弯坡路段多模式失效概率与轿车单车事故的关系

Relationship between multi⁃mode failure probability and single⁃car crashes for combination sections of vertical and horizontal curves

为促进可靠性分析(概率几何设计)在公路安全设计及事故预测中的应用,通过建立事故预测模型将轿车多模式失效概率与轿车事故之间建立关系。首先,以多模式失效为切入点,基于单个轿车在弯坡路段可能的3种失效模式(侧滑、侧翻、视距不足)建立多模式失效系统;其次,以华盛顿州10241起弯坡路段的轿车单车事故为研究对象,通过蒙特卡罗法和宽界限法求解系统的多模式失效概率;最后,将多模式失效概率、公路因素作为解释变量建立负二项模型、随机效应负二项模型、随机参数负二项模型3种事故预测模型,挖掘多模式失效概率与轿车单车事故之间的关系。结果表明:3种事故预测模型中随机参数负二项模型的拟合最优;当考虑多模式失效概率时,公路几何因素对轿车单车事故的影响被削弱;除两个暴露变量外,多模式失效概率对轿车单车事故的影响最大;多模式失效概率与轿车单车事故的拟合曲线近似为线性,且拟合曲线的截距不为0。该研究成果可用于公路的可靠性设计中。

To promote the application of reliability analysis(probabilistic geometric design)in highway safety design and crash prediction,this paper develops crash prediction models to establish the relationship between the multi⁃mode failure probability of cars and car crashes.Firstly,considering the multi⁃mode failure as the breakthrough point,a multi⁃mode failure system was established based on three possible failure modes(skidding,rollover,and insufficient sight distance)of single⁃car on combination sections of vertical and horizontal curves.Then,10241 single⁃car crashes on the combination sections of vertical and horizontal curves of highway in Washington were taken as the research objects,and the multi⁃mode failure probability of the system was solved by Monte Carlo and wide bound method.Finally,three crash prediction models including negative binomial model,random effects negative binomial model,and random parameters negative binomial model were developed by taking multi⁃mode failure probability and road factors as explanatory variables.Moreover,the relationship between multi⁃mode failure probability and single⁃car crashes was explored.Results show that among the three models,the random parameters negative binomial model outperformed the other two models.When the multi⁃mode failure probability was considered,the influence of road geometric factors on the single⁃car crashes was weakened.Except for two exposure variables,the multi⁃mode failure probability had the greatest impact on single⁃car crashes.The number of single⁃car crashes was approximately linearly related to the multi⁃mode failure probability,and the intercept of the fitting curve was not 0.The results can be used in the reliability design of highway.