New Study Links Auto Use to Neighborhood Design

Authors Say Research Proves for the First Time that Smart Growth Works

SAN FRANCISCO, CA (June 10, 2002) -- For decades, city planners have dismissed calls for building better cities, saying there's only anecdotal evidence that so-called "smart growth" works. But authors of a new, peer-reviewed study say their research proves for the first time that better urban design can reduce auto use and relieve the traffic congestion and pollution that come with it.

The researchers' analysis of the San Francisco, Los Angeles and Chicago metropolitan areas found a direct link between the amount people drive and city attributes like neighborhood density, transit access, and pedestrian- and bicycle-friendliness. According to the authors, those attributes measure an area's "location efficiency," and, not surprisingly, the more efficient the location, the less people drive.

"We now have empirical evidence that smart growth works," said David B. Goldstein, a study co-author and director of the energy program at NRDC (Natural Resources Defense Council). "This study shows that people who live in more convenient communities are less dependent on cars. These communities are not only more convenient, they're also more livable because they tend to have cleaner air and water and more protected open space."

"Smart growth has the added benefit of saving consumers thousands of dollars in car costs annually," said Hank Dittmar, study co-author and president of the Great American Station Foundation. "It's time for city and transportation planners to put an end to sprawl development, for the benefit of consumers and the environment."

The study examined auto ownership and driving patterns in nearly 3,000 neighborhoods in the three metropolitan areas, and the results were quantified. The authors used the results to construct mathematical models that allow the average number of autos owned and miles driven to be calculated for a household of any given income and size, as long as the neighborhood's density, transit access and pedestrian friendliness are known. The authors said their findings offer intriguing suggestions for how we can design our cities to reduce dependence on driving, traffic congestion, energy use, and air and water pollution.

"Over the years, sprawl development has forced us to drive more and more," said John Holtzclaw, the study's lead author and consultant to NRDC. "Not surprisingly, smarter, more convenient cities resemble the pedestrian- and transit-oriented cities of our grandparents, which were built before the car dominated our zoning laws and transportation projects."

The authors also note that, after housing, transportation is the second biggest expenditure in the average household budget. This fact can be leveraged to encourage smart growth through a new mortgage product called a Location Efficient Mortgage® or LEM®. The LEM® allows a homebuyer who purchases a home in a convenient area to qualify for a larger loan. For example, a potential buyer who would avoid $500 in auto costs by living in a convenient area could qualify for a larger mortgage. (For more information about the Location Efficient Mortgage®, visit

"The homebuyer who qualifies for a Location Efficient Mortgage® can invest their auto savings in house payments," said Peter Haas, study co-author and analyst with the Center for Neighborhood Technology in Chicago. "That means they get more house for their money in a more livable community."

The study, "Location Efficiency: Neighborhood and Socio-Economic Characteristics Determine Auto Ownership and Use - Studies in Chicago, Los Angeles and San Francisco" by John Holtzclaw, Robert Clear, Hank Dittmar, David Goldstein and Peter Haas, appeared in the March 2002 issue of Transportation Planning and Technology.

The Natural Resources Defense Council is a national, non-profit organization of scientists, lawyers and environmental specialists dedicated to protecting public health and the environment. Founded in 1970, NRDC has more than 500,000 members nationwide, served from offices in New York, Washington, Los Angeles and San Francisco.

Related NRDC Pages

FAQ: Location Efficient Mortgages

NRDC's Smart Growth/Sprawl pages