A shipping route is a trade route used by merchant ships. Early routes usually were coastal in nature as navigators had to rely on the coastal landmarks. As the knowledge of navigation and map-making increased, shipping routes became less dependent on coastal landmarks and spanned to larger seas and oceans.
In modern global commerce, merchant shipping follows the most time efficient route between available ports. The size of the ship is a key factor in determining the best route, for example a ship designed to fit through the Suez Canal in Africa with a maximum of cargo will not fit through the Panama Canal in Central America, and a cargo ship designed for maximum capacity of the Panama Canal will not fit through the Wetland Canal between Lake Ontario and Lake Erie. Ships too large for a given route must necessarily seek an alternate pathway.
Starting with test ships in 2009 and the first commercial cargoes in 2010 the Northern Sea Route, a passage between the polar ice cap and the coast of Siberia has been opened. This allows ships travelling from Europe which can not fit through the Panama Canal to reach the west coast of North America much more quickly and is also much shorter for ships going between Europe and Asia, but the route is only available on average for two months of the year. Even so the fuel and time savings make it well worth the risk during the period when the route is open. Along North America the Northwest Passage similarly has opened but only local ships have used it so far.
