The invention relates to a heavy vehicle, such as a transport vehicle or a 'civil engineering' vehicle, of a mass greater than 500 metric tons, fitted with tires of radial structure of a diameter greater than three meters fifty having an axial width greater than 37 inches, and comprising a front steering axle provided with at least two tires and at least one rear axle comprising at least two tires and by which is transmitted at least part of the motive power. According to the invention, the vehicle comprises a third, intermediate axle comprising at least two tires, said intermediate axle being a steering axle and said intermediate axle being liftable in such a way that, in the raised position, the tires of the axle are not in contact with the ground.