公路小半径曲线段外侧车道路侧事故概率预测

Probabilistic prediction of roadside accidents in outer lane of small radius curve sections of highways

为降低小半径曲线段路侧事故概率,选取道路线形指标(圆曲线半径、硬路肩宽度、纵坡坡度、超高横坡度、圆曲线加宽)、路面状况(路面附着系数)、交通特性(车速、车型)8个路侧事故风险因素进行PC⁃crash仿真试验,收集12800组数据.采用CHAID(Chi⁃squared automatic interaction detection)决策树技术识别了影响路侧事故发生的显著性风险因素,探讨各种风险因素之间交互作用对路侧事故的影响,并利用贝叶斯网络构建了路侧事故概率预测模型.根据概率模型预测结果,提出了路侧事故多发路段判别方法,并进行案例验证.研究结果表明:对路侧事故影响程度最大的显著性风险因素为车速,其次为圆曲线半径、车型、路面附着系数和硬路肩宽度;当80 km/h<v≤100 km/h,300 m<R≤600 m时,设置硬路肩宽度≥1.5 m能够明显减少路侧事故风险;与小型客车相比,载重货车更易发生路侧事故,且硬路肩宽度对载重货车路侧事故有更显著的影响,当100 km/h<v≤120 km/h,300 m<R≤600 m时,设置硬路肩宽度≥2.25 m能够明显减少载重货车路侧事故风险.

To reduce the probability of roadside accidents in small curve sections of highways,eight roadside accident risk factors including road geometric design indexes(horizontal curve radius,hard shoulder width,longitudinal slope,superelevation slope,and widen value of curve),pavement condition(adhesion coefficient),and traffic characteristics(running speed and vehicle type)were chosen to carry out PC⁃crash simulation test,and a total of 12800 accident data sets were collected.Chi⁃squared automatic interaction detection(CHAID)decision tree technique was employed to identify significant risk factors,and the comprehensive influence of the interaction of various factors on roadside accidents was discussed.These factors were then chosen as predictors of probability of roadside accidents in Bayesian network analysis to establish the probabilistic prediction model of roadside accidents.Finally,according to probabilistic prediction results,the identification method for roadside accidents black spots was proposed and verified through tests.Results show that running speed had the greatest effect on the occurrence of roadside accidents,followed by horizontal curve radius,vehicle type,adhesion coefficient,and hard shoulder width.When 80 km/h<v≤100 km/h and 300 m<R≤600 m,with the hard shoulder width not less than 1.5 m,the risk of roadside accidents could be significantly reduced.Compared with cars,trucks were more prone to be involved in roadside accidents,and the hard shoulder width had a more significant impact on the roadside accidents of trucks.When 100 km/h<v≤120 km/h and 300 m<R≤600 m,with the hard shoulder width not less than 2.25 m,the risk of roadside accidents of trucks could be significantly reduced.