Drivers are far more distracted by talking on a cellular phone than by conversing with a passenger in an automobile.
Conducted by University of Utah psychologists Frank Drews, David Strayer and Monisha Pasupathi, a recently released study found that drivers who talk on a cell phone drift out of travel lanes and miss exits more frequently than motorists who converse with a passenger.
"The passenger adds a second set of eyes and helps the driver navigate and reminds them where to go," pointed out Strayer, a professor of psychology at the U of U and a co-author of the study.
Previous studies by Strayer and Drews have found that hands-free cell phones are just as distracting as handheld models because the conversation is the biggest distraction.
The researchers also have shown that, when young adults talk on cell phones while driving, their reaction times become as slow as reaction times for senior citizens.
In addition, motor vehicle operators talking on cell phones are as impaired as motorists with the .08 percent blood alcohol level that defines drunken driving in most states.
"When you take a look at the data, it turns out that a driver conversing with a passenger is not as impaired a driver talking on a cell phone," noted Strayer. "You see bigger lane deviations for someone talking on a cell phone compared with a driver talking to a passenger. You also find when there is a passenger in the car, almost everyone takes the exit. But half the people talking on the cell phone fail to take the exit."
"The difference between a cell phone conversation and passenger conversation is due to the fact that the passenger is in the vehicle and knows what the traffic conditions are like, and they help the driver by reminding them of where to take an exit and pointing out hazards," added Strayer.
The findings of the U of U research study were released Dec. 1 by the American Psychological Association.