"Are you drunk or just talking on your cell phone?" That's my favorite bumper sticker. One of my sons pointed it out to me recently. He and I spend a lot of time together in our car and we watch for drivers on cell phones weaving their way down the freeway. In this post, I will argue that all uses of cell phones should be banned while driving because the overwhelming weight of empirical evidence supports a complete ban. So hang up and drive!

First, several researchers have found that people having cell phone conversations perform more poorly in driving simulators than people focused only on driving. Researchers at the University of Utah, led by David Strayer, have found the cell phone users miss freeway exits, fail to properly control their speed, are slower to respond to brake lights and stop lights, fail to become aware of things they look at, and hit other cars.

Second, cell phones also disrupt performance in real world settings. My students and I have found that cell phones even disrupt walking and cause people to not see a unicycling clown (see my earlier post titled: Unicycling Clowns, Train Wrecks, and Pilots Forgetting to Land). Other researchers have observed people driving on a controlled track and found that they are slower to respond to and regularly miss signals. Only a few researchers have studied cell phone driving performance in real traffic - after all, if it is dangerous, how can you ethically ask people to do it for an experiment? Those researchers have also found poorer performance when talking on a cell phone. In addition, Virginia Tech researchers and the National Highway Traffic Safety Administration have calculated that cell phone use substantially increases the likelihood of accidents.

Third, cell phones are one of the worst possible driving distractions. There are lots of other distractions in cars: radios, kids, conversations with the person next to you, food, supersized drinks, and Starbucks coffees. Should we ban all distractions? Probably not. But we should ban cell phones because cell conversations appear to be the worst form of distraction. Researchers haven't simply compared cell phone use to driving with no distractions in those simulator studies. They've compared cell phone use to listening to the radio, listening to books on tape, and talking with a person sitting next to you (but not dealing with kids fighting in the back seat). Cell phones result in the worst performance. Talking with someone sitting next to you is often found to improve performance; probably because two sets of eyes are both aware of the road.

Fourth, the problem is not simply with holding the phone. Hands-free does not mean trouble-free. I know some states have outlawed hand-held phones and texting while continuing to allow using a hands-free phone. Unfortunately, those states have it wrong. The problem is what the head is doing, not what the hands are doing. When comparisons have been made between hand-held and hands-free phones, no differences have been found: Both forms of cell phones cause problems. The most likely reason legislatures have not banned hands-free phones is not the scientific evidence, but rather the influence of telecommunication companies.

Fifth, cell phones are causing you problems even if you think you are doing fine. Many people believe they are just as aware of the world when talking on their cell phone as when not using it. In our study of people walking while talking on a cell phone, people who missed seeing the unicycling clown thought they were doing fine. When we pointed out what they had missed, they were surprised. You think you are driving competently, but you don't notice the things you miss. You don't see what you don't see - until it is too late.

My final point concerns just how bad driving performance is when people are talking on their cell phones. Cell phone use may be as bad as drunk driving. In the one study that directly compared, the researchers found that cell phone driving was as bad as, and in some ways worse than, driving under the influence. So that bumper sticker has it right. Is that weaving driver drunk or talking on the cell phone?

Recent Posts in Mental Mishaps

Memory Thieves

Has someone ever stolen one of your memories?

Can You Break the Mood-Memory Cycle?

Depression, autobiographical memory, and mood repair

Thinking Fast, Thinking Slow, Two Seconds, and a Death

Thinking fast, thinking slow, and a police shooting of a 12-year-old boy

Superstitions and the Super Bowl

Put on your jersey: Superstitions and the Super Bowl

Hands Up, Don't Shoot

Hands up, don’t shoot: Explaining memory differences of a shooting

Why We Have Small Memory Failures, Every Day

Are they a sign of a larger problem? That depends on when and why they occur.