Research On Minimum Spacing Of Expressway Interchange Based On Variant Model

In recent years,China's economy has developed rapidly,the number of small passenger cars has increased dramatically,and the demand for roads has become higher and higher.With the continuous expansion and improvement of the expressway network,the setting of interchanges has become more and more frequent,resulting in the closer spacing of adjacent interchanges.The spacing is too close to meet the operational needs of the vehicle,causing a series of problems.In order to improve the traffic capacity of interchangeable interchange sections and ensure the safety of vehicles on them,this paper attempts to study the minimum spacing of adjacent interchanges from a new perspective.Firstly,the main factors affecting the spacing of adjacent interchanges are expounded,and three kinds of connection modes of compound interchanges are proposed according to the difference of the spacing: auxiliary lanes,distribution channels and ramp connections,and each method is discussed.Advantages and disadvantages.Based on the shortcomings of the existing connection methods,a new connection method of the variant distribution model is proposed.The model eliminates the interlacing by the lane traffic organization technology,which makes it better suited to the case where the adjacent interchange spacing is smaller.Secondly,for the proposed variant distribution model,four technical indicators are studied and discussed.According to the operation law of the vehicle at the expressway exit,the combination of probability theory and differential learning is used to calculate the highway.The recommended length of the total length of the single lane deceleration lane under different main line design speeds and ramp design speeds;the length of the connecting ramp is divided into the length of the deceleration lane,the length of the transition section of the running speed,and the length of the ramp section of the ramp,so as to obtain the minimum length of the connecting ramp;The driver's reading requirements for the sign,the minimum distance between the continuous shunts on the same side of the main line is calculated;the upper and lower penetrating problems between the connecting ramp and the entrance ramp are discussed from the perspectives of design,terrain and respective features.In order to get the best choice.Finally,the variant set-distribution model has an important technical parameter,namely the length of the non-interlaced area,which can provide a new solution for the small spacing of adjacent interchanges.Since there is no interlacing behavior in the non-interlaced area,the minimum length of the non-interlaced area is calculated based on the driver's recognition process and the lane change theory.At the same time,the VISSIM traffic simulation software is used to simulate and calculate the length of the non-interlaced area obtained according to the traffic flow theory.The simulation results show that the minimum length of the non-interlaced area obtained by the traffic flow theory can meet the driving requirements of the vehicle well,and the traffic efficiency is high,which verifies the reliability of the non-interlaced area calculation model.Finally,the composite interchange of the variant distribution model on the No.1 expressway in Germany is introduced,which guarantees the practical feasibility of the model.