基于文本信息的高速公路事故持续时间 中介效应研究

Research on mediating effect of express way accident duration based on text information

为探讨交通事故持续时间影响因素的内部耦合关系,揭示文本信息在链式传导过程中的作用机制,利用自然语言处理技术和随机森林算法,提出一种基于词频-逆文本频率(TF-IDF)模型的关键词重要度分析方法。同时,建立高速公路交通事故持续时间的多重中介效应模型,采用乘积系数的Bootstrap抽样法进行中介作用检验,分别检验文本特征在并行中介路径和两级链式中介路径中的显著性,并计算中介效应强度。以陕西省高速公路3046起交通事故记录进行实例分析,结果表明:对持续时间的影响路径中,事故类型与月份存在部分链式中介关系,中介效应占比为11.868%,事故类型与天气、位置、事故范围之间存在完全链式中介关系,中介效应占比均为100%。文本信息字符数、上报次数在特定路径中是显著的中介变量,上报次数在天气对持续时间的中介效应类型为完全中介,字符数在事故范围对持续时间的中介效应类型为完全中介,时段对持续时间的影响有7.075%是通过字符数发挥作用。特定关键词集的两级链式中介作用路径存在。

In order to explore the internal coupling relationship of the influencing factors of traffic accident duration and reveal the mechanism of text information in the chain transmission process,a keyword importance analysis method based on word frequency-inverse text frequency(TF-IDF)model was proposed by using natural language processing technology and random forest algorithm.At the same time,a multiple mediating effect model of highway traffic accident duration is established,and the Bootstrap sampling method of product coefficient was used to test the mediating effect.The significance of text features in parallel mediating path and two-level chain mediating path was tested respectively,and the strength of mediating effect was calculated.Taking 3046 traffic accident records of expressways in Shanxi Province as an example,the results showed that in the influence path of duration,there is a partial chain mediating relationship between accident type and month,and the mediating effect accounts for 11.868%.There is a complete chain mediating relationship between accident type and weather,location and accident range,and the mediating effect accounts for 100%.The number of characters and the number of reports are significant mediating variables in the specific path.The number of reports is completely mediated by the type of mediating effect of the weather on the duration.The number of characters is completely mediated by the type of mediating effect of the accident range on the duration.The impact of the period on the duration is 7.075%through the number of characters.The two-level chain mediating path of specific keyword sets exists.