Reliable estimation of mobility in harsh wetlands environment and development of guidelines for forming the structure of vehicles and machines running gear still remains an open issue. This paper presents the basic methods of determining the ability of overcoming ground of low bearing capacity by wheeled and tracked vehicles and their theoretical basics. For the evaluation of ability to overcome such ground the analytical methods were used - MMP method and VCI method, which take into account the value of maximum pressure and geometrical dimensions of running gear. Based on the available data their comparison, assessment of the credibility and usefulness during research on development of equipment operating in harsh terrain were performed. Moreover, taking into consideration the impact of running gear on the ground the division on technical, economic and ecological class of mobility was conducted.