Tons Tons-km Revenue (2004)
Road ? 6,000 to 8,500 billion tons-km $796 billion
Rail 8,930 million tons 7,773 billion tons-km $330 billion
Maritime 6,758 million tons (loaded) 6,787 million tons (unloaded) 44,474 billion tons-km $484 billion
Source: Review of Maritime Transport, International Railway Association
Load of the Global Transport System by Mode
The load of the road transport system is very difficult to assess considering the variety of transport companies, many of which are of small size. Comparatively, rail and maritime companies are much less numerous (one national rail company in many cases) and can report accurate data about the volume they handle.