Driving Fatalities on US Presidential Election Days

To the Editor: The results of US presidential elections have large effects on public health by their influence on health policy, the economy, and diverse political decisions. We are unaware of studies testing whether the US presidential electoral process itself has a direct effect on public health. We hypothesized that mobilizing approximately 50% to 55% of the population,¹ along with US reliance on motor vehicle travel, might result in an increased number of fatal motor vehicle crashes during US presidential elections.

We analyzed national data from the Fatality Analysis Reporting System of fatal crashes in the United States from 1975 to 2006.² We included all presidential elections since database inception (from Jimmy Carter in 1976 through George W. Bush in 2004) during the hours of polling (defined as 8:00 AM to 7:59 PM local time). For each election, we also identified the same hours on the Tuesdays immediately before and immediately after as control days for the number of individuals in fatal crashes at the time, as described previously.³ Confidence intervals (CIs) for comparing death counts on election days and control days were calculated by binomial tests using StatView 5.0 (SAS Institute, Cary, North Carolina).

A total of 3417 individuals were involved in fatal crashes during the hours of polling on the 8 election Tuesdays and 16 comparison Tuesdays. The modal person was a young adult driving in a southern state (demographic characteristics generally stable over time). The 8 election days accounted for 1265 individuals, equivalent to 158 per day or 13 per hour. The 16 control days accounted for 2152 individuals, equivalent to 134 per day or 11 per hour. This yielded a relative risk of 1.18 on election days (95% CI, 1.10-1.26; P < .001), equivalent to an absolute increase of 189 individuals over the study interval (95% CI, 104-280).

The net increase in risk was about 24 individuals per election and was fairly stable across decades of time (Figure). The increase in relative risk extended to pedestrians and persisted across different ages, sexes, locations, polling hours, and whether a Democrat or Republican was elected. No difference in risk was observed in separate sensitivity analyses of individuals involved in fatal crashes during the same hours comparing the Monday before the election with control Mondays (relative risk, 0.97, 95% CI, 0.89-1.06) or comparing the Wednesday after the election with control Wednesdays (relative risk, 1.03; 95% CI, 0.95-1.12).

The increased risk of fatal motor vehicle crashes on presidential election days exceeds the risk on Super Bowl Sundays.^1,3 One explanation is increased traffic, but other factors might contribute. A 4% increase in average speed, for example, could yield an 18% increase in deaths even with no increase in average travel distance.⁴ Additional factors might include distraction (driver inattention), rerouting (unfamiliar pathways), enforcement (decreased police presence), and demographics (mobilizing unfit drivers).^5,6 These potential explanations suggest that the increased risk could extend to crashes of lesser severity so that the average US presidential election might also result in hundreds of additional individuals with nonfatal injuries.

Strengths of this study include use of a database that provided a systematic method for identifying individuals that was free of ascertainment bias, referral patterns, or self-report distortions.³ The main limitation of this database was missing information on risk factors such as speed and alcohol. Overall, the findings suggest the need for safety reminders by electioneers who encourage people to get out the vote. Standard advice would include ensuring seatbelt use, avoiding excess speed, abstaining from alcohol, and minimizing distractions. Other interventions could be subsidized public transportation, voting centers within walking distances, tamper-proof remote voting, or more traffic enforcement on election day.

Author Contributions: Dr Redelmeier had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis.

Study concept and design: Redelmeier.

Acquisition of data: Redelmeier.

Analysis and interpretation of data: Redelmeier, Tibshirani.

Drafting of the manuscript: Redelmeier.

Critical revision of the manuscript for important intellectual content: Redelmeier, Tibshirani.

Statistical analysis: Redelmeier, Tibshirani.

Obtained funding: Redelmeier.

Administrative, technical, or material support: Redelmeier.

Funding/Support: This work was supported by the Canada Research Chair in Medical Decision Sciences, the Canadian Institutes of Health Research, the National Institutes of Health Resuscitation Outcomes Consortium, and the Patient Safety Service of Sunnybrook Health Sciences Centre.

Role of the Sponsors: The funding sources had no role in the design and conduct of the study; in the collection, management, analysis, and interpretation of the data; or in the preparation, review, or approval of the manuscript.