The records of 24,797 traffic accidents (9039 involving fatalities or severe injury) during rainy conditions from 2007 to 2017 in Seoul, South Korea, were used to analyze the spatial distribution of the traffic accidents and rainfall events based on radar and gauge rainfall data. According to the spatial correspondence analysis between rainfall distribution and accident locations for localized and stratiform rain events, radar data in a two-dimensional grid (250 by 250 m) of 10 min temporal resolution benefited the localized rainfall distribution concerning the accident location. The relative accident rate (RAR) from radar data, which was used as a quantitative reference value for the effect of rainfall on traffic accidents, was about 18% higher than that from gauge rainfall. The radar data more clearly classified the number of traffic accidents during rainy conditions because its spatial distribution was more precise for all accidents. In addition, the RAR estimation of accidents involving fatalities and severe injury during rainfall could provide information on the district in which traffic accidents increase due to rainfall. The study results support the adoption of radar-derived rainfall data to analyze the influence of rainfall on accidents and the development of more accurate risk-assessment tools for drivers and planners.

中文翻译：

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雷达和仪表降雨数据源对交通事故和降雨事件空间分布分析的影响

以韩国首尔2007年至2017年多雨期间发生的24797起交通事故（9039起死亡或重伤）记录为基础，基于雷达和仪表降雨数据分析了交通事故和降雨事件的空间分布。根据局部和层状降雨事件的降雨分布与事故地点的空间对应分析，10分钟时间分辨率的二维网格（250×250 m）雷达数据有利于事故地点的局部降雨分布。雷达数据的相对事故率（RAR）作为降雨量对交通事故影响的定量参考值，比标准降雨量高出约18%。由于雷达数据对所有事故的空间分布更精确，因此在雨天条件下对交通事故的数量进行了更清晰的分类。此外，降雨期间涉及死亡和重伤事故的 RAR 估计可以提供有关因降雨而导致交通事故增加的地区的信息。研究结果支持采用雷达衍生的降雨数据来分析降雨对事故的影响，并为驾驶员和规划人员开发更准确的风险评估工具。