A study published in JAMA Psychiatry found that traffic fatalities increased by 14.3% nationwide the day after the 10 deadliest mass shootings, resulting in approximately 20 additional deaths. The analysis indicates that the number of extra traffic deaths was approximately 75% of the number of people killed in the shootings themselves.

The research team utilized a federal database of fatal crashes on U.S. roads and FBI data on mass shootings over a 15-year period to conduct the assessment. Researchers compared the number of traffic deaths in the days immediately preceding each shooting with the number of deaths on the day after the shooting to identify statistical deviations.

On the day after the 10 mass shootings with the highest fatality counts, traffic deaths increased by an average of 14.3%. This spike represented a significant departure from baseline traffic mortality rates observed during comparable time frames without such incidents.

To verify the findings were not due to chance, researchers repeated the analysis 10,000 times using random dates instead of actual shooting dates. A spike in traffic deaths as large as the one observed occurred only once in 10,000 iterations of the random date analysis, suggesting a strong correlation with the events.

The increase in traffic deaths persisted in states far from the location of the shootings, indicating a nationwide psychological impact rather than a localized logistical disruption. Conversely, no rise in traffic deaths was observed following active-shooter incidents that resulted in no fatalities, pointing to the severity of the outcome as a potential driver of the behavioral change.

Google search traffic data indicated that searches for the term "shooting" peak on the day after a mass shooting. This digital behavior aligns with the timeline of the observed increase in road fatalities, suggesting heightened public attention and stress coincide with the dangerous driving patterns.

Study researchers stated that mass shootings cause significant stress that may lead to risky driving behavior. This explanation posits that the emotional toll of these violent events translates into measurable physical consequences on the nation's highways.

Nearly two-thirds of Americans report that mass shootings are a significant source of stress in their lives, providing a broader context for the physiological and behavioral responses documented in the study. The findings connect individual psychological distress to public safety outcomes, illustrating how traumatic national events can have unintended secondary effects on daily activities such as driving.

This pattern mirrors other historical instances where national trauma influenced road safety. Fatal car crashes increased in the months following the September 11 attacks, and evidence showed an increase in crashes per mile driven after the September 11 attacks. Additionally, research indicates that antidepressant use increases among teenagers living near a school shooting after the event occurs, further demonstrating the wide-ranging health impacts of such violence. Gun purchases made in response to mass shooting events have also been linked to an increase in accidental gun deaths, showing another avenue through which these events alter public behavior and risk profiles.

Why It Matters

The study links mass shootings to a measurable rise in traffic fatalities, showing that the psychological impact of these events extends beyond immediate victims to affect public safety nationwide. With extra traffic deaths reaching approximately 75% of the shooting fatality count, the findings illustrate how national trauma triggers unintended secondary consequences on daily activities like driving. This pattern mirrors historical increases in crashes following other major traumatic events, showing a broader connection between collective stress and risky behavior on the roads.