Why ships still carry almost all the world's freight
In 2015 the world moved 108 trillion tonne-kilometres of cargo, and about 70 percent of it went by sea. Roads handled 18 percent, rail 9 percent, and air under a quarter of one percent. Planes are the fastest way to ship goods long distances, but they are also by far the priciest.
Early societies loaded goods onto horses, camels and donkeys. The wheel, invented in Mesopotamia around 5000 BCE, let animals pull carts instead, and Roman roads later tied the empire's cities into one trading network. On the Silk Road, camel caravans rarely covered the whole route; merchants handed goods on to others at each stage, with silk heading west and wool, gold and silver travelling east.
Industrial Britain built a dense canal system across the Midlands, then railways that started with horse-drawn wagons before switching to steam. The first air freight shipment followed in 1910, not long after the Wright brothers flew, yet demand stayed modest for decades. FedEx, founded in 1973, changed that by flying aircraft devoted solely to cargo rather than tucking parcels into passenger planes. The word logistics itself was borrowed from the military.
According to a 2018 United Nations report, merchant shipping carries 80 to 90 percent of international trade and 60 to 70 percent of its value. Barges still haul bulk cargo along rivers and canals. Ground transport by truck or train usually costs more than sea and less than air, and it is almost always needed at both ends, since factories cannot all sit beside ports.
Standard containers make it easy to shift loads between ship, train, plane and truck at hubs such as stations and airports, all under one contract. International door-to-door services quote a single price covering handling, customs and import duties, whereas ordinary shipping rates leave those charges to the buyer. Digital marketplaces now let small firms book part-container loads once reserved for big industrial shippers, and companies are trialling self-driving trucks and delivery robots to cut labour costs.
Source: Freight transport
