This is an archived article that was published on sltrib.com in 2005, and information in the article may be outdated. It is provided only for personal research purposes and may not be reprinted.
If the TV camera adds 10 pounds, maybe the cell phone adds 50 years.
When 20-year-old drivers get behind the wheel of a car and yammer away on a cell phone, their reaction times slow to the speed of 70-year-old drivers not using portable phones, according to a new University of Utah study.
"It was like instantly aging the young drivers," said David Strayer, a U. psychology professor who co-wrote a study in Human Factors.
This and previous studies have sought to provide a more complete picture about the dangers that cell-phone users face in the driver's seat. One U. report even compared cell-phone talkers to drunken drivers.
In the latest experiment, researchers tested 40 drivers, half between the ages of 18 and 25 and the other half between 65 and 74. All drivers in the study had valid driver licenses and normal vision.
Each participant took a converted Ford Crown Victoria sedan for a virtual cruise on a beltway similar to Interstate 215, Strayer said. The stationary simulator included screens with road and traffic scenes. Drivers spent 20 minutes steering while talking on cell phones with a hands-free device and another 20 minutes driving without the phones.
Sensors recorded how long it took each driver to react to brake lights from a car in front of them. Young cell-phone talkers took about nine-tenths of a second to hit the brakes - the same reaction time as older drivers without cell phones. Young drivers under normal circumstances step on the brake pedal in about eight-tenths of a second, which is 14 percent faster than with a cell phone.
Previous research suggested that senior drivers, in addition to having slower reaction times due to age, would have serious problems while driving and talking on the phone. In nondriving laboratory settings, an older person's reaction time slowed when asked to perform multiple tasks.
Reaction time for seniors in the study did get worse, but not as bad as researchers had expected, said Strayer, who conducted the study with Frank Drews, an assistant professor of psychology at the U.
Cell-phone-using drivers, both young and old, experienced a similar decrease in the time it took them to hit the brakes.
Regardless of phone use, older drivers in general tended to be slower to step on the brakes, to hit the brakes twice, to take more time to regain speed and to follow at a greater distance.
Talkers of all ages increased their following distance by about 12 percent, but this was not enough to make up for slower reaction times. Cell-phone drivers also took 17 percent more time to regain speed after hitting the brakes, he said. Taking longer to return to highway speeds creates an obstacle for nearby drivers.
Earlier U. studies suggested hands-free devices are just as distracting as holding the phone; cell-phone yakkers performed worse in simulated driving than drivers with blood alcohol levels of 0.08 (legal intoxication); and that cell-phone users experience "inattentive blindness," which is when a driver may see an object but the information does not register due to a distraction.
In future experiments, U. researchers plan to delve deeper into how cell phones affect drivers , including the use of devices that track eye movements to learn what motorists miss.
Results from the latest study did not surprise Genaro Solorzano, a 17-year-old Salt Lake City driver.
"I don't like talking on my cell phone," he said of his driving habits. "I like to concentrate on my driving."