What Is GPS Lifetime Traffic?by Milton Kazmeyer
One common option available for automotive GPS units is live traffic updates. This capability allows the GPS to receive traffic reports as you travel, using that information to adjust arrival times and re-route you around accidents if necessary. In some cases, the traffic service comes as part of a yearly subscription to cellular-delivered or satellite services. If your GPS features a lifetime traffic option, however, it may be dependent on FM radio transmissions.
The traffic reports GPS devices use come from a variety of different sources. The state Department of Transportation maintains cameras and sensors throughout the interstate highway network, monitoring traffic flow. Local municipalities may have their own system for monitoring traffic problems, and radio and TV broadcasters regularly report on notable accidents or slowdowns in their viewing area. In some cases, the data comes from other GPS owners as their devices report slowdowns and stoppages. Companies aggregate these reports in real time, producing a regularly-updated picture of the traffic situation on major thoroughfares.
In some cases, the companies sell this data directly to GPS manufacturers for distribution through their network, but they also contract to provide the data to multiple types of end-users through the FM broadcasting network. Typically, the data piggybacks onto an existing broadcaster’s signal, completely inaudible to anyone without the proper receiving equipment. Your GPS scans the local airwaves for the strongest data stream, locks on and begins downloading the traffic data, a process that can take several minutes.
How It Works
When the GPS receives the traffic data, it typically considers any incidents in terms of how many minutes it would delay a car passing through a specific area. The GPS then adds this time to your travel estimates, warning you of upcoming delays. In some cases, if the delay is significant, the device may attempt to recalculate other routes to your destination in an attempt to find a better one, guiding you to the most efficient route. If the traffic signal indicates a complete blockage of a street or highway, the GPS will consider this and remove you from the affected route as quickly as possible to minimize your chances of hitting the traffic jam.
GPS units with lifetime traffic updates require no subscription fees, only a one-time license fee covered by the unit’s manufacturer. Lifetime traffic updates are dependent on the FM stations in your area carrying the signal, and many municipalities have multiple broadcasters available for increased coverage. If you find yourself traveling away from urban areas frequently, however, you may notice a lack of traffic updates until you return to an area served by the signal. In addition, some areas may only broadcast traffic updates during heavy travel periods, or only during daytime hours.
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