STOCHASTIC TRAFFIC MODEL WITH RANDOM DECELERATION PROBABILITIES - QUEUING AND POWER-LAW GAP DISTRIBUTION

We extend the Nagel-Schreckenberg stochastic cellular automata model f or single-lane vehicular traffic to incorporate quenched random decele ration probabilities. We show, by computer simulations, that at low de nsities this model displays queueing of cars with a power-law probabil ity distribution of gaps between the cars while at high densities the behaviour of the model is similar to the jammed phase of the standard Nagel-Schreckenberg model. The approach to the steady state is charact erized by the same critical exponents as for the coarsening process in the simple exclusion processes with random rates, recently investigat ed independently by Krug and Ferrari, and Evans. The numerical values of the exponents for gap distributions are in agreement with the analy tical conjecture of Krug and Ferrari, which implies that the models be long to the same universality class.