Can we park smarter?

You turn the wheel hesitantly and crane your neck to look for any available parking down the street. The person behind you honks irritably. Feeling pressured, you impulsively turn onto the side street. As you do, you glimpse a free space on the street you just left — and it’s taken by the time you circle around again.

We’ve all been there. City parking can be a nightmare. But if you lived in a city like San Francisco or Los Angeles and had the right app on your phone, you might have found that spot sooner. These cities are using smart parking systems with sensors in the pavement to detect open spaces so that drivers can find available parking spots right from the app. And it helps reduce greenhouse gas emissions. That’s because drivers looking for parking cause about 10 percent of gasoline emissions. Drivers looking for parking go slowly, which backs up the cars behind them, and that adds up to about 30 percent of all city traffic.

But implementing citywide smart parking means significant upfront costs. Each sensor costs a few hundred dollars, though the price varies between companies, so depending on the size of the city, it can cost millions of dollars just for installation. That makes most cities reliant on outside funding from the federal government and other institutions. And once the system is in place, reliability can be an issue.

San Francisco’s sensors, provided by Fyber (formerly StreetSmart), detect large metallic objects above them. But interference from power lines and other utilities sometimes prevents the sensors from receiving a signal, so San Francisco only achieved 86 percent reliability. Los Angeles consistently achieves at least a 90 percent reliability rate, says Peer Ghent of Los Angeles’ parking management system, who also notes that it’s not realistic to expect the sensors to work 100 percent of the time.

“We know enough to continue down this path. We’re just trying to refine how we do it,” says Richard Willson, a parking and urban planning expert at California State Polytechnic Institute.

The U.S. Department of Transportation is already convinced — it has spent millions of dollars funding projects to relieve traffic congestion. In 2011, San Francisco got a $19.8 million federal grant to start a pilot smart parking program called SFpark. The program studied six areas around the city, covering 7,000 of the city’s 28,800 on-street parking spots and 15 of the 20 city-owned garages. San Francisco’s program is the most in-depth study, but other cities have made significant process as well. New York City is currently testing pilot areas in several boroughs, while Moscow and Barcelona have already installed large-scale — and successful — smart parking systems. Worldwide smart parking is expected to grow rapidly, up to one million on-street spaces by 2024, according to the research firm Navigant Research.

“If you’re in favor of revitalizing downtown areas and you’ve read the literature, I think you have to support these trends,” says Ghent.

In 2013, two years after launching SFpark, San Francisco published a detailed report asserting that the program had reduced weekday greenhouse gas emissions by 25 percent. Traffic volume went down and drivers cut their search time nearly in half. They achieved these results by incentivizing drivers to do things like park in less congested areas, or arrive at a parking garage before the morning rush and leave after the evening rush. Those incentives come in the form of variable pricing, in which drivers pay lower parking rates in underused areas or at less popular times, encouraging them to change where and when they park. This pilot program effectively demonstrated that smart parking has a significant impact on driving behavior and therefore on emissions.

Los Angeles saw similarly promising results, though the city didn’t directly measure congestion or emissions. “We wanted to prove that we could shift parking demand,” Ghent says. Occupancy increased by 15 percent in underutilized areas, he says, and while the average price per parking spot went down, total revenue went up.

San Francisco also saw a revenue increase — about $1.9 million total. That may be because smart parking systems are easier on the customer. Drivers can pay using cash or credit cards and they get an alert on their phone when their time is running out. That means fewer parking tickets, but oddly it also means more revenue for cities. In part, that’s because more cars can park each day. But it’s also because the system motivates more people to actually pay for their parking. It turns out that, before SFpark, only 45 percent of drivers fed the meter during the workweek. During the pilot, that number rose to 54 percent. That’s not a huge difference, but it was enough to offset the revenue lost to parking tickets.

A major concern is that any new system intimidates people, says Willson. And that might make people less likely to visit those districts. There hasn’t been any data so far to suggest that actually happens, he says, but adds that it’s still important to make the public aware of changes.

“We want to help people understand what the impacts are going to be,” says Mary Catherine Snyder of the Seattle Department of Transportation. Spreading awareness has helped Seattle residents feel more comfortable with the changing rules, she says. When the city implemented paid parking in the evening, for instance, it posted orange reflective signs to catch headlights. It also plays ads on television and in movie theaters, posts notices on every pay station, and distributes postcards.

Seattle, as a smaller city, has been able to collect data manually — literally having employees walk the streets — rather than spend money on a sensor system. That means they can only collect data once a year, but with that limited information they’ve been able to establish a demand pricing system that promotes more efficient parking.

“In my opinion, if you do it right, you have even fewer spaces,” Willson says. It’s a low value use of precious urban land, he says, land that could be better used for parks or bike lanes. Many cities actually have too many spaces because of mandates that require businesses to provide a certain amount of parking, but those mandates are leftover from a time when driving was considered ubiquitous. He and other parking experts, like Donald Shoup from University of California, Los Angeles, have argued that there are about twice as many spaces as are necessary.

Eliminating excess parking across an entire city could make way for more useful projects. Smart parking’s data-driven method makes it a useful tool for cities to use parking more efficiently, especially those worried about backlash from residents. “People don’t like to pay for parking,” says Snyder, “but using data takes the politics out of talking about parking meter rates.”