It is essential that you get out of the vehicle and inspect the ruts before attempting to drive them. Have you got enough ground clearance for all the vehicles in the group? Land Rovers will not be able to drive through ruts made by a farm tractor for example. You would simply ground the vehicle out on the high point in the centre and become hopelessly stuck. The photo opposite shows a Discovery high centred on the front Differential housing.
If the ruts are water filled how deep is the water? How much mud and silt is in the bottom? Are they shallow at the start becoming deeper as you progress? Could you cross them if you had to? Look for tell tale signs of differentials grounding out, indicated by scrapes on the route surface.
If you ever attempt to cross ruts it should be done at an angle of 45 to 50 degrees. This will allow one wheel at a time to pass through the ruts whilst the other three provide drive and forward momentum. Once again engage low box and diff lock if fitted, and use second or third gear dependent on the gradient.
As with driving in the mud, momentum is the key here. Try not to have to change gear during the rutted section as this will serve to decrease or even lose forward momentum altogether.
Once you are in a rut it is inevitable that you are going to remain there until the end of the rutted section. Think of them as tram or train lines. i.e. You are going to go where they take you. Once you have started the drive through maintain speed and accelerate gently to keep the momentum up.
It is also imperative that you always know in which direction your front wheels are pointing. The steering wheels if not in line with the ruts, will cause drag and increase the risk of losing momentum and stopping altogether. Another risk of not knowing where your wheels are pointing is that when the ruts end, the vehicle will then steer in whatever direction the wheels are pointing in and you may not be expecting that!.