14/09/2023
News article on Transport
The movement of people and goods from place to place is known as transportation. Together with communication—the movement of ideas—transportation has been essential in bringing about the integration of regions and nations into a single world community. Transportation movements, combined into various systems and networks, are by way of land, water, and air and by such means as automobile, airplane, railroad, ship, and pipeline.
THE NEED FOR TRANSPORTATION
Transportation is needed because few economic resources—raw materials, fuels, food, manufactured goods—are located where they are wanted. Each region or place on Earth produces more than it consumes of some goods and services and less than it consumes of others. Through transportation, goods are moved from where there are surpluses to where there are shortages. Improved transportation has extended the areas in which various goods can be profitably marketed and thus has helped make the goods widely available.
The moving of people to places of work, education, and recreation and for their other needs and wants also requires transportation. Like goods, people are moved to where they are needed. But as decision makers people also travel to where they want to be. In recreational activities, such as pleasure driving, transportation can be an end in itself.
The demand for transportation is derived from the need for people and goods to be at a particular place. In satisfying this need, transportation gives people and goods greater value and place utility. Sometimes, as in the aging of wine or the ripening of bananas while they are en route to their destinations, goods may acquire greater form utility. The in-transit storage of goods provided by a vehicle may reduce the need for warehouse space at the destination. This is an example of time utility—getting goods to a destination at the time of their greatest usefulness.
The demand for transportation—and the rate of actual traffic flow—tends to be proportional to the population of the destination area. Traffic flow between two areas also depends on their proximity—flow generally tends to be greater the closer the areas are to each other.
The concentration of transportation services in heavily urbanized and industrialized areas is a result of the great amount of traffic. However, political or military considerations or prospects for future economic growth may lead to the construction of transportation facilities even where they are not profitable. Economic development in nonindustrialized countries, for example, commonly requires extensive investment in roads, airfields, harbors, and other transport facilities long before there is much traffic.
In industrialized countries such as the United States, transportation routes traditionally have been provided for in advance of other economic development. The Cumberland Road, for example, was built early in the 1800s to open the Ohio Valley to settlement. The Erie Canal, completed in 1825, helped settle the Great Lakes region. Federal land grants to railroad companies in the 19th century helped settle the West. In Canada roads and railroads were being extended to the north in the 1960s and 1970s to facilitate settlement and the exploitation of natural resources. In the long run, transporting goods from one place to another is justified only if the goods can be produced cheaply enough at the first place so as to offset the transportation cost to the second.
TRANSPORTATION MODES
Encyclopædia Britannica, Inc.
The various means, or modes, of transportation consist of both the specific types of vehicles used and the facilities needed for their movement. The modes include people walking and carrying loads, human-powered machines such as bicycles, draft animals pulling wagons and coaches, and pack animals; motor-powered highway vehicles such as trucks, buses, automobiles, taxis, and motorcycles; water carriers such as ships, barges, hydrofoils, and hovercraft; railroad trains; aircraft; and devices such as chutes, conveyor belts, pipelines, and electric lines.
Transportation modes can be classified by whether they are by land, water, or air; by how they are powered; by whether they use continuous flow or not; by whether they carry passengers or freight or both; and by whether or not they use fixed routes. Such distinctions are blurred somewhat by the fact that several modes are typically used for the entire movement of persons or goods from initial origin to final destination.
For example, a woman traveling from Chicago, Ill., to New York City may take a bus and a subway train to get to Chicago-O’Hare International Airport, where she can board an airplane for New York’s La Guardia Airport. At La Guardia she may reverse the process, riding buses and subway trains until she reaches her destination. For the trips to and from the airports she might instead have used an automobile or a taxicab. She might have traveled cross-country by automobile, bus, or train instead of by airplane.
A transport vehicle such as an automobile, an airplane, or an ordinary ship has both its motive power and its facilities for carrying goods or people in the same unit. In other cases, such as a train of railroad cars pulled by a locomotive, the barges pushed or pulled by a towboat, or the highway trailer pulled by a truck tractor, the motive power and the cargo or passengers are in separate units. When power and payload units are separate the power vehicle can be utilized elsewhere while the carrier vehicles are being loaded or unloaded or are in storage. Separation of units also permits changes in the number of carrier vehicles, as with a railroad train or a barge tow, as the volume of traffic varies.
The power for moving a vehicle may be furnished by a natural process such as wind or gravity. The power may be generated in an engine by the burning of fuel such as wood, charcoal, coal, gasoline, kerosine, or fuel oil. Power may also be furnished by an electric motor operated from batteries, an overhead wire or third rail, or a diesel engine such as in a diesel-electric locomotive. Diesel engines have increasingly replaced steam engines in maritime and railroad transportation and are also used in buses and trucks. Gasoline engines are used in automobiles and also in many buses and trucks. Turbines—both jet and propjet—have replaced engines using reciprocating pistons in most airline transportation.
FREIGHT TRANSPORTATION
Heavy or bulky goods and those of low value in proportion to their weight or bulk generally tend to be moved by transportation modes that use large vehicles such as ships and barges, which travel at slow speeds. Compact, perishable, and high-value goods tend to be moved by transportation modes that use small vehicles such as trucks and especially aircraft, which travel at high speeds.
Goods being transported can be classified into general cargo, or package freight, on the one hand and bulk cargo on the other. General cargo usually consists of merchandise, including manufactured items such as machinery, that has a high value in proportion to its weight or to the space it occupies in a vehicle. Bulk cargo generally consists of goods that are of low value in proportion to their weight or bulk. They include ores, grains, coal, oil, petroleum products, and other raw materials and fuels.
General cargo may be transported in boxes, crates, bales, barrels, and other containers. Because of the great variety of shapes, sizes, and weights of general cargo, its handling is less easily mechanized and requires a larger labor force than the handling of bulk cargo. Bulk goods can be conveniently taken on and off ships, railroad cars, trucks, barges, and other carriers by means of gravity, suction, conveyor belts, pipes, or other continuous-flow devices. When being loaded, bulk goods also are able to flow around obstructions in a vehicle and thus fully occupy the available cargo space. Most of the world’s shipping is designed primarily for the movement of bulk goods.
Bulk cargoes can be classified into dry bulk and liquid bulk. Dry bulk goods can be packaged, such as in bags or bales, but more commonly they are not. Sugar, for example, formerly handled only in bags, is increasingly being transported in bulk. Dry bulk goods often are moved in specially designed vessels. They frequently are handled in ships as “bottoming cargo,” to fill any last-minute unused capacity. In some cases dry bulk goods are moved by overland pipeline. Even some solids, such as coal and ores, can be moved through pipes in a liquid suspension, or slurry. Electricity is transported by power lines, a continuous-flow device.
TRANSPORTATION PROBLEMS
The world’s transportation facilities are elaborate but unevenly developed. Many underindustrialized countries cannot afford the transportation services they need. At the same time, some highly industrialized countries are oversupplied. In the United States, for example, there are many miles of underused railroads, inland waterways, and rural roads.
Transportation movements are hampered by economic barriers such as tariffs and import and export quotas. Different railroad gauges on opposite sides of an international boundary often require a costly transfer of freight and passengers from one national railroad to another.
“Cargo preference” laws of some countries, restricting those vessels eligible to take particular cargoes, may impede the most economic operation of the world’s shipping fleets. The desire of many countries to have their own fleets of ships or to promote their own airlines may also divert traffic from the most efficient carriers.
Many countries regulate their transportation services so that the various modes are complementary rather than competitive. In the United States, however, government regulations vary widely from mode to mode and between those transportation movements that cross state boundaries and those that do not. A major step toward developing a unified national transportation policy was taken in 1966 with the creation of the Cabinet-level Department of Transportation.
Laws, customs, and labor agreements often require the employment of more persons than are needed for efficient transportation service, especially as technological advances such as container ships are introduced. But layoffs of unneeded workers may result in large-scale unemployment and create severe social problems. Similarly, the building of modern terminal facilities in certain ports and cities may so concentrate traffic that other, bypassed ports and cities face economic depression.
There often are costly and inconvenient delays when people and goods are transferred from one transportation mode to another. These delays include time spent by a traveler at a corner bus stop, at an airplane loading gate or baggage counter, or in the air while an airplane is waiting for clearance to land. They include the time spent by general cargo ships while in port being loaded or unloaded.
The building of expressways and tollways, with their wide rights-of-way and complex intersections, is very costly and has forced the relocation of hundreds of thousands of homes and businesses, particularly in cities. Entire neighborhoods have been destroyed. Many of the people displaced are from low-income areas in the inner cities and are those least able to find new homes.
Traffic congestion in the United States has been relieved somewhat as cities have decentralized and population and business densities have decreased. But rush-hour traffic jams and lack of parking space, especially in downtown areas, are still acute problems. Greater use of mass transit services is a likely solution. Unless mass transit is heavily subsidized, however, it can neither meet its costs from a fare structure that would be low enough nor provide service that would be frequent enough to induce people to leave their cars at home. Meanwhile, the decline of public transportation services has hit hardest at the poor, the elderly, the young, and the handicapped, who are least likely to have access to private automobiles.
Transportation facilities and operation also affect the quality of the environment. In an effort to reduce air pollution, laws in the United States set limits on automobile emissions. Such antipollution measures, however, may add to the expense of building and operating motor vehicles. Similarly, design changes required by laws limiting the noise levels and air pollution of aircraft may decrease the operating efficiency of the aircraft. The development of supersonic aircraft, in particular, has been opposed because of the loud sonic boom they create while in flight. Fear of pollution from massive oil leaks has affected plans for new pipelines and the building and operation of supertankers. Natural scenery may be marred and historical landmarks destroyed by construction for highways, railroads, and airports.
Transportation facilities also present a safety hazard. The private automobile, in particular, is one of the most dangerous modes of transportation, though accident rates are slowly being reduced. Major accidents on other transportation modes are relatively rare, though when they do occur, as in the crash of an airliner or in the collision of passenger trains, the loss of life may be great.
ADVANCES IN TRANSPORTATION
Technological advances in transportation have included the development of superspeed trains, such as Japan’s “bullet train” of the 1960s and France’s TGV (Train de Grand Vitesse) of the 1970s and 1980s. These advances gave engineers the inspiration to design such experimental railroad systems as the magnetic levitation, or maglev, train, which by the early 1990s had only short test systems set up in Germany and Japan. Improvements in power generation and transmission and concern for the air and noise pollution caused by diesel engines have prompted automobile makers to develop cars that will run on alternative types of fuel. One result has been the prototype of an electric car. (See also automobile; railroad.)
A greater variety of ships, including submarine tankers and fast, multiple-hulled surface ships, have been developed. Other new types of vessels that are available include the hydrofoil, which travels on sea wings with its hull above water, and the surface-effect ship, or hovercraft, which rides above the water on a cushion of air.
The widespread use of atomic power for ship propulsion is a major research goal. STOL (short takeoff and landing), VTOL (vertical takeoff and landing), and supersonic aircraft have been adopted. These new technologies have made vehicles quieter. Passenger travel has improved in speed and comfort. Freight transport costs less because larger vehicles are used and operating efficiency has increased. The computer is used for record keeping, traffic control, navigation, and other routine operations.
In the more distant future, rocket transportation may become feasible, perhaps in combination with orbiting satellites, enabling all points on Earth to be connected in less than an hour’s travel time. Underground gravity vacuum tubes may permit freight and passengers to travel between stations thousands of miles apart also in less than an hour.
Improvements may be expected in transportation management techniques. Some forms of transportation now under private ownership, management, and operation will increasingly depend on public financing or control, just as urban mass transit now does. Some forms of transportation will be integrated into multimodal organizations, both public and private, in order to move people and goods with a minimum of cost, inconvenience, and delay.
The need for modes of transportation will endure. Innovative communications systems, however, have already made much travel unnecessary. Teleconferencing enables people to hold meetings and see each other without having to travel. Computer networking makes cooperative work possible, without the workers leaving home or office (see telecommunication)
