Source: Shipping density data adapted from National Center for Ecological Analysis and Synthesis, A Global Map of Human Impacts to Marine Ecosystems.
(Detailed PDF Map)

Maritime Shipping Routes and Strategic Passages

The above map represents the shipping routes density for the global maritime transport system as well as the main strategic passages forcing a convergence of shipping routes at specific locations. These routes are supporting the bulk of the traffic, but numerous other routes are existing (namely for coastal shipping), depending on the origin and the destination of the maritime shipment.

Maritime routes are spaces of a few kilometers wide trying to avoid the discontinuities of land transport. They are a function of obligatory points of passage (which are strategic places), physical constraints (coasts, winds, marine currents, depth, reefs, ice) and political borders. The majority of the maritime circulation takes place along coasts and three continents have limited fluvial trade (Africa, Australia and Asia; except China). Transatlantic and transpacific traffic concerns a wide variety of ports, so there are numerous routes, most of them having a path along the great circle. Trans-Indian ocean traffic is dominantly intermediary traffic between Pacific Asia and Europe, implying a series of more clearly defined routes, namely between the Strait of Malacca and Bab el-Mandab.

The location of resources such as oil and minerals determines maritime roads for bulks. The importance of large manufacturing regions and consumption markets are structuring exchanges of semi-finished and finished goods. Oil products and minerals are the most transported commodities. Over 30 million barrels per day are going through the relatively narrow shipping lanes portrayed above. These routes are known as chokepoints due to their potential for closure. Disruption of oil flows through any of these export routes could have a significant impact on world oil prices.