A Study Of Urban Bridge Traffic Bottleneck Mechanism And Improvement Method

Traffic bottleneck is one of the key point of urban traffic congestion,which cause thelocal traffic capacity to plummet even restricts the road net. Bridge in the city, is a superbtransport hub for connecting several important areas. Because the traffic capacity of bridgeaffects the efficiency of the road network. With the rapid growth in traffic, the capacity ofsome bridge has been unable to meet the growing traffic demand. That cause the new trafficbottlenecks. However, methods as broadening the bridge to improve the capacity of thebridge, will involve heavy investment and land acquisition and resettlement. Therefore, thegeneration mechanisms of the bridge bottlenecks, improvement measures and theireffectiveness has very important realistic meaning to study.Based on the microscopic traffic simulation tool，this thesis carried out a new way ofstudies on the traffic bottleneck. First of all,built some simulation models to imitate severaltypical bridge traffic bottleneck problems by using the microscopic traffic simulation toolsVissim. And then using field survey data to calibrate the key parameters of the model.Changing car traffic volume to get input and output curve in different traffic conditions. Thusobtain the basic model of the bridge bottleneck effect. Through the analysis of themodel,researching its phenomena, the causes and the mechanism. Research shows that withthe increase of the bridge lanes, bottleneck effect decreases gradually,and the averagecapacity of each lane is improving. Road resources are used better.Then, proposed several ways to improve the problems of bridge traffic bottleneck,andcombined with practical engineering cases, for example, the packet release signal lamp, tidalvariable lane, bridge widening, etc. Elaborated on the use of traffic simulation tools for trafficimprovement steps and points, and then evaluated the improvement effect,analyzed itsapplicable conditions. Research shows that traffic simulation tool is suitable for studying theproblems of urban bridge traffic bottleneck,it can provide reference about improve programdesign and investment decision-making for bridge bottlenecks, so as to ameliorate theantiscientific of city traffic construction, ameliorate the efficiency of municipal investments.