Cell Phone Use Raises Risks While Driving, Studies Show

RAY SUAREZ: The dangers might seem obvious to most, but a series of studies and recent articles in the New York Times suggest the risks associated with calling or texting while driving are significantly higher than many people might have realized.

Among the findings: drivers making a phone call were four times as likely to cause an accident as other drivers; hands-free devices were not significantly safer; if you text and drive, it's twice as risky as just talking on the phone.

Some of the data was compiled several years ago but was only recently released through freedom of information requests. The latest research was published today. It found truckers who texted while driving were 23 times more likely to crash.

David Strayer is an expert on distracted driving who's published studies of his own. He's a professor of psychology at the University of Utah.

And, Professor Strayer, I know that these devices are in more hands every day and thus in more drivers' hands. Do we know if texting while driving is something that people are doing more frequently to begin with?

DAVID STRAYER, University of Utah: It is. It's certainly a growing problem, especially with younger drivers, teens and so forth. Up to 50 percent of the teens report that they text message while driving.

So with the advent of some of these new technologies -- the cell phone, text messaging, and some of the other aspects of things like iPods and so forth -- there's more and more gadgets that are creating substantial new sources of distraction in the vehicle.

RAY SUAREZ: Well, you mentioned all the new machines that can accompany a driver in the driver's seat. Is it possible to compare the level of distraction, to compare talking on the phone to texting, to fiddling with your iPod, to resetting the GPS?

DAVID STRAYER: Some of the studies have been done to kind of try and benchmark the hazards, so when people have looked at the risk of talking on a cell phone, you're about four times more likely to be involved in an accident when you're talking on a cell phone. And that data comes from both epidemiological crash data, as well as driving simulator data.

They provide a nice convergence showing that the risks are about four times higher and that talking on a hands-free cell phone, many people think that that would be a solution, turns out not to be a solution at all, that hands-free cell phone conversations are every bit as hazardous as using a conventional hand-held cell phone. In both cases, the risk is about four times greater than if you were driving without distraction.

And to put that number into some context, other studies that have looked at the crash risk for people who are driving when they're drunk -- at a .08 blood alcohol level -- has a crash risk that's about four times greater than if they weren't impaired. So the crash risk is quite substantial.

When you look at things like text messaging, it becomes even much greater. So our studies have found that the odds of getting into an accident are more like eight -- the odds ratio is about eight times greater than for a non-distracted driver.

And as you mentioned earlier, the work from Virginia Tech shows that some of the people who are trucking may be as much as 23 times more likely to be involved in an accident.

Diffrent levels of distraction

DAVID STRAYER: It's a good question, because you basically have two types of communication, the person sitting right next to you where the person that you would be talking to on a phone, both are conversations, but they turn out to have very different distraction profiles.

When someone has a passenger in the vehicle, they're actually slightly less likely to be involved in an accident than if they're driving by themselves. So there doesn't seem to be a substantial crash risk for passenger conversations. And, of course, cell phone conversations increase the risk substantially.

And one of the reasons for that is that, with a passenger, especially an adult passenger, they'll adjust their conversation depending on driving difficulties. So if driving becomes difficult, they might stop talking. They might alert the driver to hazards or remind them of their exit.

So what happens is you really have two sets of eyes with a passenger in the vehicle, and it produces a very different kind of conversation.

RAY SUAREZ: Is there much variation among drivers and their ability to do more than one thing at a time, between young and old drivers, between men and women, between people who are doing different kinds of driving?

DAVID STRAYER: Well, we know that there are some groups that seem to be at risk. Teen drivers, for example, tend to be at risk for trying to multitask. They're just learning how to drive, so some of the things that a more experienced driver might have automated or become habitual are still quite effortful for a teen driver, so, unfortunately, for the teens who are probably just learning to drive, and they're also probably the most likely to be multitasking, either using a cell phone, or an iPod, or text messaging.

There are some individual differences, but as far as we can tell, 98 percent of the population shows substantial significant impairments when they try and multitask using a cell phone.

RAY SUAREZ: So the bottom line, doing anything besides driving is going to make you a worse driver?

DAVID STRAYER: Well, not always. Those kinds of technologies that we just mentioned certainly are, but listening to the radio doesn't appear to produce substantial impairments. Listening to books on tape also doesn't seem to produce substantial impairments.

And that appears to be largely because a lot of the impairments associated with using a cell phone come from speech production, the actual generation of speech. And if you're just passively listening to conversations or the radio, it seems not to produce the kind of impairments that you'd see if you were actually engaged in a conversation on the phone.

RAY SUAREZ: Well, we have very little time left, but some states have passed laws against texting while driving. Others haven't. Have we seen any difference in those places yet?

DAVID STRAYER: I think it's too early to know. Utah, for example, just put a law in place, but it just went on the books July 1st. I think it's an uphill battle, just because you've got so many different ways that a person can be distracted with wireless technologies.

And so one of the things I think is likely to happen is, with text messaging and the impairments that we see, it's likely to raise the dialogue and the discourse about what we should do with driver distraction, because it's becoming a greater and greater problem.

RAY SUAREZ: Professor Strayer, thanks a lot for joining us.

DAVID STRAYER: Thank you.