Analysis On Injury Severity And Influencing Factors Of Traffic Accidents At Intersections

With the continuous development of economy,the number of cars is increasing rapidly,and frequent road traffic accidents lead to great loss of life and property.As a traffic node,road intersections are the places where road traffic accidents occur.This paper takes the road accident data recorded in the NASS/GES system of American NHTSA as the research object,selects the accident data set under the intersection scene,and establishes the prediction model of intersection accident damage severity based on generalized regression neural network and the damage severity classification model based on K-means clustering.On this basis,it explores the significant factors leading to the severity of intersection damage and provides theoretical support and reference for safe driving decision and road planning and management of driverless vehicles.The main work is as follows:(1)According to the classified analysis of the causes of traffic accidents and different influencing factors,the mechanism of the severity of traffic accidents at intersections is discussed.Based on the intersection accident data from 2014 to 2015 in the NASS/GES accident database of National Highway Traffic Safety Administration(NHTSA),the non-human factors such as vehicle,road and environment are selected as the prediction index of injury severity,and the safety of life and property is taken as the evaluation index of injury seriousness.The prediction model of accident injury severity is established by using two neural network algorithm models:generalized regression neural network(GRNN)and back propagation neural network(BPNN).The prediction accuracy of the model is compared,and the results show that the generalized regression neural network has better prediction accuracy.(2)In order to further study the classification level of traffic accident injury severity at intersections and find out the significant influencing factors leading to the difference of injury severity,this paper uses principal component analysis(PCA),to screen and reduce the dimensions of vehicle characteristics,road characteristics and environmental characteristics,and obtains important index factors through the combination of eigenvalues and cumulative contribution rate.Then the K-means clustering model is established to further analyze the composition of influencing factors under different damage levels,and the validity of K-means clustering is tested to fully mine the rules of accident injury severity and influencing factors in accident data.Different types of intersections and signal control of intersections have different effects on the severity of traffic accident injuries.The relative speed of vehicles and different types of colliding vehicles have great influence on the severity of traffic accident injuries,however,the curvature of the road,road slope and environmental weather conditions have little influence on the severity of the accident injury.(3)In view of the difference of the severity of accident injury caused by different influencing factors,the change of the severity of accident injury is studied and analyzed through different index of influencing factors.First of all,on the basis of the neural network model,the sensitivity analysis of the selected index factors is carried out,and the sensitivity analysis value of each influencing factor is determined.according to the influence degree of traffic accident injury severity from large to small,it is ranked as follows:collision vehicle type,relative speed,intersection signal control,intersection type,road linearity,road slope,weather conditions,road conditions,collision time,collision date.Taking the characteristics of the intersection,the signal control of the intersection,the relative speed of the vehicle and the type of collision vehicle as the significant factors for evaluating the severity of the accident injury at the intersection,the sensitivity analysis models of different damage levels are established respectively.The relationship between the influencing factors and the severity of accident injury is analyzed under the influence of the change of the value of each variable on the severity of injury.It provides a basis for the prevention of traffic accidents and the establishment of reasonable decision-making under emergency conditions.