Transport or transportation is the movement of humans, animals and cargo from one location to another. Modes of transport include aviation, land (rail transport and road transport), ship transport, cable transport, pipeline and space transport. The field can be divided into infrastructure, and operations. Transport is important because it enables trade between people, which is essential for the development of .
Transport infrastructure consists of the fixed installations, including , , airways, , and pipelines and terminals such as , train station, , , trucking terminals, refueling depots (including fueling docks and ) and . Terminals may be used both for interchange of passengers and cargo and for maintenance.
Operations deal with the way the vehicles are operated, and the procedures set for this purpose, including financing, legalities, and policies. In the transport industry, operations and ownership of infrastructure can be either public or private, depending on the country and mode.
Passenger transport may be public transport, where operators provide scheduled services, or private. Freight transport has become focused on containerization, although bulk transport is used for large volumes of durable items. Transport plays an important part in economic growth and globalization, but most types cause air pollution and Land use. While it is heavily subsidized by governments, good planning of transport is essential to make traffic flow and restrain urban sprawl.
The first forms of road transport involved animals, such as (domesticated in the 4th or the 3rd millennium BCE), oxen (from about 8000 BCE)
telegraphy, communication became instant and independent of the transport of physical objects. The invention of the steam engine, closely followed by its application in rail transport, made land transport independent of human or animal muscles. Both speed and capacity increased rapidly, allowing specialization through manufacturing being located independently of natural resources. The 19th century also saw the development of the steam ship, which sped up global transport.
With the development of the combustion engine and the automobile around 1900, road transport became more competitive again, and mechanical private transport originated. The first "modern" highways were constructed during the 19th century with macadam. Later, tarmac and concrete became the dominant paving materials. In 1903 the Wright brothers demonstrated the first successful controllable airplane, and after World War I (1914–1918) aircraft became a fast way to transport people and express goods over long distances.Bardi, Coyle and Novack, 2006: 158
After World War II (1939–1945) the automobile and airlines took higher shares of transport, reducing rail and water to freight and short-haul passenger services.Cooper et al., 1998: 277 Scientific spaceflight began in the 1950s, with rapid growth until the 1970s, when interest dwindled. In the 1950s the introduction of containerization gave massive efficiency gains in freight transport, fostering globalization.Bardi, Coyle and Novack, 2006: 211–14 International air travel became much more accessible in the 1960s with the commercialization of the jet engine. Along with the growth in automobiles and motorways, rail and water transport declined in relative importance. After the introduction of the Shinkansen in Japan in 1964, high-speed rail in Asia and Europe started attracting passengers on long-haul routes away from the airlines.
Early in U.S. history, private joint-stock corporations owned most aqueducts, , canals, railroads, roads, and tunnels. Most such transportation infrastructure came under government control in the late 19th and early 20th centuries, culminating in the nationalization of inter-city passenger rail-service with the establishment of Amtrak. Recently, however, a movement to privatize roads and other infrastructure has gained some ground and adherents. Clifford Winston, Last Exit: Privatization and Deregulation of the U.S. Transportation System (Washington, D.C.: Brookings Institution, 2010).
Although humans are able to walk without infrastructure, the transport can be enhanced through the use of roads, especially when using the human power with vehicles, such as bicycles and inline skates. Human-powered vehicles have also been developed for difficult environments, such as snow and water, by watercraft rowing and skiing; even the air can be entered with human-powered aircraft.
Two things necessary for aircraft are air flow over the wings for lift and an area for landing. The majority of aircraft also need an airport with the infrastructure to receive maintenance, restocking, refueling and for the loading and unloading of crew, cargo, and passengers. While the vast majority of aircraft land and take off on land, some are capable of take-off and landing on ice, snow, and calm water.
The aircraft is the second fastest method of transport, after the rocket. Commercial jets can reach up to , single-engine aircraft . Aviation is able to quickly transport people and limited amounts of cargo over longer distances, but incurs high costs and energy use; for short distances or in inaccessible places can be used.Cooper et al., 1998: 281 As of April 28, 2009, The Guardian article notes that, "the WHO estimates that up to 500,000 people are on planes at any time." Swine flu prompts EU warning on travel to US. The Guardian. April 28, 2009.
Rail transport is where a train runs along a set of two parallel steel rails, known as a railway or railroad. The rails are anchored perpendicular to railroad tie (or sleepers) of timber, concrete or steel, to maintain a consistent distance apart, or rail gauge. The rails and perpendicular beams are placed on a foundation made of concrete or compressed soil and gravel in a bed of ballast. Alternative methods include monorail and maglev.
A train consists of one or more connected vehicles that operate on the rails. Propulsion is commonly provided by a locomotive, that hauls a series of unpowered cars, that can carry passengers or freight. The locomotive can be powered by steam locomotive, diesel or by electricity supplied by trackside systems. Alternatively, some or all the cars can be powered, known as a multiple unit. Also, a train can be powered by horsecar, funicular, gravity, pneumatics and . Railed vehicles move with much less friction than rubber tires on paved roads, making trains more energy efficient, though not as efficient as ships.
Inter-city rail trains are long-haul services connecting cities;Cooper et al, 1998: 279 modern high-speed rail is capable of speeds up to , but this requires specially built track. Regional rail and commuter rail trains feed cities from suburbs and surrounding areas, while intra-urban transport is performed by high-capacity and , often making up the backbone of a city's public transport. Freight trains traditionally used , requiring manual loading and unloading of the cargo. Since the 1960s, have become the dominant solution for general freight, while large quantities of bulk are transported by dedicated trains.
The most common road vehicle is the automobile; a passenger vehicle that carries its own car engine. Other users of roads include , , motorcycles, bicycles and pedestrians. As of 2010, there were 1.015 billion automobiles worldwide. Road transport offers a complete freedom to road users to transfer the vehicle from one lane to the other and from one road to another according to the need and convenience. This flexibility of changes in location, direction, speed, and timings of travel is not available to other modes of transport. It is possible to provide door to door service only by road transport.
Automobiles provide high flexibility with low capacity, but require high energy and area use, and are the main source of noise pollution and air pollution in cities; buses allow for more efficient travel at the cost of reduced flexibility.Cooper et al., 1998: 278 Road transport by truck is often the initial and final stage of freight transport.
In the 19th century, the first steam ships were developed, using a steam engine to drive a paddle wheel or propeller to move the ship. The steam was produced in a boiler using wood or coal and fed through a steam external combustion engine. Now most ships have an internal combustion engine using a slightly refined type of petroleum called bunker fuel. Some ships, such as , use nuclear power to produce the steam. or craft still use wind power, while some smaller craft use internal combustion engines to drive one or more , or in the case of jet boats, an inboard water jet. In shallow draft areas, hovercraft are propelled by large pusher-prop fans. (See Marine propulsion.)
Although it is slow compared to other transportation, modern sea transport is a highly efficient method of transporting large quantities of goods. Commercial vessels, nearly 35,000 in number, carried 7.4 billion tons of cargo in 2007.The United Nations Conference on Trade and Development (UNCTAD) 2007, p. x and p. 32. Transport by water is significantly less costly than air transport for transcontinental shipping;Stopford, 1997: 4–6 short sea shipping and ferry remain viable in coastal areas.Stopford, 1997: 8–9Cooper et al., 1998: 280
Cable transport is a broad mode where vehicles are pulled by Wire rope instead of an internal power source. It is most commonly used at steep gradient. Typical solutions include aerial tramway, , escalator and ; some of these are also categorized as conveyor belt transport.
Space transport is transport out of Earth's atmosphere into outer space by means of a spacecraft. While large amounts of research have gone into technology, it is rarely used except to put satellites into orbit, and conduct scientific experiments. However, man has landed on the moon, and probes have been sent to all the planets of the Solar System.
Suborbital spaceflight is the fastest of the existing and planned transport systems from a place on Earth to a distant "other place" on Earth. Faster transport could be achieved through part of a low Earth orbit, or following that trajectory even faster using the propulsion of the rocket to steer it.
Terminals such as airports, ports, and stations, are locations where passengers and freight can be transferred from one vehicle or mode to another. For passenger transport, terminals are integrating different modes to allow riders, who are interchanging between modes, to take advantage of each mode's benefits. For instance, airport rail links connect airports to the city centers and suburbs. The terminals for automobiles are , while buses and coaches can operate from simple stops.Cooper et al., 1998: 275–76 For freight, terminals act as transshipment points, though some cargo is transported directly from the point of production to the point of use.
The financing of infrastructure can either be government or private. Transport is often a natural monopoly and a necessity for the public; roads, and in some countries railways and airports are funded through taxation. New infrastructure projects can have high costs and are often financed through debt. Many infrastructure owners, therefore, impose usage fees, such as landing fees at airports, or on roads. Independent of this, authorities may impose on the purchase or use of vehicles. Because of poor forecasting and overestimation of passenger numbers by planners, there is frequently a benefits shortfall for transport infrastructure projects.Bent Flyvbjerg, Mette K. Skamris Holm, and Søren L. Buhl, "How (In)Accurate Are Demand Forecasts in Public Works Projects", Journal of the American Planning Association 71:2, pp. 131–46.
Vehicles are most commonly staffed by a driving. However, some systems, such as and some rapid transits, are fully automation. For passenger transport, the vehicle must have a compartment, seat, or platform for the passengers. Simple vehicles, such as automobiles, bicycles or simple aircraft, may have one of the passengers as a driver.
Short-haul transport is dominated by the automobile and mass transit. The latter consists of in rural and small cities, supplemented with commuter rail, trams and rapid transit in larger cities. Long-haul transport involves the use of the automobile, trains, coaches and aircraft, the last of which have become predominantly used for the longest, including intercontinental, travel. Intermodal passenger transport is where a journey is performed through the use of several modes of transport; since all human transport normally starts and ends with walking, all passenger transport can be considered intermodal. Public transport may also involve the intermediate change of vehicle, within or across modes, at a transport hub, such as a bus station or railway station.
Taxis and buses can be found on both ends of the public transport spectrum. Buses are the cheapest mode of transport but are not necessarily flexible, and taxis are very flexible but more expensive. In the middle is demand-responsive transport, offering flexibility whilst remaining affordable.
International travel may be restricted for some individuals due to legislation and visa requirements.
Air medical services is a comprehensive term covering the use of air transportation to move patients to and from healthcare facilities and accident scenes. Personnel provide comprehensive prehospital and emergency and critical care to all types of patients during aeromedical evacuation or rescue operations, aboard helicopters, propeller aircraft, or jet aircraft.
Containerization, with the standardization of on all vehicles and at all ports, has revolutionized international and domestic trade, offering a huge reduction in transshipment costs. Traditionally, all cargo had to be manually loaded and unloaded into the haul of any ship or car; containerization allows for automated handling and transfer between modes, and the standardized sizes allow for gains in economy of scale in vehicle operation. This has been one of the key driving factors in international trade and globalization since the 1950s.
Bulk transport is common with cargo that can be handled roughly without deterioration; typical examples are ore, coal, cereals and petroleum. Because of the uniformity of the product, mechanical handling can allow enormous quantities to be handled quickly and efficiently. The low value of the cargo combined with high volume also means that economies of scale become essential in transport, and gigantic ships and whole trains are commonly used to transport bulk. Liquid products with sufficient volume may also be transported by pipeline.
Cargo airline has become more common for products of high value; while less than one percent of world transport by volume is by airline, it amounts to forty percent of the value. Time has become especially important in regards to principles such as postponement and just-in-time within the value chain, resulting in a high willingness to pay for quick delivery of key components or items of high value-to-weight ratio.Chopra and Meindl, 2007: 328 In addition to mail, common items sent by air include electronics and fashion clothing.
Transport is a key necessity for specialization—allowing production and consumption of products to occur at different locations. Transport has throughout history been a spur to expansion; better transport allows more trade and a greater spread of people. Economic growth has always been dependent on increasing the capacity and rationality of transport.Stopford, 1997: 2 But the infrastructure and operation of transport have a great impact on the land and is the largest drainer of energy, making transport sustainability a major issue.
Due to the way modern cities and communities are planned and operated, a physical distinction between home and work is usually created, forcing people to transport themselves to places of work, study, or leisure, as well as to temporarily relocate for other daily activities. Passenger transport is also the essence of tourism, a major part of transport. Commerce requires the transport of people to conduct business, either to allow face-to-face communication for important decisions or to move specialists from their regular place of work to sites where they are needed.
land use depends on mode of transport, with public transport allowing for better spatial utilization. Good land use keeps common activities close to people's homes and places higher-density development closer to transport lines and hubs, to minimize the need for transport. There are economies of agglomeration. Beyond transportation some land uses are more efficient when clustered. Transportation facilities consume land, and in cities, pavement (devoted to streets and parking) can easily exceed 20 percent of the total land use. An efficient transport system can reduce land waste.
Too much infrastructure and too much smoothing for maximum vehicle throughput means that in many cities there is too much traffic and many—if not all—of the negative impacts that come with it. It is only in recent years that traditional practices have started to be questioned in many places, and as a result of new types of analysis which bring in a much broader range of skills than those traditionally relied on—spanning such areas as environmental impact analysis, public health, sociologists as well as economists—the viability of the old mobility solutions is increasingly being questioned.
Transport is a major use of energy and burns most of the world's petroleum. This creates air pollution, including and , and is a significant contributor to global warming through emission of carbon dioxide, for which transport is the fastest-growing emission sector. By subsector, road transport is the largest contributor to global warming. Climate forcing from the transport sectors, Jan Fuglestvedt, Terje Berntsen, Gunnar Myhre, Kristin Rypdal, and Ragnhild Bieltvedt Skeie, January 15, 2008, vol. 105, no. 2, PNAS.org Environmental regulations in developed countries have reduced individual vehicles' emissions; however, this has been offset by increases in the numbers of vehicles and in the use of each vehicle. Some pathways to reduce the carbon emissions of road vehicles considerably have been studied.Data on the barriers and motivators to more sustainable transport behaviour is available in the UK Department for Transport study " Climate Change and Transport Choices" published in December 2010. Energy use and emissions vary largely between modes, causing environmentalism to call for a transition from air and road to rail and human-powered transport, as well as increased transport electrification and energy efficiency.
Other environmental impacts of transport systems include traffic congestion and automobile-oriented urban sprawl, which can consume natural habitat and agricultural lands. By reducing transportation emissions globally, it is predicted that there will be significant positive effects on Earth's air quality, acid rain, smog and climate change.