The United States has a car-centric culture that is inseparable from the way its communities are built. A striking example is the presence of parking lots and garages. Across the country, parking occupies about 30% of the space in cities. Throughout the country, there are eight parking spaces for each car.
The dominance of parking has devastated once-bustling downtown areas by turning large areas into unattractive paved spaces that contribute to district heating and stormwater runoff. This has driven up housing costs, as developers pass on the cost of parking to renters and buyers. And it has perpetuated people’s reliance on the car by making walking, cycling and public transport far less appealing, even for the shortest journeys.
Why, then, does the United States have so many?
For decades, cities have required developers to provide a set number of parking spaces for their tenants or customers. And while many people still rely on parking, the amount required is usually far more than most buildings need.
Columbus, Ohio pioneered this strategy 100 years ago, and by the mid-20th century minimum parking requirements were the national standard. The thought was simple: as driving became more common, buildings without enough parking would clog streets and wreak havoc on surrounding communities.
Today, however, more and more planners and policy makers recognize that this policy is narrowly focused and short-sighted. As a data scientist who studies urban transportation, I focused my early research on this topic, and it shaped the way I think about cities and towns today.
It’s encouraging to see cities rethinking minimum parking requirements, but while this is a significant reform, there is still more that city leaders can do to loosen the grip of parking on our downtowns.
Elimination of parking requirements
Despite research and advice from the Institute of Transportation Engineers, predicting parking demand is extremely difficult, especially in inner cities. As a result, for years many cities have set the highest possible targets. This has led to excess parking that is vastly underutilized, even in areas where shortages are perceived.
In 2017, Buffalo, New York, became the first major US city to eliminate its minimum parking requirement in its first major overhaul of zoning laws in more than 60 years. This change breathed new life into downtown Buffalo by spurring the redevelopment of vacant lots and storefronts. Researchers estimate that more than two-thirds of newly built homes would have been illegal before the policy change because they would not have met earlier standards.
That same year, Hartford, Connecticut followed Buffalo’s lead and eliminated mandatory parking minimums citywide. Communities, including Minneapolis; Raleigh, North Carolina; and San Jose, Calif., have since taken similar action.
Tony Jordan, president of the nonprofit Parking Reform Network, argued that once cities stop mandating specific levels of private parking, leaders will need to think more about how they manage parking. public curbside parking and spend the revenue it generates. Some communities have implemented maximum parking allowances to ensure that developers and their investors do not add to the glut.
Reduce car dependency
Parking mandates aren’t the only lever city officials can use to make their town centers less car-centric. Some local governments are now asking developers to help reduce overall traffic levels by investing in improvements such as sidewalks, bike storage and transit passes.
This approach is generally referred to as transport demand management or modern mitigation. It still leverages private investment to serve the public good, but not just focusing on parking.
And unlike parking requirements, this strategy helps connect buildings to surrounding communities. As planning expert Kristina Currans explained to me in an interview, traditional parking requirements leave developers to fend for themselves. In contrast, transport demand management policies require them to take into account the surrounding context, integrate their projects into it and help cities operate more efficiently.
This approach dates back at least to 1998, when Cambridge, Massachusetts, introduced a policy requiring developers to produce a transportation demand management plan each time they add new parking lots. This policy has now survived the city’s minimum parking requirements, which Cambridge eliminated for all residential uses in 2022.
New policies tend to incorporate point systems or calculators that directly link different policies to their potential impact on car use. These tools are common in California cities, where state law now requires city planners to assess how much new car use each new development will generate and take steps to limit the impact. Policies such as charging users directly for parking spaces or offering employees money in exchange for giving up their space are among the most effective.
The University of Wisconsin-Madison State Smart Transportation Initiative, which I lead, along with the UW Mayors Innovation Project, has outlined policies like these in a guide based on our previous work with the City of Los Angeles. We recently collaborated on a new transportation demand management program in Madison.
This program initially faced some pushback from the developers, but their input ultimately made it better. It was unanimously adopted by the city’s municipal council in December 2022.
In order for their projects to be approved, developers must now earn a certain number of traffic mitigation points based on the size of their project and the number of parking spaces they propose to include in it. For example, providing information to visitors and renters about different travel options earns one point; providing secure bike storage earns two points; providing on-site childcare scores four points; and charging parking fees at market price is worth 10 points. Reducing the scheduled parking can reduce the number of points they need to earn in the first place.