According to a study by researchers at the University of Cambridge, many consumers are underestimating how much alcohol they have consumed, meaning there may be times that they are over the drink driving limit when they get behind the wheel.
The study found that up to half of drinkers are failing to judge how drunk they are. This makes them much more likely to drive, even when they exceed the legal limit for alcohol.
During the study, 90 participants were asked by the researchers to take part in a two-day drinking and driving experiment. They were split into two groups: a control group and an experimental group.
Both groups drank a combination of beer and wine until their blood alcohol concentration reached 0.11%, which is above the legal drink driving limit in the US, as well as many other countries.
Those in the experimental group were told that when they reached the legal limit, their drink would be switched from beer to wine.
To determine how well the participants judged their alcohol levels, they asked them to say when they had reached the drink driving limit while having their BAC tracked with breathalyzer tests.
During the first day, nearly 40% of participants had exceeded the limit before they realized it. This figure increased to 50% on the second day of the study.
Researcher Dr. Kai Hensel noted, “In countries with legal alcohol limits, it’s usually the driver who makes a judgment about how much they’ve drunk and how fit they are to drive. But as we’ve shown, we are not always good at making this judgment.
“As many as one in two people in our study underestimated how drunk they were – and this can have devastating consequences.”
“Really, the best advice is that if you’re driving, just don’t drink. But if you really do feel like a drink, then look into your alcohol tolerance. This differs from one person to the next, depending on your sex, weight, and age, and there are some reliable apps out there that can help guide you.”