Nothing will ruin a pleasant drive quicker than the sight brake lights coming towards you on the highway. Miles ahead, someone or something has spooked the bejeezus out of traffic and now you're about to pay for it with your free time. The mighty flow of America's highways is about to be plugged by you and a couple hundred of your closest strangers.  
 
The next time a traffic jam's iron grip has you in its clutch, you can at least take heart knowing that scientists have figured out why they happen and who's to blame...