This paper explores the impact of lane occupancy on the actual capacity of urban roads by establishing a Greenberg model. A description of the change process of the actual traffic capacity of the cross section of the accident is given. The dredging capacity and actual traffic volume of Lane 3 are stronger than that of Lane 1, and the causes of the differences are analyzed in detail. The duration of the accident was negatively correlated with the length of the queue, the traffic volume upstream of the road segment was positively correlated with the queue length, and the actual traffic capacity was negatively correlated with the queue length. We use the regression analysis method to verify the correctness of the model through matlab programming. We modify the model and analyze and process the data to get a table of the relationship between the duration of the accident and the length of the queue. At 11 minutes, the queue length of the vehicle will reach the upstream intersection.