FIELD: automotive industry. SUBSTANCE: support-coupling car train contains a turntable fixed through brackets and a horizontal transverse axis on the tractor frame. The tractor of the road train is equipped with a hydraulic system with a source of working fluid pressure. A movable support is installed on the frame of the semi-trailer with the possibility of longitudinal movement relative to this frame, connected to the turntable by means of a pivot pin fixedly attached to the lower part of the movable support. The movable support is connected to the rear part of the semi-trailer frame by means of a double-acting power cylinder. A working fluid distributor is mounted on the turntable, connecting the hydraulic system of the tractor with the piston and rod cavities of the double-acting power cylinder through hydraulic lines. EFFECT: increasing the manoeuvrability and stability of the road train and increasing its safety. 1 cl, 2 dwg.