Government calls for total ban on cellphone use while driving, but what are real risks?

By Deborah Kotz, Globe Staff

Is it really so dangerous to talk on your phone while driving that it should be banned altogether? Well, that depends on who you ask. The National Transportation Safety Board announced today that it would like to see all states prohibit cellphone use of any kind while driving, except in emergencies.

But in a bit of strange timing, a study was released this week in the journal Epidemiology that found that speaking on a hands-free device might not be as risky as previous research suggested.

Massachusetts prohibits cellphone use by drivers under age 18 and city and school bus drivers and has banned texting and Internet use for all drivers. But the federal government has now called for a total ban on cellphone use, citing accidents that occurred due to distracted driving -- even, in some cases, when the driver was using a hands-free device.

“More than 3,000 people lost their lives last year in distraction-related accidents,” transportation safety board chairwoman Deborah Hersman said in a statement. “It is time for all of us to stand up for safety by turning off electronic devices when driving.”

Whether this is really necessary remains up for debate: Richard Young, a cognitive neuroscientist at Wayne State University who authored the Epidemiology study, has no doubt that texting and dialing a phone while driving are risky and responsible for serious accidents. But hands-free chatting? It might not be any riskier than having a conversation with the person sitting next to you in the passenger seat. (And the government can’t exactly ban that practice.)

Young analyzed crash data suggesting that cellphone users have four times the risk of getting into accidents while driving and found that the methodology used to draw the conclusions was flawed.

While researchers used cellphone bills to analyze usage before a crash and then compared it with cellphone usage at the same time on the previous day to see whether usage was less when they were driving, and thus lowered their risk of having a car accident. But they failed to take into account whether people were actually driving during that same period of time on the previous day. Using GPS data from the phones, Young found about 25 percent of the time, they weren’t.

This, he said, completely accounted for the extra risk.

More recent studies using cameras installed in cars to measure cellphone use while driving also found no increase in risk from use of hand-free phones, and Young said his finding could explain the discrepancy.

But he has done previous brain imaging research that suggests that talking on a hands-held device can still be a little distracting, slightly slowing our braking reaction time. “People also don’t change lanes as much and tend to focus more on the roadway ahead,” rather than what’s going on in their peripheral vision.

For that reason, he doesn’t recommend using phones at all in bad weather when more attention is needed to traverse dangerous roadways. And no question, we should avoid fumbling with our phones while at the wheel. “Texting and dialing is dangerous while driving and shouldn’t be performed under any circumstance,” Young said.