Hold the Phone

Splash!  The conclusions of the Insurance Institute for Highway Safety's most recent study on cellular phone use in automobiles recently got a lot of play in the worldwide media.  The conclusions of the study were stunning.  The report stated that drivers using phones are four times as likely to get into crashes serious enough to injure themselves.  And in addition, the report opined that "banning hand-held phone use won't necessarily enhance safety if drivers simply switch to hands-free phones. Injury crash risk didn't differ from one type of reported phone use to the other."

But when one takes a more critical look at the study and the press release that accompanied its publication, questions emerge.  The most telling question, of course, is: is the study a reliable, rational way to examine cellular phone usage in automobiles in the United States?

The first issue is the locale in which the study was done -- the Western Australia city of Perth.  Are the drivers and driving conditions there analogous to U.S. drivers and driving conditions?  Another issue is the inferences that were drawn to derive the conclusions.  For instance, the researchers did not ask the subjects of the study -- drivers who were treated in Western Australia emergency rooms in 2002 through 2004 -- if they were using their phone at the time of their individual crashes.  Instead, purportedly to avoid asking drivers to admit some culpability because they were talking when they should have been driving, the researchers asked the drivers how often they used their cell phones and derived from that an estimate of the numbers who were speaking on cell phones prior to or during their accidents.  As the IIHS put it, "The increased risk was estimated by comparing phone use within 10 minutes before an actual crash occurred with use by the same driver during the prior week."

Yet another question has to do with the study's conclusions on hands-free versus hand-held phones.  On this issue the IIHS was not equivocal.  

"You'd think using a hands-free phone would be less distracting, so it wouldn't increase crash risk as much as using a hand-held phone," said Anne McCartt, IIHS vice president for research and an author of the study. "But we found that either phone type increased the risk."

But one might wonder how that conclusion was drawn since Western Australia bans hand-held mobile phones from use in cars and trucks.  That being said, one-third of the drivers said their calls had been placed on hand-held phones.  Does that represent a level playing field for a comparison of risk between hands-free and hand-held phones?

According to IIHS, weather wasn't a factor in the crashes, because almost 75 percent of the crashes occurred in clear conditions. Eighty-nine percent of the crashes involved other vehicles. More than half of the injured drivers reported that their crashes occurred within 10 minutes of the start of the trip.

The implications of this data are obvious.  First, we must ban driving on clear days because that is clearly a more dangerous time to drive than during inclement weather.  Second, we must ban all other vehicles from the roadways because a huge majority of accidents involve other vehicles.  And finally, we should ban trips because a majority of injuries came soon after trips began.

A student of auto safety and the human condition, Tom Ripley writes for Driving Today and other publications from his home in Villeperce, France.