Research On Linkage Control Of Adjacent Signalized Intersections Based On Delay

As the node of urban road traffic network,intersections are the main conflict point of urban traffic.There are two ways to separate the traffic flow of intersections: traffic channelization design and traffic signal control.From the point of view of signal control,this paper studies the linkage control of adjacent signal intersections,trying to reduce vehicle delay and improve the traffic efficiency of the trunk line by optimizing the timing scheme of each signal intersection of the trunk line.The main research work of this paper includes:1.Correlation analysis of adjacent intersections.Intersection correlation analysis is a prerequisite for coordinated control of.In view of the lack of consideration of cycle length and intersection spacing in the calculation of intersection correlation in existing studies,the paper improves the correlation formula of adjacent signal intersections and concludes a calculation method that can better reflect the correlation between intersections.2.According to the characteristics of traffic flow,different control methods and timing schemes are adopted for each signal intersection of the trunk line in different periods.3.Analysis of average travel speed between intersections.The average travel speed between intersections changes with time,which brings a certain challenge to the optimization of coordinated control phase difference of the trunk line.The paper analyzes the impact of weather conditions and pedestrian crossings on vehicle speed,combined with real-time detected traffic volume of intersections,and uses the flow-speed calculation formula in the linear model to calculate the average travel speed,making the designed phase difference timing scheme more adaptable real-time changing traffic flow status.4.Establishment of trunk coordination delay model.The delay of trunk coordinated control is divided into coordinated phase delay and non-coordinated phase delay.Since the traffic flow of non-coordinated phase is not affected by the timing of adjacent signal intersections,the calculation is relatively easy.The traffic delay of the coordinated phase needs to be analyzed together with the traffic of adjacent signal intersections.According to the direction of the main traffic,it is divided into the upstream delay and the downstream delay.The delays of the upstream and downstream teams can be subdivided into delays caused by blocked heads and intercepted tails.The paper analyzes the relevant conditions and calculation formulas of the team's head is blocked or the tail is intercepted,and the calculation method of the coordinated phase delay is obtained.In addition,while keeping the average delay of coordinated phase vehicles as small as possible,the service level of non-coordinated phase vehicles is considered.5.Trunk line coordinated control timing optimization.Based on the trunk coordination delay model,the paper optimized the main parameters of trunk coordination control-period,green signal ratio and phase difference respectively.Use period-the traffic intensity model calculates the optimal period duration of each signalized intersection separately,and then determines the length of the common cycle of the trunk line.Use the green signal ratio distribution method of equal saturation or unequal saturation to calculate the green light duration of each phase of the intersection separately.Based on the principle of minimum coordination phase delay,select the appropriate phase difference scheme.Finally,through the analysis of calculation examples,the process of trunk coordination and timing optimization is shown.The optimized parameters are input into the VISSIM traffic simulation software for simulation and verification of the validity of the model.