Study On The Statistical Analysis Of Traffic Accident Characteristics In The Urban River-crossing Tunnel

As an important transportation facility along the river,urban cross-river tunnels play an important role in the economic,social and cultural relations between both shores.Taking a case study of Shanghai,now there are three major characteristics of the cross-river tunnel in Shanghai,including growing traffic demand,high traffic accident rates,and rapid development of infrastructure.Moreover,for the urban cross-river tunnels,its traffic flow is diverse,the linear combination of roads is complex,and the probability of accidents is always high.If unsafe incidents occurred,it is difficult to evacuate and the scope of impact is relatively large.Therefore,it is necessary to analyze the characteristics of statistical accidents,summarize the laws of urban cross-river tunnels,and provide suggestions for future tunnel construction and operation management.Initially,the traffic accident data of 10 cross-river tunnels in Shanghai was selected by the study.After the mathematical analysis and pretreatment,the characteristics of the accident were analyzed and studied in detail,and the time and space distribution,extent of casualties and accident type were analyzed.Furthermore,according to the severity level of traffic accidents in the cross-river tunnel is an ordered multi-class variable,it can be described as a form of “ordinary accident,serious accident,considerable accident,destroys accident”,and can construct an ordered Logit model.Based on the characteristics of vehicles,roads(tunnels)and the environment,the 14 potential influence factors of the severity level in the cross-river tunnel accident are selected as the dependent variables,and in-depth mining and analysis of dependent variables were carried out.The results show that there are seven factors that have significant impacts on the severity level of accidents in the cross-river tunnel,including trucks,3 vehicles and above,early morning,weekend,speed limit,tunnel length,and slope.on contrary,There are six factors that do not have significant impacts on the severity level of accidents in the crossriver tunnel,including private car,taxi,bus,number of lanes,season and minimum radius of the horizontal curve.In conclusion,the study reveals the rule that is related to the occurrence of cross-river tunnel accidents in Shanghai,also excavated the significant variables that have an impact on the severity level of the accident and those variables' degree of influence.It can provide advice for the management of cross-river tunnel in Shanghai and a reference for other tunnel management.