Even cars "bunch" (cause traffic jams) without any apparent reason. It's due to instabilities in traffics caused by reaction times [1]. [1] http://www.scienced

Even cars "bunch" (cause traffic jams) without any apparent reason. It's due to instabilities in traffics caused by reaction times [1]. [1] http://www.sciencedirect.com/science/article/pii/S0167278905003775 http://www.sciencedirect.com/science/article/pii/S0167278905... Direct link: http://www-personal.umich.edu/~orosz/articles/PhysicaDpublished.pdf http://www-personal.umich.edu/~orosz/articles/PhysicaDpublis...