Alcohol-Impaired Driving Is Often the Result of Drinking at Home

PISCATAWAY, NJ – Although drunk driving prevention and enforcement often focuses on people who drink at bars and restaurants, a surprising amount of impaired driving occurs after people drink at private residences, according to a new study in the Journal of Studies on Alcohol and Drugs.

The reason is that drinking is much more common in this context. According to the report, the most frequent drinking location is at home -- 73% of the time people are drinking, it’s at home. The second most common location is in restaurants (9%). Only 5% of drinking events take place in bars, and 5% take place at parties.

The research -- conducted by a group led by Dr. Paul Gruenewald of the Prevention Research Center in Oakland, Calif. -- shows that drinking-and-driving prevention should look beyond just those who drink in bars. “‘Prevention in place’ is the new mantra for modern environmental prevention programs,” Gruenewald says. “Our ability to use social media and other methods to reach out to drinkers in all environments can be extended to encouraging safe drinking practices in the home and other contexts.”

As expected, the researchers found that driving after drinking was more likely to occur after any single drinking event that occurred outside the home (e.g., bars or restaurants) compared with inside the home. A California city with 100,000 people would expect to see 26,097 events of driving after drinking at bars as well as 31,602 of such events after drinking at restaurants over a six-month period, according to their analysis. But the same city also would see 15,411 driving after drinking events in the home and 19,168 events after parties. (Driving after drinking was defined as driving within four hours of consuming any alcohol.)

Self-reported incidents of driving after drinking “too much” (defined according to the respondents’ own criteria) were 879 for restaurants, 726 for bars, 533 for parties and 428 for the home over six months for a city that size.

“Risks related to alcohol-impaired driving are broadly distributed throughout the drinking population and largely driven by drinkers’ choices of places to drink,” Gruenewald says.

The researchers based their results on a telephone survey of 8,553 Californians age 18 and older. They asked respondents questions about their alcohol consumption, including driving within four hours of drinking as well as driving after having consumed too much to drive safely. (Because what defined “too much” was based on the respondents’ own opinion, the actual incidence of impaired driving may be higher than reported.)

Just over 54% of those surveyed said they had consumed any alcohol in the last year, and nearly 41% of drinkers said they had driven within four hours of their last drink at some time in the past six months. Over this time, the average drinker drove about two times after drinking. The same average drinker had driven after drinking too much 0.028 times within the last six months. Although this may appear infrequent, a city with a 100,000 population would see 2,976 incidents of alcohol-impaired driving over any given six-month window, the researchers found.

“Overall, a very large number of driving after drinking and alcohol-impaired driving events are to be expected for any small community of 100,000 persons in California over a six-month period,” the authors conclude.

Citation:

Gruenewald, P. J., LaScala, E. A., & Ponicki, W. R. (2018). Identifying the population sources of alcohol impaired driving: An assessment of context specific drinking risks. Journal of Studies on Alcohol and Drugs, 79, 702–709. doi:10.15288/jsad.2018.79.702