The Environmental Cost of Parking has a really interesting article about the hidden and expensive costs of parking. There’s lots of interesting stuff in the article, but this bit really stood out (boldface mine):

Americans don’t object, because they aren’t aware of the myriad costs of parking, which remain hidden. In large part, it’s business owners, including commercial and residential landlords, who pay to provide parking places. They then pass on those costs to us in slightly higher prices for rent and every hamburger sold.

“Parking appears free because its cost is widely dispersed in slightly higher prices for everything else,” explains Shoup. “Because we buy and use cars without thinking about the cost of parking, we congest traffic, waste fuel, and pollute the air more than we would if we each paid for our own parking. Everyone parks free at everyone else’s expense, and we all enjoy our free parking, but our cars are choking our cities.”

It’s a self-perpetuating cycle. As parking lots proliferate, they decrease density and increase sprawl. In 1961, when the city of Oakland, Calif., started requiring apartments to have one parking space per apartment, housing costs per apartment increased by 18 percent, and urban density declined by 30 percent. It’s a pattern that’s spread across the country.
In cities, the parking lots themselves are black holes in the urban fabric, making city streets less walkable. One landscape architect compares them to “cavities” in the cityscape. Downtown Albuquerque, N.M., now devotes more land to parking than all other land uses combined. Half of downtown Buffalo, N.Y., is devoted to parking. And one study of Olympia, Wash., found that parking and driveways occupied twice as much land as the buildings that they served.

Patrick Siegman, a transportation planner, who is a principal with Nelson\Nygaard Consulting Associates in San Francisco, says Americans are gradually waking up to the downside of parking requirements — at least in one way. “Americans love traditional American small towns, main streets and historic districts,” he says. “But largely because of minimum parking requirements, it’s completely illegal to build anything like that again in most American cities. It’s really hard to build anything where anyone would want to walk from one building to the next.”

I noticed, when I moved to Boston, how car-unfriendly it is. This, believe it or not, is a good thing–it makes the city far more walkable because the buildings are much closer together. Boston has, perhaps the lowest street area to building ratio I’ve ever seen in a U.S. city, and it’s really hard to find a place to park that is free and near where you want to be. However, if you are willing to pay and walk a little, there is enough parking.
At least in my neighborhood, if you want to park your car on the street (i.e., you’re a resident), then you typically have to drive around for 10-20 minutes to find a spot that probably is a couple blocks from where you live. Alternatively, you can pay $2,000 – $3,000 per year to park your car. Which is why of the 95 people who live in my building, less than twenty own cars (Zipcar is your friend).

So why is Boston so compact and parking-challenged? Because it’s an old city (by U.S. standards, anyway). Most of the city was laid out well before the advent of the car as the dominant mode of transportation.

One of the costs of parking is environmental. This freaked me out (boldface mine):

The environmental impacts of all this parking go way beyond paving paradise. The impervious surfaces of parking lots accumulate pollutants, according to Bernie Engel, a professor of agricultural engineering at Purdue. Along with dust and dirt, heavy metals in the air like mercury, copper and lead settle onto the lots’ surfaces in a process called dry deposition. These particles come from all kinds of diffuse sources, such as industry smokestacks, automobiles and even home gas water heaters.

“If they were naturally settling on a tree or grass, they would wash off those and into the soil, and the soil would hold them in place, so they wouldn’t get into the local stream, lake or river,” Engel says.

But when the same substances settle on parking lots, rain washes them into streams, lakes and rivers. Engel calculates that the Tippecanoe land used for parking creates 1,000 times the heavy-metal runoff that it would if used for agriculture. Because the surface of the lots doesn’t absorb water, it also creates 25 times the water runoff that agricultural land would, which can increase erosion in local waterways.

Parking lots also contribute to the “urban heat island effect.” The steel, concrete and blacktops of buildings, roads and parking lots absorb solar heat during the day, making urban areas typically 2 to 5 degrees hotter than the surrounding countryside. “This is most apparent at nighttime, when the surrounding area is cooler, and the urban area starts radiating all this heat from the urban structures,” explains Dev Niyogi, an assistant professor at Purdue, who is the Indiana state climatologist.

The urban heat island effect can be so dramatic that it changes the weather. One Indianapolis study found that thunderstorms that reach the city often split in two, going around it, and merging again into one storm after the urban area. “The urban heat island is not simply a temperature issue. It could affect our water availability,” says Niyogi.

Jeepers. Discuss.

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11 Responses to The Environmental Cost of Parking

  1. Tony P says:

    Interestingly Providence, RI is a compact city and very walkable.
    The biggest parking lot mass is near Rhode Island Hospital though. It’s just one huge patch of blacktop.

  2. Stacey C. says:

    I wonder what the difference is between large scale parking lots and more compact multi-story parking garages (either above or below ground). Obviously the parking garages are more expensive to build and money is almost always the bottom line but in downtown Amherst they built a small parking lot with a ‘garage’ level underneath so as to have a fair amount of parking in a small space between the back of the storefronts of downtown and the community center. It’s not a 100% solution and there are still lots of street/lot parking spaces in town but it reduced the need to build another lot somewhere else in town. Though obviously this is also a case of large vs. small scale….Amherst doesn’t exactly need 1000 parking places or more in it’s downtown the way most large cities do.

  3. Next to the beautiful building in which I work (and blocking the long view of it) is a humungous parking garage. Every day traffic blocks up for 200m up and down the street as cars enter and emerge. But the university is going to double its size (consuming a tennis court in the process) while not increasing the number of entry and exit lanes.
    We do have parking for up to four bicycles, however. I get a ticket when the rack is full and I lock my bike to a bench or a lamp post.

  4. Erik says:

    Not only do parking lots absorb heat and shuttle contaminants into adjacent streams, but adjacent coldwater streams are extremely vulnerable to thermal pollution during storm events. Impervious surfaces transfer their heat to stormwater which creates a “flash” of high temperatures that can be immediately fatal to sensitive species and potentially cause trophic cascades that can seriously alter the aquatic assemblage.

  5. Victor says:

    It seems that proper public transport system is the best solution for large cities as private cars cause too much problems.
    The problems caused by a large number of private cars are very good seen here in Kyiv — quite recently there were not so much cars as now, in the rush hours it is like in the hell…

  6. robd says:

    A problem encountered in the Netherlands is that the increase of hard surfaces as buildings, roads and parking spaces versus soil speeds up the runoff of rainwater; as a result we need bigger pumping stations to keep our feet dry.

  7. KevinC says:

    Being in the Lower Colorado Desert in a very dry region on a river with so many dams by the time it gets here I saw a potential benefit of heavy pavement runoff. Native riparian plants need large flood events to propagate well. Many, but not all, invasive plant do better without drastic floods. I wonder (maybe a paper here); do native riparian plants do better downstream of storm runoff outlets in the Lower Colorado Desert?

  8. Sabrina says:

    Here’s a crazy idea that could help mitigate some of the harms of parking lots:
    Combine solar collectors and Crowd-Farm energy production and make it a required installation in parking lots over a certain size. The engineering requirements would be to come up with a way to make a solar collector robust enough to be rolled on many times a day by cars (perhaps use a clear panel to collect the Crowd-Farm energy, with a solar collector underneath?). But the energy produced (and the negative incentive to make large parking lots) could go a long way towards mitigating the harms of those concrete oceans.

  9. KevinC says:

    Here is another crazy idea. Make large parking lots put micro-turbines in the storm drains and capture some of the energy from the runoff.

  10. Vikingsson says:

    ^+1 for the idea of solar at parking lots. I’ve thought about this over the last few months and would offer this idea; Cover the parking lots and place the solar collectors on top. The load carrying requirement is minimal so shouldn’t be very expensive and is offset by solar generation. And, collect rain water from the roof since it will be much cleaner than from the lot, use it for whatever local usage is required (feed a tree, gray water, etc). Place small scale wind generation on the roof. Offer electricity to plugin hybrids or offset the electricity used by the establishment. The lot itself is much cooler and we loose much less fuel to evaporation.
    The best solution is to build cities and suburbs for less need of driving in the first place but build for the car smartly.

  11. danielc says:

    While low albedo plays second fiddle to low evaporation in contributing to heat islands, developments are afoot for high albedo (white) paving. What’s more, porous paving, rain gardens, and trees offer a strategic suite of approaches to mitigate quite a number of the mentioned health/enviro downsides, and then some.

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