Cruising for parking affects nearly 10% of city traffic during peak hours, according to research recently conducted by the Federal Highway Administration (FHWA). Building on work done in previous studies, FHWA used GPS breadcrumb data from smartphones to measure excess travel from parking cruising. Thanks to this work, we now have a more accurate understanding of the impact that searching for open parking spaces has on our cities. This is great news, because with better information, we can advocate more successfully for parking reform in our communities.

What did the FHWA researchers do?

Previous studies on parking cruising have used intercept surveys and wireless technology sensors to understand the proportion of drivers looking for parking at any given time in very specific locations. That was a start to understanding the issue, but those studies weren’t helpful in understanding the impact of parking cruising on excess travel (e.g. how much more someone has to drive around looking for a parking space).  

Researchers with FHWA created Cruise Detector, a tool that uses GPS breadcrumb data from smartphones and is now free for municipalities to use. They deployed Cruise Detector to examine several scenarios across four U.S. cities: Atlanta, Georgia; Chicago, Illinois, the District of Columbia; and Seattle, Washington.

The FHWA researchers wanted to answer four questions: How big is the cruising problem? Does cruising change year over year? Where do people cruise? Are policies like performance pricing having any impact on cruising?

What did the research show?

If you’re familiar with efforts to reform parking policy or have read Donald Shoup’s “The High Cost of Free Parking,” you’ve probably come across the statistic that 30% of all city traffic is made up of drivers searching for parking. According to the report released by FHWA, this is a faulty number that “has been traced to an analysis that averaged the results of a limited number of studies.”

Because of this new research, we can have greater confidence in the estimate that as many as 10% of cars are searching for parking in urban areas. Having more confidence in that data is an important step forward for parking reform. After all, one in 10 cars searching for parking at any given time is a significant number. Those drivers contribute to an array of problems for our cities, like increased congestion, air pollution, and distracted driving.

So now, rather than understanding simply how many drivers in a given location at a given time are searching for parking, we can understand how long and how far drivers have gone to find that elusive parking spot. It’s a subtle but important difference.

The FHWA also determined that the level of cruising they measured remained constant across the different areas and situations they looked at. Their report concludes that cruising is localized and typically reaches an equilibrium.

What happens now?

FHWA has released Cruise Detector, for free, so that cities can use it to understand the impact of cruising on their streets and in their communities. “The methodology and tool provide a data-driven way to identify the locations and times of day where cruising is most prevalent,” the report notes. “They can be used by municipalities and other interested parties to understand cruising for parking and the effects of policy interventions on parking search behaviors in order to develop appropriate responses.”

Equipped with better information, those of us active in the parking reform movement can advocate for more meaningful policy change — and urge our local governments to use the new tools and information available to them to understand the cruising situation on the ground.

You can read FHWA’s report here.