Study On Traffic Safety Risk Assessment Method Of National Highway Crossing Village Section

The acceleration of urban-rural integration process makes village and town traffic present new changes and new trends.As an important part of village and town traffic,the traffic safety situation is more and more severe.In order to improve the traffic safety level of national road crossing villages and towns,it is necessary to carry out research on the traffic safety risk of national road crossing villages and towns.Firstly,based on the relevant research results of road traffic safety risk,the concept of national road crossing villages and towns section was defined,and the traffic safety risk of national road crossing villages and towns section was divided into two evaluation units: intersection and section.By applying the theory of three types of risk sources,the general risk sources of national road crossing villages and towns were identified by analyzing the data of road traffic accidents in 2019,and the special risk sources of national road crossing villages and towns were identified by using the methods of feature analysis and hidden trouble investigation,and the traffic safety risk source framework of national road crossing villages and towns was established.Secondly,the discriminant principle of key risk sources was clarified,and the key risk sources were identified from the risk source framework of national highway crossing villages and towns.Then,the evaluation indexes of key risk sources were preliminarily selected according to the index selection principles and methods.Considering the significance of the indexes and the coupling of indexes,this paper selects the key risk source evaluation indexes by using correlation analysis and Delphi method,and finally builded the traffic safety risk evaluation index system of national highway crossing villages and towns by integrating dynamic risk indexes and static risk indexes.Thirdly,aiming at the fuzziness of risk grade boundary and the quantification of qualitative index,the risk assessment method of national road crossing villages and towns section based on grey cloud model was proposed.According to the fuzzy set theory,the risk assessment index was divided into grades,and the risk warning mechanism of grade 10 index,grade 5 risk and grade 4 early warning was established.The grey cloud model was used to evaluate the traffic safety risk level of each unit,and the weighted fusion model was used to integrate the evaluation results of each unit,so as to realize the overall traffic safety risk assessment of national highway crossing villages and towns.Finally,a section of Pingyao national Highway G108 is taken as an example to monitor the change of risk level of the same sample unit in continuous time period and evaluate the risk level of different sample units in the same time period.The results show that the risk level of the sample segment is level I at 15-18,level II at19-20,and level III at 18-19 and 20-21.The change of the risk level in consecutive periods is highly correlated with the number of road traffic accidents and the change of accident severity.The sample section has the highest risk level at intersection 5 and the lowest risk level at road section 2,which is consistent with the actual situation.The results show that the risk assessment method based on grey cloud model can identify the risk changes of the same sample unit in the continuous period and distinguish the risk levels of different sample units in the same period,which verifies the applicability and effectiveness of the model in the spatio-temporal dimension.