Parking sucks, and that's why there are apps to help your car find a vacant spot. The trouble is those solutions tend to require expensive sensors to be installed in each and every one of those potentially open spots. A new app called PocketParker instead leverages the power of passive, portable sensors -- the ones already installed on your smartphone.
A team from State University of New York at Buffalo is calling their idea "pocketsourcing", essentially crowdsourcing the location and movement of people who are parking their cars or about to abandon a spot. The app uses the accelerometer in your phone to measure and report behaviour. So if you're moving at a slow automobile pace in the same general area, you're probably looking for a spot to park, which would mean the lot is full. If you're moving at walking-speed and then switch to car-speed and drive away, that's a sign that a spot was probably just vacated.
By analysing the logistical information from people who have installed the app on their phones, and cross-referencing the parking space data that's readily available on any mapping service (they use OpenStreetMap), PocketParker can make a fairly well-educated guess about how many open spaces are located near your car. In a test of 105 phones, double-checking with cameras, they got it right 19 out of 20 times.
You can see how your phone already is collecting and analysing this kind of information when you've got driving directions pulled up in Google Maps. When you park your car and start walking, it senses the change in movement and switches you over to walking directions. That's why something like PocketParker would work so well as part of Google Maps' existing navigation. Imagine this kind of data becoming part of your driving directions, directing you not only to an address but to an available parking spot in real time.
The benefits of not having hundreds of cars circling a block looking for parking are obvious -- lower emissions, reduced congestion -- so to an extent, helping to direct people to available parking spaces is as important and critical for a city as monitoring traffic.