A joint connecting the cars of an articulated rail vehicle to provide a wide smooth-walled passage therebetween regardless of the relative attitudes of the cars. The joint and ends of each car are journaled on the bolster of a common truck. A rigidwalled tunnel assembly mounted on the bolster includes inner and outer telescoping tunnel shell members which are pivoted for relative pitch movement at the bolster. The tunnel shell members each include vertical arcuate surfaces cooperating with similar surfaces on the car ends to seal the ends of the tunnel passage. Side panels vertically hinged to the joint frame assembly are slidable within slots in the car bodies to externally seal the joint and provide a flush external appearance of the vehicle.