Smartphones to ease traffic snarls

All commuters have a personal bag of tricks to skirt traffic. Now, a new smartphone app under development promises to learn your tricks and let you know when to use them.

The opt-in system combines information on your typical driving patterns collected by your smartphone with mountains of historical traffic data collected by sensors at toll booths, in roads, bridges, and intersections to predict traffic snarls and ways to avoid them before you leave home.