Old_Geezer - //All distractions increase risk. Including taking one's eyes off the road to look in rear view mirrors, to check speed, to look at umpteen road signs and decypher them, or change a radio station, or speak to a passenger, or look at/listen to the sat nav. One needs a sense of proportion.//
This is not actually the same.
In my previous job, I received a large number of daily calls, and I would often walk around the office while talking on the phone. Times without number I have bumped into desks or almost collided with colleagues because your spatial awareness distorts when you are on the phone in a way that does not happen with face-to-face conversations.