Drinking & Driving Drops with Peer Awareness

David J. Hanson, Ph.D.

An ad campaign that promoted the fact that most people in Montana don’t drink and drive was followed by fewer drivers taking that risk. Here’s the explanation.

Driving the speed limit on the highway, cars keep passing you. Does that mean most people drive faster than you do? No, says Dr. Jeff Linkenbach of the University of Montana. It only means that people who drive faster are the ones who pass you. You don't see the people who drive the speed limit, because they remain either ahead of you or behind you. Linkenbach, director of the "Most of Us" program at Montana State University, likes how that story illustrates his area of research -- social norms.

Social norms theory is based on the idea that people are more likely to act safely if they know that most people act safely. However, many people are only aware of those who don't follow the rules, in other words, the cars passing them. Making people aware that most people do the right thing helps keep people safe, Prof. Linkenbach says. "Accurate awareness of peer norms encourages positive behavior and protects against risky behavior," he said. "When you think, 'everybody is doing it,' you're more likely to do whatever 'it' is, too."

Dr. Linkenbach applied that fact in a large study for the U.S. Department of Transportation's National Highway Traffic Safety Administration and the Montana Department of Transportation. The NHTSA office reviewed and recently published results of the study.

The work targeted 21-to-34 year old Montanans, the age group in the state responsible for more alcohol- and drug-related crashes than other age groups. He surveyed them before, during and after a "Most of us don't drink and drive" ad campaign to see whether such ads reduced drunk driving. Previous campaigns by others had used negative ads such as tombstones and car crashes with such messages as "Don't let Montana be your last best place." The statewide study designated 15 of Montana's western counties to receive the Most of Us ads to be compared to responses from the eastern Montana counties.

The Most of Us program produced print and television ads that used roughly $400,000 worth of television and radio airtime and print media. "The campaign changed the perceptions of the target group," Linkenbach said. Between the November 2001 and June 2003 measurements, reported driving after drinking decreased 14 percent in the targeted counties relative to the untargeted counties. That change was likely due to the campaign, he said, with statistics indicating that there are only five chances in 100 that the change was not due to the campaign. In addition, between those two dates, respondents who said they used a designated driver 100 percent of the time increased in targeted counties and dropped in control counties. The relative difference was 15 percent between the two.

Prof. Linkenbach worked with Dr. H. Wesley Perkins of Hobart and William Smith Colleges in New York. Prof. Perkins said the study "provides the first statewide experiment about the effect of communicating accurate norms about drinking and driving." Linkenbach added that "promoting the fact that most of us don't drink and drive resulted in fewer young Montanans taking that risk. We need to get drunks off the road, and this is one step in that direction."

The study also showed that most young adults support stricter drunk driving laws. Their support went up in the Most of Us campaign counties and down in the other Montana counties during the study.