Department of Civil and Construction Engineering, Swinburne University of Technology, Victoria, 3122, Australia and University of Duhok, College of Engineering, Civil Department, Kurdistan Region Iraq.
Department of Health Science and Biostatistics, Swinburne University of Technology, Victoria 3122, Australia.
J Safety Res. 2021 Feb;76:276-288. doi: 10.1016/j.jsr.2020.12.021. Epub 2021 Jan 28.
This study investigated the effects of pavement surface condition and other control factors on casualty crashes at signalized intersections. It involved conducting a before and after study for road surface condition and situational factors. It also included assessing the effects of geometric characteristics on safety performance of signalized intersections post resurfacing to control for the effect of pavement surface condition. Pavement surface condition included roughness, rutting, and skid resistance. The control factors included traffic volume, light and surface moisture condition, and speed limit. The geometric characteristics included approach width, number of lanes, intersection depth, presence of median, presence of shared lane, and presence of bus stop.
To account for the repeated observations of the effect of light and surface moisture conditions in four occasions (day-dry, day-wet, night-dry and night-wet) Generalized Estimating Equation (GEE) with Negative Binomial (NB) and log link function was applied. For each signalized intersection in the sample, condition data are collected for the year before and after the year of surface treatment. Crash data, however, are collected for a minimum of three and maximum of five years before and after treatment years.
The results show that before treatment, light condition, road surface moisture condition, and skid resistance interaction with traffic volume are the significant contributors to crash occurrence. For after treatment; light condition, road surface moisture condition, their interaction product, and roughness interaction with light condition, surface moisture condition, and traffic volume are the significant contributors. The geometric variables that were found to have significant effects on crash frequency post resurfacing were approach width interactions with presence of shared lane, bus stop, or median.
The findings confirm that resurfacing is significant in reducing crash frequency and severity levels. Practical Applications: The study findings would help for better understanding of how geometric characteristics can be improved to reduce crash occurrence.
本研究调查了路面状况和其他控制因素对信号交叉口事故的影响。它包括对路面状况和情境因素进行前后研究。它还包括评估几何特征对重新铺设后信号交叉口安全性能的影响，以控制路面状况的影响。路面状况包括粗糙度、车辙和抗滑性。控制因素包括交通量、光和表面湿度条件以及限速。几何特征包括接近宽度、车道数量、交叉口深度、中央分隔带、共享车道和公共汽车站的存在。
为了考虑光和表面湿度条件在四个时间点（白天干燥、白天潮湿、夜间干燥和夜间潮湿）的重复观测效果，应用了广义估计方程（GEE）与负二项（NB）和对数链接函数。对于样本中的每个信号交叉口，在表面处理前后的一年中收集条件数据。然而，碰撞数据在处理年份之前和之后至少收集三年，最多收集五年。
结果表明，在处理前，光条件、路面湿度条件和抗滑性与交通量的相互作用是碰撞发生的重要因素。对于处理后；光条件、路面湿度条件、它们的相互作用产物以及粗糙度与光条件、路面湿度条件和交通量的相互作用是重要的贡献者。在重新铺设后对碰撞频率有显著影响的几何变量是接近宽度与共享车道、公共汽车站或中央分隔带的相互作用。
研究结果证实，重新铺设在降低碰撞频率和严重程度方面具有重要意义。实际应用：研究结果将有助于更好地理解如何改进几何特征以减少碰撞发生。
