Abstract:An evolution model of traffic perturbation is founded to verify spontaneous traffic breakdown phenomenon indirectly. Based on the principle of car following behavior, driving behavior is defined as two styles, “inheriting” and “altering”. Deceleration wave and acceleration wave formed when vehicles drive in and drive out of a perturbation are calculated using theory of traffic wave. Driving behavior, deceleration and acceleration wave speed, and time-headway distribution of arriving traffic are used to found the evolution model of traffic perturbation. Hysteresis phenomenon and “secondary perturbation” are considered in this model. Numerical simulation is carried out using Monte Carlo method to calculate and contrast the probability of traffic breakdown (PB) of five models, and the impact of several important parameters on PB are analyzed.