OK. Well, green-lanes are an anomaly. The British roads network has evolved over a couple of thousand or more years into the utter chaos we have now.
In essence, Green-Lanes are roads that have been 'missed' by the tarmac machine. They are vehicular rights of way, just like normal roads, but they don't have a nicely made and maintained surface, like we are used to.
So technically speaking, 'Green-Laning', isn't 'off-roading', because they ARE roads.
But any way, the point is that they are so un-made, that they often have a sign saying 'Unsuitable for Motors', and are almost impassable to anything but off-road vehicles.
Now, there are may attractions to driving these roads. To some it is the challenge of the terrain, as many are quite demanding to drive, but probably the greatest attraction is the fact that these roads are well pretty much 'off the beaten track' as it were.
They pass through countryside that you just wouldn't see from a sealed road, and you aren't all that likely to encounter any one else on them.
Driving green-lanes, brings a feeling of adventure, wilderness and wonder. You KNOW you aren't the first person to drive that track, but you feel like you could be.
And that's the point of Green-Laning, its a mini adventure. You have the chance to 'discover' bits of Britain few 'tourists' get to see, and where there isn't an ice cream van in every lay by.
Now, a lot of people are put off the idea of green-laning for any of a number of reasons. So to allay a few concerns. First of all, you don't need really rugged mud terrain tyres or a boot full of recovery equipment. You don't need a heavily modified vehicle, with all manner of under-body protection, or a heavy duty winch. Green-Lanes are public roads, and for the most part, if they are so demanding to drive that you need an excess of equipment, then you probably shouldn't be driving them, as you are likely to damage track or vehicle or both.
There are a few guidelines for green-laning, that are provided in the 'tread lightly' code, and there is some 'basic' equipment that is advisable for you to carry, like a good tow rope, a first aid kit, and possibly a high-lift jack, and its recommended that you don't drive alone, and that you always take at least two cars.
But in essence, you should be able to drive most green-lanes in pretty well any standard off-road 4x4.
The next worry a lot of people have is actually finding the lanes in the first place. And to be honest, this is the biggest concern. The legal status of a lot of tracks is often in doubt, and they often aren't well marked on maps, and given a tract of forestry commission land, it is often difficult to know if the track you are looking at is a public right of way, a forest fire break or access track, or a farm driveway.
There is a thing called 'the definitive map' which should be maintained by the Rights of Way officer of each county or district council. The 'definitive' map, is supposed to show all rights of way in the district, and you should be able to make an appointment and check your own maps against the definitive map. But practically, this isn't always that practical.
But, there are a lot of Green-Lane 'gurus' who we can turn to for help in these matters.
Most 4x4 clubs have a rights of way secretary who keeps maps marked with derivable green-lanes, and often if you join, for a small fee, you can have your own maps marked up too.
Both GLASS and the TRF offer this service nationally as well, see links page for contacts
However, it's probably best to start by joining an organised Green-Lane run, where one of the GL Gurus has reconnoitred a route and checked that it is legal and driveable, and all you have to do is join the convoy and enjoy the scenery.
There are plenty of organised runs arranged by 4x4 clubs and open to members, and some organised by private individuals open to 'all-comers'. These tend to be found on the internet forums, and can be quite informal, and a good place to start.