Study On The Traffic Capacity And Safety Of Mountainous Highway Continous Uphill Sections And The Research Of Improvement

With the perfect construction of highway network in the developed economic regions, the focus of highway construction shifts to the mountains gradually. Because of the complexity of topographic and geologic conditions, the difficulties of environmental protection, and the poorness of regional economic, these natural and social conditions restrict the highway construction, designers have to use the larger slope in the highway design of mountainous area. The structure, especially the dynamical performance between cars and large vehicles is different. when the vehicles run on the continuous uphill sections, the speed will be different, owing to the large load and the short of dynamical performance, the speed of large vehicles is lower than cars'. The large vehicles with low speed seriously impact the highway capacity, and lead to the cars overtake frequently, then cause traffic accidents. Therefore, to analyze the capacity, the traffic safety of the continuous uphill sections and the improvement is very important to improve security of mountainous highway.Based on the detailed analysis of domestic and international related literature and research results, combined with the Survey data on site, this paper analyzes vehicles'driving character running on the continuous uphill sections. On the platform of VISSIM simulation, establishing simulation model, with the help of simulation technology, this paper respectively conducts simulation experiments to research traffic capacity and safety of continuous uphill sections in terms of traffic, large vehicles proportion, slope and slope length. According to the results, it defines continuous uphill sections, and obtains the Influence law of four parameters impacting capacity and traffic safety, puts forward measures to improve capacity and safety.The research results can provide reference for the design of highway long and steep longitudinal slope. Especially, it is very important for settings climbing lanes, and the safety improvements of continuous uphill sections.