In the early 1900s, before the automobile had really taken hold and shaped policies and regulations, different land uses were more integrated and less defined by car and truck transportation.
After the economic explosion following World War II in the 1940s, U.S. middle and upper classes began moving to suburbs on the outskirts of cities to find more affordable housing. This process of moving to suburbs continued and grew after the Vietnam War as well, and the transition was facilitated by government subsidies on roads and gasoline.
By the 1970s, the federal government began taking the lead and responsibility on many national environmental issues. However, land use determination remained largely in the hands of local governments.
Moving into the 1990s, interest and concern in urban sprawl issues increased, largely due to abandonment of certain inner-city areas. This was compounded by Vice President Al Gore's interest and awareness of urban sprawl problems.
One of the impacts of urban sprawl consists of agriculture land loss. Urban sprawl consumes more than one million acres per year — or two acres per minute — for development.
Urban sprawl also takes a toll on air quality, because it requires that more vehicle miles be traveled to get to work or other locations, while limiting public transport and the ability to bike or walk. The result is more emissions, such as nitrogen oxides and ground-level ozone, and more time spent in cars, which increases exposure to potential carcinogens present in vehicles.
Habitat fragmentation can also result from urban sprawl and has a number of negative effects, such as:
Some additional by-products of urban sprawl include:
|By-Product of Urban Sprawl||Reason/Related Effect|
|Loss of farmland||Affects diversity and cost of food|
|Decreased social equity||Concentration of poverty in urban areas|
|Increased crime||Higher crime rates in inner-city areas now abandoned and under-populated|
|Lowered walkability of cities||Encourages obesity and health problems|
|Increased dependence on foreign fuels||More fuel needed for extra vehicle miles traveled|
|Decreased civic engagement||Populations are spread out and isolated from each other|
A historical example of urban sprawl is the state of Utah. Utah, as of 2014, had the second-fastest urban sprawl growth rate in the United States. Utah's zoning laws encourage development designations, which facilitate urban sprawl. Between 2002 and 2010, urban expansion grew 17.6%, consuming 203 square miles of agricultural or undeveloped land.
Across the country, in that same time period, 13,000 square miles — or an area larger than the state of Maryland — underwent the same transition.