Research On Traffic Signal Timing Optimization In Urban Intersections Under Emergencies

Under emergencies,the status of urban transport network often changes suddenly,current traffic signal timing scheme may face failure,if not take effective measures promptly,can cause a wide range of traffic congestion,and even induce "secondary event",it has posed a tremendous threat to the country's economic development and people's life safety.Reasonable traffic signal timing scheme can effectively alleviate the impact of emergencies to urban transport.At present,there are few researches on the traffic signal timing of urban intersections under emergencies.My article will provide a method for urban traffic signal timing optimization of emergencies.The main content of this article:1.First,I am analyzed and summarized theory of traffic signal control so far.Due to it is a Outstanding issue with line up at the intersection,so traffic-wave theory is used to analyze the queuing rules at intersections.2.Consider the randomness of emergencies,according to the distinctive of the location of the incident and the impact,the road network is divided into three cases,all sections of road congestion,road congestion and congestion at the Intersection,discuss its traffic evacuation strategy separately.The evacuation strategies mainly include intercepting,forbidding,forcing and resetting phase sequence control measures,and establishment of bypass evacuation routes so that the traffic flow affected by the incident can bypass the "bottleneck point" of congestion.In order to improve the efficiency of evacuation,the regional road network is divided into the traffic signal coordination control and single point control.3.After determining the traffic evacuation strategy,Propose two-stage optimization models of signal timing parameters for intersection.The first-stage optimization model give basic parameters such as cycle split and so on for all intersections.Considering the queuing vehicles dissipated in advance,the second-stage optimization models is made to get the best offset,which take the minimized coordination phase delay of all detour lines for the control area.Finally,using the particle swam algorithm to solve the model.4.Actual traffic survey on the Adjacent Network of the South Gate of the Fifth Phase of the Fifth County in Ganjingzi District,Dalian.Using VISSIM to simulate and simulate the road network of under emergencies,close the road by myself to achieve the consequent of simulation traffic blocked when experimental simulation.Finally,comparative analysis the simulation consequent of current timing scheme and the optimization proposed in this paper case shows that my timing scheme can better deal with traffic conditions under emergencies.