Research On Relatively Prioritized Signal Control Of Tram By Considering The Efficiency Of Trunk Traffic

With the development of the city,travel demand is growing rapidly,and all kinds of traffic problems are becoming more and more serious.Therefore,the world's major regions have vigorously implemented many restricted policies,and have vigorously promoted the development of public transportation.At that time,as a kind of public transportation mode,trams' volume,speed,cost,and threshold are between the rail transit and conventional public transportation,and the development prospects of trams in the world are immeasurable.Since trams mostly use semi-independent road rights,the main line operation is influenced by the intersection.Although absolute prioritized control can greatly improve the efficiency of tram traffic,it may cause serious congestion for other modes of transportation on the ground at the intersection,and even spread to entire road network.While formulating the priority and compensation strategies,this paper considers optimizing the efficiency of trunk traffic and propose relatively prioritized control of trams to improve the overall operating efficiency of trunks.Firstly,this paper expounds the basic operation characteristics and related technologies of trams,and introduces road signal control from three aspects: parameters,evaluation indicators and control methods.Secondly,this paper improves the conventional absolute prioritized system based on the location of the detector and the system flow,and analyze and predict the arrival time of the tram.Formulate green time regional division rules: divides the total length of arrival phase into the front area and the back area,and determines whether the arrival phase and its previous phase or subsequent phase are against the tram,so that forms six situations.What's more,separately designes the tram prioritized strategy in the arrival cycle and the phase compensation strategy in the latter cycle.Combining with the calculation model of the general traffic delay,six different delay analysis models under the green time regional division rules were established.Finally,an example is given to verify the effect of the prioritized and compensation strategies proposed in this paper to optimize the intersection.Thirdly,aiming at optimizing the overall traffic efficiency of trunk lines,this paper considers the per-capacity rights of all travelers on the trunk line.On the one hand,the traffic weight coefficient is designed according to the relationship between the time of every type of vehicles passing through the conflict zone and the number of passengers.On the other hand,according to the relationship between proportion of every type of vehicles in the traffic flow and the number of passengers,the maximum number of queues is calculated.Then convert the two into a system that allows the maximum number of lanes in each lane when responding to a tram priority request.Moreover,based on the prioritized strategy under the green time zone division rule,a relatively prioritized control model for optimizing the overall traffic efficiency of the trunk line is established.And selects delay,travel time,and number of vehicles to verify the model.Finally,select the first phase project of China's Anshun Tram Line 3 as a case,and use the VAP sensing module in VISSIM to simulate.Two sets of comparative experiments with absolute and relative prioritized control are designed.And by changing the frequency of the trams,the consequence of delays,transit times and number of vehicles passing under different conditions in the two sets of comparative experiments are separately obtained.The experimental results show that the relatively prioritized signal control method of the tram designed in this paper can effectively improve the overall trunk traffic efficiency.