Mobile construction for freight traffic

Mobile construction for freight traffic, in the form of a semi-trailer, characterised in that it at least consists of a first part (3) which can be coupled to a hauling vehicle (2); a second part (4) which is at least largely situated behind the first part (3) which can be moved in relation to the first part (3) in the longitudinal direction of the construction (1) and which is provided with or can be provided with wheels (5-6-7); and a third part (8) which can be moved in the longitudinal direction of the construction (1) in relation to the first part (3) as well as the second part (4).