There was a really good article in Salon today that explained just why it is so much more dangerous to talk on a cell phone while driving. What your hands are doing has little to do with it, it's what your brain is doing that's the problem. Apparently, there's been some pretty interesting scientific research on the matter:
But can't you just ignore the voice chatting in your ear when
driving conditions get hairy? Apparently not. “Listening to someone
talk is a very automatic process and you can't will yourself not to,”
explains Just. “In another study, we told them [test subjects] to
ignore the sentences, but it made very little difference. You have to
block your ears. You can't turn off your brain processing.” You may
think that you're tuning out your husband or BFF on the other end of
the phone when road conditions get bad, but it's not that simple.
“It's insidious,” says Just. “If you're in a tough driving
situation, and someone talks to you, the processing of the language is
going to start right away, whether you like it or not.”
One thing I've always wondered about, though, is shouldn't it be just as potentially dangerous to hold an involved conversation with a passenger? Apparently not– phone conversations and in-car conversations are actually quite different:
As long as the Model-T has been on the road, people have been
conversing with the passengers in their vehicles, if only to scream at
the pesky kids, “Shut up! I'm trying to drive!” But there's a
difference between talking to somebody in the car and on the phone.
Most passengers in the car adjust their conversation to what's
happening on the road, quieting down when traffic gets hectic or even
pointing out hazards up ahead, acting as a second set of eyes. The
person on the other end of a cellphone call might not know you're
driving, much less be aware of the road conditions. “The difficulty is
that the party on the other line has no sense of your driving situation
and just yaks, and the driver elects to do it, too,” explains Paul
Allan Green, research professor at the University of Michigan
Transportation Research Institute, where he leads the Driver Interface Group.
Inside a car, there can be natural lulls in the conversation of 20
or 30 seconds, and there is no awkwardness associated with it. Not so
on the cellphone call, where there's more social pressure on the driver
to hold up his or her end of the conversation, if only to assure the
other party that the call hasn't been dropped. “There is all sorts of
social pressure to continue the conversation and not break it off,”
says Green. When a driver does stop talking to focus on the road, his
caller is likely to ask, “Hey, can you hear me? Are you there?” The
caller tries “to reengage the driver at the wrong time,” says Strayer.
Further, researchers find that people tend to be more chatty in a
cell conversation than an in-car one. “Cellphone conversations are more
intense than in-car conversation,” says Paul Atchley,
professor of psychology at the University of Kansas. That intensity can
be measured. Researchers in England studied drivers' conversations with
both passengers and callers. They found that people used a higher
number of words per minute on cellphone conversations.
In the end, car passengers just have more skin in the game. “People
in the car have their own safety at risk,” says Atchley. “It's to their
advantage to not put the driver in the dangerous situation, so we as
passengers tend to edit ourselves pretty effectively.”
The larger point is that laws banning cell phone use unless the cell is hands-free are pretty pointless:
Researchers doubt that banning hand-held phones gets to the root of the
problem: the conversation. Sure, it's safer to have both hands on the
wheel, but no one is passing laws banning stick shifts. Atchley
believes that the new cellphone laws may be counterproductive,
instilling a false sense of security, since they may lull drivers into
thinking that gabbing on the hands-free phone is just fine.
I generally try and keep my own automotive cell phone conversations limited to situations where traffic is light and I'm quite familiar with my route, but I'm definitely going to be more cognizant of the risks.