Buddy, I don't have this problem but Symon made some valid observations. Agreed the limit is a max not a min but 1 qualifier I would put to that is 1 lane roads in which case Symon's philosiphy comes into play: pull over when its safe if you cant keep up with the limit. We all need to be considerate of other road users and the limits of their individual set ups, but this works both ways ie patience with others tempered with consideration. In a perfect world we would all be towing with vehicles that can handle any slope etc but this aint the case, and in any event what one person considers safe and legal isnt always the same approach of the vehicle behind or in front of you. In all reality there is no right or wrong response to this, I have often pulled over for the "tailgater" behind who is in a hurry, only to pass them at the next servo while they fill up, get a pie or whatever.