The Tradeoffs of Parking Spots

Sometimes it seems as if every proposal for a new residential or commercial building in an urban or suburban area is neatly packaged with a dispute over parking. Will the new development provide  a minimum number of parking spaces? Will it be harder for those already in the are to find parking? How should the flow of drivers in and out of the parking area be arranged? Of course, all of these questions presume the cars and drivers need and deserve to be placed front and center of development decisions.

Donald Shoup, an urban economist who focuses on parking issues, discusses this focus on parking in
"Cutting the Cost of Parking Requirements," an essay in the Spring 2016 issue of Access, a research center on surface transportation issues run by a number of University of California schools. Shoup starts this way:

At the dawn of the automobile age, suppose Henry Ford and John D. Rockefeller had hired you to devise policies to increase the demand for cars and gasoline. What planning regulations would make a car the obvious choice for most travel? First, segregate land uses (housing here, jobs there, shopping somewhere else) to increase travel demand. Second, limit density at every site to spread the city, further increasing travel demand. Third, require ample off-street parking everywhere, making cars the default way to travel.

American cities have unwisely embraced each of these car-friendly policies, luring people into cars for 87 percent of their daily trips. Zoning ordinances that segregate land uses, limit density, and require lots of parking create drivable cities but prevent walkable neighborhoods. Urban historians often say that cars have changed cities, but planning policies have also changed cities to favor cars over other forms of transportation.

Minimum parking requirements create especially severe problems. In The High Cost of Free Parking, I argued that parking requirements subsidize cars, increase traffic congestion and carbon emissions, pollute the air and water, encourage sprawl, raise housing costs, degrade urban design, reduce walkability, damage the economy, and exclude poor people. To my knowledge, no city planner has argued that parking requirements do not have these harmful effects. Instead, a flood of recent research has shown they do have these effects. We are poisoning our cities with too much parking. ...

Parking requirements reduce the cost of owning a car but raise the cost of everything else. Recently, I estimated that the parking spaces required for shopping centers in Los Angeles increase the cost of building a shopping center by 67 percent if the parking is in an aboveground structure and by 93 percent if the parking is underground.

Developers would provide some parking even if cities did not require it, but parking requirements would be superfluous if they did not increase the parking supply. This increased cost is then passed on to all shoppers. For example, parking requirements raise the price of food at a grocery store for everyone, regardless of how they travel. People who are too poor to own a car pay more for their groceries to ensure that richer people can park free when they drive to the store. ...

A single parking space, however, can cost far more to build than the net worth of many American households. In recent research, I estimated that the average construction cost (excluding land cost) for parking structures in 12 American cities in 2012 was $24,000 per space for aboveground parking, and $34,000 per space for underground parking

Shoup discusses California legislation that seeks to put a cap on minimum parking requirements. You can imagine how welcome this idea is. Another one of Shoup's parking projects is discussed by Helen Fessenden in "Getting Unstuck," which asks "Can smarter pricing provide a way out of clogged highways, packed parking, and overburdened mass transit?" Fessenden's article appears in the Fourth Quarter 2015 issue of Econ Focus, which is published by the Federal Reserve Bank of Richmond. On the subject of parking, she writes:

Economist Don Shoup at the University of California, Los Angeles has spent decades researching the inefficiencies of the parking market — including the high cost of minimum parking requirements — but he is probably best known for his work on street parking. In 2011, San Francisco applied his ideas in a pilot project to set up "performance pricing" zones in its crowded downtown, and similar projects are now underway in numerous other cities — including, later this spring, in D.C. ...

"I had always thought parking was an unusual case because meter prices deviated so much from the market prices," says Shoup. "The government was practically giving away valuable land for free. Why not set the price for on-street parking according to demand, and then use the money for public services?"

Taking a cue from this argument, San Francisco converted its fixed-price system for on-street parking in certain zones into "performance parking," in which rates varied by the time of day according to demand. In its initial run, the project, dubbed SFpark, equipped its meters with sensors and divided the day into three different price periods, with the option to adjust the rate in 25-cent increments, with a maximum price of $6 an hour. The sensors then gathered data on the occupancy rates on each block, which the city analyzed to see whether and how those rates should be adjusted. Its goal was to set prices to achieve target occupancy — in this case, between 60 percent and 80 percent — at all times. There was no formal model to predict pricing; instead, the city adjusted prices every few months in response to the observed occupancy to find the optimal rates.

The results: In the first two years of the project, the time it took to find a spot fell by 43 percent in the pilot areas, compared with a 13 percent fall on the control blocks. Pilot areas also saw less "circling," as vehicle miles traveled dropped by 30 percent, compared with 6 percent on the control blocks. Perhaps most surprising was that the experiment didn't wind up costing drivers more, on net, because demand was more efficiently dispersed. Parking rates went up 31 percent of the time, dropped in another 30 percent of cases, and stayed flat for the remaining 39 percent. The overall average rate actually dropped by 4 percent.

A summary of the 2014 evaluation report for the SFPark pilot study is available here.

For many of us, parking spots are just a taken-for-granted part of the scenery. Shoup makes you see parking in a different way. Space is scarce in urban areas, and in many parts of suburban areas, too. Parking uses space. Next time you are cycling a block, looking for parking, or navigating a city street that is made narrower because cars are parked on both sides, or walking down a sidewalk corridor between buildings on one side and parked cars on the other, or wending your way in and out of a parking ramp, it's worth recognizing the tradeoffs of requiring and underpricing parking spaces.