Research On The Signal Control Conditions And Methods Of Roundabouts With Multi Branches

The key roundabouts is becoming saturated gradually as the city's traffic flow tend to be more intense,it leads the roundabouts out of order with seriously congestion and its operation efficiency is very low during the rush hours.Therefore,it is necessary to improve roundabouts' control level from right-of-way rules control to signal control.The existing research is mostly concentrated in the aspect of signal control in ordinary roundabouts with four branches,but they rarely involved roundabouts with multi branches whose traffic organization runs more complex.In this paper,I put the roundabouts with multi branches as the research object.First of all,analyze the running characteristics of traffic flow for roundabouts with multi branches from the perspective of data analysis;calculate the roundabouts' traffic state through clustering analysis,Analysis time conditions of roundabouts' setting signal based on state judging results.Secondly,this paper studies the single intersection signal control method based on model predictive control theory from the macroscopic angle.Designing of signal timing method for roundabouts with multi branches Satisfy the time-varying characteristic of traffic flow based on the study of phase Structure design and the lap joint rules,through the process of forecasting model and objective function of the optimal solution,rolling optimization of signal timing parameters of roundabouts.Finally,the article put a single point of signal control in roundabouts,expanded to coordinated optimization with each entry's first intersection upstream,through regional relationship analysis,the island's upstream intersection signal timing parameters optimization,to control the traffic demand of the island,to increase its running order,promote efficiency of roundabout traffic.