This paper investigates the effect of incidents on freeway segment capacity. Currently, the Highway Capacity Manual (HCM) provides a look-up table linking the remaining segment capacity fraction during an incident to the total and closed number of lanes on the segment. In reality, segment capacity during an incident will tend to vary over time, with the most severe effects felt early on before any type of response is initiated, with congestion progressively improving as the appropriate incident management actions are implemented. By applying a genetic algorithm calibration method on each incident day and calibrating the incident capacity adjustment factors (CAFs), optimal time-dependent CAFs were derived that best represented the effect of incidents on the freeway segment capacity. By analyzing the optimal CAFs, the strongest relationship was revealed to be between the optimal time-dependent CAF and the temporal progression of the incident. A regression model was developed to represent this behavior. This was formulated in a manner that can directly adjust the current HCM’s fixed CAF values (for a specific lane closure configuration) for modeling incidents both in single day, seed file application, or for an entire year reliability analysis. A portion of WB I-540 in Raleigh, NC was selected as the study area in which the proposed method was tested. Between January 2014 and December 2018, the team identified 22 isolated incidents (away from the recurring congestion period) that closed one or two lanes of traffic, creating a distinct congestion pattern.

本文研究了事故对高速公路路段通行能力的影响。目前，《公路通行能力手册》（HCM）提供了一个查找表，将事故期间的剩余路段通行能力分数与路段上的总车道数和封闭路数联系起来。实际上，事件期间的网段容量往往会随时间变化，在发起任何类型的响应之前就已经感受到最严重的影响，随着适当的事件管理措施的实施，拥塞逐渐改善。通过在每个事故发生日应用遗传算法校准方法并校准事故通行能力调整因子（CAF），得出了最能代表事故对高速公路路段通行能力影响的最佳时变CAF。通过分析最佳CAF，可以发现最强的关系是最佳时间依赖性CAF与事件的时间进展之间的关系。开发了回归模型来表示这种行为。它的制定方式可以直接调整当前HCM的固定CAF值（针对特定的车道关闭配置），以便在单日，种子文件应用或全年可靠性分析中对事件进行建模。选择了北卡罗来纳州罗利市的WB I-540的一部分作为研究该建议方法的研究区域。在2014年1月至2018年12月期间，研究小组发现了22个孤立的事件（远离反复出现的拥堵期），它们关闭了一条或两条车道，形成了独特的拥堵模式。种子文件应用程序，或进行全年可靠性分析。选择了北卡罗来纳州罗利市的WB I-540的一部分作为研究该建议方法的研究区域。在2014年1月至2018年12月期间，研究小组发现了22个孤立的事件（远离反复出现的拥堵期），它们关闭了一条或两条车道，形成了独特的拥堵模式。种子文件应用程序，或进行全年可靠性分析。选择了北卡罗来纳州罗利市的WB I-540的一部分作为研究该建议方法的研究区域。在2014年1月至2018年12月期间，研究小组发现了22个孤立的事件（远离反复出现的拥堵期），它们关闭了一条或两条车道，形成了独特的拥堵模式。