The Pennsylvania State University, Department of Civil and Environmental Engineering, 212 Sackett Building, University Park, PA 16802, United States.
Accid Anal Prev. 2010 Nov;42(6):1697-704. doi: 10.1016/j.aap.2010.04.009. Epub 2010 May 21.
Median barrier is used to prevent cross-median crashes on divided highways. Although it is well documented that crash frequencies increase after installing median barrier, little is known about median barrier crash severity outcomes. The present study estimated a nested logit model of median barrier crash severity using 5 years of data from rural divided highways in North Carolina. Vehicle, driver, roadway, and median cross-section design data were factors considered in the model. A unique aspect of the data used to estimate the model was the availability of median barrier placement and median cross-slope data, two elements not commonly included in roadway inventory data files. The estimation results indicate that collisions with a cable median barrier increase the probability of less-severe crash outcomes relative to collisions with a concrete or guardrail median barrier. Increasing the median barrier offset was associated with a lower probability of severe crash outcomes. The presence of a cable median barrier installed on foreslopes that were between 6H:1V and 10H:1V were associated with an increase in severe crash probabilities when compared to cable median barrier installations on foreslopes that were 10H:1V or flatter.
中央分隔带护栏用于防止分隔式高速公路对向碰撞。尽管有大量文献记录表明安装中央分隔带护栏后碰撞频率会增加，但关于中央分隔带护栏碰撞严重程度后果的了解甚少。本研究使用北卡罗来纳州农村分隔式高速公路 5 年的数据，估算了中央分隔带护栏碰撞严重程度的嵌套对数模型。模型考虑了车辆、驾驶员、道路和中央分隔带横断面设计数据等因素。用于估算模型的数据的一个独特方面是中央分隔带护栏的位置和中央分隔带横坡数据的可用性，这两个元素通常不包含在道路清单数据文件中。估计结果表明，与混凝土或护栏中央分隔带护栏碰撞相比，与电缆中央分隔带护栏碰撞会增加轻度碰撞后果的概率。增加中央分隔带护栏的偏移量与严重碰撞后果的概率降低有关。与安装在坡度为 10H:1V 或更平缓的前坡上的电缆中央分隔带护栏相比，安装在前坡坡度为 6H:1V 至 10H:1V 之间的电缆中央分隔带护栏会增加严重碰撞的概率。
