Where does Google Maps get its traffic data from?
Google Maps bases its traffic views and faster-route recommendations on two different kinds of information:
1. Real Time Data
When you choose to enable Google Maps with My Location, your phone sends anonymous bits of data back to Google describing how fast you’re moving. When we combine your speed with the speed of other phones on the road, across thousands of phones moving around a city at any given time, we can get a pretty good picture of live traffic conditions. We continuously combine this data and send it back to you for free in the Google Maps traffic layers. It takes almost zero effort on your part — just turn on Google Maps for mobile before starting your car — and the more people that participate, the better the resulting traffic reports get for everybody.
2. Historic Data
Historical data is the average time it takes to travel a particular section of road at specific times on specific days and Real-Time data is sent by smartphones (GPS) that report how fast cars are moving right then.
Historical data are important because it’s hard to acquire enough real-time information to make traffic forecasts. Think of the complications involved. There aren’t that many people with smartphones driving any given road at a given moment, and not all of them will have enabled their data-sharing software. In addition, some of the phones will be red herrings with respect to traffic. Some, for example, will be in the pockets of walkers or in the baskets of bicycles. Others might be in a car that has pulled over or is looking for a parking spot.
3. Installed traffic Sensors
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 compiling traffic data. Using radar, active infrared or laser radar technology, the sensors are able to detect the size and speed of passing vehicles and then wirelessly transmit that information to a server.