The smartphones has become a tool to make our lives easier, from apps that deliver a pizza or a pair of shoes, to those that send a car to take us home from the bars when cabs are scarce, and even open our front door when we get there. Yet for all that mobiles apps have done to make city-dwelling more efficient, there are few that have come close to fixing arguably the most stress-inducing, wallet-draining, and logistically complex ailment any urbanite with a car faces – parking.

That's precisely because parking in a large city like San Francisco, New York, or Los Angeles is a particularly hard problem to solve. Pizza with a single app tap? Relatively simple, because you, the restaurant, the payments processor and delivery driver are all part of the same system. Parking isn't as easy because historically there hasn't been a good way to bring together drivers, garage owners, and city parking administrations to share information. Even if you could bring them together, there hasn't been much information to share. So we drive someplace we want to go and circle around until we spy an open spot, or take a chance that a garage won't be filled. In that scenario our beloved smartphoness aren't much help, except to text everyone we'll be late because we can't find parking. Still, that doesn't mean enterprising startups with the help of forward-thinking cities aren't trying to bring the chore of finding parking into the ioses age.

One such parking startup is Santa Monica-based ParkMe, founded in 2007. When CEO Sam Friedman (right) first started his company, he biked around Los Angeles, writing down parking lot hours and prices and documenting street parking restrictions, and putting that static information online. Then, with the help of city parking departments, he added real-time data from smart meters and parking sensors found in LA, San Francisco, and other urban areas, that show, on a minute-by-minute basis, which spots are available. ParkMe can also tell you how many spaces are available in a private garage or lot by tapping into ticket machine data and in-ground sensors. Now all that data is available on ParkMe’s ioses app and website, so that when you’re driving to an often-crowded part of town you can either check for parking on your computer before you leave or, with the help of a passenger with an iphoness, find a space that recently opened up once you reach your destination.

Friedman's intent isn't to get more people on the road, but to help those that will drive anyway find a spot faster. “Our end goal is to help people find parking on an individual level and help urban cores reduce traffic congestion,” he says. "If you solve the finding of parking, you solve many more problems." Those problems, according to Friedman, include increased traffic, distracted drivers, pollution, and decreased local business when drivers give up on trying to find a space. His solution is to arm drivers with hand-collected and sensor-generated parking information right on their smartphones.

While that information can help drivers make better-informed decisions about where to find parking and how much it will cost, it can also ultimately affect parking supply, which is the number one reason you can't find a space, says UCLA professor of urban planning Donald Shoup, who advised San Francisco on how to free up spots. As Shoup explains, there's only a finite supply of spaces in any given city, meaning your odds of getting parking hinge on whether someone else beats you to a spot first. Fed up with that inefficiency, Shoup helped San Francisco become one of the first cities to experiment with the idea of using static and real-time data to tweak parking supply and demand.

In April 2011, San Francisco launched a federally-funded parking initiative called SFpark and installed several thousand in-ground sensors in city parking garages and in metered spots in the most congested parts of San Francisco, including the Financial District, SoMa, and the Marina. Additionally, the city replaced thousands of old parking meters with new smart meters that accept credit cards. The sensors keep tabs on how often, and for how long, a car occupies a space, and meters can record when someone has paid for the space. ParkMe, for one, uses that data to tell drivers where they can find parking in the city, and SFpark has its own website and app to do the same.

The sensors and meters do more than just tell us where to park: They also allow for dynamic pricing, which Shoup says is the most promising approach to alter parking supply and ultimately cut down on congestion. “If you have better prices (more in line with demand), there will always be one or two open spaces on every block wherever you go,” he says. San Francisco does this by analyzing data from parking sensors and smart meters to raise rates on continually full blocks and drop rates on empty ones. That forces some drivers to migrate to less-crowded blocks because they don't want to pay a higher rate, and thus opens up more parking spaces. While it is too soon to say it's working definitively, the program’s goal is to have at least one to two empty paid parking spaces on every busy block in San Francisco.

Those empty spaces come at a price. Since 2011, the city has adjusted meter rates nine times. Prices have ranged from 25 cents to $5.75 per hour. As of February 7 the cheapest we found was 50 cents per hour. Though the sting of paying more than $5 per hour for a spot might be painful, Shoup argues it's the price we must pay to have parking at all. In fact, having vacant parking spots is all about paying. If parking is free, there's no way to regulate demand. "For example, most of the on-street parking is free in Manhattan, and they have alternate parking rules, but people still say it’s a nightmare," Shoup says. "In a free parking scenario an app that shows you a space is opening up on 96th Street is useless, because about 10 seconds later it will be filled." The same is theoretically true if the spot is $5 per hour, but your odds are better it will be free when you get there.

Under Shoup's parking system, drivers in San Francisco heading to overcrowded parts of the city get two options: pay more for a desirable spot or park further away to save a few bucks. The good news. Shoup says, is that it doesn't take mass behavior change to smooth out parking congestion in the city. "Only a few people have to move from the crowded blocks to the uncrowded blocks to solve the problem on both streets," he says. Those few people could be habitual commuters that park a few blocks away from their office to free up spaces in the city for others.

For now dynamic pricing seems to be the best option we have to help free up parking in congested cities, but it requires cities and taxpayers to foot the bill for city-wide sensors and upgraded parking meters. If those sensors prove to be worth the cost in San Francisco, it could spur other cities to follow suit. Shoup is optimistic that will happen, saying that Los Angeles, Ventura, Seattle, Washington D.C., and St. Louis are all trying out programs similar to San Francisco's.

While they dither, ParkMe's Friedman is pushing ahead where he can, using on hand-collected static data from garages and street parking signs, to help people make better parking decisions. ParkMe would love the realtime data, but Friedman is less hopeful that cities will decide to pay for sensors.

If Shoup is right, we could get to a point where we don't even need to check a website or app for parking availability, because dynamic pricing will guarantee that we'll always get a space. On the other hand, if ParkMe is right that sensors aren't coming to a city near you anytime soon, even with our nifty smartphoness guiding the way, chances are we'll still be stuck circling the block and praying to the parking gods for any spot at all.