Until now there have been few good ways for drivers to find out in real time about traffic accidents or rush-hour jams on their routes. Radio traffic reports can be hit-or-miss, and most local governments have been loath to invest in roadside sensors costing $100,000 a mile in order to provide more timely information. Atlanta's AirSage says it has a way to get the job done. It uses proprietary soft ware algorithms that measure the number, speed, and density of cell-phone signals in cars along the road. The more concentrated the signals, the heavier the traffic volume. In 46 cities in the U.S., AirSage receives a continuous feed of radio-signal data (with the identifying information stripped out) from Sprint. It then looks for high signal density and slow vehicle speeds, which indicate a traffic jam.
展开▼
