"" Smartphone users are helping one another when it comes to sending data to the Google Maps app. Justin Sullivan/Getty Images The green, yellow and red routes that Google Maps uses to indicate clear, slow-moving, or heavily congested traffic are a great help when you're trying to determine the fastest way to your destination, but how does Google know the traffic conditions between where you are and where you're trying to go? Google Maps bases its traffic views and faster-route recommendations on two different kinds of information: historical data about the average time it takes to travel a particular section of road at specific times on specific days and real-time data sent by sensors and smartphones that report how fast cars are moving right then [source: Barth]. Advertisement Advertisement Early versions of Google Maps relied only on data from traffic sensors, most of which were installed by government transportation agencies or private companies that specialize in … [Read more...] about How Does Google Maps Predict Traffic?