ITASCA, IL --- A new study reported in the National Safety Council's Journal of Safety Research suggests drivers tend to overestimate their driving skills and underestimate their distraction caused by other activities while they drive. 

The study suggests that drivers may engage in other distracting activities while they drive because they don't accurately perceive the danger of doing so. 

Led by William J. Horrey of the Liberty Mutual Research Institute for Safety, based in Hopkinton, Mass., the study involved 41 drivers willing to test the effects of engaging in other distracting activities while they drive. Participants first demonstrated their driving ability in three key areas: lane keeping, speed control, and quick response to a changing traffic light.

Next, they demonstrated these abilities while also performing a relatively easy distracting activity (recalling, adding and repeating simple numbers presented while driving) and a relatively difficult one (developing and asking yes-or-no questions to identify an object while driving). Researchers expected that the more difficult activity would require more thought and thereby distract drivers more significantly from safe driving. 

Indeed, results showed that the more difficult activity reduced driving safety more than the easier one. Yet they also showed that drivers did not recognize one activity as more difficult than the other and estimated no difference between the activities' affect on their driving abilities. According to Horrey and his researchers, these results, combined with previous studies, suggest that drivers are not aware of their own performance loss due to distraction. 

"Today it is important to understand how new in-vehicle tasks affect drivers' performance as well as how they affect drivers' perceptions of their own performance," the study concludes.

National Safety Council President & CEO Janet Froetscher identified cell phone use while driving as one of America's most urgent traffic safety issues. In January, the NSC became the first national organization to call for a total ban on that activity, based on scientific estimates that cell phone use while driving contributes to 6 percent of crashes -- or 636,000 crashes, 330,000 injuries, 12,000 serious injuries, and 2,600 deaths each year. The same research put the annual financial toll of cell phone-related crashes at $43 billion. 

"Our nation has reached a point where we estimate more than 100 million people are engaging in this dangerous behavior daily," Froetscher said. She added that the issue is not the type of phone a driver uses; rather it is the distraction caused by the conversation.

"Hands-free devices do not make cell phones any safer," Froetscher explained. "Several studies indicate that the principal risk is the cognitive distraction. Studies also show that driving while talking on a cell phone is extremely dangerous and puts drivers at a four-times greater crash risk." 

To work toward improving driving safety, the JSR study calls for more research on drivers distracted by activities of different degrees of difficulty, in both laboratory and naturalistic settings.

To access the study, visit Elsevier's Science Direct at and enter the title Journal of Safety Research, Volume 40, Issue 1.