Distracted drivers think of themselves as good drivers, research suggests

"When you ask people to rate how good they are at driving and the kind of risks they pose, they often have very positive assessments," said Chaparro. "They believe that they're good drivers."

"But what we see when we look at participants in our experiments is that their driving is affected. What people believe in terms of their capabilities isn't reflected in the data."

Chaparro has researched drivers' behavior since 1998.

"Some tasks may be more distracting than others," Chaparro said. "For example, there's evidence that listening to a book on tape doesn't seem to interfere much with driving."

Driving interference

One of the experiments Chaparro conducted was reading a set of letters to each participant while driving. Some only had to repeat the letters back in the order they received them, and that didn't seem to affect their driving.

"But when you asked drivers to alphabetize their set of letters it has a big impact on their driving," he said. "Thinking about generating a response is perhaps the main source of interference in driving."

Chaparro said when you're thinking about generating a response, you're not thinking about what's going on in the road ahead.

Most recently he has been directing his research at texting while driving.

"We did an initial study looking at texting versus talking, and we found that texting was a lot worse," he said. "On virtually every measure we found that drivers who were texting were significantly worse than drivers who were just talking on the phone."

When you're texting, Chaparro said, you have the cognitive demands of talking. But now, you also have to physically interact with a device using small buttons that require visual confirmation.

Chaparro cited a study done at Virginia Polytechnic Institute and State University that used video cameras in vehicles to record drivers' behavior on the road. The study attempted to correlate crashes and near misses with the drivers' behavior.

The study found evidence that texting while driving increases the chance of a crash by as much as 23 times. That compares to being four times as likely to crash while talking on the phone.

Timely research

With Kansas' new laws against texting while driving, Chaparro's research has become more timely than ever.

"I think the law highlights the difficulties faced by both the police and drivers when it has to be enforced," he said.

Kansas law now allows law enforcement officers to stop motorists for "sending, receiving or reading text messages or emails on their wireless devices."

"First, it appears that many drivers are not aware of the law and that it covers not only the typing of a text message but also the act of reading a text message," Chaparro said. "A public education program may be needed to raise awareness and educate drivers."

"Second, enforcement poses a challenge because it is not always clear from a short glance whether the driver was texting, using the phone to check the time or to turn off an alarm. Would all of these cases be treated as if the person was texting? Is dialing a telephone number any less risky than texting 'got 2 go'?"

Even though some people are naturally better at multitasking than others, that doesn't mean that they are immune from the risk, he said.

"When people are engaged in these tasks, even when they're good at them, those tasks still place a burden on the driving performance," Chaparro said.

This can be demonstrated without even getting in a car.

"We've been walking since about age 1. It's the most practiced motor task that we engage in. Yet walking is affected by the simple task of listening for two tones and responding to just one of them," he said.

We're not nearly as practiced at driving as we are at walking.

Chaparro said that we shouldn't be surprised that using a mobile device behind the wheel impacts driving performance.

"Anything that distracts drivers is a risk. Looking at accident statistics, you find that driver distraction is the most common cause of mishaps," Chaparro said. "Anything in a car that serves as a source of distraction in a car is problematic."