Study On Ramp Merging Zone Lane Changing Model And Bottleneck Characteristics

With the construction of expressways in cities,expressway bottlenecks attach more and more attention.Bottlenecks restrict the capacity of expressways and affect their functions,which also cause much potential traffic danger.In this paper,for a practical example,traffic data before,during and after a bottleneck in Lushan ramp merging zone of Yingtian Elevated Avenue in Nanjing are collected by video observation and analyzed by software.The bottleneck characteristics are studied based on macroscopic traffic flow and microscopic vehicle behavior.A vehicle lane changing model is structured,proved by traffic simulation.And occurrence conditions of bottlenecks are analyzed through traffic simulation.In this paper,methods of collecting vehicle data through video observation and video process are introduced firstly,which are proved to be valid and reliable by error experiment.Based on measured data,features of traffic flow,vehicle motion and vehicle merging lane changing are analyzed in macroscopic or microscopic level to study characteristics of bottleneck and the relationship between traffic parameters.Then a vehicle lane changing model is structured according to features of ramp merging zone,to describe vehicle behavior with a car following model together.The lane changing model is proved by traffic simulation.At last,occurrence conditions of bottleneck are studied through traffic simulation.Besides,main content of the paper is summarized and future research interests are discussed.