The increased awareness of environmental issues has created a need for evaluating the usefulness of mobility models for Nordic forestry conditions. A frame of reference based on the WES-method was used for developing empirical rut depth models for moraine forest sites. It was found that the penetration resistance in critical layers alone was an adequate soil input variable, even if the studied soils had very large variations in stoniness. When comparing the results with earlier models developed for organic soils, it was found that the same models apply for both types of soils. The method and models seem reliable enough for avoiding operations on too risky soils
