The article reviews those major soil properties and traffic factors, which together influence subsoil compaction resulting from the passage of agricultural vehicles. Likewise, the effects of subsoil compaction on soil properties, processes and crop growth are discussed on several levels, from methods of measuring to the persistence of compaction effects. The risk of subsoil compaction exists whenever moist soils are loaded with heavy axle load and moderate to high ground contact stress. Subsoil compaction tends to be highly persistent. To avoid the risk of long-term deterioration, limits for the induction of mechanical stresses in the subsoil should be established through international teamwork.;