Coordinated control of urban expressway ramp flow based on model prediction

Ramp metering is one of the most important parts of expressway traffic control.In this paper,a flow prediction method based on nonlinear model is adopted by the prediction of expressway flow,the multiple ramp flow of the expressway is coordinatedly controlled for the expressway running on the largest capacity state.A traffic congestion sector of a expressway is simulated,the results show that this coordinated control method can efficiently eliminate traffic congestion,the multiple ramps flow metering rate is smooth,and expressway traffic flow is stable,in the meanwhile,the multiple ramps are equal.