Compared to road transport, inland waterway transport has lower CO2 emissions in relation to its energy input and emits considerably less hydrocarbons and carbon monoxide. A comparison with rail transport depends on the source of the electricity used for railway operation. If the energy for rail transport was supplied solely by caloric power plants, emission levels would be three times higher than those of inland navigation vessels. In Austria, rail transport has a slight advantage over inland waterway transport in terms of CO2 emissions, since the current share of hydropower in energy supply for rail transport is relatively high. Future increases in rail transport and hence in energy demand, however, in most cases can no longer be covered by hydropower (there are no new hydropower plants), so that in view of increasing transport volumes inland navigation will have a clearly positive CO2 balance compared to rail transport.