Transport

• 1. The Intentional Movement

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  Transport is the intentional movement of humans, animals, and goods from one location to another. That single idea splits into air, land, water, cable, pipelines, and even space. It is the thing that enables human trade, which the source calls essential to the development of civilizations. But the field is messier than the word suggests. It breaks into three parts: infrastructure, vehicles, and operations. How does a system this large hold together when a privately owned car shares a city with government-owned urban transit? Why does the fastest method on Earth turn out to be a rocket, and the most efficient for bulk goods a slow ship? What forces a person to move at all, when home and work could in theory sit side by side? The answers run from human muscle to nuclear reactors, from canoes cut out of tree trunks to spacecraft sent to every planet of the Solar System. They also run straight into a problem. Transport is the largest drainer of energy, and burns most of the world's petroleum. The chapters ahead trace how movement built the modern world and what it now costs to keep moving.

• 2. Powered By Muscle

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  Human muscle-power was the first engine, in the form of walking, running, and swimming. The source classes this as sustainable transport, and notes it survives for reasons of cost-saving, leisure, physical exercise, and environmentalism. In underdeveloped or inaccessible regions it is sometimes the only type available. Roads, sidewalks, and shared-use paths can enhance what a body does on its own. Human power has also been paired with vehicles like bicycles, inline skates, and wheelchairs, and pushed into difficult environments through rowing, skiing, and even human-powered aircraft that fly through the air. Working animals carried the next leap. Humans ride some directly, load others as pack animals, or harness them in teams to pull sleds or wheeled vehicles. The animals noted for muscular strength are the bovids, equids, and camelids, though the source also lists the dog, the elephant, the ostrich, the sheep, and even the dolphin. These creatures still earn their place in rough terrain that automotive transport cannot easily reach. Two inventions made animal labor far more productive: the wheel and the sled. Horses were domesticated in the 4th or the 3rd millennium BCE, and oxen from about 8000 BCE, hauling goods over dirt tracks that often followed game trails.

• 3. Riding On Rails

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  Two parallel steel rails, anchored perpendicular to ties of timber, concrete, or steel, set the distance called gauge. That bed of ballast carries wheeled vehicles known as rolling stock, and where dual gauge is needed the track runs three or four rails for trains of two or three gauges. For steep grades a railway can add a toothed rack rail just for traction. Propulsion usually comes from a locomotive hauling unpowered cars, drawing on steam, diesel, gas turbine, or electricity from trackside systems. When some or all of the cars are powered, the result is a multiple unit. A tram is the smaller cousin, running on rails set into the streets, typically electric but historically pulled by horses, cables, gravity, or pneumatics. Railed vehicles move with far less friction than rubber tires on paved roads, which makes trains energy efficient, though still not as efficient as ships. Speed climbs steeply on purpose-built track. Modern high-speed rail reaches up to 350 km/h, while commercial maglev transport in Shanghai runs at 460 km/h. Freight told a parallel story. Box cars once demanded manual loading, but since the 1980s container trains became the dominant solution for general freight. Bulk now travels on dedicated rolling stock, including tank cars specially designed for hazardous materials. Long-haul rail later began pulling passengers back from the airlines, a shift that started with one Japanese line.

• 4. The Flexible Road

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  A road is an identifiable route, way, or path between two or more places. Many historically were just recognizable routes with no formal construction or maintenance, and in cities they double as streets, serving as urban space and route at once. The most common road vehicle, at least within the U.S., is the automobile, a light-duty wheeled passenger vehicle carrying its own motor. The numbers are staggering. As of 2015 there were 950 million passenger cars worldwide, with a projected total of 2.5 billion in 2050. Road transport sells flexibility. Users can move a vehicle from lane to lane and road to road according to need, a combination of changes in location, direction, speed, and timing no other motorized mode offers. It is the only way to provide efficient intracity door-to-door service. That freedom carries a bill. A road system consumes large amounts of space, costs much to build and maintain, leads to urban congestion, and has only limited ability to achieve economies of scale. Automobiles pair high flexibility with low capacity, demand high energy and area, and are the main source of harmful noise and air pollution in cities. Buses trade some flexibility for more efficient travel. The first modern highways arrived in the 19th century built with macadam, before tarmac and concrete took over as the dominant paving materials.

• 5. Lift And Buoyancy

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  A fixed-wing aircraft generates lift from the movement of air over its wings, distinct from the rotary wings of a helicopter, while a gyroplane is both. The aircraft is the second fastest method of transport, after the rocket: commercial jets reach up to 955 km/h and single-engine aircraft 555 km/h. The trade is speed for cost. Aviation moves people and limited cargo over long distances at high cost and energy use, and for inaccessible places helicopters fill in. The scale of the sky is constant. As of the 28th of April 2009, a Guardian article noted the WHO estimate that up to 500,000 people are on planes at any time. Lighter-than-air craft work on a different principle. An aerostat gains lift from a gas less dense than the surrounding atmosphere, usually helium, since hydrogen is highly flammable, or from heated air in hot air balloons. Zeppelins were used on long-ranged bombing raids during World War I. Water offered the oldest answer of all. The first watercraft were canoes cut from tree trunks or made of animal hides, and before the Industrial Revolution water was the only efficient way to move large quantities over large distances. Steam ships arrived in the 19th century, driving a paddle wheel or propeller from a boiler burning wood or coal. Today most commercial ships run an internal combustion engine on bunker fuel, while submarines use nuclear marine propulsion. Slow as it is, sea transport moves enormous loads cheaply. Nearly 35,000 commercial vessels carried 7.4 billion tons of cargo in 2007.

• 6. Pipelines And Beyond Earth

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  Pipeline transport pushes goods through a pipe, most commonly chemically stable liquids, vapors, and gases, with a slurry used to carry solids. Pneumatic tubes can send solid capsules on compressed air. Short-distance systems handle sewage, slurry, water, and even beer, while long-distance networks move freshwater, petroleum, and natural gas. Cable transport pulls vehicles by cable rather than an onboard engine, favored on steep gradient. The family includes aerial tramways, funiculars, elevators, material ropeways, and ski lifts, plus the zip line, which uses gravity alone. The most dramatic mode leaves the planet entirely. Spaceflight carries a spacecraft outside Earth's atmosphere, most often to place satellites in Earth orbit. Human spaceflight missions have landed on the Moon and rotate crew-members to space stations, while uncrewed spacecraft have been sent to all the planets of the Solar System. Suborbital spaceflight is the fastest of the existing and planned systems from one point on Earth to another. These rocket-propelled systems could potentially deliver passengers or cargo anywhere on the globe in less than 90 minutes.

• 7. Containers And Commerce

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  Containerization revolutionized international and domestic trade by standardizing ISO containers across all vehicles and ports. Before it, all cargo had to be manually loaded and unloaded into the hull of any ship or car. Standardized sizes brought automated handling, transfers between modes, and economies of scale, a key driving factor in international trade and globalization since the 1950s. Bulk transport followed a different logic. Cargo that survives rough handling, like ore, coal, cereals, and petroleum, moves in enormous quantities because uniformity allows fast mechanical handling. Low value plus high volume makes economies of scale essential, so gigantic ships and whole trains are common. Air freight inverts that math. Less than one percent of world transport by volume travels by airline, yet it amounts to forty percent of the value. Principles like postponement and just-in-time raise the willingness to pay for quick delivery of high value-to-weight items. Beyond mail, common air cargo includes electronics and fashion clothing. The whole apparatus has a name and a critique. Logistics covers the entire process from producer to consumer, including storage, transshipment, warehousing, material-handling, and packaging. Yet in lean thinking, moving materials from one location to another counts as one of the seven wastes, the Japanese term muda, because it adds no value to a product.

• 8. The Cost Of Moving

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  Road traffic accidents are one of the leading causes of death worldwide, killing or injuring nearly 1.35 million people every year. Significant accidents draw review by law enforcement and independent investigators from a safety board, such as the NTSB in the U.S. Statistics gathered from accidents are analyzed to determine measures that lower the casualty rate, supported by emergency medical services and sea rescue. The environmental ledger is heavier still. According to the International Energy Agency, the transportation sector accounts for more than one-third of CO2 emissions globally in the early 2020s, with road transport the largest contributor to global warming. In 2022 global CO2 emissions from the sector grew by more than 250 Mt CO2 to nearly 8 Gt CO2, more than 3% above 2021, with aviation a significant part of that increase. Emissions vary sharply by mode. City buses produce about 0.3 kg per passenger mile, dropping to about 0.08 kg on long-distance trips over 20 miles, while commuter trains run around 0.17 kg and long-distance trains about 0.19 kg per passenger mile. The world keeps urbanizing into this. The United Nations reports 55% of the world's population live in cities, expected to rise to 68% by 2050. Recognition of the stakes has been formal and global. The United Nations first acknowledged transport's role in sustainable development at the 1992 Earth summit, and meeting sustainable transport targets is now called particularly important to achieving the Paris Agreement.