The Study On Cross Section Layout And Transition Section Setting Of Intercity Road

With the advancement of the new urbanization strategy,the phenomena of regional economic integration,group urbanization and industrial cluster are very prominent.High density,speediness and integration have become the general demand of intercity traffic.Inter-city roads,such as "urban expressway","urbanized highway" or "urban expressway",have emerged as the times require.On the basis of the traditional highway,some functions of "urban road" are added to these "inter-city roads".Their road functions and traffic characteristics,especially the elements and the layout form of cross-section are quite different from those of highways and urban roads.Simply referring to the existing highway and urban road standards,the design of inter-city roads will result in design fingers.Traffic problems such as inconsistent standards,inconsistent road design and functional requirements,etc.Therefore,from the point of view of road function,aiming at the functional characteristics of inter-city roads and the existing traffic problems,it is urgent to put forward cross-section layout and transitional section setting methods that meet the functional requirements.Firstly,by analyzing the characteristics of functional requirements of intercity roads,the functions along the roads are divided into urban planning areas,planning impact areas and field highways.Based on the analysis of the development and evolution of inter-city traffic,the traffic characteristics of inter-city road are studied from three aspects: traffic volume,traffic composition and operation speed,and the impact of urbanization on inter-city road traffic is analyzed.Secondly,according to Polinkov's theoretical model of lane width,the theoretical value of lane width is calculated.Using VISSIM simulation software to simulate different width Lane models,the lane width index of intercity road is proposed.It also puts forward that the width of lanes on intercity roads can be divided into vehicle types and lane values.Then,according to the extended FCS theory,a cross-sectional layout method based on extended FCS is proposed.Extended FCS matrix is obtained to provide theoretical support for cross section layout.Combining with the influencing factors of cross-sectionlayout and taking "function deciding form" as the main line,this paper puts forward the cross-section layout form adapting to road function,and analyses its advantages and disadvantages and trial conditions.Finally,the model of vehicle lane change is introduced to analyze the setting index of cross-section transition section.The force analysis of vehicles during lane change is carried out,and the safe driving radius of vehicle lane change is put forward.The lane change model is used to calculate and analyze the transition index of lane width and split width.The calculation model of lane width gradient rate is constructed,and the recommended values of lane width gradient rate,speed change lane gradient rate and split belt gradient rate are put forward.