Cities That Grow Out, Not Up
On the outskirts of nearly every city on the planet, new developments are subsuming farms and undeveloped land, causing the environmental problem known as urban sprawl. In broad strokes sprawl contributes to over-consumption, climate change, air pollution, energy insecurity, and habitat destruction.
High-density living in Washington DC compared with low-density living in Brisbane, Australia.
Unlike much of a city's urban core, the sprawling peripheries have relatively few people living on a single acre of land. Settlements in sprawling areas tend to be free-standing, single-family homes, which typically have larger lots than their urban counterparts.
What makes the peripheries desirable for real estate developers and residents is the affordability and availability of land. As the logic goes, people can own more for less.
the size of the average new house in square feet in the 1950s
the size of the average new house in square feet in 2000
between 1992 and 1997, the amount of farmland in acres lost per year to development
*Source: A Field Guide to Sprawl
No Mass Transit and Lots of Cars
Photo by Atwater Village Newbie
Because sprawling areas are so thinly populated they are essentially unserviceable by mass transport. As a result, the automobile has become the primary mode of transport for people living in sprawling areas.
percent of New York City households that own a vehicle
percent of suburban households that own a vehicle
*Source: Transportation and Land Use Coalition.
Building for Cars, Not for People
Bad design: Getting from Point A to Point B is much more difficult in sprawling ares.
Most sprawling areas are not designed according to a grid layout, the most efficient way to organize a city. Instead, developers have used curving roads as a selling point because they are said to evoke the feel of a winding country road. But with winding roads it's more difficult and time consuming for people to move around.
As the two maps above show, a routine 2 minute walk to the store in Washington DC becomes a several minute car ride in suburban Maryland. Because sprawling areas are designed for cars, even the most basic tasks require them.
Vehicle Miles Traveled
*Source:US Department of Transportation
Thanks in large part to urban sprawl, Americans are driving more now than they ever have been. With the looming challenges of climate change and energy insecurity this is a disturbing trend.
On a personal level, increased driving has considerable financial costs. Owning a vehicle, paying insurance, filling up on fuel, and getting the recommended check ups costs the average American household nearly $8,000 per year. If urban areas were better designed a big chunk of that money could go to other things, like health care, food, vacations, etc.
Average household expenditures on private transport per year
Average household expenditures on public transport per year
*Source:Department of Labor
Percent of suburban household income spent on transport
Percent of walkable urban household income spent on transport
*Source: Christopher Leinberger
What to Do with All The Cars?
Because cars are the primary mode of transport, areas where people congregate - churches, schools, offices, stores, etc. - must have sufficient space for people to park them. The prevalence of large parking lots is a symptom of urban sprawl.