I've saved my car from rear ending the one in front using exactly that manoeuvre - escaping onto the gravel between the fast lane and the central reservation.

I've saved my car from rear ending the one in front using exactly that manoeuvre - escaping onto the gravel between the fast lane and the central reservation. I now leave a lot more space between me and the car in front, and I've trained myself to remember that traffic might stop dead at any time.