College of LAS « Illinois


The Illusion of Safety

Hands-free phones are just as distracting.

driving safety

Driving while talking on a cell phone is roughly the equivalent of driving while under the influence of alcohol. But perhaps even more surprising, hands-free cell phones do not make you any safer, says Daniel Simons, an LAS psychology professor who specializes in visual perception.

Simons and his colleague, Christopher Chabris at Union College in New York, have consistently made this point in the wake of legislation in various states, such as a law passed in Washington state this year that bans holding a phone while driving.

“The dangers of driving while talking on the phone come not from our hands or from our eyes, but from our brains,” they wrote in The Seattle Times. Simons’ research backs this up.

In one of his driving experiments at the University of Illinois’ Beckman Institute, participants drove on a simulator depicting a four-lane, divided highway. Their sole task was to follow the car in front while performing a counting task. In this case, Illinois researchers found that if drivers are distracted while simply following traffic, they instinctively give themselves a little extra space with the car in front.

“This suggests that distractions wouldn’t be as bad as long as drivers don’t have to make any decisions and provided that nothing unexpected happens,” he says.

But unexpected things do happen, and distractions like talking on the phone can make you slower to respond. Problems also arise when drivers have to make a tactical maneuver, such as passing. If drivers are being distracted in these situations, Illinois researchers found that they usually drive too close—dangerously close.

“Making a tactical maneuver requires thought,” Simons says. “And when something requires thought, doing other things that require thought—such as talking on a cell phone—impairs your abilities.”

He says the physical act of holding a phone is not what limits our abilities. What raises the risk is the brain’s inability to adequately process both tasks—your phone conversation and driving.

But what is the difference between holding a conversation on a hands-free cell phone and talking with a passenger? Simons identifies three important differences.

First, the audio quality is much worse on a cell phone, meaning that it takes more effort to hear the conversation, and more effort means more distraction. Second, if an unexpected event occurs on the highway, passengers actually provide an added set of eyes; they might even yell “watch out” to alert the driver.

“The third reason is the most interesting,” Simons says. “The social demands of a cell phone conversation are completely different. If a driver stops talking to a passenger to make a maneuver, the first thing the passenger will do is look out the window. The passenger adjusts the conversation based on the situation on the road.”

On a cell phone, however, if the driver stops talking, the person on the other end of the line might think the call has been dropped or something else is wrong. They have no idea of the situation.

“On a cell phone, there is a lot of pressure to keep up the conversation, and that’s a big demand on the driver,” he points out.

Simons says that simply banning the use of hand-held phones while driving will probably not have any impact on safety if hands-free cell phones are still permitted, or even encouraged as is the case in some states. For example, when New York first banned hand-held phones, drivers who received tickets for talking on their phones could get the tickets waived if they brought in a receipt showing they had bought a hands-free set.

“The one way that banning only hand-held phones could help is that by doing so you’re effectively banning texting while driving. And texting while driving is much, much worse.”

By Doug Peterson
September 2010