Cargo stands for what you are carrying through life, often more than you show. Heavy freight is traditionally read as responsibility; lost freight as worry about what will arrive safely.
When this appeared in your dream, what were you feeling?
My Cosmic Code has a private dream journal. Write a dream down and the app picks out the symbols in it, shows what dream books say about them and, over time, which words recur across your entries. The journal is stored on your device only.