基于随机参数Logit模型的校车事故伤害严重程度分析

为深入分析安全因素对校车事故伤害严重程度的影响，探寻事故数据中未观察到的异质性，基于随机参数Logit模型从驾驶员、车辆、道路特征及环境4个方面构建校车事故伤害严重程度模型。结果表明:①涉事车辆数为2辆且对应参数服从正态分布时，不发生死亡受伤事故的概率为83.84%；②驾驶员年龄35~44岁、涉事车辆数为1辆时，死亡受伤事故概率均降低0.58%；③道路限速值为40~50 km/h时发生死亡受伤事故概率增加0.35%，道路限速值大于60 km/h时发生死亡受伤事故概率增加0.96%；④安全气囊状态打开，死亡受伤事故概率增加2.35%；⑤交通控制方式为车道标线时可能伤害事故概率增加1.85%，控制方式为中央分隔带时未受伤事故概率降低1.44%，死亡受伤事故发生概率却增加0.48%；⑥不安全时倒车转弯时发生可能伤害事故概率降低0.42%，分心驾驶、未按规定车道行驶、跟车太近和其他（饮酒）时未受伤事故概率分别增加1.36%，0.56%，0.39%和0.97%，可能受伤事故和死亡受伤事故发生概率却有所降低。 

An Analysis of Injury Severities in School Bus Accidents Based on Random Parameter Logit Models

This study develops an injury severity prediction model for the accidents involving school buses based on random parameter Logit model, in order to analyze the impacts of relevant factors on the injury severity of school bus accidents and the heterogeneity that is not observed in the accident data. The independent variables are from the following aspects: driver, vehicle, road characteristics and environment. It is found that: ①under the assumption that the corresponding parameters of the two involved vehicles follow the normal distribution, the probability of not having fatal and injury accidents of the school bus is 83.84%. ②The probability of a fatal injury is reduced by 0.58% when the driver is between 35 and 44 years old and the number of vehicles involved is one. ③When the road speed limit is between 40 and 50 km/h, the probability of injuries and fatal crashes increases by 0.35%;when the road speed limit is greater than 60 km/h, it increases by 0.96%. ④When the airbag is triggered, the probability of injuries and fatal crashes increases by 2.35%. ⑤When the traffic control mode is lane markings, the probability of possible injury accidents increases by 1.85%;when the control mode is the central divider, it decreases by 1.44%, while the probability of injuries and fatal crashes increases by 0.48%. ⑥The probability of possible injury accidents decreases by 0.42% when reversing turns under unsafe conditions; the probability of uninjured accidents increases by 1.36%, 0.56%, 0.39%, and 0.97%, respectively as distracted driving, missing lane driving, being too close to cars, and other factors(i.e. drinking), but the probability of accidents involving possible injury, and fatal crashes reduces.