Short sea shipping (S3), the shipping of cargo or goods over relatively short distances or to nearby coastal ports, has many advantages over trucking and rail transport. In addition to reducing road congestion (its greatest benefit), waterborne transport often uses less fuel, costs less, produces less air pollution, is faster, and has greater space capacity as there are extensive shipping lanes. Despite its many selling points, S3 currently is hampered by a lack of adequate port infrastructure. Historically, rivers such as the Mississippi and Hudson were the primary means of cargo transport before the advent of the now-mature Interstate highway
The 2016 Summer Olympics boating and swimming events have put an international spotlight on what has been a long-running problem in Rio de Janeiro—untreated sewage and trash are clogging up major bays and waterways.