Research On The Coordinated Control Method Of Traffic Signal In The Impact Area Of Urban Work Zone

With the continuous advancement of urbanization,the number of urban work zone is increasing,such as section reconstruction,track construction,etc.The road occupation construction compressed the road space,resulting in a decrease in the traffic capacity of the road section where the construction area is located and a decrease in the vehicle speed;especially in the peak hours,the traffic volume of the road increases sharply,and the traffic demand of the vehicle is not satisfied due to the decrease of the traffic capacity of the road section.It will accumulate queues and cause traffic congestion.As time goes by,this state of queue congestion will spread to the intersections and road sections around the work zone where the road construction area is located,resulting in a wide range of traffic congestion.The signal timing scheme of the existing intersection will no longer be applicable to the current traffic state,and the effect of the regional signal coordination control scheme will also be reduced,which cannot meet the actual needs.The coordinated optimization control of urban regional traffic signal can improve the efficiency of traffic operation and is an effective control method.At present,there are few studies on the coordinated control of regional signal under the influence of urban road occupation construction.Therefore,this paper aims at the traffic congestion caused by the existence of urban work zone.On the basis of determining its influence range,the research on the coordinated optimization control of traffic signal within the scope is carried out.This paper mainly focuses on the signal coordination problem in the affect area of urban work zone.Firstly,based on the existing research results,a method is proposed to determine the scope of the construction affected area by taking the overall service level of the typical signalized intersection before and after construction as the convergence condition.Considering the difference between the travel time of the normal road section and the travel time of the construction section,the calculation method of the travel time of the construction section is proposed based on the fluctuation theory,which makes the whole distribution process closer to the actual traffic situation,and the final influence range obtained is more reasonable.Secondly,after comprehensively considering the relationship between traffic control system and traffic guidance system,from the perspective of system optimization,this paper proposes a signal control and guidance collaborative optimization model with the first goal of dissipating congestion and the second goal of minimizing the total travel time as much as possible.Aiming at the first layer target of the model,the method of small step adjustment and trial optimization is adopted,and the rolling judgment and optimization are continuously carried out to achieve the purpose of alleviating congestion.The improved ant colony algorithm is used to solve the second layer target of the model,and the relevant signal timing parameter values are obtained to achieve the purpose of minimizing the total travel time.Finally,this paper takes the construction area of Xuanwu Street in Wuwei City as an example,through the traffic survey,the calculation of the traffic capacity of the construction section and the distribution of traffic flow,the influence range is determined.After optimizing the signal timing in the construction affected area,the VISSIM simulation software is used to simulate.The results show that the total travel time in the affected area is 17.52 % lower than that before construction,and the traffic flow of each section tends to be balanced,indicating that the model and algorithm proposed in this paper have better optimization effect.