Study On The Bottleneck Characteristics And Driver’s Lane Changing Behavior Of Freeway Ramp

With the rapid development of urbanization and urban motor vehicles,the number of car ownership in our country has been increasing year by year,followed by many problems such as energy consumption,pollution,traffic safety,traffic congestion and so on.In this regard,China’s major cities have made many attempts,not only to control the growth of traffic demand,but also to improve the status of traffic supply.Long-term practical experience shows a fact that this series of measures cannot effectively improve traffic congestion.Instead,it should begin to enhance the tapping of of the transportation system’s potential.As an important part of urban traffic system,the efficiency of expressway is mainly affected by traffic bottleneck and vehicle lane changing behavior.Therefore,based on the actual data,this paper studies the traffic bottleneck and the lane change behavior of the freeway ramp;combined with macro and micro analysis,constructs a forced lane change model,which lays the foundation for the improvement of traffic condition and the whole system operation efficiency.Firstly,based on the existing theory research,the traffic state division parameters are analyzed,to put forward the method of traffic state division and divide the traffic flow state of the road.The characteristics of traffic time variation,traffic flow and traffic bottleneck are analyzed respectively,and the evolution mechanism and propagation characteristics of traffic bottleneck are pointed out,which provides reference for microanalysis below.Secondly,according to the measured data of the section,the lane changing condition of the road is analyzed from the type of lane change,lane change position and lane changing speed to pointe out the lane changing characteristic of the road.On the basis of the definition,from the whole to the part,lane transfer characteristics of drivers were analyzed.The cost of driving lane change is analyzed from three aspects of time cost,space cost and speed cost.Taking the influence of lane changing vehicle on the speed of the rear vehicle as an example,the influence of driver lane changing behavior is analyzed,and the main factors affecting the behavior of pedestrian forced lane change are also pointed out.The influence is mainly reflected in the choice of lane spacing and lane changing speed of the driver.Finally,based on the acceptable spacing,the lane change model of freeway ramp inlet is constructed.Considering the significance of the influence,the internal and external factors that affect the acceptable distance are analyzed and screened.According to the microscopic dynamics law of the vehicle,the critical acceptable spacing of pre vehicle and rear vehicle are modeled respectively,and the applicability and use of the model are explained.The model is calibrated by the measured data and the performance of the model is evaluated.