Heat Waves and Road Traffic Collisions in Alabama, United States

• Published in: Annals of the American Association of Geographers Vol. 112; no. 5; pp. 1313 - 1327
• Main Author: Wu, Connor Y. H.
• Format: Journal Article
• Language: English
• Published: Washington Routledge 14.06.2022; Taylor & Francis Ltd
• Subjects: Alabama heat; cambio climático; case-crossover design; climate change; colisiones de tráfico; Collisions; Confidence intervals; diseño de caso cruzado; el calor de Alabama; Employment status; Extreme heat; Gender; Heat; Heat waves; Heatwaves; Meteorological data; oleadas de calor; Race; Road traffic; Rural roads; Speed limits; Traffic; traffic collisions; 交通事故; 案例交叉设计; 气候变化; 阿拉巴马州高温; Alabama; United States > US
• ISSN: 2469-4452; 2469-4460
• DOI: 10.1080/24694452.2021.1960145

The effects of heat waves on traffic collisions require investigation to improve traffic safety during extreme heat events. A time-stratified case-crossover design was used to examine associations between heat waves and traffic collisions in Alabama between May and September from 2009 to 2018. We derived a heat wave index, defined as the daily mean temperature greater than the 95th percentile for two or more consecutive days, by meteorological data from Phase 2 of the North American Land Data Assimilation System. We obtained traffic collision records from the Alabama Department of Transportation. A nonsignificant and negative association between traffic collisions and heat waves was noted, with a 1.4 percent decrease (95 percent confidence interval [CI] [−3.1 percent, 0.4 percent]) in traffic collisions on heat wave days compared to non-heat wave days. Similar results were found when the analysis was stratified by driver-related factors (i.e., gender, age, race, employment status, and driver residence distances), vehicle-related factors (i.e., vehicle usage), and collision-related factors (i.e., rural or urban roads, speed limits, and intersections). A significant and positive association was observed on heat wave days without precipitation, however (23.5 percent increase; 95 percent CI [7.3 percent, 42.3 percent]). In conclusion, traffic collisions were not associated with heat waves in many collision-related conditions in Alabama.