This isn't a new video but is still interesting nonetheless. The University of Nagoya in Japan performed an experiment to try and determine what causes random traffic jams. The video doesn't explain much past the observations of the experiment but there are probably two schools of thought in how to interpret this.
One side thinks that people brake too often causing cars to line up behind. The other group thinks people wouldn't have to brake if they didn't have such lead foots in the first place and close-in on the leading car. I have a third opinion and it's a bit more objective. There is a small amount of variation from car to car regarding speedometer readings. American law states that speedometers may be calibrated from the factory to be optimistic but it is illegal for a speedometer to indicate a slower speed than the actual road speed of the car. Notice the vehicles in the test are not all the same model.