How Does GPS Get Traffic Updates?

Information flows to your in-car GPS unit from many sources.

The global positioning system (GPS) portable navigator in your car helps you to find direct routes and guides you around traffic problems. A GPS device aggregates this information from a variety of government and private sources.

Department of Transportation

The U.S. Department of Transportation collects traffic data for 6,000 miles of highways using electronic and solar-powered sensor boxes, fiber-optic cables embedded in the road and even manual counts by people on the scene.

Traffic Aggregators

Inrix provides traffic data to 70 percent of all live-traffic subscribers. It gathers data from GPS units in taxis, fleet vehicles, shuttle services and long-haul trucking firms. It also collects data from cell phones, using GPS to seek their locations. Inrix shares data with the Clear Channel traffic network.

Data Delivery to GPS Devices

Bluetooth can deliver traffic data to the GPS unit in your car. Data can also be delivered by FM radio, using a sideband channel known as the Radio Data System-Traffic Message Channel, by satellite radio or by MSN Direct.

References

• Consumer Reports: Cars Blog: Understanding GPS Navigation Traffic Services
• Laptop: How Real-Time Traffic GPS Works