single-family housing. A more finegrained and pedestrian-friendly street pattern is a key part of the plan; so, too, is a system of walkways, trails, bicycle paths, shuttles, and other non-automobile-accessible measures designed to turn Tyson's Corner into a densely developed, pedestrian-friendly, highly accessible place. The obvious place to find the space for new streets and new housing will be in some of the areas now devoted to parking. Charging for parking will be part of the plan to shift people away from driving and onto public transportation.
Le Corbusier's "Voisin" plan for Paris 1922-1925 (top). Building very high would permit extreme population density while leaving 95 percent of the land vacant. Although never built, this plan exerted enormous influence on design, for both better and worse, in many countries. Below is the planned community of Roehampton in Great Britain. Note the Le Corbusier influence in the large amounts of interior open space and the use of columns referred to as pilote.