The practice of following predetermined routes for shipping originated in 1898 and was adopted, for reasons of safety, by shipping companies operating passenger vessels across the North Atlantic. Related provisions were subsequently incorporated into the original SOLAS Convention.
Traffic separation schemes and other vessel routing systems have now been established in most of the major congested, shipping areas of the world, and the number of collisions and groundings has been reduced.
Elements used in vessel routing:
Traffic Separation Scheme: a routing measure aimed at the separation of opposing streams of traffic by appropriate means and by the establishment of traffic lanes
Traffic Lane: an area within defined limits in which one-way traffic is established. natural obstacles, including those forming separation zones, may constitute a boundary
Separation Zone or Line: a zone or line separating traffic lanes in which vessels are proceeding in opposite or nearly opposite directions; or separating a traffic lane from the adjacent sea area; or separating traffic lanes designated for particular classes of a vessel proceeding in the same direction
Roundabout: a separation point or circular separation zone and a circular traffic lane within defined limits
Inshore Traffic Zone: a designated area between the landward boundary of a traffic separation scheme and the adjacent coast
Recommended Route: a route of undefined width, for the convenience of vessels in transit, which is often marked by centreline buoys
Deep-Water Route: a route within defined limits that have been accurately surveyed for clearance of sea bottom and submerged articles
Precautionary Area: an area within defined limits where vessels must navigate with particular caution and within which the direction of flow of traffic may be recommended
Area to be avoided: an area within defined limits in which either navigation is particularly hazardous or it is exceptionally important to avoid casualties and which should be avoided by all vessels, or by certain classes of vessels