Risk Assessment Of Urban Road Public Transportation System Based On Attack And Defense Tree Principle

By the developing of the China’s economy,Transportation becomes an indispensable element in people’s lives.In order to meet the needs of people’s travel,the urban road public transportation industry is also developing.Due to the large passenger capacity and complex operating environment,accidents in the road may cause life-threatening danger to passengers and other traffic participants in the vehicle.Therefore,identifying the risks existing in the operation of public transportation on the road,scientifically and comprehensively assessing the public transportation safety status of urban roads,it is important to reduce the occurrence of casualties,improve the safety management level of enterprises and ensure the safe operation of public transportation in the city.significance.This paper takes the operation route of urban road public transportation vehicles as the research object,and conducts risk assessment research on its safe operation from the perspective of safety management.The specific contents are as follows:(1)Based on accident data,the overall trend,morphological characteristics,time and spatial distribution characteristics of road public traffic accidents are analyzed.Based on system engineering,the four aspects of people,vehicles,roads and environment that affect road public traffic accidents are analyzed and identified.Risk factors for safe operation of road public transportation.(2)According to the results of risk factor identification,combined with the operational characteristics of road public transportation,from the perspective of system,the risk of urban road public transportation is designed by four secondary indicators of people,vehicles,environment and roads and eighteen three-level indicators.Evaluate the indicator system,identify the risk mitigation measures adopted by the road public transportation industry,and construct a performance evaluation indicator system for risk mitigation measures.(3)Based on the constructed index system,the urban road public transportation risk assessment model is established by using the attack and defense tree principle,and the system as a whole and various indicators are calculated by means of analytic hierarchy process,entropy weight method and risk grading to determine the risk situation and the risk level,judging the actual risk level of urban road public transportation system operation.(4)Based on the constructed risk assessment model,a class of public transportation enterprises in Shenzhen is taken as the research object.Through expert consultation and field research,data is obtained,and the safety management,expected safety management and the current safety of the enterprise are calculated.The risk probabilities under management are: 0.162,0.0525,and 0.067.The overall risk occurrence probability of the shift is II,and the specific risk changes of each sub-node are calculated and analyzed.According to the calculation results,the paper puts forward some suggestions and suggestions for the risk situation of a certain class line operation of a road public transportation group in Shenzhen,and provides some reference for improving the safety management of road public transportation.