A driver talks on his cellphone while making his way through downtown Ottawa. Ontario became the fourth province to ban hand-held electronic devices by drivers in October 2009. (Sean Kilpatrick/Canadian Press)The coroner's report said Benôit Sauvageau was talking to his wife about a "delicate matter" when he rammed his car into the back of a tow truck on Aug. 28, 2006 in Repentigny, east of Montreal. Sauvageau had told his wife he was on his way home to continue the discussion.

Instead, the Bloc Quebecois member of Parliament became a statistic. His accident happened while he was talking on a cellphone. While no study has proven — or disproven — that talking on a cellphone causes accidents, dozens of studies have shown there is a statistical association between cellular phone use while driving and motor vehicle collisions.

In 2001, New York State became the first jurisdiction in North America to respond to a growing body of research by making it illegal to use hand-held cellphones while driving. Newfoundland and Labrador became the first province to ban hand-held cellphone use by drivers in 2003. Quebec and Nova Scotia joined the movement in 2008, and Ontario passed legislation in 2009. Several other provinces are considering restrictions.

In 1997, University of Toronto researcher Donald Redelmeier and Robert Tibshirani of Stanford University wrote in the New England Journal of Medicine that the risk of getting into an accident while talking on a cellphone was four times higher than when the phone was not being used. Their study was conducted over a 14-month period — at a time when about 15 per cent of the population owned cellular phones.

The researchers concluded that decisions about regulating cellphone use in cars should take into account "the benefits of the technology and the role of individual responsibility."

Other research made similar findings.

Dr. Charlie Klauer, Senior Research Associate, Center for Automotive Safety Research at the Virginia Tech Transportation Institute, is shown inside a test vehicle equipped with a complex data aquisition system to record detailed driver information. A study using similarily equipped vehicles found that driver inattention is the leading factor in most crashes and near-crashes. (Don Petersen/Associated Press)A study out of the Rochester Institute of Technology in 1998 suggested a nine-fold increase in the risk of fatality when a cellphone is present in a vehicle involved in an accident. Two years earlier, the same researcher found the risk of being involved in an accident increased by a factor of more than 5.5 when the driver talked on the phone in the car for 50 minutes or more a month.

In the May 29, 2001 edition of the Canadian Medical Association Journal, Redelmeier and Tibshirani took a harder line. They said what they had failed to clarify in their initial study was that "making calls on a cellular telephone is distinctly more risky than listening to the radio, talking to passengers and other activities commonly occurring in vehicles." In its lead editorial in that edition, the CMAJ said regulating the use of cellphones and other driver-distracting devices is "a no-brainer."

Dozens of studies have looked at the extent to which cellphone use distracts drivers. Among the findings are:

• Drivers are more distracted by cellphone conversations than by conversations with passengers. Published in the Dec. 15, 2008 issue of the Journal of Experimental Psychology: Applied, the study found that under simulated driving conditions, drivers talking on cellphones missed exits and drifted out of their lanes more often than drivers talking to passengers. A year later, another study found that cellphone conversations impair decision-making processes for drivers, while listening to someone talking to you (not on a cellphone) did not.
• Hands-free devices may not make cellphone use any safer. Published in Human Factors: The Journal of the Human Factors and Ergonomics Society in January 2005, this study found that if a hands-free device is not easy to use, it could be more distracting than a regular cellphone. The study suggested that other car-related technological advances — such as such as wireless internet, speech recognition systems, satellite radio, and email — could be even more distracting than cellphones. Another study found that using hands-free devices added five metres to drivers' braking distances.
• Another study — published in The Journal of the Human Factors and Ergonomics Society in 2005 — found that "the impairments associated with using a cellphone while driving can be as profound as those associated with driving while drunk."

But it's not just drivers who may be a little less than completely focused while using cellphones. In a study published in the journal Applied Cognitive Psychology in October 2009, researchers found that people tend to miss things when they talk on a cellphone while walking.

The researchers — from Western Washington University — conducted two studies of people who were either walking while talking on a cellphone, listening to an MP3 player, walking without any electronics or walking in pairs. In the first study, they found that people who were walking across a university square and talking on a cellphone walked more slowly, changed directions more frequently and were less likely to acknowledge others than people who were listening to music, walking in pairs or walking without any electronic equipment.

The second study went further. This time the researchers added a clown wearing vivid clothing, a bright red nose and large shoes riding a unicycle around a sculpture in the same university square. They then asked people walking through the square whether they had seen anything unusual. Those who answered "yes" were asked what they had seen. Those who did not mention seeing the clown were asked directly whether they had seen the clown riding a unicycle.

The researchers found that cellphone users were the least likely to say they had seen anything unusual and the least likely to say they had seen the clown when they were asked directly whether they had seen the clown. More than half the people in the other groups said they saw the clown — including 61 per cent of the people listening to music and 75 per cent of the people walking in pairs.

Distraction is not just a hazard for drivers. The British Medical Journal reported in December 2006 that distraction poses problems for sword swallowers. The study found that sword swallowers are more likely to be injured when they're distracted or swallowing "unusual" swords.

So, it's a good idea to keep your mind free of distractions and on the task at hand.