Suburban Sprawl

Do you have to drive a car to get to school? Can you take public transportation? Or can you walk or bike? For many students, the decision is made for them depending on where they live and how far places are. If you can only take a car or one of your school's yellow buses to school, it's likely you live in the suburbs. There's a whole history as to why the suburbs exist in the US, and we'll explore how and why.

Suburban Sprawl Definition

Suburban sprawl (also known as urban sprawl) is the unrestricted growth outside of major urban areas with separate designations for residential, commercial, entertainment, and other services, usually only accessible by car. These separate designations are called single-use zoning.

Suburban sprawl is developed over large areas of land, usually farmland or greenfields. It's characterized by single-family housing and communities have very low population density. This is because fewer people live across a much larger area of land.

Fig. 1 - Suburan development in Colorado Springs, CO; large-scale residential development connected by major roadways are characteristics of suburban sprawl

Suburban sprawl development has increased in all countries over the last few decades.¹ This is due to a multitude of reasons. For instance, some people simply prefer to live in open and natural spaces, with less noise and air pollution. It can also be cheaper or more affordable to build homes outside of cities, as urban growth boundaries may set limits on infrastructure growth.

However, encouragement of high car use, with supporting infrastructure (i.e. abundance of highways and roads), has also been linked to suburban sprawl. This is because car ownership has become more affordable, and people are more willing to make longer commutes to work (usually in cities) and home.

Suburban Sprawl Examples

Different types of suburban sprawl have been identified. These development types depend on the urban area and already existing infrastructure.

Radial or Extension Sprawl

Radial or extended sprawl is continual urban growth from urban centers but with lower-density construction. Usually, there's already some form of development around the area in the form of streets and utility services. This is typically what most suburban development around cities is—it's usually already in close proximity to jobs, services, and other stores.

Ribbon or Linear Sprawl

Ribbon or linear sprawl is development along major transportation arteries, i.e. highways. Development usually occurs on the land next to, or in close proximity to these roads for quicker access to commute to work or get to other services. There's usually a high conversion of greenfields and farms to urbanized space in this case.

Fig. 1 - Strip Mall in Metairie, Louisiana; strip malls are an example of ribbon or linear sprawl

Leapfrog Development

Leapfrog development is a scattered type of urbanization further out of cities in greenfields. This kind of development favors areas further in the countryside over existing development, primarily due to costs and lack of regional development policies in place. This kind of development also consumes large amounts of land as there's nothing physically restricting construction and car infrastructure takes up a lot of space (i.e. bigger roads, parking lots).

Causes of Suburban Sprawl

Suburban sprawl is primarily caused by increasing housing costs, population growth, lack of urban planning, and changes in consumer preferences. Among these issues, there's also the matter of the history of suburban sprawl, especially in the US.

Housing demands and costs have steadily increased in the US over the last few decades.² This is due to the high demand for homes and lower home construction. As a result, house prices within cities are high, while prices in more sprawled areas outside of urban cores are significantly lower. Population growth contributes to this, as more people move into cities and compete for housing.

A lack of strong urban planning both within cities and regionally, where most of the sprawl occurs, is also an important factor. The US federal government has few strong laws on urbanizing; states, regions, and cities often have their own different laws. With a lack of centralized planning, sprawl appears as an easier and cheaper remedy.

Aside from cities, consumer preferences have a major influence on where people want to live. Larger homes, more space, a backyard, or less noise pollution are all factors that drive people to the suburbs. However, the history of suburban sprawl also provides insights into how the federal government was heavily involved in the desire for suburban homes.

Suburban Sprawl: History in the US

Suburban sprawl began in the early 1800s as larger estate developments outside of cities by wealthy individuals in both the US and UK. Although unattainable for middle-class workers, much of this changed after World War II. As war veterans flew back to the US and needed to integrate as civilians again, the US federal government took proactive measures to help them through a series of legislation and programs—notably through the creation of the GI Bill in 1944 and through President Truman's Fair Deal legislation from 1945 to 1953.

The creation of the GI Bill in 1944 provided veterans with a series of benefits from employment, free tuition, loans for homes, businesses, farms, and universal healthcare. Later, the Housing Act of 1949, part of the Fair Deal, created housing developments outside of cities for very cheap, in the form of what we would now call suburban sprawl. The combination of the GI Bill and the Housing Act began to fuel initial suburban sprawl development in the US.

Fig. 3 - Levittown, Pennsylvania (1959); one of the earliest suburban developments made possible with the Fair Deal and GI Bill

Aside from cheaper land costs, major waves of migration to the suburbs also occurred due to racism. Rising stigmas not only against minority groups, but the social and economic mixing seen in cities drove white, more affluent people out of cities (otherwise known as white flight). Racial segregation, along with practices such as redlining and blockbusting were supported at financial and institutional levels.

This created a major shift in American society and perceptions of life. The discrimination not only for minority groups but also for cities themselves led to the perception that suburban life was superior and the so-called 'American Dream.' It's also evident how little care there was for the remaining residents in cities, which tended to be lower-income and/or minority groups in the development of highways and urban renewal projects through communities and neighborhoods as a way to clean up and better connect suburban areas to jobs.

Although historically, the history of suburban sprawl is attributed to these factors, the Federal Aid Highway Act of 1956, created the transportation links between cities and suburbs. The federal government's direct and indirect involvement in land and transportation developments largely caused suburban sprawl in the US.

Suburban Sprawl Problems

There are numerous problems associated with suburban sprawl. Car dependency is a concerning element, not just in suburbs but within US cities as well. With a lack of incentives to densify, even people that live in cities may still need a car to transport themselves. Less density means it takes longer to get to destinations, requiring public transportation or cars to bridge the gap. However, successful public transportation is usually paired with good walking and cycling conditions (density). When cars bridge the gap, transportation costs largely fall on people, excluding lower-income residents who can't afford a car, and vulnerable groups unable to drive (elderly and children).

Fig. 4 - Density vs. Car use; There's a clear correlation between lower density and high car use (with the exception of Los Angeles with medium density but high car use)

Effects of Suburban Sprawl

Aside from car dependency, there are also numerous environmental effects of suburban sprawl. The discussion of the negative effects of suburban sprawl has taken a long time not only to witness but to calculate. This is primarily because institutions have promoted suburban sprawl for a long time, believing it was a healthier and more environmentally sustainable form of development. However, suburban sprawl is linked with land loss, higher vehicle travel, resource use, energy consumption, and greenhouse gas emissions.

Resource and Energy Consumption

The high conversion of land to sprawl leads to a loss of habitats for both flora and fauna, decreasing biodiversity rates. Further, the conversion of greenfields and farmlands has been linked with higher rates of flooding, as the construction of more impervious surfaces prevents the soil underneath to absorb water.

Fig. 4 - Highway in Houston; Houston is one of the most sprawled cities in the US and is experiencing higher rates of extreme flooding as a result

Due to longer commute times and larger, single-use residential homes, higher rates of fuel and electricity are needed. The costs of maintaining water, energy, and sanitation services also increase as it has to cover more area and land (as opposed to a denser city).

Pollution

Due to a greater separation of activities and destinations from each other, longer car commutes also mean greater greenhouse gas emissions. With limited options in public transportation, walking, and cycling, car dependency is the main form of transportation. This can make it difficult to transition to more sustainable forms of transportation.

Air and water pollution are also linked with suburban sprawl. Suburban residents emit more air pollution per capita than people living in denser, urban areas. Runoff contaminants from highways and roads find their way into water supplies, increasing water pollution.

Solutions to Suburban Sprawl

Local urban planners and government officials have the power to target urban growth in a denser and more targeted way. Urban sustainability has the goal of developing in a way that takes into account the social, environmental, and economic well-being of people. Some forms of sustainable urban growth include mixed land use, where residential, commercial, and recreational areas can be built on the same lot or location to optimize walking and cycling. New Urbanism is a major proponent of mixed land use and encourages other sustainable development policies.

In the end, it can be very difficult to change infrastructure and buildings once they're in place. It's not environmentally or economically efficient to tear down homes and buildings and build them up again closer together. Suburban sprawl can only be prevented, not corrected.