Safe Transportation Research & Education Center, University of California, Berkeley, 2614 Dwight Way, #7374, Berkeley, CA 94720, USA.
Accid Anal Prev. 2011 Jan;43(1):301-6. doi: 10.1016/j.aap.2010.08.028.
Of the numerous factors that play a role in fatal pedestrian collisions, the time of day, day of the week, and time of year can be significant determinants. More than 60% of all pedestrian collisions in 2007 occurred at night, despite the presumed decrease in both pedestrian and automobile exposure during the night. Although this trend is partially explained by factors such as fatigue and alcohol consumption, prior analysis of the Fatality Analysis Reporting System database suggests that pedestrian fatalities increase as light decreases after controlling for other factors. This study applies graphical cross-tabulation, a novel visual assessment approach, to explore the relationships among collision variables. The results reveal that twilight and the first hour of darkness typically observe the greatest frequency of pedestrian fatal collisions. These hours are not necessarily the most risky on a per mile travelled basis, however, because pedestrian volumes are often still high. Additional analysis is needed to quantify the extent to which pedestrian exposure (walking/crossing activity) in these time periods plays a role in pedestrian crash involvement. Weekly patterns of pedestrian fatal collisions vary by time of year due to the seasonal changes in sunset time. In December, collisions are concentrated around twilight and the first hour of darkness throughout the week while, in June, collisions are most heavily concentrated around twilight and the first hours of darkness on Friday and Saturday. Friday and Saturday nights in June may be the most dangerous times for pedestrians. Knowing when pedestrian risk is highest is critically important for formulating effective mitigation strategies and for efficiently investing safety funds. This applied visual approach is a helpful tool for researchers intending to communicate with policy-makers and to identify relationships that can then be tested with more sophisticated statistical tools.
在导致行人致命事故的众多因素中，一天中的时间、一周中的天数和一年中的季节都可能是重要的决定因素。尽管夜间行人和汽车的暴露量都被认为会减少，但 2007 年仍有超过 60%的行人事故发生在夜间。尽管这种趋势部分可以用疲劳和饮酒等因素来解释，但对致命事故分析报告系统数据库的先前分析表明，在控制了其他因素后，行人死亡人数会随着光照的减少而增加。本研究采用图形交叉制表，即一种新颖的可视化评估方法，来探索碰撞变量之间的关系。结果表明，黄昏和黑暗的最初一小时通常观察到行人致命碰撞的最高频率。然而，这些时间不一定是每英里旅行风险最高的时间，因为行人的数量通常仍然很高。需要进一步分析来量化这些时间内行人暴露（行走/穿越活动）在行人事故参与中的作用程度。由于日落时间的季节性变化，行人致命事故的每周模式因季节而异。在 12 月，碰撞集中在黄昏和黑暗的最初一小时，而在 6 月，碰撞主要集中在周五和周六的黄昏和黑暗的最初几小时。6 月的周五和周六晚上可能是行人最危险的时间。了解行人风险何时最高对于制定有效的缓解策略和高效地投资安全资金至关重要。这种应用的可视化方法是研究人员与决策者沟通以及识别关系的有用工具，然后可以使用更复杂的统计工具对这些关系进行测试。
