-Ralph-

I don't have an issue with following a truck at 40mph on a single carriageway, that's the speed limit* for that vehicle.

*(a stupid speed limit maybe, I don't know, it's not about how fast they can go, it depends on how good trucks are at stopping nowadays whether that limit should be lifted)

I generally don't have an issue with anyone's driving in any vehicle if they are doing what they should be doing, show consideration for other drivers and use common sense. If I get inconvenienced in some way under those circumstances, then that's just the way the cookie crumbled on that occasion, it's just traffic.

I don't think it's about who is correct, it's just common sense and courtesy. If your doing 1/2mph faster, then don't overtake, running 1/2 mph slower won't affect your journey time. If somebody is "elephant racing" with you, knock off the cruise control and let them past, they'll pass you eventually anyway and it won't affect your journey time at all.

I doubt many drivers have actually done the mathematics and realised how pointless elephant racing is, so maybe it's just education that's needed.