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
Arch dams, classically curved monoliths situated in narrow valleys, are not as common as other types of dams, such as embankment dams and gravity dams. ENR takes a look at some of the biggest arch dams in the world, both completed and under construction.