To each his own to determine what your driving capability is, road and traffic conditions, RV handling capability. Not sure what highway you were traveling on, but 2-lane 55 MPH roads to the coast of Oregon often form long chains of vehicles during the busy summer.
These chains usually travel at 55 MPH. I think this is partly because Oregonians tend to follow the traffic laws more often than folks in other states. This has been going on for decades. Sure, one BIL spent all his time in the left lane in his Superbee in the 70's, but that was before the population increased greatly.