Is Parking Policy Stunting Urban Sustainability?

Planet

Planet may be the second of the Ps in the Triple Bottom Line conceptualization of sustainability (the other two are People and Profit), but it is certainly the centerpiece of much discussion. According to Shoup, the effect that parking has on the environment is partially due to economics. The example at the beginning of this article illustrates how the price of parking -- or lack of a price -- influences the choices we make when considering transportation. Under the predominant economic model, demand coexists in partial equilibrium with supply. When supply is high, the price is substantially low. Parking policy dictates that a certain amount of off-street parking be supplied by every building according to its use. According to Shoup, “Parking is free for 99 percent of all automobile trips in the U.S.” When practically unlimited free parking is available, why not drive? This makes driving much less expensive and pushes more frequent automobile usage, which in turn increases the number of total car trips made and the quantity of emissions making their way into the air.

“Many residential streets have become garagescapes -- appearing to be a place not where people live, but where cars are parked -- and the only obvious way to enter a building is with an electronic garage-door opener.” Donald Shoup, The High Cost of Free Parking

Those who drive, however, need not feel demonized. Shoup likens the process of determining parking requirements to the medieval practices of ancient doctors -- perhaps not malicious but based on a pseudo-science that leads to the creation of far more parking spaces than are necessary for a building’s given use. He reports that planners often use the requirements of other cities, or parking generation rates that are often based on research with insufficient data or statistical significance. This research, too, is usually conducted in the suburbs, where transit lines are limited and parking is, of course, free. The number of spaces is typically determined by the square footage of a building, and many of those required spaces sit empty but for a few days of the year. As the land gets less dense, points of interest get farther apart, making public transit and walking even less convenient. The car, again, wins. Shoup explains the impact of mobility on proximity, and the way in which this relationship not only effects the means of reaching a destination but the idea that parking lots can necessitate driving. He says, “In the U.S., mobility has come to mean mainly the ability to drive wherever you go and to park free when you get there. A problem with using off-street parking requirements to provide this mobility is that they reduce proximity. Abundant parking makes it easier and cheaper to drive, but pandemic parking lots spread activities farther apart, making cars more necessary.”

With an increased number of cars comes not only more parking but bigger roads to ease congestion, which in turn encourages more drivers to take to the road. Shoup warns us that this cycle perpetuates urban sprawl, the growth in the area of a city and the shrinking density of urban centers. Large roads and parking and structures have other adverse effects. Impermeable materials, in these cases asphalt and concrete, start to cover the surface area of the city, and less water can soak into the ground. It has to go somewhere, however. Often it runs to the city sewer systems, leading to a greater potential for flooding and stress on water treatment facilities. As water moves from the cities and urban centers, it carries oil and contaminants, which quickly erode the banks of streams and rivers. Permeable surfaces and wetlands prevent flooding and serve as a natural filtration system for water that will eventually travel to water treatment plants and drinking water sources. As we cover green spaces with half-empty parking lots and mammoth roads, however, we limit these options.

Profit

As the old adage goes, there is no such thing as a free lunch. Nor is a parking space free. It requires digging, sometimes demolition, raw materials, and manpower to build. Once built, a parking lot or structure requires maintenance and repair, sometimes lighting, security cameras, or elevators. Who is paying for all of this if the driver is not? One might answer, “The owner of the building.” Shoup, however, would point out that these costs, then, are incorporated into whatever products or services are associated with that particular building. We all pay for parking through the increased prices of the goods and services we purchase, regardless of whether we own a car or park at a lot.

Shoup explains that the number of parking spots that a building is required to supply is usually based on the use and size of the building. In some cases, the number of seats, tables, bowling lanes, or other relevant elements is used in place of square footage. For example, a church might be required to supply one parking space per every four seats in the main assembly room. A restaurant, in comparison, might have a requirement of one parking space per three seats. If one wished to convert that old church to a restaurant (assuming that the number of seats would stay the same), changing that land use would not be allowed unless additional parking was provided. Adaptive reuse and repurposing of buildings must take parking, including the determination of whether sufficient land is available for parking, into account.

“In the U.S., mobility has come to mean mainly the ability to drive wherever you go and to park free when you get there. A problem with using off-street parking requirements to provide this mobility is that they reduce proximity. Abundant parking makes it easier and cheaper to drive, but pandemic parking lots spread activities farther apart, making cars more necessary.” Donald Shoup, The High Cost of Free Parking

This issue becomes particularly salient when considering buildings constructed before these regulations went into effect. Such older buildings usually do not have to meet the regulation, unless they change land use. However, as Shoup explains, “Parking requirements triggered by a change of use severely limit the possible occupants for older buildings and stunt the economic development of older areas.” Parking policy then causes economic growth, as well as the likelihood of sustainable adaptive reuse, to stagnate. As well as limiting change of use, parking policy may stunt the growth of a particular business. Taking the example of the restaurant, Shoup explains that adding additional tables, whether inside the restaurant or perhaps on an outdoor patio, will increase the amount of parking that will be required. This again adds cost and many times is implausible, particularly for small businesses already stretching the use of their lots.

People

Minimum parking requirements can put a damper on commercial development, but their effect extends even to our backyards, or perhaps lack thereof. Shoup reminds us that parking requirements cause the cost of the parking to be “bundled” with the cost of the housing itself. “Parking requirements,” Shoup says, “increase the price of housing not only by adding to the cost of constructing the housing but also by restricting its supply. Parking requirements often reduce the number of dwelling units on a site below what the zoning allows because both the permitted dwelling units and the required parking spaces cannot be squeezed onto the same site.” This is particularly important when we consider housing for those who generally can’t afford or do not own vehicles. Shoup decries the fact that every car is required to have a home, but in return “parking requirements make the real homelessness problem even worse.” Even those who live in low-income housing but do not own a car pay a bundled price -- these same people still pay for parking every time they purchase goods and services.

Shoup references the 2001 Nationwide Household Travel Survey, explaining that “only 73% of urban households with incomes less than $20,000 a year own a car.” That remaining 27%, then, uses an alternative form of transportation: walking, bicycling, or public transit. Because our urban design is primarily car-centered, people in this demographic are disadvantaged yet again by a lack of efficiency in their everyday survival (for example, in searching for a job or getting to and from the grocery store). Shoup mentions that even those 73% able to afford cars are even further disadvantaged, because the “cost of supporting a car then consumes a greater share of household income for poorer families.”

“Parking requirements triggered by a change of use severely limit the possible occupants for older buildings and stunt the economic development of older areas.” Donald Shoup, The High Cost of Free Parking

The truth of the matter is that parking lots are just plain ugly. They deface the architectural beauty of any community because they are built for cars, not people. More parking lots mean more private car trips and less carpooling and public transit, both of which are venues for social interaction. Our cars become small, private pods. Our cities become compartmentalized. “Many residential streets,” Shoup says, “have become garagescapes -- appearing to be a place not where people live, but where cars are parked -- and the only obvious way to enter a building is with an electronic garage-door opener.” Car-centered urban design makes cities less walkable, spontaneous conversation less probable, and the community at large less pleasant to be in.

So then, you ask, what is the solution? Does Shoup have all the answers? Of course he doesn’t. He does, however, have a slew of wonderful recommendations, from changing parking requirements to parking limits (as some regions have already done), letting the market determine the price of parking, and encouraging improved parking design (including more landscaping or street-level retail in multi-level parking structures). Shoup makes a great case for parking policy reform. The question is, then, where do we go from here, and how do you want to get there?