Many people underestimate their blood alcohol level, according to a recent experiment conducted by scientists at the University of Witten/Herdecke in Germany. The study, published in the Harm Reduction Journal, involved 90 participants who drank beer and white wine under controlled conditions. The participants were on average 24 years old and physically fit. During the experiment, they were asked to continue drinking until they believed they had reached the legal limit for driving, which is 0.5 blood alcohol concentration (BAC) in Germany.
On the first day of the study, 39% of the participants did not realize they had exceeded the legal limit until after they had already done so. On the second day, this number increased to 53%. Some participants even exceeded the legal limit on both days but still believed they were fit to drive. On average, the participants consumed 1.4 liters of beer and one bottle of white wine in about two hours before reaching the legal limit. The study found that these misjudgments occurred regardless of whether the participants drank beer or wine first and regardless of gender.
The lead researcher, Kai Hensel, warns that these misjudgments are concerning because even a small number of impaired drivers can cause serious accidents. According to the World Health Organization, road traffic injuries are now the leading cause of death among people aged 5 to 29 globally, and drunk driving is one of the main causes of serious accidents. However, the study also suggests that education campaigns could help raise awareness of the effects of alcohol on driving ability. Hensel suggests setting up testing stations in areas where alcohol is typically consumed to help people understand how quickly alcohol can impair their driving.
