Many effects have been observed as a consequence of introducing machinery to agricultural land and forestry. In the main these effects are due to induced compaction. Moreover, off-road development must look to more and more vehicles with different types of tyres for different purposes. Thus it is important to deal with the problems of flexible tyres in order to see how it may be possible to adapt their design to the unprepared soils on which they must run. The characteristics necessary for developing new concepts must include firstly the flexibility of the type identifying the properties of each of the principal parts of the tyre in transmitting loads to the supporting surface.