Study On The Traffic Connection Between Exit Ramp And Ground Road Of The First Ring Expressway In Nanchang City

There are some problems in the connection between urban expressway exit ramp and ground road,which may lead to traffic congestion and low traffic efficiency at downstream intersection,and the long queue of vehicles at the intersection will lead to the queuing of the exit ramp,which will have a certain impact on the operation of the main line of the expressway.Therefore,the research on the traffic connection between the expressway exit ramp and the ground road will help to eliminate the congestion problem in the area near the exit ramp and ensure the traffic efficiency and service level of the expressway and the ground road.The first ring expressway is an important part of the road network system of Nanchang.Taking the first ring expressway of Nanchang as an example,this paper analyzes the existing problems and find out the improvement measures.Firstly,the paper carries out the traffic investigation of the first ring expressway and the main interchanges along the route,and expounds the present situation and planning situation of the road network.The paper mainly introduces the general situation of the first ring expressway,takes summary analysis of the important interchanges of the first ring expressway,puts forward traffic forecasting on the line in the year when the first ring expressway is completed,and analyses the present problems of some important interchange nodes.Secondly,in order to explore the main causes of congestion in the junction area between the exit ramp of interchange node and the ground road intersection,the layout of the exit ramp and the traffic characteristics of the junction area are discussed comprehensively.The paper analyzes exit ramp setting forms from three respects,such as the form of off-ramp separation from expressway,the horizontal position of off-ramp grounding and the vertical position of off-ramp grounding are analyzed.Aiming at traffic characteristics of the connecting area,the paper discusses the factors affecting the weaving operation,traffic flow characteristics,queuing length and traffic organization of the connecting section.The main causes of congestion of adjacent area are summarized lastly.Thirdly,there are many factors affecting the operation of the connecting section,and this paper chooses two main factors such as horizontal position of the grounding of exit ramp and length of weaving section to carry out the simulation study,and explores the influence of different factors on the operation of the connecting section.Taking the intersection of Diezihu Avenue and Luyin Road and its adjacent areas as simulation objects,the parameters of lateral and longitudinal motion of simulated vehicles are calibrated,and road network is established,and other parameters are calibrated.The rationality of the model is verified by t-test method,and the validity of the simulation method is confirmed.Formulating the simulation scheme for the research target,the paper carries out sorts of simulation experiments,and analyzes simulation results.Finally,aiming at some interchange nodes of the first ring expressway in Nanchang,this paper uses qualitative and quantitative analysis methods,such as investigation or simulation analysis,to determine whether there are problems in the connection of the interchange exit ramp and the ground road.According to the specific conditions of each interchange,different improvement strategies are put forward,such as engineering renovation or optimization of traffic organization and management.