Take a typing test without a cell phone. Hold a cell phone to your ear and talk.
While talking take same test again.
Turn the radio on.
While listening and talking take same test again.
Hold a hamburger in your other hand.
While listening and talking and eating take same test again.
Consider if you'd like someone else driving with those changes in their thinking, fine motor coordination and physiology up and down a street your 6 year old only son was playing on . . . or driving on the streets you drive on . .
TOO TRUE!
Doesn't negate the point about alcohol, though!
And, probably, in SOME contexts, distracted is not QUITE the same as asleep.