when technologies collide

On the interstate the other day, I was trying to change lanes when a large white Ford SUV moved up and blocked my way. I braked, pulled in behind, and the Ford in front slowed down. Then the driver braked suddenly, then sped up. I needed to take the next exit. I was glad about that, because I could be free of this idiotic driver. But at the last minute, with no indicator, the car in front also exited. As we came up to a set of traffic lights, I pulled beside the Ford SUV out of sheer curiosity. What sort of maniac was behind the wheel? What deranged menace would I see there?
It was a well-dressed woman in her forties, talking on her cellphone.
And this is what I have found time after time: erratic driving, dangerous driving, even aggressive driving, is usually done by a very normal person whose mind is elsewhere. You might ask, well if their mind is elsewhere, who is doing the driving?
Yes, you might well ask indeed. And the answer is far from comforting. Because while that woman was talking on the phone, her cerebrum was entirely engaged, leaving her cerebellum to do the driving. Yes, that's right. The much-vaunted cerebrum, that mammalian triumph of nature, was busy, so all the important decisions were left to a part of the brain that we have in common with lizards.
It would be stretching a point to say that you might as well leave a lizard to do the driving, but not by much. The cerebellum does skilled, co-ordinated activity, but it's the cerebrum that makes higher level decisions. The cerebrum also provides feedback, monitoring, and adjustment.
Unfortunately, cellphone conversations chew up a lot of cerebral resources, leaving just a few morsels of attention for the task of driving. That's okay, because that's when the automatic processes kick in. They take over at other times, too.
Have you ever arrived home from work, only to realise that you don't remember the journey home at all? The reason is that the pathway home is so well-known, and the sequence of movements to follow it so overlearned, that there is really nothing for your cerebrum to do except sit back and enjoy the ride. Let the lizard drive for a while. And if you call someone up and talk to them, so much the better: conversation makes a trip pass quickly.
The problem comes when you're not driving on that route between home and work, that you've driven maybe thousands of times. The problem comes on pathways that are not so overlearned that they are burned deeply into your neural pathways, and where you have to make judgements, decisions, adjustments. If you talk on the phone, you're depriving the driving task of resources that it probably needs. One study on this topic found that talking on a phone while driving produced a performace drop that was equivalent to a blood-alcohol reading of .05. That roughly doubles the chances of a car accident.
So it seems, two of humanity's greatest inventions, the car and the phone, can't get along. One needs our attention to protect us from danger. The other demands our attention to fulfil our need for society.
This is why 'hands-free' phones don't improve driver safety. It's not holding the phone to your ear that's the problem. It's what's going on in your head. The conversation is keeping you in a constant state of maximum cognitive load. You don't have cognitive overload as such - that would be unpleasant - just a nice warm feeling of having your brain completely entertained, while leaving that boring 'driving' stuff to the chauffeur.
One question remains. What about passengers? Surely that would be as dangerous, talking to someone next to you. But when we are talking to someone who is physically next to us, it's very different to talking to someone who is at an arbitrary location at an arbitrary distance. You share context- the here and now- and that makes talking so much easier. You can also give subtle non-verbals, chortles, hand-gestures, and so on, that enrich the message and make it more easily understood. When you're getting the message through a tiny earpiece, it is so much harder to figure out what the person is saying, and what they really mean. Much is lost in the transmission. Because of this, it is more cognitive effort to reconstruct and understand what the other person is saying.
My father is someone who loves to talk to people face-to-face, but hates phone conversations. I used to think that this was just some idiosyncracy, but now, I think he's probably not alone. There are probably many people who secretly don't like talking on the phone. The message is stripped of some of its meaning, its nuance. It is harder to interpret. It takes more mental effort. All in all, it's just not as high-quality an interaction as a face-to face-conversation.
We can use the technology, but it comes at a cost- mental resources. Most of the time, this doesn't matter. But when we're driving, it quietly saps our attention, degrading our performance at a high-stakes, high-risk task. Before we know it, we're driving erratically and unpredictably, increasing the stress of the drivers around us (except for the other drivers that are also talking on the phone). "Lizard-brained driver" would not be too far from the truth.
Of course, when I drive and talk on the phone, I'm perfectly safe!