Think before you speak

THE driver who killed Jennifer Smith's mother in 2008 by hitting her car at a crossroads was sober and had never received a speeding ticket. But he was talking on his mobile phone. He was so engrossed that when the policeman later asked him what colour the traffic light had been, the driver said he had not even seen one.

Her bereavement prompted Ms Smith to start FocusDriven, a group modelled on Mothers Against Drunk Driving (MADD), which began in 1980. Indeed, Ms Smith is one of many people who consider “distracted driving” today the direct equivalent of drunk driving a generation ago. This is why April is “distracted driving awareness month” in America, with cops issuing more tickets and more publicity.

Through a combination of laws, education and cultural change, the struggle against drunk driving has come a long way since the 1970s. This is one reason why traffic fatalities have been falling in America—to some 32,800 deaths in 2010, the lowest since the Truman administration. Other reasons include safer cars (with anti-lock brakes, air bags and such) and stricter seat-belt and speeding enforcement.

The counter-trend has been increased distraction. Many things can compromise drivers' attention, from kids to food or the radio. But mobile phones pose the biggest risk, for research shows that these gadgets distract in a more pernicious way.

The human brain has to work harder to process language and communication with somebody who is not physically present. (Conversation with passengers is much less distracting, apparently because those passengers are also aware of the traffic situation and moderate their conversation.) A study by Carnegie Mellon University using brain imaging found that merely listening to somebody speak on the phone led to a 37% decrease in activity in the parietal lobe, where spatial tasks are processed. This suggests that hands-free use of mobile phones cannot help much. Such distractions, according to one study, make drivers more collision-prone than having a blood-alcohol level of .08%, the legal limit in America. It appears to raise the risk of an accident by four times. Texting multiplies the risk by several times again.

Officially, distraction accounted for 16% of traffic deaths in 2009 (up from 10% in 2005) and for 20% of injuries. The age group at greatest risk is, unsurprisingly, teenagers, though older drivers are not immune. But these statistics understate the truth, because few drivers after a crash admit to using mobiles, and police rarely demand phone records, says Joe Farrow, the head of California's Highway Patrol.

Laws vary widely. Japan in 1999 became the first large country to ban hand-held mobile-phone use while driving, and most rich countries and many poor ones have since followed. America is behind the trend. New York in 2001 became the first state with a similar law, and seven have since followed. Thirty states have banned texting while driving.

But these laws are fiendishly difficult to enforce, says Mr Farrow. For instance, his officers must directly observe a driver texting (as opposed to just looking down) for several seconds to pull him over, which is not easy on a freeway. That said, highly visible enforcement makes a huge difference. Syracuse, New York, and Hartford, Connecticut, last year tried an experiment in which cops issued dramatically more citations for two weeks and mobile-phone use fell sharply in both places.

“I don't think we'll see an outright ban in my lifetime in California,” says Joe Simitian, a state senator who has written California's three laws against distracted driving. In a car-and-gadget culture, he reckons, the best hope is gradually to raise compliance over time, as with drunk driving. Technology might help—Google, for instance, is already testing cars that drive themselves and avoid accidents. In the meantime, says Ms Smith, driving distracted must become, like drunk driving, “totally uncool, socially unacceptable”, especially among teenagers.