Since some countries, such as Morocco/ West Sahara, the USA, some Pacific islands and the USSR have deposits that are important on an international scale, while Japan and many European countries have no indigenous supplies, the main traffic routes are predictable.
Kuba amazwe anje nge Movocco/Ntsona Sahava; USA nezinye iziqithi ze Pacific ne-USSR zinogciniso olubalulekileyo kunyukela kwamanzi ngelixa iJapan namanye amazwe ase-Europe abaxhasi abayi nkulelwano, ezona ndlela zixakeke kakhulu sezisaziwa.