The combined transport may cause a delay in shipment or even lose the goods completely. Besides, the formalities are too complicated.
联运很可能会引起运输延误甚至造成货品全部丢失。另外，手续也太复杂。
英语百科
Combined transport
Combined transport is a form of intermodal transport, which is the movement of goods in one and the same loading unit or road vehicle, using successively two or more modes of transport without handling the goods themselves in changing modes. Combined transport is intermodal transport where the major part of the journey is by rail, inland waterways or sea, and any initial and/or final legs carried out by road are as short as possible.