IHSDM高速公路事故预测模型

IHSDM freeway accident prediction models

应用交互式道路安全设计模型(IHSDM)对11类高速公路进行事故预测,并对比了预测事故数与实际事故数,给出了基本事故预测模型与线形指标修正系数,构建了一组IHSDM事故预测改进模型,分析了线形指标的敏感性与线形指标的变化对预测事故率的影响,并计算了各类高速公路线形指标的安全取值范围。分析结果表明:采用IHSDM预测的高速公路事故数小于实际事故数,最小误差为13%,最大误差为52%;改进模型事故总数预测值与实际值的相对误差小于10%,具体路段上的皮尔逊相关系数不小于0.60,均方根误差小于0.30,平均相对误差小于30%;事故率对各线形指标敏感性由高到低依次为直线段长度、纵坡坡度、平曲线偏角、平曲线半径、竖曲线半径。可见,与IHSDM相比,改进模型具有更高的精度和更好的适用性。

IHSDM（interactive highway safety design model）was used to predict accidents of 11 types of freeways,and the predicted accident numbers were compared with the actual accident numbers.The basic accident prediction models and the modification coefficients of alignment indexes were obtained,a set of IHSDM accident prediction improved models were built to carry out the sensitivity analysis of alignment indexes,the effects of alignment indexes on the predicted accident rates were explained,and the safe value ranges of alignment indexes for freeways were obtained.Analysis result shows that the accident numbers predicted by IHSDM are lower than the actual accident number,the least error is 13%,and the maximum error is 52%.The relative error between total accident number predicted by the improved model and the actual value is less than 10%.At specific road sections,Pearson＇s correlation coefficients are 0.60 at least,the root mean square errors are less than 0.30,and the mean relative errors are less than 30%.The sensitivities of accident rates to alignment indexes from high to low are straight line length,longitudinal slope,horizontal curve angle,horizontal curve radius and vertical curve radius.Obviously,compared with IHSDM,the improved model has higher accuracy and better applicability.14 tabs,6figs,20 refs.