Five basic modes of freight transportation – sea, rail, road, air and parcel post – are used, either individually or in combination, in international transportation. Business Units should consider modes of transport that are both economical and efficient. In general, rail, road and air transport costs are comparatively higher than freight by sea, thus UNDP recommends sea transport. To ensure sound delivery however, it is advisable to select a conference liner, which operates along definite routes and pre-determined ports of call.