The new app for Windows Phones, called Greenway, works by plugging "its users' locations, destinations, and speeds into an algorithm to figure out where and when traffic jams are likely to occur. Then, it provides a route to steer cars away from those roads. The route is called, appopriately [sic], the "Greenway," and it's optimized for traffic, time, and the amount of gas used based on data about where other drivers are headed at the same time."
According to Stone, "One of the more interesting parts of the app is the business model. The app is free to use, but users who select the Greenway route will pay a small fee for the insider information: five percent of the cost of fuel they'll save by taking the Greenway, but never more than 30 cents per route. If it takes users longer than it should to get to their desintation [sic], the information is on the house."
There is one catch, however: "The founders estimate that for the app to truly be effective, they'd need to get at least 10 percent of a city's drivers on board."