Most drivers will be familiar with the feeling that trying a slightly different route, or leaving a few minutes later, would have saved them time in traffic, and some may have tweaked a familiar route to test the notion. A free navigation app for smart phones called Waze performs such experiments at a grand scale by treating its users as road-going data probes.
Waze users automatically broadcast their GPS position and speed to Waze over the Web at all times. Social-networking and gaming features built into the app also encourage them to actively share information such as the location of hazards and traffic jams. When a user asks the app for directions, those sources of information influence Waze’s routing algorithm. Users can see the position and speed of other users on a map, and also receive live hazard reports. The data collected by the app is used to refine Waze’s map in other ways, showing, for example, the location of unmapped streets.
“In the old world, you would flash your lights at someone. Now we can deliver the experience and intuition of other drivers to you through the app,” says Noam Bardin, the company’s CEO. Waze, which is based in Israel and Palo Alto, California, currently has more than 2.6 million users worldwide, roughly 800,000 of whom are in the U.S.
Waze awards points to drivers for miles driven with the app running, and also for submitting hazard reports. Making a report while driving, to indicate problems such as traffic jams, speed traps, or accidents, requires just three taps on the phone. Users can also create and join groups to follow reports from people who drive a particular route or area, or compete with friends to rack up the most points.
Those points do more than just make users feel good, says Di-Ann Eisnor, vice president and community geographer at Waze. “We use it as a confidence score for the contributions that user makes,” says Eisnor. A report of a traffic jam from a low-ranked user is less likely to change the route suggested by Waze than one from a high-ranked user, for example.
Social features like that are what really set Waze apart, says Alex Bayen, a researcher at University of California, Berkeley, whose group previously developed a phone app that simply collects traffic data. “There are many sources of traffic information but no other app lets you see other drivers around you and actively work together to post about traffic problems,” he says.
Most GPS navigation devices and apps that advise on traffic do so based on a mixture of historical traffic patterns and input from sparsely distributed road sensors, says Eisnor. Google’s free navigation app for Android phones combines users’ GPS trails with more traditional sources, although it offers fewer features than Waze.