Recent advancements in analytical processes have used probabilistic approaches to examine the efficacy of the point mass model (and other Green Book models) to develop reliability-based approaches for geometric design. However, there has been minimal research establishing the link between reliability measures and substantive safety (expressed through crash frequency). The objective of this paper is to use empirical data supporting the calculation of reliability index for existing horizontal curves and to estimate the relationship between reliability index and crash frequency. Other horizontal curve-related characteristics that may have an impact on crash frequency on horizontal curves for rural two-lane highways and rural freeway facilities are controlled for in the evaluation. The safety analysis showed that the wet pavement reliability index was significantly associated with crash frequency for total curve-related crashes, single-vehicle run-off-road crashes, rollover crashes, truck-related crashes, and weather-related crashes. The relationship was strongest for the reliability index in its continuous form, meaning that the effect is continuous across the range of wet pavement reliability that was observed.

分析过程的最新进展已使用概率方法来检查点质量模型（和其他“绿皮书”模型）的有效性，以开发基于可靠性的几何设计方法。但是，很少有研究建立可靠性措施与实质安全性之间的联系（通过碰撞频率表示）。本文的目的是使用经验数据支持现有水平曲线的可靠性指标的计算，并估计可靠性指标与碰撞频率之间的关系。在评估中控制了其他可能影响农村两车道高速公路和农村高速公路设施的水平曲线碰撞频率的与水平曲线相关的特征。安全分析表明，湿路面可靠性指数与总弯道相关事故，单车径流非公路事故，侧翻事故，卡车相关事故和天气相关事故的发生频率显着相关。该关系对于连续形式的可靠性指标最强，这意味着在所观察到的湿路面可靠性范围内，效果是连续的。