March 3, 2006
Posted online April 12, 2006

Study shows cell conversations put drivers at risk

By Tom Woolf

CARBONDALE -- Jacob M. Rose and James E. Hunton want to put a bug in somebody's ear about distracted drivers, their cell phones and hands-free devices.

Rose is an associate professor of accounting at Southern Illinois University Carbondale, and Hunton is an accounting professor at Bentley College in Waltham, Mass. They are the authors of a study that contends it's the actual conversation – regardless of whether you're holding the phone or talking on a hands-free device – that causes driver distraction, and therefore, serious accidents.

The bottom line of their study is this: If you are using a hands-free device with a cell phone, you are four and half times more likely to be in a serious accident than if you are not talking on the phone at all.

In fact, that "virtual" conversation is more distracting than talking with a passenger, their study shows. In their study, Rose and Hunton suggest that "cell phone conversations consume significantly more attention than passenger conversations, resulting in more incidents and crashes during simulated driving.

"Due to the lack of nonverbal cues, conversations on cellular telephones demand more cognitive resources than conversations with passengers," the study notes. "More working memory is consumed by cell phone conversations relative to passenger conversations, and fewer resources are available for the driving task."

While Rose and Hunton are accounting professors, both specialize in studying the effects of technology on learning and awareness. Their study, "Cellular Telephones and Driving Performance: The Effects of Attentional Demands on Motor Vehicle Crash Risk," appeared late last year (October) in Risk

Analysis, the journal of the Society for Risk Analysis. Rose noted the researchers received no outside funding for their study.

"What we're trying to figure out is if there is a way we can reduce accident rates and deaths through some kind of driver training," Rose said. "The reason we're looking at this is because of the number of countries and cities that have started to ban handheld phones, such as all of Australia, a lot of Europe and some cities in the U.S. Our evidence and the evidence of other studies that have come out recently have said those bans won't do any good because it's just as distracting to be on a hands-free device."

"It's the actual conversation," Rose said. "If you go back to basic psychology research, you find a few things that suggest conversing is far more demanding than listening, because you have to understand what's being said to you and then prepare for your reply. Having a conversation is very demanding."

In their experiment, drivers with and without communication training completed a simulated city driving course while engaged in one of three conversation modes: no conversation, conversation with a passenger and conversation on a hands-free cell phone. Fifty-six pilots and 55 non-pilots participated in the study. Trained questioners carried on the same conversations with all the study participants.

Hunton is also a pilot and pilot instructor. He and Rose chose airline pilots as the perfect "trained" study participants, since they safely fly airplanes while physically talking to crew members and virtually conversing over the radio with air traffic controllers – behavior the authors believe is similar to talking with a passenger and on a cell phone while driving.

Key findings included:

• When not involved in a conversation, the driving performance of pilot-drivers and non-pilot-drivers was equivalent.

• When talking with a passenger, the performance of pilot-drivers was superior to non-pilot-drivers.

• When talking on a cell phone, the performance of pilot-drivers deteriorated slightly, but the performance of non-pilot-drivers dropped sharply.

"Whatever the topic of conversation is, you're processing it very actively," Rose said. "The cell phone industry has basically said, ‘Look, you talk to passengers all the time, and we can't ban that, so why should we ban phones?' We experimentally investigated this issue and compared speaking to a passenger versus speaking on a hands-free phone. We found the accident rates were more than twice as high when you're on a hands-free phone versus talking to a passenger for the exact same conversation."

"The real issue seems to be when you lack all of the non-verbal cues of a close-contact conversation, the conversation is that much more demanding," Rose explained. "Some research suggests that 90 percent or more of a conversation is actually non-verbal. It uses a huge amount of your attention to try to deal with the fact that you're missing all those cues."

The study presents the first evidence to dispel what Rose called the "myth" that talking on a cell phone or hands-free device is no different than speaking to a passenger.

"It is, and it's more dangerous," he said.

The researchers looked at what pilots do differently compared to non-pilots. They found that non-pilots try hard to visualize the person they are speaking to on a cell phone, while pilots do not. Non-pilots also said they try to imagine the gestures and non-verbal cues of the people they are speaking with on a cell phone, while again, pilots do not.

The answer, Rose and Hunton contend, is training.

"Most people would say they don't need that, and our drivers thought that as well," Rose said. "We had people in our simulators hitting two or three cars and pedestrians in one sitting, because we programmed a difficult driving course. We also measured smaller things, like running red lights and missing traffic signs, and those rates are even higher than the serious accident rates."

They propose that instead of an outright ban on cell phones and hands-free devices, governments require drivers to complete an endorsed training program.

"Basically it's a ban unless you get the training," Rose said. "States or cities would have to say ‘you have until this date to come and do the training and get the certification because we know it's going to reduce the chances that you will have an accident.'"

He acknowledges that there are some researchers who are upset with their conclusions because the study could be interpreted to suggest an outright ban on wireless communication. However, Rose also emphasizes that their study differs significantly from other research on the topic.

"This is the only study that has looked at the training issue, the only study that has looked at how we can reduce accidents, the only study that has looked at whether it is different speaking to a passenger versus talking hands free," he said. "This is one of the few studies actually using lab experiments versus studying accident reports."

The researchers' next step is to design and test a short-term training program for drivers.

"People tend to believe, especially after hearing about laws banning cell phone use in cars, that they can put their headset on and it has no effect on them," Rose said. "That's scary."

Leading in research, scholarly and creative activity is among the goals of Southern at 150: Building Excellence Through Commitment, the blueprint the University is following as it approaches its 150th anniversary in 2019.

(Caption: Cell phone safety – Jacob M. Rose, an associate professor of accounting at Southern Illinois University Carbondale, is co-author of a study that contends it’s the actual conversation – regardless of whether you’re holding the cell phone or talking on a hands-free device – that causes driver distraction, and therefore, serious accidents.)

Photo by Russell Bailey