The modern terms short-sea shipping (sometimes unhyphenated), marine highway, and motorways of the sea, and the more historical terms coastal trade, coastal shipping, coasting trade, and coastwise trade, all encompass the movement of cargo and passengers mainly by sea along a coast, without crossing an ocean. Short-sea shipping (or a translation thereof) is the term used by the European Commission and commonly throughout the Europe Union. Many English-speaking countries have used the British terms coasting trade and coastwise trade. The United States maintained these term from its colonial era, including for domestic slave trade that shipped slaves by water from the Upper South to major markets, especially New Orleans. The US and began regulating general coasting trade as early as 1793, with "An act for enrolling and licensing ships and vessels to be employed in the coasting trade and fisheries, and for regulating the same", which passed Congress on 18 February that year. Over the years, it has been codified as Title 46 of the United States Code, Chapter 551 (46 USC Ch. 551), "Coastwise Trade". Some short-sea ship vessels are small enough to travel inland on inland waterways. Short-sea shipping includes the movements of wet and dry bulk cargoes, containers and passengers around the coast (say from Lisbon to Rotterdam or from New Orleans to Philadelphia). Typical ship sizes range from 1,000 DWT (tonnes deadweight – i.e., the amount of cargo they carry) to 15,000 DWT with drafts ranging from around . Typical (and mostly bulk) cargoes include grain, fertilisers, steel, coal, salt, stone, scrap, minerals, and oil products (such as diesel oil, kerosene, and aviation fuel), containers, and passengers. In Europe, short-sea shipping is at the forefront of the European Union's transportation policy. It currently accounts for roughly 40% of all freight moved in Europe. In the US, short-sea shipping has yet to be used to the extent it is in Europe, but there is some development. The main advantages promoted for this type of shipping are alleviation of congestion, decrease of air pollution, and overall cost savings to the shipper and a government. Shipping goods by ship (one 4,000 DWT vessel is equivalent to between 100–200 trucks) is far more efficient and cost-effective than road transport (though the goods, if bound inland, have to be transferred and delivered by truck) and is much less prone to theft and damage. Roughly 40% of all freight moved in Europe