New Study Reveals the Hidden Environmental Cost of Parking

נשלח 19 בינו׳ 2011, 3:55 על ידי Sustainability Org   [ עודכן 19 בינו׳ 2011, 5:38 ]
Posted on Wednesday January 12th by Eric Jaffe


The price of free parking keeps going up. One cost is painful urban congestion, which is made worse by drastically under-priced street parking. Another is a relative cost to the environment, which occurs when the near-certain prospect of free (or cheap) parking entices people into their cars and away from alternative forms of transportation. Recently a team of researchers from the University of California at Berkeley, writing in a recent issue of Environmental Research Letters, described a previously unknown cost — energy and emissions that come from building America’s vast parking infrastructure:

The environmental effects of parking are not just from encouraging the use of the automobile over public transit or walking and biking (thus favoring the often more energy-intensive and polluting mode), but also from the material and process requirements in direct, indirect, and supply chain activities related to building and maintaining the infrastructure.

To estimate just how great this toll is, the researchers first had to estimate exactly how many parking spots exist in the United States. Turns out that’s no easy task; in fact, according to the authors, no such “nationwide inventory” has ever been done. “It’s kind of like dark matter in the universe,” Donald Shoup, the so-called “prophet of parking” (and not part of the study), told Inside Science. “We know it’s there, but we don’t have any idea how much there is.” When the Berkeley researchers crunched the numbers, they came up with five scenarios of available U.S. parking that ranged from 105 million spots to 2 billion. Give or take, I guess.

The most likely estimate points to roughly 800 million spaces across the country, and the construction and maintenance of those spaces do, in fact, take a large cumulative toll on the environment. When parking spots are taken into account, an average car’s per-mile carbon emissions go up as much as 10 percent, the authors conclude. They also report that, over the course of a car’s lifetime, emissions of sulfur dioxide and soot rise 24 percent and 89 percent, respectively, once parking is properly considered.

Those are just part of a broad “suite of impacts” that includes previously studied costs like the “heat island effect” — the term for when dark pavement raises the temperature of a city, leading to additional energy demands for cooling. And atmospheric costs are only part of the suite. According to the paper’s lead author, Mikhail Chester, there may be a larger infrastructure for parking than for roadways. If that’s the case, there would seem to be another great cost to all this parking: the relative cost of useful space.