Mountainous Area Freeway Capacity And Improvement Measures Of Continuous Upgrade Sections Research

With the development of highway network, the focus of the highway building began to shift to the mountains. However, due to the limits of the mountainous area highway's terrain, topography, complex geological conditions, environmental protection , construction difficulties and other factors, designers have to use the larger slopes or the longer slope lengths to make the mountainous area highways continuous upgrade sections. So when the large vehicles run on these Longitudinals,the space of the vehicles vary greatly. Besides, the capacity and the traffic safety of the highways will be impacted. This paper studies on the mountainous area freeway continuous upgrade sections, which study's focus is capacity, and proposes the corresponding improvement measures.In this paper, based on a large number of measured data, we can determine that the traditional classification of vehicles doesn't apply to the study of the capacity,so this paper proposes a new classification of vehicles-make the weight/horsepower as the first standard,and gets three typies of vehicles:small cars,large and medium-sized cars,and large cars. The paper studys the calculation method of PCE from the headway and traffic density and determines the representative vehicle on the continuous upgrade sections of the mountainous area highways. By studying the stress analysis of the representative vehicle,the paper can determine its technical parameters and the maximum speed,critical speed and shifting speed under every stalls. According to critical speed and critical slope length,drawing the representative vehicle's climbing performance curves. Studying the changes of the trucks' speeds on the different gradients and summarizing the trucks' running characteristics, comparing the capacity computing models of the China and the U.S.A and analyzing the models' impaction factors and correction factors, determining the model of the equivalent slope-slope length on the continuous upgrade of the mountainous area highways and the method of capacity. Finally, there are three measures to improve the capacity.