This has all been interesting, but the OP was talking about a situation where he had no choices other than to maintain his speed, not move over and hope for the best.
Still of the opinion that a the best offense is a good DEFENSE, so when push comes to shove, if I have a choice I'll either move over, slow down or speed up depending on the situation....the avoidance of an accident is the main objective.
Side note, personal opinion is that 67 is a bit faster than most of us travel and I am not comfortable at that speed....I feel less in control of the truck and trailer. Traveling speed is a topic that has been beaten to death and hope this doesn't start another.
Safe travels, all.