Exurban Sprawl


Lilian Lam

What is exurban sprawl?

Beginning in the 1950s, the growth of America has taken the form of exurban sprawl, in which more and more people are migrating out of cities and into rural areas.  There are two main forms of this exurban development:

  • Urban fringe development (UFD): the expansion of exurban densities on the outer periphery of cities
  • Rural residential development (RRD): development taking place in rural areas distant from cities
Summary of readings:

Charles Barnard discusses some of the factors and determinants that encourage current exurban growth trends.  Population growth, which we have previously discussed in class, is one part of the problem in that it results in the continued growth of cities.  However, cities can grow upwards (in the form of taller skyscrapers) or outwards (in the form of sprawl).  From 1980-1990, the population grew by 31% while developed land areas grew by 74% indicating that population pressures are not the only factor, and that socioeconomic changes also play a prominent role.  Today, America is characterized by smaller household sizes, consumer housing preferences favoring large lots, and business relocation out of the city.  Technology has an important role in promoting this growth trend as digital microelectronics and improvements in communications have decreased the importance of proximity to urban centers.  As businesses move into the suburbs and exurbs, so do employees.  In addition, technological advances in transportation have further encouraged people to take up residence further away from the city.

John Bergstrom provides insight on changing rural land values.  The young, developing United States was characterized by a Hamiltonian view, in which land was seen solely as an input for commercial productivity.  As a result, our early policies followed productivism and commitment to commercial production values.  However, as the nation developed, productivism helped to nullify the scarcity problem such that it was no longer of major concern.  Since then, postproductivist attitudes gained dominance as the demand for noncommercial land values began to increase at a greater rate than the demand for food.  At this point, land took on increasingly Jeffersonian “character-building” values and became valued for natural amenities including open space, unique physical terrain, natural water supply systems, and places for recreation and spiritual health. 

The Andrew Hansen et al. paper focused on the effects of exurban development on biodiversity through habitat fragmentation, disruption of nutrient cycling, alteration of ecological processes, and human disturbance from vehicles and pets.  In the Seattle case study for urban fringe development (UFD), the results showed that native species richness decreases as housing density increases along a rural-urban gradient; the opposite effect was observed in exotic species.  Another important finding is the possibility that negative effects on biodiversity may continue to intensity for several decades after the initial start of the housing disturbance.  The case study of rural residential development (RRD) in the Rocky Mountains of Colorado disproved a common misperception that homes scattered at low densities have little influence on biodiversity.  The study revealed the harmful effects of ecological fragmentation caused by extensive networks of roads that break the ecosystem up into smaller areas of land with fewer resources.  Hansen also suggests that RRD may have a devastatingly disproportionate effect on the environment since rural homes are more likely to be placed in attractive landscapes, which also serve as natural habitats with better soil and water quality for native species. 

Class Discussion:

The class discussion began with more focus on the different factors that encourage exurban sprawl.  The modern economy is no longer agriculture-based but is now based on information services and communications, which have very different infrastructures that do not require a core economic center in the city.  Furthermore, technologies such as cell phones and wireless Internet have made it much easier for people to spread into deeper rural areas.  The interstate highway system, initially approved by President Eisenhower to tie America together to thwart Communism, pointed the nation’s development down a path of suburban and exurban sprawl. 

Next, the class discussed the alluring values of the rural countryside that make permanent residency worth the hassle of increased driving time.  The class listed values of aesthetic beauty, living in a natural ecosystem, and opportunity for recreation among the top incentives.  Another point was that the natural ecosystem was more “complex” than a city environment, and parents would value a more nurturing environment for their children.  Furthermore, the rural countryside is perceived as being safer than the city, which is also important to those with children.  Along similar lines, the city is sometimes perceived as housing for the poor, and the rich can afford to “flee” from urban centers to scenic, low-density, large-lot housing in the countryside.  Another point is that technological advances in vehicles (such as climate control, audio systems, and comfortable chairs) make the drive more enjoyable, such that time spent driving is not a major issue.

One of the lasting questions of the discussion was how to control exurban sprawl, and what methods could be used to promote upward city growth instead of outward spread. Currently, technology has made it less expensive to spread outwards into rural areas than to increase the height of skyscrapers and other residential buildings.  A possibility to restrict current outer growth may be government subsidies for constructing taller buildings, or perhaps a tax based on ecological damage caused by sprawl.  The class also thought that another method would be to use incentives to lure people back into the city.  Perhaps a more convenient and “posh” public transportation system may be used to keep people in the city, or some other way to make living in a city skyscraper the fad.  This may be a stretch, but when Gwenyth Paltrow was photographed riding the bus, bus ridership was greatly heightened in the following months.  This is a difficult problem to solve as the population will undoubtedly continue to grow, and the halt of sprawl will come from changes in technology, consumer preferences and values, or an unfortunate consumption of all remaining open space.




Barnard, C. "Employment growth, population growth and electronic technologies as determinants of land use." Land Use Problems and Conflicts: Causes, consequences and solutions. London and New York, 2005.

Bergstrom, J.C., "Postproductivism and changing rural land use values and preferences." Land Use Problems and Conflicts: Causes, consequences and solutions. London and New York, 2005.

Hansen, A.J., Knight, R.L., et al. "Effects of exurban development on biodiversity: patterns, mechanisms, and research needs." Ecological Applications: 15(6), 2005. pp. 1893-1905.

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last updated 1/25/06