It almost happened to me - I was stopped on a 2-lane road behind a guy waiting to turn left. I happened to look up into my rear view mirror and saw a car approaching at speed (posted as 50 MPH). Kept getting closer & closer w/o slowing down. I had no escape route (steep embankment to the right, oncoming traffic in the lane to my left). By now, I could see the idiot driver had his head down, so all I could do was brace for impact and lay on the horn. I pretty much thought I was a goner, but as I watched in the rear view mirror his head snapped up as he locked up the brakes and skidded to a stop beside me in the oncoming lane. Fortunately, my horn (and probably the loud tire screech) had alerted oncoming traffic so everything came to a standstill without impact.
I thought about calling the police, but decided to leave it be. The guy pulled in behind me as traffic resumed, keeping a good distance back, and pulled into the first gas station we passed. After the shakes passed and he made it into the men's room, I imagine he was wishing he had a spare pair of pants to put on...
Just a (thankful) Shooter