Macroscopic simulation of widely scattered synchronized traffic states

Recently, a phase transition to synchronized congested traffic has been observed in empirical highway data (Kerner B S and Rehborn H 1997 Phys. Rev. Lett. 79 4030). This hysteretic transition has been described by a non-local, gas-kinetic-based traffic model (Helbing D and Treiber M 1998 Phys. Rev. Lett. 81 3042) that did not, however, display a wide scattering of synchronized states. Here, it is shown that the latter can be reproduced by a mixture of different vehicle types like cars and trucks. The simulation results are in good agreement with Dutch highway data.