摘要：Nowadays, the traffic safety problem has become the focus of attention and making a sound and reasonable traffic rules and regulations is the trend. In this paper, based on the traffic rules of driving on the right lane unless overtaking happen, the study first establish the car-following and overtaking model .In car-following model, analyzing the traffic features to obtain the function relationship between the safety distance and speed change; in the overtaking model, TWOPAS stimulation model is adopted to analyze the traffic capacity of highway, and obtain the speed-flow relation graph, overtaking ratio—flow relation scatter graph. It is known through the graph analysis that: (1)when the traffic is sparse, most drivers tend to do free driving with less overtaking, and the traffic rules have no obvious facilitation function on traffic smooth; (2)with the increase of the car flow, the lane becomes narrower, and the overtaking rate decreases continually until it becomes zero. In the process of changing, when the overtaking rate is , overtaking stimulates the traffic flow; when the overtaking rate is , overtaking has a decreasing facilitation effect on traffic flow until it becomes zero. Then, construct the analytical model about speed, flow and traffic capacity only in the state of car following. It is found that overtaking has less influence on traffic capacity. And the role this traffic rule plays on traffic smooth is not obvious
