I don't post much here on ORE but here is my small bit of input.
Oh and 10 pages made for a interesting Sunday night read
As a kid while mowing the lawns for mum in the winter the push mower would leave deeper ruts in the lawn than my 2.5t patrol running slick 31"

over similar wet ground.. tire size has NOTHING to do with it.
To maintain access to private and DOC land EVERYONE needs to have 3 things in there mind when being offroad
1. An understanding of there truck knowing its capabilitys being able to look at a track and think to them selves yes I can drive it or give it a go once or twice if ya make it sweet if not lets find a bypass or there is no way im going to make that I'm only going to damage my truck and the track.
2. little bit of commen seance, if your on a main track/access etc etc track where is the fun in ripping the shite out of it (personally I would rather be playing bingo with the elderly) go and have fun on the side tracks where you can spin ya wheels and find the limits of your truck but don't be a knob and just sit there moving no where digging big holes.
3. RESPECT or the lack of, in my view probably the biggest thing that is going to stop US the 4x4 community from getting access to land. If you have been granted permission to private land and have been asked to stay out of places STAY OUT OF THEM! If you do have to travel on land that may be in the grey area of should I be here is it really that hard or expensive to say to the land owner sorry and at least offer to go back next weekend with a bag of grass seed to sprinkle over your wheel tracks? If your on approved DOC land and there is a donation box put a donation is to help to pay for track maintence etc etc
But hey it seems you can't teach "some old dogs" new tricks I guess
Just another thought how about imposing a rule that EVERY 4x4 / SUV / Remuera tractor owner must either belong to a 4x4 club or do a NZQA approved course?
http://www.nzqa.govt.nz/nqfdocs/units/pdf/18492.pdfThat's all I have to say for now
Cheers Yael