Urban sprawl

Cities can grow very big.

They spread out over the land. This is called sprawl.

This growth can take up farm land. It can also hurt the countryside. People often build many roads to move around.

In these areas, homes are far apart. Shops and jobs are also far away. This means people must use cars to travel.

Driving more can make the air dirty. It can also make trips take longer. Some people find this hard.

Many people move to these new areas. They want to live away from the loud city. It is a big change for the land.

Urban sprawl is when cities and towns grow very fast.

This growth often spreads out over large areas of land. It can happen in a messy or unplanned way.

In many sprawling areas, homes are far apart. These places often use "single-use zoning." This means homes, shops, and offices are in different spots.

Because these places are far apart, people must use cars. Walking or riding a bike is often not easy.

Sprawl can cause many problems. It can lead to more pollution and longer travel times. It can also destroy the countryside and farm land.

Why do people move to these areas? Some people want to leave loud or crowded cities. They look for better houses or quieter spots. Other reasons include better jobs and new roads.

Sprawl looks different in every place. In the United States, many jobs are now in the suburbs. In some parts of Europe, experts call this "peri-urbanisation."

Even big cities like Los Angeles show signs of sprawl.

Yet, Los Angeles is still a very dense city.

Urban sprawl is a special way that cities and towns grow. It happens when a city expands very quickly over a large area.

This growth is often unplanned or uncoordinated. It usually features houses that are spread far apart. These areas often have low density, which means there are fewer people in a given space. People in these areas often rely on private cars to get around. This is because things like shops and offices are not close to homes.

This type of growth works through a system called single-use zoning. In this system, different parts of a city are kept separate. One large area might be only for houses. Another area might be only for stores or factories. Because these places are far apart, walking or biking is often not practical. This makes driving a car a main way to travel.

Some experts also look at "leapfrog development." This is when new buildings are placed in spots that leave empty land in between. This can create a patchy pattern across the countryside.

People have talked about this idea for a long time. The term was used in letters between Lewis Mumford and Frederic J. Osborn between 1938 and 1970. They were worried about the waste of farmland and beautiful landscapes. In 1955, a newspaper called The Times used the word to talk about the edges of London. Today, many researchers still study how to define it. Some use the number of homes on an acre to measure it. Others look at how much people have to travel to reach important places.

There are many real numbers that show how much land changes. In the United States, much land was developed between 1982 and 2017. The National Resources Inventory says about 100,000 square kilometers of land is classified as developed. That is an area almost as big as the state of Kentucky!

In 2002, 37 large urban areas in the U.S. held about 40% of the total population. Some cities like Detroit have grown in size even while they lost people. Other cities in Europe, like Brussels or Munich, also saw sprawl between 1970 and 1990.

Sprawl connects to many parts of our daily lives. It can lead to more pollution and longer travel times for workers. It can also change how people find jobs. This is sometimes called "job sprawl," where jobs move away from the city center.

This can make it hard for people without cars to reach work. In places like Los Angeles, the city is very large but also very dense.

This shows that sprawl can look different in every part of the world.

Urban sprawl, also called suburban sprawl or urban encroachment, describes the rapid expansion of cities and towns. It is a specific form of urbanization that changes how land and people are organized.

Sprawl is often defined by low-density residential housing and single-use zoning. This means different parts of a city are kept strictly separate. For example, one area might only have houses, while another only has shops. This separation forces an increased reliance on private automobiles for transportation. Because these areas are spread out, walking or bicycling becomes impractical for most people.

The mechanism of sprawl relies on how land is used and how people move. In a sprawling system, residential, commercial, and industrial zones do not mix. This creates a pattern where people live far from where they work or shop.

One specific type of growth is called leapfrog development. This occurs when new developments are built in patches, leaving vacant land in between. This creates a discontinuous landscape rather than a solid, connected urban area. Another pattern is strip development, where buildings follow major roads in long lines. These patterns often lead to inefficient resource utilization and higher transport costs.

Researchers identify several distinct characteristics to define this phenomenon. One key indicator is residential density, which measures how many housing units exist per acre. Another is decentralization, which is the spread of a population without a clear center. Some experts, like Reid Ewing, suggest using "accessibility" and the "lack of functional open space" as better indicators. He argues that using specific indicators is more flexible than just looking at negative characteristics. This helps distinguish between simple suburbanization and true, unplanned sprawl.

The history of this term is tied to debates about land use. The term was frequently used in letters between Lewis Mumford and Frederic J. Osborn between 1938 and 1970. They used the term to condemn the waste of agricultural land and natural landscapes. In 1955, the term appeared in The Times to criticize the outskirts of London. Today, the term is highly politicized and usually carries a negative connotation. It is often used as a rallying cry by those wanting to manage urban growth more effectively.

Significant data illustrates the scale of land development in the United States. According to the National Resources Inventory, about 100,000 square kilometers of land was classified as developed between 1982 and 2017. This is an area roughly the size of Kentucky.

While the 2000 Census showed that only 2.6 percent of U.S. land is urban, the footprint of development is much larger. In 2002, 37 large urbanized areas supported about 40% of the American population. Even in Europe, cities like Amsterdam, Brussels, and Munich saw population losses in urban centers alongside the expansion of sprawl between 1970 and 1990.

There are many surprising examples of how sprawl manifests in different ways. Los Angeles is a major example because it is both sprawling and very dense.

Unlike New York or Chicago, which have dense cores and very thin edges, Los Angeles has a more uniform density across its large area. This makes it the densest major built-up urban area in the U.S. despite its car culture. In contrast, China shows a phenomenon called "high-density sprawl."

In these areas, massive residential superblocks are surrounded by giant roads, making them unfriendly to pedestrians.

Urban sprawl connects to complex economic and social systems. One major issue is job sprawl, where employment moves from the central business district to the suburbs.

This can lead to a "spatial mismatch." This occurs when low-income or minority citizens cannot easily reach new jobs because they lack transportation. Economic studies show this trend is growing; for instance, in 2006, 45.1% of jobs in large U.S. metropolitan areas were located in the outer ring, 10 to 35 miles from the center. This movement of jobs and people continues to shape the environmental and social landscape of modern nations.