The term “urban sprawl” has a bad ring to it. The name reinforces the view that metropolitan growth is ugly, inefficient, and the cause of traffic congestion and environmental harm. Before we decide we are against urban sprawl, however, we should be clear about what it is and why we do not like it. Once we look at its specific characteristics, we can recognize their causes and what, if anything, to do about them.
My study of metropolitan growth indicates that three kinds of development are typical of what we call “urban sprawl.” They include: leapfrog development, strip or ribbon development, and low-density, single-dimensional development. Let us look at each type in turn.
Leapfrog development occurs when developers build new residences some distance from an existing urban area, bypassing vacant parcels located closer to the city. In other words, developers choose to build on less expensive land farther away from an urban area rather than on more costly land closer to the city. Because land prices are lower, housing in these developments is more affordable. Some people decide to accept longer commutes in exchange for more comfortable, lower-priced housing.
What few people realize is that leapfrog development nurtures compact commercial development-retail stores, offices, and businesses. The empty parcels that have been “leapfrogged” create an ideal location for commercial activity. It is a fact of economic life that developers are reluctant to place new commercial buildings on the outskirts of an urban area because these areas lack a large market to draw shoppers from. When new development bypasses vacant land, however, the land in between is suddenly accessible to more people and thus attractive to commercial developers. Thus, leapfrogging is a vital part of development in growing areas.
Leapfrog development does create some extra costs. Infrastructure must be extended farther and the longer distance creates more traffic and longer commutes into the city. For a leapfrog development to be cost-effective, the outlying development must pay the full costs of the infrastructure it requires. It is the responsibility of local governments to see that the costs of water, sewer, roads, and so forth are charged to the development.(1) As long as the new residents pay their share of the costs, leapfrog development benefits those who choose to live there and encourages commercial development at the edge of the urban area.
Strip or ribbon development, the second category, takes place when extensive commercial development occurs in a linear pattern along both sides of major arterial roadways. Like other aspects of urban sprawl, it is viewed as ugly and as a cause of traffic congestion, since shoppers and workers are often entering into and exiting from the street.
Yet strip development has its benefits. It brings together businesses that depend on high auto traffic. In fact, strips reduce overall traffic, since fewer cars must travel long distances from store to store or office to office. Strip development also creates natural locations for residential development. Between the commercial arteries, residential streets can have relatively little traffic yet be conveniently located near commerce.
In many situations, strip or ribbon development does cause problems, but the reason is poor planning. Every business fifty feet from another business does not have to have a driveway opening onto a major thoroughfare, creating congestion as people enter and leave. Access lanes can be built to permit the smooth merging of traffic entering and leaving.
Nor does strip development have to be unsightly. If the rightof- way is wide enough, landscaped buffers can separate the road from the businesses. To achieve this separation, though, governments must plan ahead to secure sufficient rights-of-way for major streets before they are built.
The third characteristic of “urban sprawl” is low-density, single-dimensional development. This is typified by large residential subdivisions. Houses are situated on relatively large lots, with only other houses nearby. Residents must drive nearly everywhere they go. Critics say that low-density developments take up too much space, especially space that ought to be preserved in a pristine state. They say that they lengthen commuting distances, and, in general, that they harm the environment.
Low-density developments do take up space and may increase driving time. However, they have an important argument in their favor: People like them. Low density means more room and a higher standard of living. While every city has apartments available for those who prefer them, many people choose (and more people aspire to have) their own detached homes.
Low density is likely to help the environment. Yards filled with trees and shrubs absorb dust and chemicals, so smaller amounts of pollutants escape into the air and water. In contrast, in dense urban areas buildings, roads, and parking lots take up a higher percentage of the land, leaving little of the natural environment to absorb pollutants.
As for single-dimensional development (that is, residences only), this is often the result of zoning laws. Some zoning laws flatly prohibit mixed uses of property. Prohibitions against leapfrogging mean that development on the perimeter of a city is mostly residential, since no business wants to put its commercial establishment on the edge of an urban area. Prohibitions against strip or ribbon development also keep commercial establishments distant from residential areas.
Thus, when the components of urban sprawl are examined, they can be seen as components of a healthy and efficient development process that is sometimes thwarted or distorted by regulations. I do not mean to imply that all instances of these development processes are efficient but that they can be. Underlying all the complaints is what troubles people most about urban sprawl-transportation problems. Many of these problems arise because the government has not effectively controlled access to its roads. Traffic is clogged because there are too many access points to highways and because insufficient rights-of-way were planned to handle the traffic load. To avoid these problems, local governments should obtain adequate rights of- way for roads, limit the number of allowable curb cuts, and require access lanes or separate access roads rather than direct access to thoroughfares.
Specific policies to stop or slow down urban sprawl reflect a more general vision of how metropolitan development takes place. Planners assume that suburban areas spread out from a central urban core. They assume that people work in the central cities, commuting from the suburbs. Growth management policies are designed to keep people living and working in central districts. If left to its own devices, development will occur in a decentralized manner, which will usually lead different types of activities to be conveniently located in relation to one another. Decentralized growth will provide nodes of development. People can live close to the node where they work, allowing a more efficient pattern of two-way traffic as people travel between nodes. Decentralized development keeps commuting distances short but allows the amenities of suburban living for those who want them.
In sum, the invisible hand of the market guides property owners to develop their property in ways that result, over time, in efficient land-use patterns. When government land-use planning is examined, we find that land-use decisions made under the name of growth management will more likely hinder than help the development process.