Abstract: The invention relates to a traction vehicle (21) for semi-trailers (3), preferably for loading and unloading the semi-trailers (3) onto and off of a freight train (18), in particular, as part of the rolling highway, wherein the freight train (18) comprises several freight cars coupled to one another, in particular low-floor railcars (10), and a continuous driving lane in the longitudinal direction (20) of the train for moving the semi-trailers (3) on the freight train (18), wherein the traction vehicle (21) is unmanned and self-propelled, as well as a tractor-trailer unit (30) formed from the traction vehicle (21) and a semi-trailer (3), a method for transferring semi-trailers (3) from the railway (12) to the roadway and vice versa, as well as a freight transfer terminal thereto, and a method for transferring semi-trailers (3) from the railway (12) to the roadway and vice versa and for transporting the semi-trailers (3) on the railway (12).