It is proposed to improve functioning of transport vehicles in a way of dismemberment of its main masses with the help of tractive-joint devices with the further joint of these masses. Prismatic and turning kinematic pairs are combined in the tractive-joint devices. Limited full-scale and extended computer experiments were held. They proved efficiency of the proposed construction decision. The worked out mathematical model allows to investigate the operating modes of operations of three-unit lorry convoys at different travelling terms.