While the COVID-19 pandemic has undoubtedly had an unquantifiable negative impact on the world, I wanted to explore the potential positive effects that the reduction in travel during the pandemic may have had on car crashes. The government of Monterey county, California publishes data on car accidents in the county including information about drivers, car types, injuries, and fatalities. To understand how car crashes may have been affected by coronavirus and California’s stay-at-home order enacted on March 19, 2020, I extracted Monterey’s data on car accidents from January 1, 2017 through February 21, 2021.
The number of car accidents in Monterey dropped significantly once the stay-at-home order was put into place: 99 accidents occurred in the 90 days before the stay-at-home order while only 32 accidents occurred in the 90 days after the stay-at-home order.
For a clearer picture of the effects of the stay-at-home order, I observed accident characteristics during three time periods: the 120 days after the stay-at-home order began, the 120 days before the stay-at-home order began, and a 120 day period in 2019 between March 19 and July 17 (the same start and end dates as the “after stay-at-home order” time range). Including this third range helps limit the confounding effects of seasonal factors in analyzing crashes during the stay-at-home order.
This graph demonstrates the degree of injury sustained in accidents in the three time periods. Compared to both the 2019 period and the period before the stay-at-home order began, the period during the stay-at-home order had a higher proportion of accidents involving just property damage and accidents inducing visible injury. By contrast, compared to the period before the stay-at-home order, a smaller proportion of accidents involved complaints of pain or severe injury. The proportion of accidents with severe injuries appears relatively consistent with seasonal expectations from the 2019 period, whereas the proportion of accidents involving complaints of pain has markedly decreased across all three periods.
Next, I examined how the parties involved in accidents changed with the stay-at-home order.
These data show that, compared to the period before the stay-at-home order, a larger proportion of accidents after the stay-at-home order involved alcohol, pedestrians, or bicyclists. While the proportion of accidents involving alcohol is roughly consistent with the same period in 2019, the increase from the pre-COVID period is consistent with studies reporting increased alcohol consumption during the pandemic. The increased proportion of crashes during the stay-at-home order involving pedestrians and bicycles does not appear to be seasonally-driven, as such crashes were also higher during the stay-at-home order than they were during the same period in 2019. Studies of physical activity levels during the pandemic differ on whether walking and biking has increased during the past year, but the stay-at-home restrictions may have increased the number of journeys on local roads where pedestrians and bicycles are common, which would explain the increase in pedestrian- and bicycle-related accidents. Additionally, the proportion of accidents involving motorcycles decreased during the stay-at-home order compared to both the period just before the order and the same period in 2019.
The global pandemic has dramatically decreased the number of car accidents reported in Monterey, with the most dramatic drop in accidents immediately following the implementation of California’s stay-at-home order. The proportion of accidents involving property damage or inducing visible injury increased with the stay-at-home order, whereas the proportion of accidents causing a complaint of pain or a severe or fatal injury decreased. There were also notably fewer accidents involving any complaint of pain than would be expected given data from the previous year, and many more accidents involving visible injuries.
Despite the decrease in total accidents during the stay-at-home order, the proportion of accidents involving pedestrians, bicyclists, and alcohol increased after the order began. While the stay-at-home order may have saved lives in Monterey by not only preventing COVID deaths but by reducing accident-related deaths,as vaccine distribution continues and restrictions are lifted, accident-related fatalities may begin rising again.