Perception-reaction time (PRT) and deceleration rate are two key components in geometric design of highways and streets. Combined with a design speed, they determine the minimum required stopping sight distance (SSD). Current American Association of Highway Transportation Officials (AASHTO) SSD guidance is based on 90th percentile PRT and 10th percentile deceleration rate values from experiments completed in the mid-1990s. These experiments lacked real-world distractions, and so forth. Thus, the values from these experiments may not be applicable in real-world scenarios. This research evaluated (1) differences in PRTs and deceleration rates between crash and near-crash events and (2) developed predictive models for PRT and deceleration rate that could be used for roadway design. This was accomplished using (1) genetic matching (with Rosenbaum’s sensitivity analysis) and (2) quantile regression. These methods were applied to the Strategic Highway Research Program 2 (SHRP2) Naturalistic Driving Study (NDS) data.

The analysis results indicated that there were differences in PRT and deceleration rates for crash and near-crash events. The specific estimates were that, on average, drivers involved in crash events took 0.487 s longer to react and decelerated at 0.018 g’s (0.58 ft/s²) slower than drivers in equivalent near-crashes. Prediction models were developed for use in roadway design. These models were used to develop tables comparing existing SSD design criteria with SSD criteria based on the results of the predictive models. These predicted values indicated that minimum design SSD values would increase by 10.5–129.2 ft, dependent on the design speed and SSD model used.

感知反应时间（PRT）和减速度是高速公路和街道几何设计中的两个关键组成部分。结合设计速度，它们确定了所需的最小停车视距（SSD）。当前美国公路运输官员协会（AASHTO）的SSD指导基于1990年代中期完成的实验的90％的PRT和10％的减速率值。这些实验缺乏现实世界的干扰力，等等。因此，来自这些实验的值可能不适用于现实情况。这项研究评估了（1）碰撞和近碰撞事件之间的PRT和减速度的差异，以及（2）开发了可用于道路设计的PRT和减速度的预测模型。这是通过（1）遗传匹配（使用Rosenbaum的敏感性分析）和（2）分位数回归来实现的。这些方法已应用于战略公路研究计划2（SHRP2）自然驾驶研究（NDS）数据。

分析结果表明，碰撞和接近碰撞事件的PRT和减速率存在差异。具体的估计是，与碰撞事故相当的驾驶员平均而言，与碰撞事故相关的驾驶员做出反应和减速的时间平均为0.487 s，而减速速度为0.018 g（0.58 ft / s ²）。开发了预测模型以用于巷道设计。这些模型用于根据比较模型的结果来开发表格，将现有的SSD设计标准与S​​SD标准进行比较。这些预测值表明，最小设计SSD值将增加10.5-129.2 ft，具体取决于设计速度和所使用的SSD模型。