Comment by nudgeee

I used to work for a mapping & navigation company that offered a traffic API service. It worked by using anonymized cell phone data to predict traffic patterns. I once heard a story that during peak hour, every five minutes or so the jams on a highway would magically disappear then reappear. After some head scratching, turns out there is a train track inbetween the lanes of the highway full of high speed commuters that would cancel out the stationary car commuters.