Research On Signal Control Method Of Intersections Adjacent To The Accidental Congestion Road

The frequent occurrence of traffic congestion has had a serious impact on the development of today's cities,and traffic congestion can be divided into frequent congestion and accidental congestion according to the causes.Compared with the frequent traffic congestion which often occurs during the relatively concentrated periods,accidental congestion has more difficulty to evacuation and control because of its randomness and derivative.Under the condition of accidental congestion occurring in road,original intersection signal control scheme can not adapt to the dynamic change of congested traffic flow,and the unreasonable signal control scheme is an important cause of the congestion spread.In this paper,the signal control method of the adjacent intersection of the occasional congested road section is studied.The main work is as follows:(1)Based on the extensive research and summarization,the signal control parameters and evaluation indexes of the intersection are introduced,and the signal control strategy commonly used in the crowded intersection is analyzed in detail.(2)This paper studies the propagation law of the accidental congestion road by using the theory of traffic wave,and simulates the queuing length of congested sections under different traffic demand.Then it analyzes the propagation process of accidental congestion and the influence on adjacent intersections.Through the establishment of the traffic capacity model of the congested road section under the condition of traffic incident,the influencing factors of the traffic capacity of the congested road section are expounded,and the change of the remaining capacity of the congested road section is studied.(3)Based on the analysis of the signal control strategies of intersections which are adjacent to the accidental congestion road,the paper proposes an intersection signal control model based on the capacity limit of crowded road which aims to improve the intersection traffic capacity.Considering the phase saturation and the remaining capacity of the road section,the method of determining the green time of each phase to avoid traffic overflow and congestion transfer is given.When the residual capacity of the road is limited,and need to compression the green time of the phases which are related to traffic incident,this paper considers the redistribution phenomenon of the intersection traffic flow which is caused by lane and route changing of crowded traffic,and then the calculation method of signal cycle is given.Then we put forward the implementation procedures and processes of this control method.(4)Using the VISSIM simulation software,the paper simulate the traffic operation of intersections adjacent the crowded road in the common and peak hours respectively.Considering the different remaining capacity of congested road,the control scheme of this paper is designed and compared with the timing control scheme of different periods of Synchro optimization.The simulation results show that,comparing with the timing control method,this control method can improve the traffic capacity of intersection,reduce the average queue length and delay of the vehicle under the condition of accidental congestion,and the control effect is more obvious in the case of large traffic flow.This shows that this control method is suitable for the accidental congestion intersection.