利用冲击波理论估计路口的排队消散速度,利用累积的原理估计路段的最大排队长度。下游路口周期开始到最大排队期间,根据上游到达排队车辆加路段初始排队车辆等于下游消散排队车辆的基本物理原理,建立发生交通溢流时的临界相位差模型。通过改变等长度路段的流量和等流量下路段的长度,分别计算临界相位差。结果显示,该模型能够有效避免交通溢流现象的发生。 The use of shock wave theory to estimate the intersection of the queue and dissipate speed, using the cumulative principle to estimate the maximum queue length. During the period from the beginning of the downstream intersection to the maximum queuing period, a critical phase difference model for traffic overflow is established according to the basic physical principle that the initial queuing vehicles arriving at the queuing vehicles plus the queuing vehicles are equal to the vehicles dissipating in the downstream. The critical phase difference is calculated separately by changing the flow rate of the equal length section and the length of the section under the equal flow rate. The results show that the model can effectively avoid the occurrence of traffic overflow phenomenon.