Philadelphia has 2,172,896 parking spaces. So how come you’re still circling the block?

There are few things Philadelphians like to complain about more than parking.

There's not enough, some argue. There's too much, others contend. Finding a spot takes too long, garages are too expensive. Some residents believe on-street permit prices should increase — even five or tenfold. Others say parking should be free.

But never before have there been comprehensive, concrete data to back up Philadelphia's parking arguments. Sure, a South Philadelphia block with cars wedged bumper to bumper — or sometimes parked on sidewalks, or illegally in the street — may give the impression that parking is hard to come by. But a half-empty Center City garage may make it seem as if there's parking to spare.

So how much parking is actually out there?

In a study released Monday by the Research Institute for Housing America, a division of the Mortgage Bankers Association, one researcher found that as a whole, Philadelphia's parking stock is plentiful. So plentiful, in fact, that he estimates there are 2,172,896 parking spaces across Philadelphia's 134 square miles — a number that includes public parking garages, surface lots, on-street parking, and private driveways. Put another way, nearly 1.4 parking spaces are available for every one of Philadelphia's 1.5 million residents, or 3.2 spaces per household.

For residents who regularly circle blocks scouring for parking, the findings by data scientist Eric Scharnhorst seem almost impossible. But according to the data analyst, who has spent stints at Redfin and Denmark's Gehl Architects, Philadelphia's parking count was derived from an analysis of three complex data sets. Using a combination of high-resolution aerial satellites, parcel information from the city's assessment office, and streets data, Scharnhorst, who now works for the start-up Parkingmill, believes he captured a near-exact count of Philadelphia's parking inventory.

In a city where parking complaints often extend beyond neighborhood disputes and social media and flow into politics and planning, Scharnhorst's findings could have massive implications about the way Philadelphia — and its land — is designed and used. According to Paul Chrystie, a City Planning Commission spokesperson, Philadelphia keeps no official or citywide count of parking spaces. What that means, Scharnhorst argues: Cities often make planning decisions without knowing how much parking they have.

"Inventories can identify parking shortages and expose parking surpluses," Scharnhorst wrote in the paper. The information "uncovers an opportunity to build more capitally efficient buildings and cities that contain fewer unused parking spaces and more of everything else."

Americans have started driving less, but people still need parking — 69 percent of Philadelphia residents own at least one car, according to U.S. census data — and they use their cars to transport them to jobs, doctor's appointments, school, and more.

Philadelphia has been grappling with legislation that could change its parking inventory — and even its development boom. This year, Councilwoman Jannie Blackwell, who represents part of West Philadelphia, revived a two-year-old bill that would require many developers to significantly increase the number of parking spaces they provide in the majority of Philadelphia's zoning districts.

Blackwell's parking ambitions were scaled down in May, and the revised version of Blackwell's bill remains held in committee. Council President Darrell L. Clarke has previously supported increasing parking minimums.

Developers and affordable housing advocates have argued that requiring more parking could increase the cost of a development, squeezing margins that builders claim are already tight as land, labor, and building costs rise. Increasing parking minimums could make some projects financially impossible, many developers say — or, more likely, increase the housing costs of buyers and renters. One UCLA study from 2016 showed that rent prices in American cities increased 17 percent when "free" parking was included at apartment developments. That result, some contend, reduces the availability of affordably priced housing.

Unlike other cities that Scharnhorst studied, Philadelphia's parking is distributed widely across the city. There are clusters of high-density parking in obvious areas — Center City and South Philadelphia near the stadiums — but also plenty of spots in the the Northeast and North Philadelphia. Most of Philadelphia's 2.1 million spaces, Scharnhorst found, are in off-street surface parking (including private driveways) –68.4 percent. On-street parking represented 20.4 percent of spaces, he found, and parking garages, 11.2 percent.

Philadelphia has the greatest amount of parking in areas where land is most expensive, Scharnhorst found. Combined, all of Philadelphia's parking spaces, he estimates, contain nearly $17.5 billion in value.

In 2015, the Planning Commission studied Center City's public parking inventory (facilities containing 30 or more spaces) and found that fewer people were using public parking in the 169 surveyed sites compared with 10 years before.

According to Scharnhorst, decreasing occupancy rates present a "land bank" of sorts for cities and developers who often claim a shortage of developable land. "Surface parking — that's a huge opportunity," he said in an interview. "It's easier to change a parking lot into something than a parking [garage] into something else."

And if those lots give way to housing, it could help ease the affordability concern growing in many cities, said Michael Fratantoni, senior vice president and chief economist at the Mortgage Bankers Association.

"At the end of the day, [there are] questions about how land and how space is being used," Fratantoni said. "And according to Eric's study, too much space is being occupied by parking."

Jon Geeting, a Fishtown urbanist who works at the political organization Philadelphia 3.0, describes parking in Philadelphia as "an emotional powder keg."

"It's driven by the emotional experience of driving around looking for parking and feeling totally frazzled," Geeting said. "It's a horrible feeling, and I think a lot of the politics are driven by the pain-avoidance instinct."

From social media to neighborhood meetings, complaints of parking abound. It's one of the reasons Blackwell said she has tried repeatedly to increase parking minimums.

"Years ago, when I would call meetings, people would not discuss parking," Blackwell said Wednesday. "Now, it's on the front of everyone's lips. … It needs to be discussed to help us maintain the quality of life in our city."

Donald Shoup, a UCLA urban planning professor known as the "Parking Guru," said part of the reason Philadelphia residents believe there's no parking is that they are often searching for limited on-street spaces.

"The on-street parking is usually cheaper, and all of us want that," Shoup said. "Unless there is one or two open spaces on every block, people will always say there's a shortage of parking.

With parking occupancy rates ticking down, land harder to come by, and land values increasing, Philadelphia already has seen some development on some longtime parking spots. On the 2000 block of Lombard Street, townhouses are expected at the site of an 150-car garage. At 17th and Chancellor Streets, where the Little Pete's diner and a garage stood, a 13-story hotel is planned. The surface lot at Eighth and Market Streets was sold to the Goldenberg Group for $24 million.

Meanwhile, developers have begun thinking about how to offer more than just parking at garages and lots in the city. At the FMC Tower in University City, developer Brandywine Realty Trust placed an elevated park with skyline views, Cira Green, atop a 90-foot parking garage.

Shoup has long advocated for cities to better manage on-street parking by limiting the number of permits to the number of spaces available — and raising prices. Currently, Philadelphia's on-street permits cost $35 annually, less than 10 cents a day, Shoup said. He argues that funds from increased permit revenue could be poured back into neighborhoods for beautification projects and amenities.

"I look at a city like Philadelphia … and I think, it's a fool's paradise," Shoup said. "If people paid for parking the way they paid for gasoline — the more you use, the more you pay — you'd have much less of it in the end."