Functional unit in life$-$cycle assessment: transport of goods Transport of goods is another important energy$-$consuming and greenhouse$-$gas$-$emitting activity, and, as for personal mobility, there are choices in modes of freight transportation.

In the table below, data are presented on three modes of freight transportation: by road $($heavy trucks$),$ by rail, and by ship $($oceanic freighter$).$ Use these data to answer the questions that follow.

Annual Average Freight Transportation Da