Lower Volumes, Higher Speeds: Changes to Crash Type, Timing, and Severity on Urban Roads from COVID-19 Stay-at-Home Policies

Abstract

Stay-at-home policies in response to COVID-19 transformed high-volume arterials and highways into lower-volume roads, and reduced congestion during peak travel times. To learn from the effects of this transformation on traffic safety, an analysis of crash data in Ohio’s Franklin County, U.S., from February to May 2020 is presented, augmented by speed and network data. Crash characteristics such as type and time of day are analyzed during a period of stay-at-home guidelines, and two models are estimated: (i) a multinomial logistic regression that relates daily volume to crash severity; and (ii) a Bayesian hierarchical logistic regression model that relates increases in average road speeds to increased severity and the likelihood of a crash being fatal. The findings confirm that lower volumes are associated with higher severity. The opportunity of the pandemic response is taken to explore the mechanisms of this effect. It is shown that higher speeds were associated with more severe crashes, a lower proportion of crashes were observed during morning peaks, and there was a reduction in types of crashes that occur in congestion. It is also noted that there was an increase in the proportion of crashes related to intoxication and speeding. The importance of the findings lay in the risk to essential workers who were required to use the road system while others could telework from home. Possibilities of similar shocks to travel demand in the future, and that traffic volumes may not recover to previous levels, are discussed, and policies are recommended that could reduce the risk of incapacitating and fatal crashes for continuing road users.

Near-term impact of COVID-19 pandemic on seniors’ crash size and severity

“…Future studies are recommended to conduct self-reported surveys as well as driving simulator experiments to investigate changes in senior drivers’ behavior at nighttime with and without the presence of street lighting. It should be noted that peak-hours were not found to be a risk factor to crash size and severity of senior drivers which is consistent with Stiles et al (2021) who also observed a lower proportion of collisions during morning peak period during the COVID-19 pandemic and a reduction in types of collisions that occur in congestion.…”

An Interrupted Time Series Analysis of the Sociodemographics of Crash Victims during the Illinois Stay at Home Order

“…Odds ratios of greater than one imply an increased likelihood of the dependent variable being true, while those less than one imply a decreased likelihood. Results suggest speeding was a significant predictor of White males being in a MVC during the 2020 stay at home order, where previously it was not, consistent with other speeding studies (Lee, Porr, and Miller 2020;Liao and Lowry 2021;Stiles et al 2021). Conversely, speeding correlates with a diminished likelihood of White females' MVC involvement where it did not previously.…”

Urban Road Safety and Crash Severity during the 2020 COVID-19 Pandemic: The Case of Seattle, WA

“…And would these impacts vary during different phases of the pandemic? Besides a descriptive analysis of crash characteristics before and after the pandemic, the study employed a multinomial logistic regression model (Stiles et al 2021), in conjunction with a difference-in-differences or DID approach, to quantify the impact of the pandemic on crash severity. The empirical model assumes that in the absence of the pandemic, temporal changes in crash severity before and after the onset of the COVID-19 outbreak would be essentially the same in 2020.…”