In the state of Florida, work-zone related crashes and their resulting injury severities have been increasing recently, particularly over the 2015 to 2017 time period. In the current study, we seek to provide insights into the factors that have been influencing this trend. Using work zone data from the 2012 to 2017 time period, resulting driver-injury severities in single-vehicle work zone crashes were studied using random parameters logit models that allow for possible heterogeneity in the means and variances of parameter estimates. The available data included a wide variety of factors known to influence driver injury severity including data related to the crash characteristics, vehicle characteristics, roadway attributes, prevailing traffic volume, driver characteristics, and spatial and temporal characteristics. The model estimates produced significantly different parameters for each of the year from 2012 to 2017, and a fundamental shift in unobserved heterogeneity, suggesting statistically significant temporal instability. In addition, in several key instances, the marginal effects of individual parameter estimates show marked differences between one year and the next. However, these findings may not be the sole result of variations in driver behavior over time as has been argued in past research that has found temporal instability. This is because each work zone has a unique set of characteristics and, with the sample of work zones changing from one year to the next as highway maintenance and construction is undertaken in different locations, this work-zone sample variation could be a substantial source of the observed temporal instability.

在佛罗里达州，与工作区相关的撞车事故及其造成的伤害严重程度最近一直在上升，尤其是在2015年至2017年期间。在当前的研究中，我们试图提供对影响这一趋势的因素的见解。使用2012年至2017年期间的工作区数据，使用随机参数logit模型研究了单车工作区碰撞中导致的驾驶员伤害严重性，该模型允许参数估计的均值和方差可能存在异质性。可用数据包括各种已知会影响驾驶员伤害严重性的因素，包括与碰撞特征，车辆特征，道路属性，主要交通量，驾驶员特征以及时空特征有关的数据。从2012年到2017年，每年的模型估算值产生了明显不同的参数，并且未观测到的异质性发生了根本性变化，这表明统计上的时间不稳定。此外，在几个关键实例中，单个参数估计的边际效应显示一年与下一年之间的显着差异。然而，这些发现可能不是驾驶员行为随时间变化的唯一结果，正如过去发现时间不稳定的研究所指出的那样。这是因为每个工作区都有一套独特的特征，并且由于在不同位置进行公路维护和建设时，工作区的样本从一年变化到下一年，因此，该工作区样本的变化可能是产生变化的重要原因。观察到的时间不稳定。