On country roads it is a lot less stressful for you and the trucker if you have a cb radio. You don't need a massive areal and all wired in, just a little handheld for to communicate to a truck in front or behind.

Say you're towing a caravan at 90kmh. You can just say to the truck behind "white land cruiser and van to linfox truck, I'm slow, in 3km there's a overtaking area I'll let you go around."