You want to build a road for a 44 tonne vehicle to pass along in the winter?are they not for cars? ie upto 3.5 tone and not 44 tone
Any fertile material will need removing first as all the hard core and all the will in the world, wont stop a 44 tonner from sinking. You will then need a bed layer of large gear, i.e. brick sized or larger grade hardcore. This will need compacting (roller). Then a finer layer compacted on top.

