The worst kind of traffic jam is a “phantom” traffic jam \u2014 those backups that occur for seemingly no reason. Phantom jams leave you sitting there wondering: Why? Fact is, we do know what causes them, and we can change our driving behavior to prevent them.<\/p>\n
On a recent road trip<\/a>, my family got caught in two such jams \u2014 each on I-90 in Eastern Washington out in the absolute freaking middle of nowhere. Eastbound, we got jammed up for 15 miles over 1\u00bd hours. Occupants in thousands of trapped cars clogged the cell towers trying to find out why. Turned out the state DOT had set out orange barrels in one lane; at least there was an explanation. On the return trip, even though I checked websites and traffic cams ahead of departure, we got stuck again, for a 30-mile stretch over 2\u00bd hours. This time, no explanation. Traffic eventually and mysteriously broke loose, and everyone took their turn speeding away like a bat outta hell. Probably to find a restroom.<\/p>\n Being stuck gave me time to think about the science of traffic flow. It’s a discipline steeped in mathematics, with some human behavior thrown in. If you\u2019re math-inclined, be sure to check out the federal government\u2019s \u201cRevised Monograph on Traffic Flow Theory\u201d<\/a> or some of<\/a> the various research<\/a> out of Delft University in the Netherlands, or MIT<\/a>. Oh the formulas, oh the charts!<\/p>\n It might be simpler to just watch this now-legendary video from the University of Nagoya in Japan. Researchers put 22 drivers on a circular track and asked them to maintain a constant speed of 30 kph. Sounds easy, right? But guess what happened:<\/p>\n