To increase the mobility of tracked vehicles in deep snow with the payload capacity preserved and the maintenance costs kept low, improved design is required. To optimise new tracked vehicles intended to operate in deep snow, more knowledge about the vehicle design parameters that affect the tractive performance in deep snow is needed, especially regarding the design of the track assembly and of the vehicle belly. A new tracked vehicle has been developed for use in studying the influence of different vehicle parameters on mobility in soft terrain, particulary on muskegs and in deep snow. The vehicle makes it possible to vary several design parameters in the field, and it is equipped with transducers to measure the vehicle thrust, track motion resistance, belly resistance, drawbar pull, the trim angle of the vehicle and the slip between the tracks and snow.Experimental studies show that increased nominal ground pressure significantly decreases the tractive performance of the vehicle. Increasing the ground clearance and moving the centre of gravity well ahead of the midpoint of the track contact length increase the drawbar pull of the vehicle