Research On The Capacity Of Round About And Its Simulation

The roundabout was once popular in the eighties and nineties of the last century.However,with the development of society,urban traffic increased dramatically,the conventional roundabout was becoming less and less suited to the current traffic environment,and its passage efficiency decreased.To improve this situation,the domestic proposed roundabout to be signal control: Single-signal control(control of the incoming vehicle only at the entrance)and Left-turn with two stops control(secondary control of the left-hand vehicle on the ring road)to improve the prevailing traffic.However,different types of roundabout should be how to choose,how should the calculation of traffic capacity,domestic and foreign research in this area is relatively small.The paper will study the roundabout from the following aspects:(1)This paper introduces the development and research status of the roundabout around the country at home and abroad,and summarizes and analyzes the current model of the traffic around the roundabout without signal,and through the analysis of the running rules around the roundabout,based on the parking line method,Signal control roundabout capacity model,and the relevant parameters of the model using MATLAB software programming analysis,obtained the relationship between the parameters and the ability to pass the law.(2)In this paper,the timing of the roundabout signal is studied,and the phase sequence of the single-signal control and the left-turn secondary control roundabout is determined,and the green time and green time interval are determined in detail.According to its operating characteristics,The calculation method of each parameter and the corresponding calculation formula.(3)In this paper,VISSIM traffic simulation software is used to simulate the traffic capacity and delay of the typical circular intersection between the signal and the no-signal control in different turn left rate,different flow rate and control mode.The advantages and disadvantages of different control methods under different left rate and flow rate are given reference for the selection of roundabout control mode.(4)In this paper,the traffic situation of the case is analyzed,and the improvement of the secondary control is put forward according to the present situation.VISSIM is used to compare the effectiveness of the proposed scheme with no signal control scheme and single signal control scheme,and the rationality of the research results is verified.