Nonlinear stability of optimal velocity traffic flow model to unsteady disturbance

Nonlinear stability to unsteady disturbance of an optimal velocity traffic flow model is investigated. The single-lane traffic flow behavior is numeri cally simulated based on the car-following scheme. Two kinds of the leading car motion are examined as the prescribed disturbance: The first one is st op-and-go motion; the strength of the disturbance is controlled with the du ration time of the stop. The second one is deceleration-and-acceleration at a constant rate; the strength is controlled both by the rate and the durat ion period. Resulting stability is summarized in diagrams on coordinates ch aracterizing the disturbance and relaxation performance. For a large car se paration, there exists a metastable state, in which the stability of the sy stem depends on the strength of the disturbance. The critical relaxation ti me to the metastable state depends on the initial car separation.