双车道公路线形一致性评价模型

Evaluation Model for Alignments Consistency of Two-lane Highways

公路线形设计的一致性水平与交通安全有很大的关联性,然而国内还缺少对双车道公路路段线形质量的评价方法和评价标准.在国内外关于运行速度及运行速度差值研究的基础上,构建了一个评价双车道公路路段线形一致性的综合模型.该模型以运行车速图中第85%位车速与平均车速所围成的相对面积和路段各相邻单元运行车速差值的平均值为参数,融合了整条路段的运行速度及其差值的分布信息.通过灵敏度分析,标定了模型的参数,建立了评价标准和阈值.多个双车道公路路段的事故调查数据表明,模型建立的线形一致性评价指标与交通事故有较好的相关性,初步验证了模型的适用性和有效性.

Much research has ascertained the existence of a relationship between alignments consistency level and safety;however,the evaluation methods and criterions for alignments consistency of two-lane highway sections are still rare in China.Based on the research of operating speed and speed differential in the literature,an integrated model is proposed in this paper to evaluate the alignments consistency level of two-lane highway sections.Taking the relative area bounded between the speed profile and the average weighted speed（Ra） and the average speed differential between successive highway elements（Δ） as parameters,the model synthesizes the distribution information of operating speed and speed differential of the full highway section.Parameters in the model are calibrated through sensitivity analyses,and evaluation criterions and thresholds are therefore developed.A number of accidents investigations indicate that the evaluation criterions presented in the paper have inherence contact with accidents,which proves the adaptability and validity of the model elementarily.