Abstract: In a highway train, a wheeled and steerable, motor-driven vehicle is combined with at least a first load carrier having its forward end portion rested on a first "fifth wheel" supported by the rear portion of the tractive vehicle. An auxiliary wheeled vehicle has a front portion with a second "fifth wheel" supporting the rearward end portion of the first load carrier. A second load carrier has its forward end portion rested on a third "fifth wheel" supported by a rear portion of the auxiliary vehicle. An additional wheeled vehicle supports the rear end portion of the second load carrier. While en route, the first load carrier is supported solely by the first and second "fifth wheels" in such a manner that it is free to occupy a limited angular position in a generally horizontal plane, relative to both the tractive vehicle and the auxiliary vehicle.