Diversity and Deviance of Traffic

"The success of biological systems in general is due not to homogeneity but to heterogeneity: they depend critically on the existence of differences in the elements which make them up."

- Paul Grobstein

"It is shown that, in an initially homogeneous traffic flow, a region of high density and low average velocity of cars can spontaneously appear, if the density of cars in the flow exceeds some critical value. This region - a cluster of cars - can move with constant velocity in the opposite direction or in the direction of the flow, depending on the selected parameters and the initial conditions of the traffic flow. Based on numerical simulations, the kinetics of cluster formation and the shape of stationary moving clusters are found. The results presented can explain the appearance of a 'phantom traffic jam,' which is observed in real traffic flw."

- Cluster effect in initially homogeneous traffic flow by BS Kerner and P Konhäuser