GPS is a powerful tool with numerous applications—including keeping you out of those nasty rush hour commuter traffic jams, and helping engineers develop techniques to avoid traffic congestion. Here's an overview.
How Does Traffic Reporting Work?
Typically, traffic reporting is done through an app on a GPS-enabled phone. This app both reports the location of the phone (and thus the car) to the phone company and also receives real time traffic data overlaid on a map of the area. People are able to find better, faster alternative routes, easing traffic congestion and altogether speeding up the whole commuting process. This is easily combined with existing GPS car devices.
A great example of this is Nokia's Mobile Millennium project, launched in 2008 and jointly developed by UC Berkeley's California Center For Innovative Transportation. At the time of release, this was only available in the Bay Area of California. TomTom developed a similar program in the Netherlands. Most traffic projects have this data available for free on their respective websites, though they require a subscription fee to access it from the mobile phone and join the project.
Want in on it? Well, most major providers are not offering such traffic services quite yet. Stay tuned however, as Nokia has plans to expand this project from the Bay Area—and other phone companies are sure to follow.
To protect privacy, GPS tracking for traffic purposes is theoretically turned off by default, and needs to be turned on by the user. However, many privacy advocates are still worried that the app can be used to hack, track and stalk and unknowing victim. People would have to remember to turn it on and off when appropriate, lest they (in the words of one critic) create a non-existent traffic jam in their roadside office.
If the app does indeed work only when the user wants it to work, then there's another inherent problem: enough people need to enable this so that a relevant amount of data can come in and be analyzed. Whether any particular phone company can gather enough of a sample size for accurate traffic reporting is a steep question.
Such plans also require a considerable amount of bandwidth, so affordable unlimited data plans must be available for this to work. It would also suck up battery life with the constant streaming of data. There is also a potential danger of drivers be so distracted with checking up on the real time data while in the car that they might get themselves into an accident.
More Than GPS
This doesn't necessarily require the use of a GPS-enabled phone. If a cell phone is located in an area where there are many cell towers—probably where you'll be getting all this traffic—then you can use simple cell tower triangulation to track cars. This could easily be done without requiring individual phones to give up their exact location—just see which towers are getting more pings. However, going purely by pings may not be as accurate.
Many newer roads also have sensors installed in them, which automatically takes in traffic data for the government to analyze so that it may develop better roads and traffic management. It would be possible for a cell phone app to take advantage of this more accurate data. Again, this would only work on the roads with sensors on them, which is an expensive process.