Texting and driving are two things that cannot be done at the same time, at least not psychologically.
Those are the findings of new research from the University of Utah that will be published this week. The research is the first peer-reviewed study that details the psychological effects of texting while driving.
"When we look at dual-tasking — doing two things at once — there is a limited amount of attention that we can dedicate to each of those tasks," said Frank Drews, associate professor of psychology at the U. "With text messaging and driving, it's not one or the other; it's either, or."
Our brains, he said, can't maintain control of one while doing the other.
"During the time people are text messaging, they are driving blind," Drews said, adding that when performing both those tasks, attention and efforts are switched between the two and not shared, as in other tasks.
The hazards of texting while driving continue to receive broad national and international attention as accident rates attributed to this practice increase. Utah law already bans texting while driving, and most people already know it isn't safe, but new U. research actually quantifies the risk.
"People who text message while driving are six times more likely to get into a crash than people who are not text messaging while driving," Drews said. Not only are they more likely to have or cause an accident, but texting while driving decreases response times to traffic signals and brake lights by about 20 to 30 percent, according to Drews' study, which used 40 participants in simulated driving situations. Talking on the phone while driving slows reflexes by about 9 to 10 percent, much less than that of text messaging, which requires more attention to execute.
The study also found that drivers who text have difficulty maintaining lateral control of their vehicle, which causes them to swerve within and often out of their lane of travel, having two times as many lane crosses as usual, Drews said.
"It's the first peer-reviewed research that has said why texting while driving is unsafe and how it is unsafe," he said. "It leads to a degradation of driving ability."
Drews has been researching the effects of dual-tasking for more than a decade and is specifically focused on how people sacrifice performance on one task to do another. In addition to texting and talking on the phone while driving, he has looked at the behavior of multi-tasking intensive-care nurses.
Like some things in life, he said, traffic is not forgiving.
It is estimated that more than 6,000 people die every year as a consequence of multi-tasking while driving. However, those figures cannot be proven because some circumstances are unknown and not all people who cause road deaths admit what they were doing before an accident occurs, Drews said.
Unfortunately, drivers have to look out for themselves and be aware of any distracted drivers around them.
"They are putting a significant burden on everyone else to keep themselves safe," Drews said. Distracted drivers often increase their following distance from other cars, move more slowly than other traffic and move more within their lanes, among other signs..
"You want to get away from those drivers," Drews said. Drivers who are text messaging, he said, aren't prepared to react to unpredictable situations and therefore won't in the case of a potential accident.
"People who are using a cell phones while driving have an impaired ability to self-monitor what they are doing," he said. "Their ability to criticize their own performance is impaired."
Drews' research, performed with several other psychologists and researchers at the U., is available online and will be published in the upcoming issue of Human Factors, from the Human Factors and Ergonomics Society.