高速公路平纵线形与事故率的关系及其安全性评价

通过分析高速公路平纵线形指标与事故率的关系,引入线形影响因子,提出了基于线形影响因子的高速公路基本路段安全评价方法。首先,应用回归分析的方法,确定了平曲线半径、平曲线偏角、直线段长度、竖曲线半径及纵坡坡度与事故率的关系,在此基础上分析了弯坡组合、平竖曲线组合以及长大坡组合路段上的事故率。进而,结合事故率与线形的关系,以线形影响因子表征几何线形指标对高速公路事故率的影响,据此评价高速公路的行车安全性。案例分析结果表明,基于线形影响因子确定的危险路段与由实际事故率确定的危险路段具有极高的一致性,达到了81%。

A Study of the Relationship between Crash Rate,Geometric Alignment and Freeway Safety

A safety evaluation method for freeway segments is proposed in this study by analyzing the relationship between crash rates and road geometric alignment.First,the relationship between crash rates and road geometric features including radius of horizontal curves,deflections of horizontal curves,length of tangents,radius of vertical curves,longi-tudinal gradient is analyzed through linear regression.Then,the relationship between a combination of different alignment features and crash rates is studied.Further,the alignment factors analyzed over the first two steps are used to evaluate the impacts of geometric alignment features on crash rates and the method is then proposed to evaluate the safety of freeway. The results of a case study indicated that up to 81% of"dangerous highway sections" identified by proposed method are confirmed by the crash data.The proposed highway safety evaluation method is practical to identify collision prone sec-tions of freeways.