Max Smith, wtop.com
WASHINGTON - There's a new hi-tech way to track the speed of traffic on key commuter routes.
Calgary, Alberta, Canada, has installed a system that detects bluetooth signals from phones and other devices in cars on some major roads.
The system uses the time it takes to get to the next checkpoint to update variable road signs with accurate travel times from one point to the next.
The city says it tracks the unique identifying number of any device set to "discoverable," without collecting any other identifiable information.
People with a device capable of bluetooth, including the systems built into many cars, would not be tracked if the system is not set to "discoverable" mode.
In the D.C. area, similar information is gathered through sensors built into the roads and radar-based systems alongside major roads.
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