Abstract:The traffic between urban elevated expressways and surface roads mainly transforms through off-ramps and downstream intersections. The traffic congestion occurs frequently at off-ramps and downstream intersections during peak hours. Based on the cellular transport model, a prediction model for the traffic of off-ramp and downstream intersection is built. The intersection signal control model based on cell transmission model is established by adopting the control strategy of dynamically adjusting the cycle length and signal phase. The dynamic optimization of signal time is carried out by taking the queue length, green light and cycle time as the constraints and the weighted average delay of each entrance as the objective function. The example of ramps and intersections in Chengdu is verified, which shows that the signal control strategy proposed can effectively reduce the saturation, delay and queue length of such intersections, and improve the traffic efficiency.