One Drink Max for Older Drivers

Moderate alcohol consumption found to impair driving for older drivers more than younger drivers

/ Author:  / Reviewed by: Robert Carlson, M.D Beth Bolt, RPh

(RxWiki News) Young adults are often warned about the dangers of drinking and driving, but new research shows that the dangers may be even greater for seniors. 

A recent study found that older adults performed worse on two driving measures after consuming alcohol when compared to younger adults who consumed similar amounts.

The study authors concluded that adults may have to adjust their alcohol intake as they age to stay safe on the road.

"Avoid alcohol if you plan to drive."

This study was led by Alfredo Sklar, PhD candidate, in the Department of Psychiatry at the University of Florida in Gainesville. The research team compared the effects of moderate alcohol consumption on the driving of older and younger adults.

Study participants included 36 younger adults between the ages of 25-35 and 36 older adults between the ages of 55-70 who were all healthy and considered to be social drinkers (those who drink primarily in social situations and don’t have an alcohol dependency).

Participants were asked to record information about their alcohol use histories, average daily alcohol consumption in the past six months, maximum amount of time gone without a drink in the past six months, medical history, and current medications. They also completed surveys to determine driving experience, anxiety levels, and presence of depression or depressive symptoms.

Individuals were excluded from the study if they tested positive for drug use, were pregnant, were currently taking medications that could not be mixed with alcohol, were smokers, or if they did not have an active driver’s license.

Participants were then randomly assigned to one of the alcohol dosage groups: no alcohol, a low dose of alcohol which would result in a blood alcohol concentration level of 0.04, or a moderate dose of alcohol which would result in a blood alcohol concentration level of 0.065. The legal limit for blood alcohol level is 0.08. Blood alcohol levels were measured at 10, 25, 60, 75, and 85 minutes after initial consumption.

After 25 minutes, participants were given another beverage with a dose of alcohol. One hour after consuming the first alcoholic beverage, participants drove on a three-mile long stretch of road, occasionally being shown oncoming traffic.

Driving was performed using drive simulator technology which included a speedometer, side-view mirrors, a steering wheel, an accelerator, and brake pedals.

Four areas of precision were used to measure driving performance including: steering rate (how rapidly the driver attempted to adjust their lane position suggesting jerks or sharp, sudden movements), deviation in lane position, deviation in average speed, and average speed over the course of the drive.

The researchers found that older adults in the moderate alcohol group performed more poorly in the steering rate assessment (higher steering rates) and the deviation in speed assessment (greater deviation) than younger adults in the moderate alcohol group. However, there was no significant effect of age seen for average speed over the course of the drive or deviation in lane position.

The study authors concluded that their findings suggest that older individuals are more susceptible to the effects of alcohol on certain aspects of driving than are younger individuals. 

This study was published on March 6 in Psychopharmacology.

The study authors reported no competing interests. 

Review Date: 
March 22, 2014
Last Updated:
March 24, 2014