Distracted Driving and Statistics

It is generally common knowledge that 90% of statistics are made up on the spot.

Of course, who knows what the actual numbers are (I'm sure someone has written a thesis on this), but it is true that a surprising number of statistics are wrong.  But what's worse are the statistics that aren't wrong, but are used incorrectly.  These statistics are used to influence people and are a terrible abuse of math and science.  Math and science are supposed to be about truth, but what happens when the "truth" isn't what it sounds like?  To quote Mark Twain,

"There are three kinds of lies: lies, damned lies, and statistics."

One example is from an article I read recently on daydreaming while driving.  It turns out that Detroit has been busy using its copious extra money on useless studies instead of trying to make jobs and save its crumbling economy.  According to this report, daydreaming while driving is the cause for 62% of fatal accidents caused by distraction, while only 12% of such accidents were caused by cell phone use.

Those in charge of this study then went ahead and claimed that "daydreaming is more dangerous than texting."  Does anyone else see the gap in logic here, or is it just me?

While on the surface this may seem alarming, which is probably why the news has picked up the story. But let's just dig a little deeper.

What are the statistics for the percentage of people who regularly use cell phones while driving?  What about those who text while driving?  Or who use phones without hands-free devices?  I do not know these numbers, but if I were to guess, I'd say something like.. oh.. 10% of people will text while driving.

Now, how many people daydream while driving?  Again, I don't know the number, but my uneducated guess would be... 100%.  Yes, I firmly believe that everyone at some point lets their mind wander while they are behind the wheel.

Now, let's put these two together.  Again, I am making up the numbers to prove a point.  Let's say the percentage of people who get into fatal accidents is 1%.  That makes 0.62% of those caused by drivers who daydream.  This means that if you daydream, you have a 0.62% chance of getting into a fatal accident, because 100% of drivers daydream.  Now let's say you are texting.  Although only 0.12% of that 1% of fatal accidents is caused by texting... only 10% of the drivers text.  That means, if you text, you have a 1.2% chance of getting into a fatal accident.  That's TWICE as dangerous as daydreaming.

Now, I do not know if daydreaming really is more dangerous than texting, but I seriously, seriously doubt it.  However, the point I am trying to make is that you have to think about the statistics you are being told.  Just because the news report or some study jumps to conclusions doesn't mean you have to.  Particularly when it comes to statistics.