A new study shows that designated drivers may not always guarantee safe driving as 35 percent of them were found to have alcohol levels that could impair their driving capabilities.
A new study from the University of Florida has found that not all designated drivers refrain from drinking and often exceed the recommended blood-alcohol levels, which impair driving capabilities.
Adam Barry, an assistant professor of health education and behavior at UF, and his team questioned over 1,000 bar customers in the downtown restaurant and bar district of a major university town in the Southeast. Researchers discovered surprising results after interviewing and breath-testing all the participants who had been assigned as designated drivers.
The study results showed that more than half of all the designated drivers had exceeded the newly recommended threshold of 0.05 percent for drunken driving. The United States has the highest recommended alcohol threshold for driving at 0.08 percent, while other countries such as Denmark, Finland and Greece have 0.05 percent threshold. Russia and Sweden use the 0.02 level and Japan does not tolerate any alcohol level in the body before driving.
For this study, Barry and his team conducted interviews with 1,071 bar customers. The study is based on the results of the questionnaires for six Friday nights before the home football game in fall 2011. Most of the participants were white male college students and 10 percent Hispanic, 6 percent Asian and 4 percent African-American were also included in this study.
Barry said in a press release that a designated driver is chosen from a group based on the least alcohol consumed and his/her driving capabilities in the past. Barry suggests that such a decision is alarming as the recommended threshold for drunken driving is not usually considered.
Researchers found that designated drivers had lower alcohol levels in the body compared to non-driving participants. Out of the 165 self-identified designated drivers who had been drinking, the results showed that 17 percent of the drivers had alcohol levels in the body between 0.02 and 0.049 and an alarming 18 percent exceeded the recommended threshold of 0.05.
According to Barry, the National Transportation Safety Board had recommended last month that threshold for all 50 states be reduced to 0.05 percent.
Barry also looked at the reasons why a designated driver may get involved in drinking and found that drivers were not assigned until before the drinking started. Barry also said that at times group dynamics or driver's belief that a drink or two could not impair his/her driving capabilities also made the person quaff a few drinks.
"That's the insidious nature of alcohol -- when you feel buzzed, you're drunk," Barry said.
The findings are published in the July issue of the Journal of Studies on Alcohol and Drugs.
