I am discussing very cool research by Denis Bartolo and colleagues in Lyon and Paris on the appearance of traffic jams. In short: traffic jams appear in dense crowds very much like ice cubes form in freezing water.
Their experiment does not involve people, but millions of tiny beads that roll together on a track, in well controlled conditions. Their conclusion is that very large traffic jams may form only because people tend to slow down when surrounded by too many others. These results need to be taken into account when designing smart cars to make them avoid the conditions of traffic jam formation.
Suitable for anybody with an interest in science, not a specialist article. To know more, click here.