Department of Civil and Environmental Engineering, University of Texas at San Antonio, One UTSA Circle, San Antonio, TX 78249, United States.
Accid Anal Prev. 2018 Aug;117:10-20. doi: 10.1016/j.aap.2018.03.030. Epub 2018 Apr 4.
Interaction between adverse weather conditions and motor vehicle crashes is an important topic for traffic engineers and hydrometeorologists. With the recent availability of high resolution precipitation products (hourly, 4 × 4 km), it is possible to evaluate crash risk during rainfall events more accurately. Texas, the second largest state in the U.S., with a relatively high population density in its eastern part that receives significant rainfall from tropical events, experiences many hazardous traffic conditions every year. This study investigates temporal and spatial variability of the Relative Accident Risk (RAR) due to rainy conditions across Texas during the year 2015 using a Crash-Based Matched Pairs Analysis (CB-MPA) approach for every 4 × 4 km grid using an hourly time scale. The overall findings show that rainfall increases crash risk across the state by about 57%, while seasonal-based analysis confirms the role of precipitation patterns on crash rates. Although eastern and central counties (wetter and more urbanized) have remarkably higher rates of crash occurrence, the western counties (mainly rural and dry) show higher RAR values. Moreover, higher rainfall intensity can increase RAR up to three-fold while directly having an adverse effect on crash injury type. There is a relatively high correlation between rainfall intensity and RAR values (R = 0.76). The analysis also shows higher RAR values on high-speed interstate highways and tollways compared to urban local streets. RAR values also vary according to the gender and age of drivers. The study findings shed light on future paths toward more detailed applications of high-resolution environmental data in crash risk analysis.
不利天气条件与机动车事故之间的相互作用是交通工程师和水文气象学家的一个重要研究课题。随着高分辨率降水产品（每小时、4×4 公里）的最新可用性，有可能更准确地评估降雨事件期间的碰撞风险。美国第二大州德克萨斯州，其东部人口密度相对较高，且经常受到热带风暴的影响，每年都会经历许多危险的交通状况。本研究使用基于事故的匹配对分析（CB-MPA）方法，针对 2015 年德克萨斯州每小时每 4×4 公里网格的相对事故风险（RAR）的时空变化进行了研究。总体研究结果表明，降雨会使全州的碰撞风险增加约 57%，而基于季节性的分析则证实了降水模式对碰撞率的作用。尽管东部和中部县（降水较多且城市化程度较高）的碰撞发生率明显较高，但西部县（主要是农村且干燥）的 RAR 值较高。此外，较高的降雨强度会使 RAR 值增加三倍，同时对碰撞伤害类型产生直接的不利影响。降雨强度与 RAR 值之间存在较高的相关性（R=0.76）。分析还表明，与城市当地街道相比，高速公路和收费公路的 RAR 值更高。RAR 值还根据驾驶员的性别和年龄而有所不同。本研究结果为未来在碰撞风险分析中更详细地应用高分辨率环境数据指明了方向。
