Infrastructure

From Wikipedia, the free encyclopedia
Jump to: navigation, search
Highway 401, the busiest highway in North America.

Infrastructure is the basic physical and organizational structures needed for the operation of a society or enterprise,[1] or the services and facilities necessary for an economy to function.[2] The term typically refers to the technical structures that support a society, such as roads, water supply, sewers, power grids, telecommunications, and so forth. Viewed functionally, infrastructure facilitates the production of goods and services; for example, roads enable the transport of raw materials to a factory, and also for the distribution of finished products to markets. In some contexts, the term may also include basic social services such as schools and hospitals.[3] In military parlance, the term refers to the buildings and permanent installations necessary for the support, redeployment, and operation of military forces.[4]

In this article, infrastructure will be used in the sense of technical structures or physical networks that support society, unless specified otherwise.

Contents

[edit] History of the term

According to etymology online,[5] the word infrastructure has been used in English since at least 1927 and meant: The installations that form the basis for any operation or system. Other sources, such as the Oxford English Dictionary, trace the word's origins to earlier usage, originally applied in a military sense. The word was imported from French, where it means subgrade, the native material underneath a constructed pavement or railway. The word is a combination of the Latin prefix "infra", meaning "below" and "structure". The military sense of the word was probably first used in France, and imported into English around the time of the First World War. The military use of the term achieved currency in the United States after the formation of NATO in the 1940s, and was then adopted by urban planners in its modern civilian sense by 1970.[6]

The term came to prominence in the United States in the 1980s following the publication of America in Ruins (Choate and Walter, 1981)[1] , which initiated a public-policy discussion of the nation’s "infrastructure crisis", purported to be caused by decades of inadequate investment and poor maintenance of public works.

That public-policy discussion was hampered by lack of a precise definition for infrastructure. A U.S. National Research Council panel sought to clarify the situation by adopting the term "public works infrastructure", referring to:

"...both specific functional modes - highways, streets, roads, and bridges; mass transit; airports and airways; water supply and water resources; wastewater management; solid-waste treatment and disposal; electric power generation and transmission; telecommunications; and hazardous waste management - and the combined system these modal elements comprise. A comprehension of infrastructure spans not only these public works facilities, but also the operating procedures, management practices, and development policies that interact together with societal demand and the physical world to facilitate the transport of people and goods, provision of water for drinking and a variety of other uses, safe disposal of society's waste products, provision of energy where it is needed, and transmission of information within and between communities."[7]

In Keynesian economics, the word infrastructure was exclusively used to describe public assets that facilitate production, but not private assets of the same purpose. In post-Keynesian times, however, the word has grown in popularity. It has been applied with increasing generality to suggest the internal framework discernible in any technology system or business organization.

[edit] "Hard" versus "soft" infrastructure

"Hard" infrastructure refers to the large physical networks necessary for the functioning of a modern industrial nation, whereas "soft" infrastructure refers to all the institutions which are required to maintain the economic, health, cultural and social standards of a country, such as the financial system, the education system, the health care system, the system of government and law enforcement, as well as emergency services.[8]

[edit] Uses of the term

[edit] Engineering and construction

Engineers generally limit the use of the term infrastructure to describe fixed assets that are in the form of a large network, in other words, "hard" infrastructure. Recent efforts to devise more generic definitions of infrastructure have typically referred to the network aspects of most of the structures and to the accumulated value of investments in the networks as assets. One such effort defines infrastructure as the network of assets "where the system as a whole is intended to be maintained indefinitely at a specified standard of service by the continuing replacement and refurbishment of its components."[9]

[edit] Civil defense and economic development

Civil defense planners and developmental economists generally refer to both "hard" and "soft" infrastructure, including public services such as schools and hospitals, emergency services such as police and fire fighting, and basic financial services.

[edit] Military

Military strategists use the term infrastructure to refer to all building and permanent installations necessary for the support of military forces, whether they are stationed in bases, being deployed or engaged in operations, such as barracks, headquarters, airfields, communications facilities, stores of military equipment, port installations, and maintenance stations.[10]

[edit] Critical infrastructure

Main article: critical infrastructure

The term critical infrastructure has been widely adopted to distinguish those infrastructure elements (both hard and soft) that, if significantly damaged or destroyed, would cause serious disruption of the dependent system or organization. Storm, flood, or earthquake damage leading to loss of certain transportation routes in a city (for example, bridges crossing a river), could make it impossible for people to evacuate and for emergency services to operate; these routes would be deemed critical infrastructure. Similarly, an on-line booking system might be critical infrastructure for an airline.

[edit] Urban infrastructure

Urban or municipal infrastructure refers to "hard" infrastructure systems generally owned and operated by municipalities, such as streets, water distribution, sewers, etc. It may also include some of the facilities associated with "soft" infrastructure, such as parks, public pools and libraries.

[edit] Marxism

In Marxism, the term "infrastructure" is sometimes used as a synonym for base in the dialectic synthetic pair base and superstructure

[edit] Other uses

In other applications, the term infrastructure may refer to information technology, informal and formal channels of communication, software development tools, political and social networks, or beliefs held by members of particular groups. Still underlying these more conceptual uses is the idea that infrastructure provides organizing structure and support for the system or organization it serves, whether it is a city, a nation, a corporation, or a collection of people with common interests. Examples: IT infrastructure, research infrastructure, terrorist infrastructure, tourism infrastructure.

[edit] Related concepts

The term infrastructure is often confused with the following overlapping or related concepts:

[edit] Land improvement and land development

Main articles: Land improvement and Land development

The terms land improvement and land development are general terms that in some contexts may include infrastructure, but in the context of a discussion of infrastructure would refer only to smaller scale systems or works that are not included in infrastructure because they are typically limited to a single parcel of land, and are owned and operated by the land owner. For example, an irrigation canal that serves a region or district would be included with infrastructure, but the private irrigation systems on individual land parcels would be considered land improvements, not infrastructure. Service connections to municipal service and public utility networks would also be considered land improvements, not infrastructure.[11][12]

[edit] Public works and public services

Main article: public works

The term public works includes government owned and operated infrastructure as well as public buildings such as schools and court houses. The term public works generally refers to physical assets needed to deliver public services.

Main article: public services

Public services include both infrastructure and services generally provided by government.

[edit] Typical attributes

"Hard" infrastructure generally has the following attributes:

[edit] Capital assets that provide services

[edit] Large networks

[edit] Historicity and interdependence

[edit] Natural monopoly

[edit] Types of "hard" infrastructure

Chicago Transit Authority control tower 18 guides elevated Chicago 'L' north and southbound Purple and Brown lines intersecting with east and westbound Pink and Green lines and the looping Orange line above the Wells and Lake street intersection in the loop.

The following list is limited to capital assets that serve the function of conveyance or channelling of people, vehicles, fluids, energy or information, and which take the form either of a network or of a critical node used by vehicles, or used for the transmission of electro-magnetic waves. Infrastructure systems include both the fixed assets and the control systems and software required to operate, manage and monitor the systems, as well as any accessory buildings, plants or vehicles that are an essential part of the system. Also included are fleets of vehicles operating according to schedules such as public transit busses and garbage collection, as well as basic energy or communications facilities that are not usually part of a physical network (oil refineries, radio and TV broadcasting facilities).

[edit] Transportation infrastructure

[edit] Energy infrastructure

[edit] Water management infrastructure

[edit] Communications infrastructure

[edit] Waste management

[edit] Earth monitoring and measurement networks

[edit] Types of "soft" infrastructure

"Soft" infrastructure includes both physical assets such as highly specialized buildings and equipment, as well as non-physical "systems" such as the body of rules and regulations governing the various systems, the financing of these systems, as well as the systems and organizations by which highly skilled and specialized professionals are trained, advance in their careers by acquiring experience, and are disciplined (if required) by professional associations (professional training, accreditation and discipline).

[edit] Institutional infrastructure

[edit] Industrial infrastructure

[edit] Social infrastructure

[edit] Cultural, sports and recreational infrastructure

[edit] Economics, management and engineering

The following concerns mainly "hard" infrastructure and the specialized facilities used for "soft" infrastructure.

[edit] Ownership and financing

Infrastructure may be owned and managed by governments or by private companies, such as public utility or railway companies. Generally, most roads, major ports and airports, water distribution systems and sewage networks are publicly owned, whereas most energy and telecommunications networks are privately owned. Publicly owned infrastructure may be paid for from taxes, tolls or metered user fees, whereas private infrastructure is generally paid for by metered user fees. Major investment projects are generally financed by the issuance of long-term bonds.

Note that government owned and operated infrastructure may be developed and operated in the private sector or in public-private partnership in addition to in the public sector.

In the United States, public spending on infrastructure has varied between 2.3% and 3.6% of GDP since 1950.[13]

[edit] Planning and management

Main article: Infrastructure Asset Management

The method of 'Infrastructure Asset Management' is based upon the definition of a Standard of Service (SoS) that describes how an asset will perform in objective and measurable terms. The SoS includes the definition of a minimum condition grade, which is established by considering the consequences of a failure of the infrastructure asset.

The key components of 'Infrastructure Asset Management' are:

The 2009 report card produced by the American Society of Civil Engineers [3] gives America's Infrastructure a grade of "D".

[edit] Engineering

Main articles: engineering and project_management

Most infrastructure is designed by engineers, urbanists or architects. Generally road and rail transport networks, as well as water and waste management infrastructure are designed by civil engineers; electrical power and lighting networks are designed by electrical engineers; and telecommunications, computing and monitoring networks are designed by systems engineers. In the case of urban infrastructure, the general layout of roads, sidewalks and public places may sometimes be designed by urbanists or architects, although the detailed design will still be performed by civil engineers. If a building is required, it is designed by an architect, and if an industrial or processing plant is required, it may be designed by industrial engineer or a process engineer.

In terms of engineering tasks, the design and construction management process usually follows these steps:

[edit] Impact on economic development

Main article: economic development

Investment in infrastructure is part of the capital accumulation required for economic development.[citation needed]

[edit] Use as economic stimulus

During the Great Depression of the 1930s, many governments undertook public works projects in order to create jobs and stimulate the economy. The economist John Maynard Keynes provided a theoretical justification for this policy in The General Theory of Employment, Interest and Money,[14] published in 1936. Following the global financial crisis of 2008–2009, some are again proposing investing in infrastructure as a means of stimulating the economy (see the American Recovery and Reinvestment Act of 2009)

[edit] History

Main articles: History of road transport, Freeway#History, Canal#History, History of rail transport, Electric power transmission#History, Electrical telegraph#History, Telephone#History, and Public switched telephone network#Early history

The following concerns mainly "hard" infrastructure.

[edit] Before 1700

Infrastructure before 1700 consisted mainly of roads and canals. Canals were used for transportation or for irrigation. Sea navigation was aided by ports and lighthouses. A few advanced cities had aqueducts that serviced public fountains and baths, and even fewer had sewers.

Roads:

The first roads were tracks that often followed game trails, such as the Natchez Trace.[15]

The first paved streets appear to have been built in Ur in 4000 BC. Corduroy roads were built in Glastonbury, England in 3300 BC[16] and brick-paved roads were built in the Indus Valley Civilization on the Indian subcontinent from around the same time. In 500 BC, Darius I the Great started an extensive road system for Persia (Iran), including the Royal Road.

With the advent of the Roman Empire, the Romans built roads using deep roadbeds of crushed stone as an underlying layer to ensure that they kept dry. On the more heavily traveled routes, there were additional layers that included six sided capstones, or pavers, that reduced the dust and reduced the drag from wheels.

In the medieval Islamic world, many roads were built throughout the Arab Empire. The most sophisticated roads were those of the Baghdad, Iraq, which were paved with tar in the 8th century.[17]

Canals and irrigation systems: The oldest known canals were built in Mesopotamia circa 4000 BC, in what is now modern day Iraq and Syria. The Indus Valley Civilization in Pakistan and North India (from circa 2600 BC) had a sophisticated canal irrigation system.[18] In Egypt, canals date back to at least 2300 BC, when a canal was built to bypass the cataract on the Nile near Aswan.[19]

In ancient China, large canals for river transport were established as far back as the Warring States (481-221 BC).[20] By far the longest canal was the Grand Canal of China, still the longest canal in the world today at 1,794 kilometres (1,115 mi) long, and completed in 609.

In Europe, canal building began in the Middle Ages because of commercial expansion from the 12th century AD. Notable canals were the Stecknitz Canal in Germany in 1398, the Briare Canal connecting the Loire and Seine in France (1642) followed by the Canal du Midi (1683) connecting the Atlantic to the Mediterranean. Canal building progressed steadily in Germany in the 17th and 18th centuries with three great rivers, the Elbe, Oder and Weser being linked by canals.

[edit] 1700 to 1870

Roads: As traffic levels increased in England and roads deteriorated, toll roads were built by Turnpike Trusts, especially between 1730–1770. Turnpikes were also later built in the United States. They were usually built by private companies under a government franchise.

Water transport on rivers and canals carried many farm goods from the frontier U.S. (between the Appalachian mountains and Mississippi River) in the early 19th century, but the shorter route over the mountains had advantages.

In France, Pierre-Marie-Jérôme Trésaguet is widely credited with establishing the first scientific approach to road building about the year 1764. It involved a layer of large rocks, covered by a layer of smaller gravel. John Loudon McAdam (1756–1836) designed the first modern highways, and developed an inexpensive paving material of soil and stone aggregate (known as macadam).[16]

Canals: In Europe, particularly Britain and Ireland, and then in the young United States and the Canadian colonies, inland canals preceded the development of railroads during the earliest phase of the Industrial Revolution. In Britain between 1760 and 1820 over one hundred canals were built.

In the United States, navigable canals reached into isolated areas and brought them in touch with the world beyond. By 1825 the Erie Canal, 363 miles (584 km) long with 82 locks, opened up a connection from the populated Northeast to the fertile Great Plains. During the 19th century, the length of canals grew from 100 miles (160 km) to over 4,000, with a complex network making the Great Lakes navigable, in conjunction with Canada, although some canals were later drained and used as railroad rights-of-way.

Railways: The earliest railways were used in mines or to bypass waterfalls, and were pulled by horses or by people. In 1811 John Blenkinsop designed the first successful and practical railway locomotive,[21] and a line was built connecting the Middleton Colliery to Leeds. The Liverpool and Manchester Railway,[22] considered to be the world's first "Inter City" line, opened in 1826. In the following years, railways spread throughout the United Kingdom and the world, and became the dominant means of land transport for nearly a century.

In the United States, the 1826 Granite Railway in Massachusetts was the first commercial railroad to evolve through continuous operations into a common carrier. The Baltimore and Ohio, opened in 1830, was the first to evolve into a major system. In 1869, the symbolically important transcontinental railroad was completed in the United States with the driving of a golden spike at Promontory, Utah.[23]

Telegraph service: The first commercial electrical telegraph was first successfully demonstrated on 25 July 1837 between Euston and Camden Town in London.[24] It entered commercial use on the Great Western Railway over the 13 miles (21 km) from Paddington station to West Drayton on 9 April 1839.

In the United States, the telegraph was developed by Samuel Morse and Alfred Vail. On 24 May 1844, Morse made the first public demonstration of his telegraph by sending a message from the Supreme Court Chamber in the U.S. Capitol in Washington, D.C. to the B&O Railroad "outer depot" (now the B&O Railroad Museum) in Baltimore. The Morse/Vail telegraph was quickly deployed in the following two decades. On 24 October 1861, the first transcontinental telegraph system was established.

The first successful transatlantic telegraph cable was completed on 27 July 1866, allowing transatlantic telegraph communications for the first time. Within 29 years of its first installation at Euston Station, the telegraph network crossed the oceans to every continent but Antarctica, making instant global communication possible for the first time.

[edit] 1870 to 1920

Roads: Tar-bound macadam (tarmac) was applied to macadam roads towards the end of the 19th century in cities such as Paris. In the early 20th century tarmac and concrete paving were extended into the countryside.

Canals: Many notable sea canals were completed in this period: the Suez Canal (1869); the Kiel Canal (1897) - which carries tonnage many times that of most other canals; and the Panama Canal, opened in 1914.

Telephone service: In 1876, Alexander Graham Bell achieved the first successful telephone transmission of clear speech. The first telephones had no network but were in private use, wired together in pairs. Users who wanted to talk to different people had as many telephones as necessary for the purpose. A user who wished to speak, whistled into the transmitter until the other party heard. Soon, however, a bell was added for signalling, and then a switchhook, and telephones took advantage of the exchange principle already employed in telegraph networks. Each telephone was wired to a local telephone exchange, and the exchanges were wired together with trunks. Networks were connected together in a hierarchical manner until they spanned cities, countries, continents and oceans.

Electricity: At the Paris Exposition of 1878, electric arc lighting had been installed along the Avenue de l'Opera and the Place de l'Opera, using electric Yablochkov arc lamps, powered by Zénobe Gramme alternating current dynamos.[25][26] Yablochkov candles required high voltage, and it was not long before experimenters reported that the arc lights could be powered on a 7 mile circuit.[27] Within a decade scores of cities would have lighting systems using a central power plant that provided electricity to multiple customers via electrical transmission lines. These systems were in direct competition with the dominant gaslight utilities of the period.

The first electricity system supplying incandescent lights was built by Edison Illuminating Company in lower Manhattan eventually serving one square mile with 6 "jumbo dynamos" housed at Pearl Street Station.

The first transmission of three-phase alternating current using high voltage took place in 1891 during the international electricity exhibition in Frankfurt. A 25 kV transmission line, approximately 175 kilometers long, connected Lauffen on the Neckar and Frankfurt. Voltages used for electric power transmission increased throughout the 20th century. By 1914 fifty-five transmission systems operating at more than 70,000 V were in service, the highest voltage then used was 150,000 volts.[28]

Water distribution and sewers: In the 19th century major treatment works were built in London in response to cholera threats. The Metropolis Water Act 1852 was enacted. "Under the Act, it became unlawful for any water company to extract water for domestic use from the tidal reaches of the Thames after 31 August 1855, and from 31 December 1855 all such water was required to be "effectually filtered".[15] The Metropolitan Commission of Sewers was formed, water filtration was made compulsory, and new water intakes on the Thames were established above Teddington Lock. The technique of purification of drinking water by use of compressed liquefied chlorine gas was developed in 1910 by U.S. Army Major (later Brig. Gen.) Carl Rogers Darnall (1867–1941), Professor of Chemistry at the Army Medical School. Darnall's work became the basis for present day systems of municipal water 'purification'.

Subways: In 1863 the London Underground was created in 1890 it first started using electric traction and deep-level tunnels. Soon afterward Budapest and many other cities started using subway systems including New York. By 1940 19 subway systems were in use.

[edit] Since 1920

Roads: In 1925, Italy was the first country to build a freeway-like road, which linked Milan to Lake Como.[29] It is known in Italy as the Autostrada dei Laghi. In Germany, the autobahns formed the first limited-access, high-speed road network in the world, with the first section from Frankfurt am Main to Darmstadt opening in 1935. The first long-distance rural freeway in the United States is generally considered to be the Pennsylvania Turnpike, which opened on October 1, 1940.[30] In the United States, the Interstate Highway System was authorized by the Federal-Aid Highway Act of 1956.[31] Most of the system was completed between 1960 and 1990.

A multi lane, multi carriageway freeway.

Rural electrification: This is a stub.

Telecommunications: This is a stub.

[edit] National Infrastructure Bank Act of 2007

In 2007, Senator Christopher Dodd of Connecticut and Senator Charles Hagel of Nebraska introduced the National Infrastructure Bank Act of 2007. This bill would provide for a national fund to help pay for large infrastructure projects in the United States.

[edit] See also

[edit] References

  1. ^ Infrastructure, Online Compact Oxford English Dictionary, http://www.askoxford.com/concise_oed/infrastructure (accessed January 17, 2009)
  2. ^ Sullivan, arthur; Steven M. Sheffrin (2003). Economics: Principles in action. Upper Saddle River, New Jersey 07458: Pearson Prentice Hall. pp. 474. ISBN 0-13-063085-3. http://www.pearsonschool.com/index.cfm?locator=PSZ3R9&PMDbSiteId=2781&PMDbSolutionId=6724&PMDbCategoryId=&PMDbProgramId=12881&level=4. 
  3. ^ Infrastructure, American Heritage Dictionary of the English Language, http://education.yahoo.com/reference/dictionary/entry/infrastructure (accessed January 17, 2009)
  4. ^ Infrastructure, JP1-02, Department of Defense Dictionary of Military and Associated Terms, p. 260, 12 April 2001 (rev. 31 August 2005) http://www.dtic.mil/cgi-bin/GetTRDoc?AD=ADA439918&Location=U2&doc=GetTRDoc.pdf(accessed January 17, 2009)
  5. ^ Online Etymology Dictionary. Douglas Harper, Historian. http://dictionary.reference.com/browse/infrastructure (accessed: April 24, 2008)
  6. ^ The Etymology of Infrastructure and the Infrastructure of the Internet, Stephen Lewis on his blog Hag Pak Sak, posted September 22, 2008. http://hakpaksak.wordpress.com/2008/09/22/the-etymology-of-infrastructure-and-the-infrastructure-of-the-internet/ (accessed: January 17, 2008)
  7. ^ Infrastructure for the 21st Century, Washington, D.C.: National Academy Press, 1987.
  8. ^ http://www.opendb.net/element/19099.php
  9. ^ Association of Local Government Engineers New Zealand: "Infrastructure Asset Management Manual", June 1998 - Edition 1.1
  10. ^ D.O.D. Dictionary of Military and Associated Terms, 2001 (rev. 2005)
  11. ^ Land improvement, Online BusinessDictionary.com, http://www.businessdictionary.com/definition/land-development.html (accessed January 31, 2009)
  12. ^ Land development, Online BusinessDictionary.com, http://www.businessdictionary.com/definition/land-development.html (accessed January 31, 2009)
  13. ^ "Money for Public Projects", The New York Times, November 19, 2008 http://www.nytimes.com/imagepages/2008/11/19/business/economy/19leonhardt_graphic.ready.html (accessed January 26, 2009)
  14. ^ Keynes, John Maynard (2007) [1936]. The General Theory of Employment, Interest and Money. Basingstoke, Hampshire: Palgrave Macmillan. ISBN 0230004768 http://cepa.newschool.edu/het/essays/keynes/keynescont.htm.
  15. ^ Lay, M G (1992). Ways of the World. Sydney: Primavera Press. pp. 401. ISBN 1-875368-05-1.
  16. ^ a b Lay (1992)
  17. ^ Dr. Kasem Ajram (1992). The Miracle of Islam Science (2nd ed.). Knowledge House Publishers. ISBN 0-911119-43-4. 
  18. ^ Rodda 2004, p. 161.
  19. ^ Hadfield 1986, p. 16.
  20. ^ Needham 1971, p. 269.
  21. ^ "John Blenkinsop". Encyclopedia Brittanica. http://www.britannica.com/eb/article-9001800. Retrieved 2007-09-10. 
  22. ^ "Liverpool and Manchester". http://www.spartacus.schoolnet.co.uk/RAliverpool.htm. Retrieved 2007-09-19. 
  23. ^ Ambrose, Stephen E. (2000). Nothing Like It In The World; The men who built the Transcontinental Railroad 1863–1869. Simon & Schuster. ISBN 0-684-84609-8. 
  24. ^ The electric telegraph, forerunner of the internet, celebrates 170 years BT Group Connected Earth Online Museum. Accessed July 2007
  25. ^ David Oakes Woodbury (1949). A Measure for Greatness: A Short Biography of Edward Weston. McGraw-Hill. p. 83. http://www.archive.org/stream/measureforgreatn001419mbp/measureforgreatn001419mbp_djvu.txt. Retrieved 2009-01-04. 
  26. ^ John Patrick Barrett (1894). Electricity at the Columbian Exposition. R. R. Donnelley & sons company. p. 1. http://books.google.com/?id=lF5KAAAAMAAJ&pg=PA3. Retrieved 2009-01-04. 
  27. ^ Engineers, Institution of Electrical (1880-3-24). "Notes on the Jablochkoff System of Electric Lighting". Journal of the Society of Telegraph Engineers IX (32): 143. http://books.google.com/?id=lww4AAAAMAAJ&pg=PA143. Retrieved 2009-01-07. 
  28. ^ Bureau of Census data reprinted in Hughes, pp. 282–283
  29. ^ Paul Hofmann, "Taking to the Highway in Italy", New York Times, 26 April 1987, 23.
  30. ^ Phil Patton, The Open Road: A Celebration of the American Highway (New York: Simon & Schuster, 1986), 77.
  31. ^ "The cracks are showing". The Economist. 2008-06-26. http://www.economist.com/world/unitedstates/displayStory.cfm?story_id=11636517. Retrieved 2008-10-23. 

[edit] External links

Wikimedia Commons has media related to: Infrastructure
Look up infrastructure in Wiktionary, the free dictionary.
v • d • e
Infrastructure

Bridge · Canal · Dam · Drainage · Footbridge · Interchange · Levee · Overpass · Road · Skyway · Storm drain · Tunnel
Retrieved from "http://en.wikipedia.org/wiki/Infrastructure"
Personal tools
Namespaces
Variants
Actions
Navigation
Interaction
Toolbox
Print/export
Languages