Research On The Setting Basis Of Y-shaped Multi-lane Incoming Intersection Signals

With the increase of urban traffic demand,the congestion problem of the Y-shaped multi-lane inbound intersection is also becoming more and more prominent due to the compression of the lane during the confluence.At present,some cities in China adopt the signal light control method to limit the amount of traffic entering the intersection to achieve the purpose of improving the traffic capacity of the intersection and reduce the occurrence of accidents.However,the phenomenon of high and low peaks in urban traffic is obvious.When the signal lights are opened and closed,the traffic efficiency of intersections is significantly affected.If the traffic light is too low,turning on the signal light will increase the delay at the intersection and reduce the traffic efficiency.When the traffic volume is too high,the traffic lights will not be turned on.The disorderly traffic will increase the intersection accident rate and increase the intersection delay.At the same time,there are few studies on whether it is necessary to set the signal control aspect of a Y-shaped multi-lane inbound intersection with no signal control,and it can only be determined by experience.Therefore,determining the scientific and reasonable setting basis for the Y-shaped multi-lane entrance intersection signal has extremely important practical significance for improving the intersection traffic capacity,reducing junction delays,and guiding the setting of signal lights.In this paper,four representative Y-shaped multi-lane inbound intersections(2 invariants and 2 augmentations)are taken as examples for the following major work:(1)Classify Y-shaped multi-lane entrancesThe Y-shaped multi-lane entrance type intersection is divided into two types: invariable type and increased type according to whether the number of main lanes before and after the convergence increases,focusing on:Invariant type(main road 3 lanes after convergence = main road 3 lanes + lane 2 lanes before convergence);Increased type(main road 3 lanes after convergence = main road 2 lanes+ lane 2 lanes before convergence).(2)Established traffic volume models for two types of intersectionsBy summarizing and analyzing the traffic data laws such as speed,density,traffic volume,headway time,and traffic flow characteristics,the traffic volume at different cross-sections of the two types of intersections is calculated,and the traffic volume of the main road,the traffic volume of the ramp,and the distance from the nose are established.The multiple regression empirical model.(3)Established a headway distribution model of junctionsBased on the analysis and processing of the survey data,the probabilistic theory and mathematical statistics method are used to determine the distribution law of the headway time at the junction,and the headway distance distribution model is obtained.(4)Established a critical traffic volume curve model at an invariant intersectionThe theoretical calculation and numerical simulation were used to obtain the critical traffic volume curve model of the invariant intersection.There was a small error between the two calculation results,and the average value was taken as the critical traffic curve model.(5)Determined critical traffic volume at increased intersectionsThe theoretical traffic and numerical simulation are used to obtain the critical traffic volume of the double-lane ramp of the increased intersection(research shows that the intersection is more reasonable than the signal control of the ramp),and the average value of the two is taken as the critical traffic volume.(6)Validation of the effectiveness of two types of intersection critical traffic modelsSimulation simulation software was used to simulate and contrast the two states of Y-shaped multi-lane entrance type intersections and the status of non-installed signal lights respectively,which confirmed the effectiveness of the critical traffic model.