Analysis Of Traffic Accident Characteristics And Safety Improvement Of Expressway In Difficult And Dangerous Mountainous Areas

Mountainous expressway refers to the expressway located in mountainous areas.Due to the natural characteristics of mountainous areas,there are more special structures,and it passes through in the form of tunnels or viaducts in special difficult sections.difficult and dangerous mountain areas are those with poor natural conditions,fragile natural environment and backward social economy.Compared with plain areas,the technical standard of Expressway in mountainous areas is lower.Taking the southwest mountainous areas as an example,the expressway usually adopts the technical standard of 80km/h,resulting in greater twists and turns of the route,greater longitudinal slope gradient and longer slope length.On the whole,the road conditions of highways in mountainous areas have the characteristics of low technical standards,large proportion of bridges and tunnels,low linear indicators,complex combinations and so on.The characteristics of highway conditions in mountainous areas lead to many high-speed accidents and high severity of accidents in mountainous areas.Therefore,analyzing the causes of accidents in mountainous areas plays a positive role in ensuring the safety of high-speed driving in mountainous areas.This thesis takes Yu Xiang expressway as the representative object of mountain expressway.By analyzing the data of 1169 accidents in the Jie-Shui section of Yu Xiang Expressway in the five years from 2016 to 2021,it explores the characteristics and causes of mountain expressway accidents,investigates the hidden dangers of expressway safety,and puts forward rectification suggestions.First,according to the accident data,analyze the spatial-temporal distribution characteristics of the accident,the distribution characteristics of the accident type,the distribution characteristics of the accident model and the number of participating vehicles,the distribution characteristics of the accident weather,the distribution characteristics of the accident lane,and the distribution characteristics of the accident severity.Through the analysis,determine the factors affecting the number of accidents,and clarify the accident prone road section,so as to provide support for the following accident multi factor analysis,simulation analysis,and safety improvement;Secondly,a binary logistic regression model is established to analyze the factors that affect the magnitude of the accident,and explore the significance of each factor on the magnitude of the accident and the probability of multiple accidents under the conditions of each influencing factor.The results show that the conditions of truck accidents are more concentrated than passenger cars,and trucks and passenger cars are the main objects of multiple accidents,which defines the object for the following simulation research;Thirdly,using Carsim/Trucksim Simulink joint simulation,this thesis explores the formation mechanism of vehicle rear end collision,collision with fixed objects(tunnel wall,guardrail)and truck rollover accidents,so as to provide theoretical support for the prevention of such accidents.Finally,according to the above analysis of the accident influencing factors and the accident formation mechanism,combined with the on-site investigation,the potential safety hazards of the accident prone locations(including tunnel sections,curved slope sections,and interchange areas)in the Jie-Shui section of the Yu Xiang expressway are investigated and improved.The proposed potential safety hazard rectification plan can be the focus of the work of the Jie-Shui section management department of the Yu Xiang expressway.This thesis takes the Jie-Shui section of Yu Xiang expressway as the research object of mountain expressway.The research results can provide reference for the research of other mountain expressway and play a positive role in improving the safety of mountain expressway.