No major city in the country, or probably the world, has been able to say for sure how many parking spaces it has, public or private, so far. For the past 18 months, the San Francisco Municipal Transportation Agency (MTA) has surveyed all publicly accessible parking spaces within the city limits, including free and metered spaces on the street and all garages accessible to the public. public. [PDF map].
The total number of spaces, as Mayor Gavin Newsom recently announced on his Youtube site, is 441,541. Of the total, more than 280,000 are on-street spaces, of which 25,000 are metered. For street spaces alone, that’s roughly the equivalent area of Golden Gate Park.
“Most cities know very little about their parking inventory,” said Rachel Weinberger, a planning professor at the University of
Pennsylvania and former transportation policy advisor to the Mayor of New York
Michael Bloomberg. Weinberger called the parking census a “considerable effort.”
“Without the basic knowledge [city planners] have no basis for doing
decisions regarding future procurement policy, current management policy or
even on how their transportation systems work.”
Don Shoup, professor of planning at UCLA and author of the definitive book on parking history, The high cost of free parkingwas delighted to hear the
news. “The San Francisco Parking Census is a great achievement, and the
the first of its kind in the world,” he said.
The publication of the census of public parking spaces coincides with the redesign of the website of SF-Park, an occupancy-based parking management trial funded by a $19.8 million federal congestion mitigation grant, which, among many goals, aims to manage parking supply by adjusting the cost depending on demand. To put it in simple terms, if SFPark is doing well, there should be enough curbside parking that drivers don’t have to circle the block endlessly looking for that elusive space. By gradually adjusting the price of parking up or down in the pilot areas, the city plans to create approximately one or two free spaces per block face at all times, which was the original goal of the parking meters when they were introduced in the 1930s.
Jay Primus, who leads the SFPark trial for the MTA, said the parking census was the first step toward better understanding how parking works in San Francisco, filling a void where city planners previously could only make rough estimates. . “If you can’t manage what you can’t count, thoroughly investigating and documenting all publicly accessible parking lots was an essential first step for the MTA to learn how we manage parking smarter,” he said. he declares.
Primus explained that his team combed through numerous records to determine the total number of public garage spaces, including the MTA’s own facilities and city tax records for private facilities. For unmetered spaces on the street, he sent interns across town to count every fifth block, a 20% sample. With each free opportunity, he sends more interns and recently estimated that they had increased their sample size to 35%. In time, he hoped to count every space in every street.
As well as satisfying its own penchant for good data, Primus said the data is essential if they expect SFPark pilots to be successful in making parking more convenient for drivers and reducing traffic.

In order to extend the impact of the data, the MTA released it to third-party developers on the Data SF websitewhich the agency hopes will spur creative apps for smartphones, just as software engineers did
with the MTA route and schedule information. With these apps, Primus expected to “see fewer detours to park, fewer
waste fuel and reduce greenhouse gas emissions. It could help save people
in time and money,” he said.
“San Francisco is on the cutting edge of parking management,” the mayor said
Newsom, who championed open data through DataSF. “By combining this data with our innovative approach to
open government data, we continue to transform government to work better
for all of us.”
Beyond the benefits to drivers and savings from reduced congestion, parking census data will inform the general discussion about parking supply and development, which can become highly contentious and emotional.
Jason Henderson, a professor of geography at San Francisco State University, said San Francisco Planning Commission hearings sometimes turn into useless arguments about parking supply without good data to back up claims by officials. two parts.
“It’s very important to have as factual a conversation as possible,” Henderson said.
Joshua Switzky of the San Francisco Planning Department agreed on the importance of data. “This is the kind of information that always comes up when reviewing large
projects, especially when parking is up for debate,” he said. “Everyone – from
neighborhood groups, planning commissioners, public transit advocates —
wants to know the general parking supply in an area.”
Now that the spaces accessible to the public have been counted, the MTA plans
move forward with a count of private garages. Some of these
interviewed for this story imagined there could be as many as 800,000
spaces in total, or at least one parking space for each San Franciscan.
What the census reveals
Should San Francisco have a parking spot for every person residing in the city? Should the city continue to mandate a new parking space for every residential unit built, the metric required in planning code in much of the city?
Using data from the MTA Transportation Fact SheetWeinberger noted that although 28.5% of San Francisco households do not own a car, “enough households own multiple vehicles for the city’s population,
collectively own more than 8% more vehicles
than households.”
“As we all know, the more parking spaces, the more convenient it is
car use becomes relative to other travel options,” said
Weinberger. “The most practical
car use is more likely that a car will be used.”
Shoup marveled at how free parking in San Francisco is, especially compared to the price of housing. “A surprising result is that 72%
of all publicly accessible parking spaces in the city are free,” he said.
San Francisco, housing is expensive for people but free for most cars.”
Todd Litman, the director of the Canadian think tank Victoria Transport Policy Institute, said the census showed that “in many situations there is not really a shortage of parking spaces, but rather that the available spaces are not being well used”. Litman said the solutions are parking management strategies such as more carpooling, efficient pricing and parking payments, which “can solve parking problems in ways that also help achieve economic, social and environmental goals. “.
All parking experts agreed that San Francisco is leading the way in the effort to better understand the relationship between parking policy and the context of the urban environment.
“Parking policy is quite a powerful tool to shape street use,
fabric and fashion choices,” Weinberger said. “The true power of this
the information is based on the use that the city decides to make of it. »