This replaces the Roadtrain truck and the Artic1 trailer, with monsterous results.
The truck itself has excellent offroad capabilities and with trailer attached it will still shame most offroad vehicles.
My only advice is avoid low bridges and the motorway signs, you know, the indestructable ones.
Otherwise, if it gets in your way flatten it.
The Artic trailer handles slightly better than the standard one, jacknifing is still gonna happen though.
I have included GGMMs and files for manual install.

Handling, from the top:

ARTICT1       3800.0 	30000.0 	2.0 	0.0 	0.0 	-0.5 	90 	0.65 	0.85 	0.5 	5 	120.0 	18.0 	5.0 	R 	D 	8.0 	0.30 	0 	25.0 	1.5 	0.05 	0.0 	0.30 	-0.15 	0.5 	0.0 	0.65 	0.25 	35000 	20002000 	30CC03 	0 	1 	0 	

RDTRAIN       3500.0 	20000.0 	3.0 	0.0 	0.0 	-0.35 	80 	0.65 	0.85 	0.55 	5 	110.0 	45.0 	25.0 	4 	P 	7.0 	0.45 	0 	35.0 	1.5 	0.07 	0.0 	0.45 	-0.30 	0.5 	0.3 	0.44 	0.35 	40000 	28 	170CC47 	0 	1 	20 	

Enjoy it,
pinky.