People ages 55 and older may be too dangerous to drive after just a single alcoholic drink, though younger drivers were not affected in a new study from the University of Florida.

Psychologist Sara Jo Nixon says new findings on the safety of driving after moderate alcohol doses may convince policymakers to strengthen impaired driving laws. In the study, she and her colleague Alfredo Sklar tested the driving abilities of 36 study participants ages 25 to 35, which they compared to scores for another three-dozen older people ages 55 to 70.