I must admit to feeling some self-righteous vindication here, because a new study from the University of Utah confirms something I’ve been saying (even shouting) for years: drivers who talk on their cell phones are just as impaired—and perhaps just as dangerous—as drunk drivers. Furthermore, the study found that use of hands-free cell phones was just as distracting as using a handheld phone.
The study from the University of Utah’s David Strayer is published in the summer issue of the Journal of the Human Factors and Ergonomics Society (PDF).
“Although we all have our suspicions about the dangers of cell phone use while driving, human factors research on driver safety helps us move beyond mere suspicions to scientific observations of driver behavior,” said Human Factors Editor Nancy J. Cooke, who praised the study.
The study analyzed the actions of 40 participants who each took four passes through a driving simulator: one pass had no distractions, one used a handheld phone, one used a hands-free cell phone, and one pass was conducted while the participants were intoxicated with a 0.08 percent blood alcohol level (courtesy of vodka and orange juice). The study found no significant difference between the level of distraction created by the use of either handheld and hands-free cell phones while driving: participants were 9 percent slower to brake, 24 percent more varied in their following distance, and 19 percent slower to resume normal speed after braking. Three phone-using participants rear-ended the simulated pace car. One analysis found that cell-phone using drivers were 5.36 times more likely to get into an accident than undistracted drivers.
Intoxicated participants were apt to drive more slowly than either undistracted or cell phone-using drivers, but they were likely to be more aggressive. Intoxicated drivers followed the pace car more closely, were twice as likely to brake only four seconds before a collision would have occurred, and slammed the brakes with 23 percent more force. The intoxicated drivers didn’t get any accidents, which researchers possibly attributed to having conducted the tests during mornings, when the participants were likely to be reasonably well-rested. Most drunk driving accidents
