Research On Bus Priority Control Strategy For Reserved Intersection

The implementation of bus priority at the intersection is conducive to the rapid transit of buses through the intersection,saving passenger travel time and effectively improving the attractiveness of public transport.However,at present,when the bus priority strategy is adopted under the condition of oversaturated traffic flow,it is often difficult to balance the road right or signal phase right of buses and social vehicles,and the ideal strategy control effect cannot be achieved.With the development of autonomous vehicle technology,many scholars have proposed an intersection-booking intersection based on intelligent network technology.Different from the traditional signalized intersection,the reserved intersection is no longer equipped with signal lights,but through the communication between the road and the vehicle to make an independent traffic plan for the vehicle to pass safely,which provides a new idea to solve the problem of bus priority at the intersection.Based on this,this paper proposes two bus priority control strategies for scheduled intersections to further improve the spatial utilization rate of intersections,so as to realize the priority of buses passing through the intersections under the oversaturated state of intersections,and reduce the per capita delay of intersections.The main work of this paper is as follows :Firstly,based on the basic characteristics of traditional signalless intersections and the characteristics of intelligent network traffic environment,this paper analyzes the control characteristics of the reserved intersection.Referring to the strategies of bus green time advance and bus lane left turn in the traditional road environment,this paper puts forward the setting conditions and control logic of the two strategies of bus clearing priority and bus lane priority in the reserved intersection environment,and reconstructs the inlet lane of the intersection.According to the different road functions,it is divided into the detection interval,clearing interval(lane interval)and acceleration interval.Secondly,the internal space of the reserved intersection is gridded,and the grid coordinate equation is established.According to the vehicle driving characteristics,the vehicle driving trajectory equation is established.After the intersection of the path and the grid is obtained by the simultaneous equation,the dimension reduction projection method is used to solve the grid length of the intersection occupied by the path.On this basis,taking the minimum delay per capita as the objective function,the actual time of vehicle entering the intersection as the decision variable,and the vehicle conflict and bus priority as the main constraints,a mixed integer programming model of two bus priority strategies is established.Finally,the effectiveness of the strategy is verified by the design example analysis.According to the strategy,the intersection inlet and internal layout are reformed,and the intersection per capita delay and vehicle delay variance are set.The two control strategies are compared with the strategy without bus priority.The results show that when the total vehicle arrival rate is 6000 pcu / h,the total vehicle delay of the bus clearing priority strategy and the bus bypass priority strategy increases by only 1.57 % and 1.22 %,respectively,while the per capita delay decreases by 30.69 % and 30.94 %,respectively.The optimization effect is obvious.In contrast,the influence of bus lane-taking priority strategy on social vehicles is lower,and the variance of vehicle delay is only 42.45 % of that of bus clearing priority strategy.The sensitivity analysis shows that with the increase of the total vehicle arrival rate,the effect of the two strategies to reduce the per capita delay is more obvious.Among them,the influence of bus lane priority vehicles on other social vehicles is small,and the change of the traffic flow in and out of the bus direction has a great influence on the bus lane priority strategy.