Research On Signal Control Method Of Roundabout Based On Phase Priority Combination

With the increasing demand for traffic,the phenomenon of congestion,chaos and congestion at the roundabout is becoming more and more serious during peak hours.The signal control method has good applicability to the traffic situation with symmetric traffic flow.When asymmetric traffic flow occurs,the space resource utilization rate of the ring road is very low.Based on this,on the basis of considering the demand of popular cars,the paper proposes a combined phase and idle phase release method.The traffic lights of the entrance road are delayed to light up in advance to separate the conflicting car flow.The free space of the ring road is used to evacuate the car flow.Improve the utilization rate of ring road space resources under the condition of various driving needs.First,The thesis analyzes the distribution of traffic flow conflict points,traffic flow conflicts,regional divisions and regional traffic flow characteristics of signal-controlled roundabouts.According to the spatial composition and vehicle flow characteristics of common roundabouts,the signal control for single entrance and the secondary signal control for left turn The applicability and phase design of the three signal control methods of left turn single signal control and roundabout intersection are analyzed.Secondly,on the basis of studying the characteristics of traffic flow conflict points at signal-controlled roundabouts,this paper gives the calculation method of the capacity of signal-controlled roundabouts based on the traffic flow through the parking line;by analyzing the distribution characteristics of the traffic flow,give the delay calculation model under the condition of combined phase release,which provides a basis for the subsequent comparative study of signal control.Thirdly,On the basis of considering the characteristics of traffic flow conflict points,the thesis puts forward the design idea of combined phase,elaborated the design idea of the combination of main phase and auxiliary phase,the design idea of following phase and idle phase in the process of combined phase design.the paper puts forward the signal control method of roundabout intersection with phase priority combination on the basis of considering the demand of popular cars,and elaborate the flow of this signal control method:including the main phase selection method and the auxiliary phase priority selection method,Calculation method of ring road capacity and idle phase green light duration,auxiliary phase green light start and end time calculation method.And the signal control timing parameter optimization model with the main phase saturation and the main phase green light duration as constraints,with the minimum vehicle delay and the maximum throughput as the target is constructed.Finally,the VISSIM simulation software was used to build the road network model,input multiple sets of traffic flow data,and compare and analyze the operational benefits of the three control methods of single entrance signal control,left-turn secondary signal control,and phase priority combined signal control;the Harbin City Museum Take the roundabout as an example.By collecting the actual traffic flow data and improving the channelization method,the simulation shows that there is no significant difference in the total throughput of the roundabout.The average vehicle delays are 44.4s,39.8s,and 37.3s respectively.The phase priority combined signal control method has the lowest delay,which is 16.0%and 6.3%lower than the previous two.To verify the effectiveness of the phase priority combination control method...