Cell phone tracking system reveals how traffic jams start

Smartphones have changed the way we drive, both by adding new distractions and by helping us get where we’re going with GPS-assisted directions and real-time information on traffic jams.

But what if smartphones could help eliminate some traffic jams, instead of just warning us when they exist? That’s the goal of a study using cell phone records and GPS data to track drivers’ movements and identify the sources of traffic.