The Rhine was declared free to international navigation in 1868, and in 1919 navigation of the river between Basel and Krimpen, on the Lek, and Gorinchem, on the Waal, was placed under the authority of the Central Rhine Commission, with headquarters at Strasbourg. Navigation above Basel is controlled jointly by Switzerland and Germany.
The river carries more traffic than any other waterway in the world and is navigable by oceangoing vessels as far as Mannheim, Germany, by river barges to Basel, Switzerland, and by pleasure craft and sightseeing boats on navigable stretches as far as Rheinfelden, Switzerland. Coal, coke, grain, timber, and iron ore are the principal cargoes carried on the river. Rotterdam is the chief outlet to the North Sea, and Duisburg, the outlet for the Ruhr industrial region, is the leading river port. The Rhine-Main-Danube canal, completed in 1992, now allows barge traffic between the North Sea and the Black Sea.