Research On Coordinated Control Methods Of Arterial Highway Under Oversaturated Conditions

With the rapid development of city,the traffic problem is becoming more and more serious,which has become an important factor restricting the development of the city.Now China is at a time of rapid development.People's demand for vehicles is increasing rapidly.But the corresponding highway construction is not able to keep pace with development.The problem of traffic jam is becoming more and more serious.However the traditional signal control method is only applicable to the traffic state of low saturation density.For facing the serious traffic problem,need a traffic control method adapt to the saturation state or the oversaturated state to alleviate the adverse effects of traffic congestion and the gradually eliminate of vehicles stranded queue length,so as to solve the problem of congestion.The main task of this paper is to study the signal coordination control scheme based on oversaturated state recognition.The main work is as follows:Frist,a oversaturated state recognition model need to be established.On the step of analyzing the reason for oversaturated state,the original and extended definition of saturation have been put forward.The breakthrough point is queue length,a oversaturated state recognition standard is designed based on time and space dimensions.And then highway oversaturated state recognition method is proposed to detect based on real-time monitoring of highway queue length which calculated by the curve of the vehicle arriving and leaving.Then,a signal timing model for key intersection is set up.The concept of key intersection is proposed.According to the characteristics of urban highway importance,the identification model of key intersection is established by analogy with three conditions of capacity,connectivity and storage capacity to judge the importance of intersection importance.Using Fixed Number Theory,the theory is taken as the core and minimizing the average vehicle delay and minimizing the number of vehicle stops,the signal timing scheme of critical intersection atoversaturated state recognition is modeled.Finally,the signal coordination control model of the interrelated intersection is set up.The effect of phase difference on coordinated control of trunk highways is analyzed.A method for calculating the phase difference of adjacent intersection is proposed.Then considering the problem of preventing signal from empty and queuing overflow,the green light time of straight intersection of main highways is determined.The distribution of other phase signals at adjacent intersection is calculated by the way of equal saturation distribution.Based on the signal timing scheme of the adjacent intersections,the signal timing schemes at the other intersections of the main highways is calculated later.Last,Changchun Ziyou Road is taken as an example to illustrate the applicability of the method.According to calculation,Ziyou Road and Renmin Street intersection is chosen as the key intersection,and the signal timing scheme and phase difference of each intersection have been get.By comparing with the queue length of existing schemes,the effectiveness of the proposed scheme is verified.