You assume your designated driver would refrain from drinking, but a new study suggests they might not be as sober as you think.
Researchers conducted breath tests on more than 1,000 people, including 165 who identified themselves as designated drivers, while they left bars in Florida, according the New York Times.
They did the tests six times in a three-month period and found only 65 percent of designated drivers showed no blood alcohol content, 17 percent had a 0.02 percent to 0.049 percent BAC and 18 percent had a 0.05 percent BAC or higher.
Experts say people will often choose the person in their group who drank the least, which makes the idea behind having a designated driver null and void. They suggest if your designated driver had a few drinks, call a cab.