“Minimum parking requirements act like a fertility drug for cars,” Donald Shoup famously wrote. Shoup is professor of urban planning at the Luskin School of Public Affairs at the University of California at Los Angeles, and is a prominent critic of parking policy, such as free parking and minimum parking requirements.

As urban populations grow, a variety of outdated rules create hurdles for cities trying to accommodate more people while maintaining and improving livability and walkability. Minimum parking requirements, or parking minimums, are a prime example. These municipal rules are simple enough: developers building a new residential or commercial project must also provide a minimum number of new parking spaces, usually based on the square footage of the building. There is typically no consideration of nearby transit options or, indeed, of the need for the new parking spaces. These spaces are nearly always free for the user, according to Shoup, because “Most cities are planned on the unstated assumption that parking should be free—no matter how high the cost.”

Free parking, however, results in major problems, including sprawling development, and the continued preferential treatment for cars. Shoup’s book, The High Cost of Free Parking, notes that drivers in America can park for free on nearly ninety-nine per cent of their car trips, thanks to parking minimums. The result, Shoup wrote, is “sprawling cities that are better suited to cars than people and a nationwide fleet of motor vehicles that consume one-eighth of the world’s total oil production.”

All this sprawling development has a high cost, according to Sarah Kobos, a blogger focused on urban planning, who explained the issue in her blog: http://www.accidentalurbanist.com/2015/09/

“As communities, we pay because abundant parking makes land less productive. More asphalt means fewer businesses, fewer jobs, and fewer tax dollars per acre,” she wrote. All that space devoted to parking also spreads developments across the landscape, requiring more infrastructure to link everything.

“Spreading out these destinations means that our tax dollars must fund additional miles of roadway,” according to Kobos. “We also must provide and maintain more water, sewer, and stormwater pipe; more pumping stations; more fire stations; more police officers…. You get the idea.”

In addition to the high cost, minimum parking requirements prioritize car use over all other options, and stimulate demand for free parking, even when other options would be more cost effective, or residents would prefer them.

Even if they’re located next to a bus stop, or a bike route, or a residential neighborhood where their customers live,” Kobos noted, “businesses across America must purchase extra land to build parking lots.”

As Shoup also noted, parking minimums results in cities that are better suited for cars than people. “Our zoning code essentially dictates that developments prioritize cars over people,” Kobos wrote. “So what do we get?  A city full of cars.”

Not only do parking minimums encourage sprawl, the numbers are generated through a flawed process, leading to an excess number of required parking spaces for each project. According to Shoup, planners and traffic engineers have developed rules that cities adopt as requirements, but those rules have been created based on erroneous assumptions. “Parking generation rates typically measure the peak parking demand observed at a few suburban sites with ample free parking and no public transit,” Shoup wrote. Those demand studies obviously don’t apply to dense urban areas, where increasing numbers of people choose to live, often without a car.

“Urban planners who use these rates to set off-street parking requirements are therefore planning a city where people will drive wherever they go and park free when they get there,” Shoup noted.

In addition, Shoup called into question the notion that parking needs can be accurately measured. “Many planners treat parking and trip generation like physical laws and the reported rates like scientific observations,” he wrote. “But parking and trip generation are poorly understood phenomena, and they both depend on the price of parking.”

The solution, then, is to end parking minimums, and to price all parking effectively. According to Shoup, “Demand is a function of price, not a fixed number, and this does not cease to be true merely because transportation engineers and urban planners ignore it.”

Getting the price right requires some experimentation, according to Shoup. Cities should substantially raise rates for curbside parking. The extra money generated should be used to improve infrastructure in the affected area, including lighting, sidewalks, street trees. “When the perfect price is established,” Shoup noted, “no area is ever more than 85 percent full, so parking spaces are always available, and the district becomes a destination unto itself.”

This approach has proven successful in many cities, including San Francisco, California. The city installed electronic parking meters that can adjust rates by time of day and day of the week. The program is credited with decreasing the number of cars cruising while searching for a parking space by 50 per cent. The program’s occupancy goal of 60–80 per cent was also achieved.

As Shoup has mentioned, free parking is not really free. “Without off-street parking requirements, the price of parking will rise toward the cost of providing parking spaces. Post-parking-requirement cities will become more compact and less automobile dependent over time.”