An increasingly large amount of wheel traffic, from a variety of machines and transporters, is necessary for management and harvesting of grass and legume forage species. The soil compaction problem in perennial forage crop production has been recognised in both farming practice and in a number of research activities. Research has shown that any significant deterioration in soil conditions brought about by wheel traffic leads to impaired crop performance and yield, particularly if the traffic is imposed on wet soil or if the soil remains relatively wet during the main period of crop growth. The influence of traffic on land in forage cropping and the subsequent effects on yield, can be moderated by use of alternative machinery or traffic management systems. These alternatives are discussed, together with techniques for improvement of over-compacted grassland. Research has indicated that measures taken to avoid compaction are more likely to be beneficial than most ameliorative operations.