Safety Evaluation Model Of Urban Cross-river Tunnel

Urban cross-river tunnels are an important traffic corridor connecting areas divided by wide rivers such as Paris,London,New York City,and Seoul.They are also common in Shanghai,Hangzhou,Nanjing,Wuhan and other major cities in China.Nowadays Shanghai urban cross-river tunnels have three main characteristics,including increasing traffic demand,high accident rate and rapid development of construction.Due to the complex geographic,hydrological characteristics and closed environment,the difficulty in responding to the rescue timely in the event of accidents is likely to cause significant casualties.So accidents analysis and safety evaluation of urban cross-river tunnels are very urgent.Statistical analysis was used to examine the characteristics of 4539 traffic accidents that have occurred in twelve Shanghai cross-river tunnels for the period 2011-2012.An ordered logit model was conducted to real the correlation between potential factors and injury severity of accidents in Shanghai cross-river tunnels.The potential factors consisted of eighteen variables,including drivers' information,vehicle factors,environment conditions,and tunnel characteristics.Tunnel safety index(TSI)of urban river-cross tunnel was proposed in this study.And an index system was constructed according to the current study and eight factors output by driving simulator from three aspects of the car-following risk,lateral accident risk and driver workload.Methods of analytic hierarchy process(AHP),experts marking and normalization processing are applied to construct the mathematical model of TSI.Then the accident rate(AR)of each Shanghai urban cross-river tunnel was figured out.Twelve Shanghai urban cross-river tunnels were instructed in the driving simulator.And the relationship is obtained between the TSIs of twelve Shanghai urban cross-river tunnels and corresponding ARs through the regression analysis.The regression analysis results show that the relationship between the TSI and the AR is coincided with exponential function with high degree of fitting.This study examined the weekly distribution,hourly distribution,spatial distributions of traffic accidents and accident types of Shanghai cross-river tunnels,and acquired the effects of the various risk factors on accident severity.Further more,the safety evaluation model based on the output by driving simulation was proposed and proved effectively to assess the driving safety of urban cross-river tunnel not only constructed but also in design.