Necessity and sufficiency
In logic and sufficiency are terms used to describe a conditional or implicational relationship between statements. For example, in the conditional statement "If P Q", we say that "Q is necessary for P" because P cannot be true unless Q is true. We say that "P is sufficient for Q" because P being true always implies that Q is true, but P not being true does not always imply that Q is not true; the assertion that a statement is a "necessary and sufficient" condition of another means that the former statement is true if and only if the latter is true. That is, the two statements must be either true or false. In ordinary English, "necessary" and "sufficient" indicate relations between conditions or states of affairs, not statements. Being a male sibling is a necessary and sufficient condition for being a brother. In the conditional statement, "if S N", the expression represented by S is called the antecedent and the expression represented by N is called the consequent; this conditional statement may be written in many equivalent ways, for instance, "N if S", "S only if N", "S implies N", "N is implied by S", S → N, S ⇒ N, or "N whenever S".
In the above situation, we say that N is a necessary condition for S. In common language this is saying that if the conditional statement is a true statement the consequent N must be true if S is to be true. Phrased differently, the antecedent S cannot be true without N being true. For example, in order for someone to be called Socrates, it is necessary for that someone to be Named. In the above situation, we can say S is a sufficient condition for N. Again, consider the third column of the truth table below. If the conditional statement is true if S is true, N must be true. In common terms, "S guarantees N". Continuing the example, knowing that someone is called Socrates is sufficient to know that someone has a Name. A necessary and sufficient condition requires that both of the implications S ⇒ N ⇒ S hold. From the first of these we see that S is a sufficient condition for N, from the second that S is a necessary condition for N; this is expressed as "S is necessary and sufficient for N ", "S if and only if N ", or S ⇔ N.
The assertion that Q is necessary for P is colloquially equivalent to "P cannot be true unless Q is true" or "if Q is false P is false". By contraposition, this is the same thing as "whenever P is true, so is Q"; the logical relation between P and Q is expressed as "if P Q" and denoted "P ⇒ Q". It may be expressed as any of "P only if Q", "Q, if P", "Q whenever P", "Q when P". One finds, in mathematical prose for instance, several necessary conditions that, taken together, constitute a sufficient condition, as shown in Example 5. Example 1 For it to be true that "John is a bachelor", it is necessary that it be true that he is unmarried, adult, since to state "John is a bachelor" implies John has each of those three additional predicates. Example 2 For the whole numbers greater than two, being odd is necessary to being prime, since two is the only whole number, both and prime. Example 3 Consider thunder, the sound caused by lightning. We say. Whenever there's lightning, there's thunder; the thunder does not cause the lightning, but because lightning always comes with thunder, we say that thunder is necessary for lightning.
Example 4 Being at least 30 years old is necessary for serving in the U. S. Senate. If you are under 30 years old it is impossible for you to be a senator; that is, if you are a senator, it follows that you are at least 30 years old. Example 5 In algebra, for some set S together with an operation ⋆ to form a group, it is necessary that ⋆ be associative, it is necessary that S include a special element e such that for every x in S it is the case that e ⋆ x and x ⋆ e both equal x. It is necessary that for every x in S there exist a corresponding element x″ such that both x ⋆ x″ and x″ ⋆ x equal the special element e. None of these three necessary conditions by itself is sufficient, but the conjunction of the three is. If P is sufficient for Q knowing P to be true is adequate grounds to conclude that Q is true; the logical relation is, as before, expressed as "if P Q" or "P ⇒ Q". This can be expressed as "P only if Q", "P implies Q" or several other variants, it may be the case that several sufficient conditions, when taken together, constitute a single necessary condition, as illustrated in example 5.
Example 1 "John is a king" implies. So knowing that it is true that John is a king is sufficient to know that he is a male. Example 2 A number's being divisible by 4 is sufficient for its being but being divisible by 2 is both sufficient and necessary. Example 3 An occurrence of thunder is a sufficient condition for the occurrence of lightning in the sense
A national park is a park in use for conservation purposes. It is a reserve of natural, semi-natural, or developed land that a sovereign state declares or owns. Although individual nations designate their own national parks differently, there is a common idea: the conservation of'wild nature' for posterity and as a symbol of national pride. An international organization, the International Union for Conservation of Nature, its World Commission on Protected Areas, has defined "National Park" as its Category II type of protected areas. While this type of national park had been proposed the United States established the first "public park or pleasuring-ground for the benefit and enjoyment of the people", Yellowstone National Park, in 1872. Although Yellowstone was not termed a "national park" in its establishing law, it was always termed such in practice and is held to be the first and oldest national park in the world. However, the Tobago Main Ridge Forest Reserve, the area surrounding Bogd Khan Uul Mountain are seen as the oldest protected areas, predating Yellowstone by nearly a century.
The first area to use "national park" in its creation legislation was the U. S.'s Mackinac, in 1875. Australia's Royal National Park, established in 1879, was the world's third official national park. In 1895 ownership of Mackinac National Park was transferred to the State of Michigan as a state park and national park status was lost; as a result, Australia's Royal National Park is by some considerations the second oldest national park now in existence. Canada established Parks Canada in 1911, becoming the world's first national service dedicated to protecting and presenting natural and historical treasures; the largest national park in the world meeting the IUCN definition is the Northeast Greenland National Park, established in 1974. According to the IUCN, 6,555 national parks worldwide met its criteria in 2006. IUCN is still discussing the parameters of defining a national park. National parks are always open to visitors. Most national parks provide outdoor recreation and camping opportunities as well as classes designed to educate the public on the importance of conservation and the natural wonders of the land in which the national park is located.
In 1969, the IUCN declared a national park to be a large area with the following defining characteristics: One or several ecosystems not materially altered by human exploitation and occupation, where plant and animal species, geomorphological sites and habitats are of special scientific and recreational interest or which contain a natural landscape of great beauty. In 1971, these criteria were further expanded upon leading to more clear and defined benchmarks to evaluate a national park; these include: Minimum size of 1,000 hectares within zones in which protection of nature takes precedence Statutory legal protection Budget and staff sufficient to provide sufficient effective protection Prohibition of exploitation of natural resources qualified by such activities as sport, fishing, the need for management, etc. While the term national park is now defined by the IUCN, many protected areas in many countries are called national park when they correspond to other categories of the IUCN Protected Area Management Definition, for example: Swiss National Park, Switzerland: IUCN Ia - Strict Nature Reserve Everglades National Park, United States: IUCN Ib - Wilderness Area Victoria Falls National Park, Zimbabwe: IUCN III - National Monument Vitosha National Park, Bulgaria: IUCN IV - Habitat Management Area New Forest National Park, United Kingdom: IUCN V - Protected Landscape Etniko Ygrotopiko Parko Delta Evrou, Greece: IUCN VI - Managed Resource Protected AreaWhile national parks are understood to be administered by national governments, in Australia national parks are run by state governments and predate the Federation of Australia.
In Canada, there are both national parks operated by the federal government and provincial or territorial parks operated by the provincial and territorial governments, although nearly all are still national parks by the IUCN definition. In many countries, including Indonesia, the Netherlands, the United Kingdom, national parks do not adhere to the IUCN definition, while some areas which adhere to the IUCN definition are not designated as national parks. In 1810, the English poet William Wordsworth described the Lake District as a sort of national property, in which every man has a right and interest who has an eye to perceive and a heart to enjoy; the painter George Catlin, in his travels through the American West, wrote during the 1830s that the Native Americans in the United States might be preserved...in a magnificent park... A nation's Park, containing man and beast, in all the wild and freshness of their nature's beauty! The first effort by the U. S. Federal government to set aside such protected lands was on 20 April 1832, when President Andrew Jackson signed legislation that the 22nd United States Congress had enacted to set aside four sections of land around what is now Hot Springs, Arkansas, to protect the natural, thermal springs and adjoining mountainsides for the futur
A swimming pool, swimming bath, wading pool, or paddling pool is a structure designed to hold water to enable swimming or other leisure activities. Pools can be built into the ground or built above ground, are a common feature aboard ocean-liners and cruise ships. In-ground pools are most constructed from materials such as concrete, natural stone, plastic or fiberglass, can be of a custom size and shape or built to a standardized size, the largest of, the Olympic-size swimming pool. Many health clubs, fitness centers and private clubs have pools used for exercise or recreation. Many towns and cities provide public pools. Many hotels have pools available for their guests to use at their leisure. Educational facilities such as universities have pools for physical education classes, recreational activities, leisure or competitive athletics such as swimming teams. Hot tubs and spas are pools filled with hot water, used for relaxation or hydrotherapy, are common in homes and health clubs. Special swimming pools are used for diving, specialized water sports, physical therapy as well as for the training of lifeguards and astronauts.
Swimming pools may be unheated. The "Great Bath" at the site of Mohenjo-Daro in modern-day Pakistan was most the first swimming pool, dug during the 3rd millennium BC; this pool is 12 by 7 metres, is lined with bricks, was covered with a tar-based sealant. Ancient Greeks and Romans built artificial pools for athletic training in the palaestras, for nautical games and for military exercises. Roman emperors had private swimming pools in which fish were kept, hence one of the Latin words for a pool was piscina; the first heated swimming pool was built by Gaius Maecenas of Rome in the 1st century BC. Gaius Maecenas was a rich Roman considered one of the first patrons of arts. Ancient Sinhalese built pairs of pools called "Kuttam Pokuna" in the kingdom of Anuradhapura, Sri Lanka in the 4th century BC, they were decorated with flights of steps, punkalas or pots of abundance, scroll design. Swimming pools became popular in Britain in the mid-19th century; as early as 1837, six indoor pools with diving boards existed in England.
The Maidstone Swimming Club in Maidstone, Kent is believed to be the oldest surviving swimming club in Britain. It was formed in 1844, in response to concerns over drownings in the River Medway since would-be rescuers would drown because they themselves could not swim to safety; the club used to swim in the River Medway, would hold races, diving competitions and water polo matches. The South East Gazette July 1844 reported an aquatic breakfast party: coffee and biscuits were served on a floating raft in the river; the coffee was kept hot over a fire. The last swimmers managed to overturn the raft, to the amusement of 150 spectators; the Amateur Swimming Association was founded in 1869 in England, the Oxford Swimming Club in 1909. The presence of indoor baths in the cobbled area of Merton Street might have persuaded the less hardy of the aquatic brigade to join. So, bathers became swimmers, bathing pools became swimming pools.. In 1939, Oxford created its first major public indoor pool at Temple Cowley.
The modern Olympic Games started in 1896 and included swimming races, after which the popularity of swimming pools began to spread. In the US, the Racquet Club of Philadelphia clubhouse boasts one of the world's first modern above-ground swimming pools; the first swimming pool to go to sea on an ocean liner was installed on the White Star Line's Adriatic in 1906. The oldest known public swimming pool in America, Underwood Pool, is located in Belmont, Massachusetts. Interest in competitive swimming grew following World War I. Standards improved and training became essential. Home swimming pools became popular in the United States after World War II and the publicity given to swimming sports by Hollywood films such as Esther Williams' Million Dollar Mermaid made a home pool a desirable status symbol. More than 50 years the home or residential swimming pool is a common sight; some small nations enjoy a thriving swimming pool industry. A two-storey, white concrete swimming pool building composed of horizontal cubic volumes built in 1959 at the Royal Roads Military College is on the Registry of Historic Places of Canada.
According to the Guinness World Records, the largest swimming pool in the world is San Alfonso del Mar Seawater pool in Algarrobo, Chile. It has an area of 8 ha. At its deepest, it is 3.5 m deep. It was completed in December 2006; the largest indoor wave pool in North America is at the West Edmonton Mall and the largest indoor pool is at the Neutral Buoyancy Lab in the Sonny Carter Training Facility at NASA JSC in Houston. In 2014, the Y-40 swimming pool at the Hotel Terme Millepini in Padua, Italy became the deepest indoor pool, certified by the Guinness Book of World Records The recreational diving center Nemo 33 near Brussels, Belgium held the record until the Y-40 was completed; the Fleishhacker Pool in San Francisco was the largest heated outdoor swimming pool in the United States. Opened on 23 April 1925, it measured 1,000 by 150 ft and was so large that the lifeguards required kayaks for patrol, it was closed in 1971 due to low patronage. In Europe, the largest swimming pool opened in 1934 in Elbląg, providing a water area of 33,500 square metres (3
International Monetary Fund
The International Monetary Fund is an international organization headquartered in Washington, D. C. consisting of "189 countries working to foster global monetary cooperation, secure financial stability, facilitate international trade, promote high employment and sustainable economic growth, reduce poverty around the world." Formed in 1944 at the Bretton Woods Conference by the ideas of Harry Dexter White and John Maynard Keynes, it came into formal existence in 1945 with 29 member countries and the goal of reconstructing the international payment system. It now plays a central role in the management of balance of payments difficulties and international financial crises. Countries contribute funds to a pool through a quota system from which countries experiencing balance of payments problems can borrow money; as of 2016, the fund had SDR477 billion. Through the fund, other activities such as the gathering of statistics and analysis, surveillance of its members' economies and the demand for particular policies, the IMF works to improve the economies of its member countries.
The organisation's objectives stated in the Articles of Agreement are: to promote international monetary co-operation, international trade, high employment, exchange-rate stability, sustainable economic growth, making resources available to member countries in financial difficulty. IMF funds come from two major sources:quotas and loans. Quotas, which are pooled funds of member nations, generate most IMF funds; the size of a member's quota depends on its financial importance in the world. Nations with larger economic importance have larger quotas; the quotas are increased periodically as a means of boosting the IMF's resources. The current Managing Director and Chairwoman of the International Monetary Fund is French lawyer and former politician, Christine Lagarde, who has held the post since 5 July 2011. Gita Gopinath was appointed as Chief Economist of IMF from October 1, 2018, she received her Ph. D. in economics from Princeton University. According to the IMF itself, it works to foster global growth and economic stability by providing policy advice and financing the members by working with developing nations to help them achieve macroeconomic stability and reduce poverty.
The rationale for this is that private international capital markets function imperfectly and many countries have limited access to financial markets. Such market imperfections, together with balance-of-payments financing, provide the justification for official financing, without which many countries could only correct large external payment imbalances through measures with adverse economic consequences; the IMF provides alternate sources of financing. Upon the founding of the IMF, its three primary functions were: to oversee the fixed exchange rate arrangements between countries, thus helping national governments manage their exchange rates and allowing these governments to prioritize economic growth, to provide short-term capital to aid the balance of payments; this assistance was meant to prevent the spread of international economic crises. The IMF was intended to help mend the pieces of the international economy after the Great Depression and World War II; as well, to provide capital investments for economic growth and projects such as infrastructure.
The IMF's role was fundamentally altered by the floating exchange rates post-1971. It shifted to examining the economic policies of countries with IMF loan agreements to determine if a shortage of capital was due to economic fluctuations or economic policy; the IMF researched what types of government policy would ensure economic recovery. A particular concern of the IMF was to prevent financial crisis, such as those in Mexico 1982, Brazil in 1987, East Asia in 1997–98 and Russia in 1998, from spreading and threatening the entire global financial and currency system; the challenge was to promote and implement policy that reduced the frequency of crises among the emerging market countries the middle-income countries which are vulnerable to massive capital outflows. Rather than maintaining a position of oversight of only exchange rates, their function became one of surveillance of the overall macroeconomic performance of member countries, their role became a lot more active because the IMF now manages economic policy rather than just exchange rates.
In addition, the IMF negotiates conditions on lending and loans under their policy of conditionality, established in the 1950s. Low-income countries can borrow on concessional terms, which means there is a period of time with no interest rates, through the Extended Credit Facility, the Standby Credit Facility and the Rapid Credit Facility. Nonconcessional loans, which include interest rates, are provided through Stand-By Arrangements, the Flexible Credit Line, the Precautionary and Liquidity Line, the Extended Fund Facility; the IMF provides emergency assistance via the Rapid Financing Instrument to members facing urgent balance-of-payments needs. The IMF is mandated to oversee the international monetary and financial system and monitor the economic and financial policies of its member countries; this activity facilitates international co-operation. Since the demise of the Bretton Woods system of fixed exchange rates in the early 1970s, surveillance has evolved by way of changes in procedures rather than through the adoption of new obligations.
The responsibilities changed from those of guardian to those of overseer of members' policies. The Fund analyses the appropriateness of each member country's economic and financial policies for achieving orderly economic growth, assesses the consequences of these policies for other countries and for the global e
The United States of America known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U. S. is the third most populous country. The capital is Washington, D. C. and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico; the State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean; the U. S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The diverse geography and wildlife of the United States make it one of the world's 17 megadiverse countries.
Paleo-Indians migrated from Siberia to the North American mainland at least 12,000 years ago. European colonization began in the 16th century; the United States emerged from the thirteen British colonies established along the East Coast. Numerous disputes between Great Britain and the colonies following the French and Indian War led to the American Revolution, which began in 1775, the subsequent Declaration of Independence in 1776; the war ended in 1783 with the United States becoming the first country to gain independence from a European power. The current constitution was adopted in 1788, with the first ten amendments, collectively named the Bill of Rights, being ratified in 1791 to guarantee many fundamental civil liberties; the United States embarked on a vigorous expansion across North America throughout the 19th century, acquiring new territories, displacing Native American tribes, admitting new states until it spanned the continent by 1848. During the second half of the 19th century, the Civil War led to the abolition of slavery.
By the end of the century, the United States had extended into the Pacific Ocean, its economy, driven in large part by the Industrial Revolution, began to soar. The Spanish–American War and World War I confirmed the country's status as a global military power; the United States emerged from World War II as a global superpower, the first country to develop nuclear weapons, the only country to use them in warfare, a permanent member of the United Nations Security Council. Sweeping civil rights legislation, notably the Civil Rights Act of 1964, the Voting Rights Act of 1965 and the Fair Housing Act of 1968, outlawed discrimination based on race or color. During the Cold War, the United States and the Soviet Union competed in the Space Race, culminating with the 1969 U. S. Moon landing; the end of the Cold War and the collapse of the Soviet Union in 1991 left the United States as the world's sole superpower. The United States is the world's oldest surviving federation, it is a representative democracy.
The United States is a founding member of the United Nations, World Bank, International Monetary Fund, Organization of American States, other international organizations. The United States is a developed country, with the world's largest economy by nominal GDP and second-largest economy by PPP, accounting for a quarter of global GDP; the U. S. economy is post-industrial, characterized by the dominance of services and knowledge-based activities, although the manufacturing sector remains the second-largest in the world. The United States is the world's largest importer and the second largest exporter of goods, by value. Although its population is only 4.3% of the world total, the U. S. holds 31% of the total wealth in the world, the largest share of global wealth concentrated in a single country. Despite wide income and wealth disparities, the United States continues to rank high in measures of socioeconomic performance, including average wage, human development, per capita GDP, worker productivity.
The United States is the foremost military power in the world, making up a third of global military spending, is a leading political and scientific force internationally. In 1507, the German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere America in honor of the Italian explorer and cartographer Amerigo Vespucci; the first documentary evidence of the phrase "United States of America" is from a letter dated January 2, 1776, written by Stephen Moylan, Esq. to George Washington's aide-de-camp and Muster-Master General of the Continental Army, Lt. Col. Joseph Reed. Moylan expressed his wish to go "with full and ample powers from the United States of America to Spain" to seek assistance in the revolutionary war effort; the first known publication of the phrase "United States of America" was in an anonymous essay in The Virginia Gazette newspaper in Williamsburg, Virginia, on April 6, 1776. The second draft of the Articles of Confederation, prepared by John Dickinson and completed by June 17, 1776, at the latest, declared "The name of this Confederation shall be the'United States of America'".
The final version of the Articles sent to the states for ratification in late 1777 contains the sentence "The Stile of this Confederacy shall be'The United States of America'". In June 1776, Thomas Jefferson wrote the phrase "UNITED STATES OF AMERICA" in all capitalized letters in the headline of his "original Rough draught" of the Declaration of Independence; this draft of the document did not surface unti
A postage stamp is a small piece of paper issued by a post office, postal administration, or other authorized vendors to customers who pay postage, who affix the stamp to the face or address-side of any item of mail—an envelope or other postal cover —that they wish to send. The item is processed by the postal system, where a postmark or cancellation mark—in modern usage indicating date and point of origin of mailing—is applied to the stamp and its left and right sides to prevent its reuse; the item is delivered to its addressee. Always featuring the name of the issuing nation, a denomination of its value, an illustration of persons, institutions, or natural realities that symbolize the nation's traditions and values, every stamp is printed on a piece of rectangular, but sometimes triangular or otherwise shaped special custom-made paper whose back is either glazed with an adhesive gum or self-adhesive; because governments issue stamps of different denominations in unequal numbers and discontinue some lines and introduce others, because of their illustrations and association with the social and political realities of the time of their issue, they are prized for their beauty and historical significance by stamp collectors whose study of their history and of mailing systems is called philately.
Because collectors buy stamps from an issuing agency with no intention to use them for postage, the revenues from such purchases and payments of postage can make them a source of net profit to that agency. Throughout modern history, numerous methods were used to indicate that postage had been paid on a mailed item, so several different men have received credit for inventing the postage stamp. William DockwraIn 1680, William Dockwra, an English merchant in London, his partner Robert Murray established the London Penny Post, a mail system that delivered letters and small parcels inside the city of London for the sum of one penny. Confirmation of paid postage was indicated by the use of a hand stamp to frank the mailed item. Though this'stamp' was applied to the letter or parcel itself, rather than to a separate piece of paper, it is considered by many historians to be the world's first postage stamp. Lovrenc KoširIn 1835, the Slovene civil servant Lovrenc Košir from Ljubljana in Austria-Hungary, suggested the use of "artificially affixed postal tax stamps" using "gepresste papieroblate", but although civil bureaucrats considered the suggestion in detail, it was not adopted.
Rowland HillIn 1836, a Member of Parliament, Robert Wallace, gave Sir Rowland Hill numerous books and documents about the postal service, which Hill described as a "half hundred weight of material". After a detailed study, on 4 January 1837 Hill submitted a pamphlet entitled Post Office Reform: Its Importance and Practicability, marked "private and confidential," and not released to the general public, to the Chancellor of the Exchequer, Thomas Spring Rice; the Chancellor summoned Hill to a meeting at which he suggested improvements and changes to be presented in a supplement, which Hill duly produced and submitted on 28 January 1837. Summoned to give evidence before the Commission for Post Office Enquiry on 13 February 1837, Hill read from the letter he wrote to the Chancellor that included a statement saying that the notation of paid postage could be created "...by using a bit of paper just large enough to bear the stamp, covered at the back with a glutinous wash...". This would become the first unambiguous description of a modern adhesive postage stamp.
Shortly afterward, Hill's revision of the booklet, dated 22 February 1837, containing some 28,000 words, incorporating the supplement given to the Chancellor and statements he made to the Commission, was published and made available to the general public. Hansard records that on 15 December 1837, Benjamin Hawes asked the Chancellor of the Exchequer "whether it was the intention of the Government to give effect to the recommendation of the Commissioners of the Post-office, contained in their ninth report relating to the reduction of the rates of postage, the issuing of penny stamps?"Hill’s ideas for postage stamps and charging paid-postage based on weight soon took hold, were adopted in many countries throughout the world. With the new policy of charging by weight, using envelopes for mailing documents became the norm. Hill’s brother Edwin invented a prototype envelope-making machine that folded paper into envelopes enough to match the pace of the growing demand for postage stamps. Rowland Hill and the reforms he introduced to the United Kingdom postal system appear on several of its commemorative stamps.
James ChalmersIn the 1881 book The Penny Postage Scheme of 1837, Scotsman Patrick Chalmers claimed that his father, James Chalmers, published an essay in August 1834 describing and advocating a postage stamp, but submitted no evidence of the essay's existence. Until he died in 1891, Patrick Chalmers campaigned to have his father recognized as the inventor of the postage stamp; the first independent evidence for Chalmers' claim is an essay, dated 8 February 1838 and received by the Post Office on 17 February 1838, in which he proposed adhesive postage stamps to the General Post Office. In this 800-word document concerning methods of indicating that postage had been paid on mail he states: "Therefore, of Mr Hill’s plan of a uniform rate of postage... I conceive that the most simple and economical mode... would be by Slips... in the hope that Mr Hill’s plan may soon be carried into operation I would sugg
A toll road known as a turnpike or tollway, is a public or private road for which a fee is assessed for passage. It is a form of road pricing implemented to help recoup the cost of road construction and maintenance. Toll roads have existed in some form since antiquity, with tolls levied on passing travellers on foot, wagon, or horseback; the amount of the toll varies by vehicle type, weight, or number of axles, with freight trucks charged higher rates than cars. Tolls are collected at toll booths, toll houses, stations, bars, or gates; some toll collection points are unmanned and the user deposits money in a machine which opens the gate once the correct toll has been paid. To cut costs and minimise time delay many tolls are collected by some form of automatic or electronic toll collection equipment which communicates electronically with a toll payer's transponder; some electronic toll roads maintain a system of toll booths so people without transponders can still pay the toll, but many newer roads now use automatic number plate recognition to charge drivers who use the road without a transponder, some older toll roads are being upgraded with such systems.
Criticisms of toll roads include the time taken to stop and pay the toll, the cost of the toll booth operators—up to about one-third of revenue in some cases. Automated toll-paying systems help minimise both of these. Others object to paying "twice" for the same road: with tolls. In addition to toll roads, toll bridges and toll tunnels are used by public authorities to generate funds to repay the cost of building the structures; some tolls are set aside to pay for future maintenance or enhancement of infrastructure, or are applied as a general fund by local governments, not being earmarked for transport facilities. This is sometimes prohibited by central government legislation. Road congestion pricing schemes have been implemented in a limited number of urban areas as a transportation demand management tool to try to reduce traffic congestion and air pollution. Toll roads have existed for at least the last 2,700 years, as tolls had to be paid by travellers using the Susa–Babylon highway under the regime of Ashurbanipal, who reigned in the 7th century BC.
Aristotle and Pliny refer to other parts of Asia. In India, before the 4th century BC, the Arthashastra notes the use of tolls. Germanic tribes charged tolls to travellers across mountain passes. A 14th-century example is Castle Loevestein in the Netherlands, built at a strategic point where two rivers meet. River tolls were charged on boats sailing along the river; the Øresund in Scandinavia was once subject to a toll to the Danish Monarch, who derived a sizable portion of his revenue from it. Many modern European roads were constructed as toll roads in order to recoup the costs of construction, maintenance and as a source of tax money, paid by someone other than the local residents. In 14th-century England, some of the most used roads were repaired with money raised from tolls by pavage grants. Widespread toll roads sometimes restricted traffic so much, by their high tolls, that they interfered with trade and cheap transportation needed to alleviate local famines or shortages. Tolls were used in the Holy Roman Empire in the 15th centuries.
Industrialisation in Europe needed major improvements to the transport infrastructure which included many new or improved roads, financed from tolls. The A5 road in Britain was built to provide a robust transport link between Britain and Ireland and had a toll house every few miles. In the 20th century, road tolls were introduced in Europe to finance the construction of motorway networks and specific transport infrastructure such as bridges and tunnels. Italy was the first European country to charge motorway tolls, on a 50 kilometres motorway section near Milan in 1924, it was followed by Greece, which made users pay for the network of motorways around and between its cities in 1927. In the 1950s and 1960s, France and Portugal started to build motorways with the aid of concessions, allowing rapid development of this infrastructure without massive state debts. Since road tolls have been introduced in the majority of the EU member states. In the United States, prior to the introduction of the Interstate Highway System and the large federal grants supplied to states to build it, many states constructed their first controlled-access highways by floating bonds backed by toll revenues.
Starting with the Pennsylvania Turnpike in 1940, followed by similar roads in New Jersey, New York and others, numerous states throughout the 1950s established major toll roads. With the establishment of the Interstate Highway System in the late 1950s, toll road construction in the U. S. slowed down as the federal government now provided the bulk of funding to construct new freeways, regulations required that such Interstate highways be free from tolls. Many older toll roads were added to the Interstate System under a grandfather clause that allowed tolls to continue to be collected on toll roads that predated the system; some of these such as the Connecticut Turnpike and the Richmond–Petersburg Turnpike removed their tolls when the initial bonds were paid off. Many states, have maintained the tolling of these roads as a consistent source of revenue; as the