Estimating blood alcohol content turns out to be quite difficult

We all know that it is better to get behind the wheel with just a cold drink. At the same time, drinking alcohol is not completely prohibited. For example, an experienced driver is allowed to have up to 0.5 per mille alcohol in the blood. Recent research among students shows, however, that estimating that amount is not easy.

Alcohol and driving don't mix well. Drinking alcohol reduces your ability to react, you see less well what is happening and you can concentrate less well. This makes you react more impulsively and take more risks. At the same time, you think you can still drive just fine. Experienced drivers are allowed to have a maximum of 0.5 per mille alcohol in their blood. The common belief is that this allows men to drink about two standard glasses. Women are at the limit after one to one and a half glasses.

However, this general guideline is not entirely valid. For example, the speed at which you reach the maximum blood alcohol level depends on your amount of body water. And that in turn is determined by your height, weight, bone structure and fat content. A German study shows that estimating when the personal limit of 0.5‰ alcohol has been reached is quite difficult.

Research among social drinkers

Harm Reduction Journal recently published a German study into the risks of self-assessment in alcohol consumption and driving. In this study, 90 students, an average of 24 years old, were tested for two days on their ability to estimate their own blood alcohol content. The students were offered wine and beer until they had a blood alcohol content of 1.1 permille. They had to estimate for themselves when they had reached the legal driving limit of 0.5 per mille.

What turned out? On the first day, 39 to 53% of all participants exceeded the legal limit, while they themselves thought they could still drive just fine. About half of all participants estimated their own alcohol content too low. Source: Stap.nl

The research shows that we easily overestimate ourselves when it comes to alcohol and our fitness to drive. It is therefore not surprising that the general advice is to leave the alcohol completely behind if you still have to drive. Another dilemma that does not bother you as an IkPasser!

Facts and figures about alcohol and traffic accidents

• In 2020, 5,000 people ended up in a hospital emergency room due to an alcohol-related accident.
• Accidents involving alcohol increase the risk of serious injury.
• Traffic accidents in which alcohol plays a role are more often single-vehicle accidents.
• More than half (56%) of the traffic victims in a traffic accident involving alcohol suffered brain damage, compared to 20% in the accidents in which alcohol did not play a role.

Source: 'Alcohol poisoning and accidents with alcohol', research report of SafetyNL, September 2021