Although there has been considerable effort devoted to the study of soil vehicle interaction and soil working processes, very little attention has been paid to the effect of vegetation on these processes. Greater attention is being given to the reinforcement of soils using geotextiles, and the use of polymer based structural matting to provide temporary refurbishment to weakened soils for vehicle passage over strategically important areas. It is now pertinent therefore to examine the contribution made by fibrous material to soil strength and the possibility of enhancing the strength of soils by the addition of artificial fibres. Clearly the traction that a vehicle is able to mobilise from a soil is determined by certain vehicle parameters e.g. weight, contact area, tyre tread or track configuration and certain soil properties. Equally the sinkage and rolling resistance of a vehicle is governed by vehicle characteristics e.g. wheel size, track size, and weight and certain soil properties. In each case the dominant soil characteristic which affects traction, sinkage and and rolling resistance is shear strength. A high shear strength will enhance traction and reduce resistance giving rise to a higher draw-bar pull and generally better cross-country mobility. Similarly, the greater the shear strength of soil, the greater will be the forces acting on earth working implements and the energy dissipated during working.