Hard infrastructure, also known as tangible or built infrastructure, is the physical infrastructure of roads, bridges, tunnels, railways, airports, ports, and harbors, among others, as opposed to the

soft infrastructure Soft infrastructure is all the services that are required to maintain the economic, health, cultural and social standards of a population, as opposed to the hard infrastructure, which is the physical infrastructure of roads, bridges etc. It inc ...

or "intangible infrastructure of human capital in the form of education, research, health and social services and "institutional infrastructure" in the form of legal, economic and social systems. This article delineates both the

capital goods In economics, capital goods or capital are "those durable produced goods that are in turn used as productive inputs for further production" of goods and services. A typical example is the machinery used in a factory. At the macroeconomic level, ...

, or

fixed assets Fixed assets (also known as long-lived assets or property, plant and equipment; PP&E) is a term used in accounting for assets and property that may not easily be converted into cash. They are contrasted with current assets, such as cash, bank acc ...

, and the

control systems A control system manages, commands, directs, or regulates the behavior of other devices or systems using control loops. It can range from a single home heating controller using a thermostat controlling a domestic boiler to large industrial co ...

, software required to operate, manage and monitor the systems, as well as any accessory buildings - such as airports, 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 buses and garbage collection, as well as basic energy or communications facilities that are not usually part of a physical network, such as

oil refineries An oil refinery or petroleum refinery is an industrial process plant where petroleum (crude oil) is transformed and refined into products such as gasoline (petrol), diesel fuel, asphalt base, fuel oils, heating oil, kerosene, liquefied pet ...

, radio, and television broadcasting facilities.

Attributes

Hard infrastructure in general usually has the following attributes:

Capital assets that provide services

These are physical assets that provide services. The people employed in the hard infrastructure sector generally maintain, monitor, and operate the assets, but do not offer services to the clients or users of the infrastructure. Interactions between workers and clients are generally limited to administrative tasks concerning ordering, scheduling, or billing of services.

Large networks

These are large networks constructed over generations and are not often replaced as a whole system. The network provides services to a geographically defined area, and has a long life because its service capacity is maintained by continual refurbishment or replacement of components as they wear out.

Historicity and interdependence

The system or network tends to evolve over time as it is continuously modified, improved, enlarged, and as various components are rebuilt, decommissioned or adapted to other uses. The system components are interdependent and not usually capable of subdivision or separate disposal, and consequently are not readily disposable within the commercial marketplace. The system interdependency may limit a component life to a lesser period than the expected life of the component itself.

Natural monopoly

The systems tend to be natural monopolies, insofar that

economies of scale In microeconomics, economies of scale are the cost advantages that enterprises obtain due to their scale of operation, and are typically measured by the amount of Productivity, output produced per unit of cost (production cost). A decrease in ...

means that multiple agencies providing a service are less efficient than would be the case if a single agency provided the service. This is because the assets have a high initial cost and a value that is difficult to determine. Once most of the system is built, the marginal cost of servicing additional clients or users tends to be relatively inexpensive, and may be negligible if there is no need to increase the peak capacity or the geographical extent of the network. In

public economics Public economics ''(or economics of the public sector)'' is the study of government policy through the lens of economic efficiency and Equity (economics), equity. Public economics builds on the theory of welfare economics and is ultimately used as ...

theory, infrastructure assets such as highways and railways tend to be

public goods In economics, a public good (also referred to as a social good or collective good)Oakland, W. H. (1987). Theory of public goods. In Handbook of public economics (Vol. 2, pp. 485–535). Elsevier. is a goods, commodity, product or service that ...

, in that they carry a high degree of non-excludability, where no household can be excluded from using it, and non-rivalry, where no household can reduce another from enjoying it. These properties lead to

externality In economics, an externality is an Indirect costs, indirect cost (external cost) or indirect benefit (external benefit) to an uninvolved third party that arises as an effect of another party's (or parties') activity. Externalities can be conside ...

, free ridership, and

spillover Spillover may refer to: * Adsorption spillover, a chemical phenomenon involving the movement of atoms adsorbed onto a metal surface * Catalyst support#Spillover * Behavioral spillover, the effect that one behavior has on other behaviors with a s ...

effects that distort perfect competition and market efficiency. Hence, government becomes the best actor to supply the public goods.

Transportation

Transportation infrastructures such as canals, railways, highways, airways and pipelines include the following: *

road A road is a thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. Th ...

and

highway A highway is any public or private road or other public way on land. It includes not just major roads, but also other public roads and rights of way. In the United States, it is also used as an equivalent term to controlled-access highway, or ...

networks, including structures (bridges, tunnels,

culvert A culvert is a structure that channels water past an obstacle or to a subterranean waterway. Typically embedded so as to be surrounded by soil, a culvert may be made from a pipe (fluid conveyance), pipe, reinforced concrete or other materia ...

retaining wall Retaining walls are relatively rigid walls used for supporting soil laterally so that it can be retained at different levels on the two sides. Retaining walls are structures designed to restrain soil to a slope that it would not naturally keep to ...

s), signage and markings, electrical systems (

street lighting A street light, light pole, lamp pole, lamppost, streetlamp, light standard, or lamp standard is a raised source of light on the edge of a road or path. Similar lights may be found on a railway platform. When urban electric power distribution b ...

and

traffic light Traffic lights, traffic signals, or stoplights – also known as robots in South Africa, Zambia, and Namibia – are signaling devices positioned at intersection (road), road intersections, pedestrian crossings, and other locations in order t ...

s), edge treatments (kerbs,

footpaths A footpath (also pedestrian way, walking trail, nature trail) is a type of thoroughfare that is intended for use only by pedestrians and not other forms of traffic such as motorized vehicles, bicycles and horses. They can be found in a wide ...

landscaping Landscaping refers to any activity that modifies the visible features of an area of land, including the following: # Living elements, such as flora or fauna; or what is commonly called gardening, the art and craft of growing plants with a goal ...

) and specialised facilities such as road maintenance depots and

rest area A rest area is a public facility located next to a large thoroughfare such as a motorway, Limited-access road, expressway, or highway, at which drivers and passengers can rest, eat, or refuel without exiting onto secondary roads. Other names ...

s * mass transit systems (

commuter rail Commuter rail or suburban rail is a Passenger train, passenger rail service that primarily operates within a metropolitan area, connecting Commuting, commuters to a Central business district, central city from adjacent suburbs or commuter town ...

systems, subways,

light rail Light rail (or light rail transit, abbreviated to LRT) is a form of passenger urban rail transit that uses rolling stock derived from tram technology National Conference of the Transportation Research Board while also having some features from ...

ferries A ferry is a boat or ship that transports passengers, and occasionally vehicles and cargo, across a body of water. A small passenger ferry with multiple stops, like those in Venice, Italy, is sometimes referred to as a water taxi or water bus. ...

tram A tram (also known as a streetcar or trolley in Canada and the United States) is an urban rail transit in which Rolling stock, vehicles, whether individual railcars or multiple-unit trains, run on tramway tracks on urban public streets; some ...

s, city bicycle sharing systems, city car sharing systems and bus transportation) *railways, including track, structures, terminal facilities (

rail yard A rail yard, railway yard, railroad yard (US) or simply yard, is a series of Track (rail transport), tracks in a rail network for storing, sorting, or loading and unloading rail vehicles and locomotives. Yards have many tracks in parallel for k ...

s, railway stations),

bridge A bridge is a structure built to Span (engineering), span a physical obstacle (such as a body of water, valley, road, or railway) without blocking the path underneath. It is constructed for the purpose of providing passage over the obstacle, whi ...

level crossing A level crossing is an intersection where a railway line crosses a road, Trail, path, or (in rare situations) airport runway, at the same level, as opposed to the railway line or the road etc. crossing over or under using an Overpass#Railway, o ...

s, signalling, and communications systems *

canals Canals or artificial waterways are waterways or engineered channels built for drainage management (e.g. flood control and irrigation) or for conveyancing water transport vehicles (e.g. water taxi). They carry free, calm surface flow u ...

and navigable waterways requiring continuous maintenance (dredging, etc.) * seaports and

lighthouse A lighthouse is a tower, building, or other type of physical structure designed to emit light from a system of lamps and lens (optics), lenses and to serve as a beacon for navigational aid for maritime pilots at sea or on inland waterways. Ligh ...

s *

airports An airport is an aerodrome with extended facilities, mostly for commercial air transport. They usually consist of a landing area, which comprises an aerially accessible open space including at least one operationally active surface such ...

, including

air navigation The basic principles of air navigation are identical to general navigation, which includes the process of planning, recording, and controlling the movement of a craft from one place to another. Successful air navigation involves piloting an airc ...

al systems * bicycle paths and pedestrian walkways, including pedestrian bridges, pedestrian underpasses and other specialised structures for cyclists and pedestrians.

Energy

The OECD classifies coal mines, oil wells and natural gas wells as part of the mining sector, and power generation as part of the industrial sector of the economy, not part of infrastructure.OEC
Economic Infrastructure. Common Reporting Standard (CRS) Codes
2 pages, n.d. * Electrical power network, including generation plants,

electrical grid An electrical grid (or electricity network) is an interconnected network for electricity delivery from producers to consumers. Electrical grids consist of power stations, electrical substations to step voltage up or down, electric power tran ...

, substations, and local distribution. *Natural gas

pipelines A pipeline is a system of pipes for long-distance transportation of a liquid or gas, typically to a market area for consumption. The latest data from 2014 gives a total of slightly less than of pipeline in 120 countries around the world. The Un ...

, storage and distribution terminals, as well as the local distribution network. Some definitions may include the gas wells, as well as the fleets of ships and trucks transporting liquefied gas. *Petroleum

, including associated storage and distribution terminals. Some definitions may include the oil wells, refineries, as well as the fleets of tanker ships and trucks. *Specialised coal handling facilities for

washing Washing is a method of cleaning, usually with water and soap or detergent. Regularly washing and then rinsing both body and clothing is an essential part of good hygiene and health. Often people use soaps and detergents to assist in the emulsific ...

, storing, and transporting coal. Some definitions may include

Coal mines Coal mining is the process of resource extraction, extracting coal from the ground or from a mine. Coal is valued for its Energy value of coal, energy content and since the 1880s has been widely used to Electricity generation, generate electr ...

. *Steam or hot water production and distribution networks for

district heating District heating (also known as heat networks) is a system for distributing heat generated in a centralized location through a system of insulated pipes for residential and commercial heating requirements such as space heater, space heating and w ...

systems. * Electric vehicle networks for charging

electric vehicle An electric vehicle (EV) is a motor vehicle whose propulsion is powered fully or mostly by electricity. EVs encompass a wide range of transportation modes, including road vehicle, road and rail vehicles, electric boats and Submersible, submer ...

Water management

* Drinking water supply, including the system of pipes, storage reservoirs, pumps, valves,

filtration Filtration is a physical separation process that separates solid matter and fluid from a mixture using a ''filter medium'' that has a complex structure through which only the fluid can pass. Solid particles that cannot pass through the filte ...

and treatment equipment and meters, including buildings and structures to house the equipment, used for the collection, treatment and distribution of drinking water *

Sewage Sewage (or domestic sewage, domestic wastewater, municipal wastewater) is a type of wastewater that is produced by a community of people. It is typically transported through a sewerage, sewer system. Sewage consists of wastewater discharged fro ...

collection, and disposal of waste water *

Drainage Drainage is the natural or artificial removal of a surface's water and sub-surface water from an area with excess water. The internal drainage of most agricultural soils can prevent severe waterlogging (anaerobic conditions that harm root gro ...

systems (storm sewers, ditches, etc.) *Major

irrigation Irrigation (also referred to as watering of plants) is the practice of applying controlled amounts of water to land to help grow crops, landscape plants, and lawns. Irrigation has been a key aspect of agriculture for over 5,000 years and has bee ...

systems (reservoirs, irrigation

) *Major

flood control Flood management or flood control are methods used to reduce or prevent the detrimental effects of flood waters. Flooding can be caused by a mix of both natural processes, such as extreme weather upstream, and human changes to waterbodies and ru ...

systems ( dikes,

levee A levee ( or ), dike (American English), dyke (British English; see American and British English spelling differences#Miscellaneous spelling differences, spelling differences), embankment, floodbank, or stop bank is an elevated ridge, natural ...

s, major pumping stations and floodgates) *Large-scale

snow removal Snow removal or snow clearing is the job of removing snow after a snowfall to make travel easier and safer. This is done both by individual households and by governments institutions, and commercial businesses. De-icing and anti-icing De-icin ...

, including fleets of salt spreaders, snow plows,

snowblower A snow blower or snowblower or snow thrower is a machine for removing snow from an area where it is problematic, such as a driveway, sidewalk, roadway, railroad track, ice rink, or runway. The commonly used term "snow blower" is a misnomer, a ...

s, dedicated

dump truck A dump truck, known also as a dumping truck, dump lorry or dumper lorry or a dumper for short, is used for transporting materials (such as dirt, gravel, or demolition waste) for construction as well as coal. A typical dump truck is equipped ...

s, sidewalk plows, the dispatching and routing systems for these fleets, as well as fixed assets such as snow dumps, snow chutes, snow melters *

Coastal management Coastal management is defence against flooding and erosion, and techniques that stop erosion to claim lands. Protection against rising sea levels in the 21st century is crucial, as sea level rise accelerates due to climate change. Changes in s ...

, including structures such as

seawall A seawall (or sea wall) is a form of coastal defense constructed where the sea, and associated coastal processes, impact directly upon the landforms of the coast. The purpose of a seawall is to protect areas of human habitation, conservation, ...

breakwaters A breakwater is a permanent structure constructed at a coastal area to protect against tides, currents, waves, and storm surges. Breakwaters have been built since antiquity to protect anchorages, helping isolate vessels from marine hazards ...

groyne A groyne (in the U.S. groin) is a rigid aquatic structure built perpendicularly from an ocean shore (in coastal engineering) or a river bank, interrupting water flow and limiting the movement of sediment. It is usually made out of wood, concrete ...

floodgate Floodgates, also called stop gates, are adjustable gates used to control water flow in flood barriers, reservoir, river, stream, or levee systems. They may be designed to set spillway crest heights in dams, to adjust flow rates in sluices and ...

s, as well as the use of soft engineering techniques such as

beach nourishment Beach nourishment (also referred to as beach renourishment, beach replenishment, or sand replenishment) describes a process by which sediment, usually sand, lost through longshore drift or erosion is replaced from other sources. A wider beach c ...

, sand dune stabilisation and the protection of

mangrove A mangrove is a shrub or tree that grows mainly in coastal saline water, saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen a ...

forests and coastal

wetlands A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

Communications

OECD lists communications under its economic infrastructure

Common Reporting Standard The Common Reporting Standard (CRS) is an information standard for the Automatic Exchange Of Information (AEOI) regarding financial accounts on a global level, between tax authorities, which the Organisation for Economic Co-operation and Develo ...

codes. *

Postal service The mail or post is a system for physically transporting postcards, letters, and parcels. A postal service can be private or public, though many governments place restrictions on private systems. Since the mid-19th century, national postal sy ...

, including sorting facilities *

Telephone network A telephone network is a telecommunications network that connects telephones, which allows telephone calls between two or more parties, as well as newer features such as fax and internet. The idea was revolutionized in the 1920s, as more and more ...

s (land lines) including

telephone exchange A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits ...

systems * Mobile phone networks *Television and radio transmission stations, including the regulations and standards governing broadcasting *Cable television physical networks including receiving stations and cable distribution networks (does not include content providers or "cable networks" when used in the sense of a specialised channel such as CNN or MTV) *The Internet, including the

internet backbone The Internet backbone is the principal data routes between large, strategically interconnected computer networks and core routers of the Internet. These data routes are hosted by commercial, government, academic and other high-capacity network ...

core router A core router is a router designed to operate in the Internet backbone, or core, or in core networks of internet service providers. To fulfill this role, a router must be able to support multiple telecommunications interfaces of the highest spe ...

s and

server farms A server farm or server cluster is a collection of computer servers, usually maintained by an organization to supply server functionality far beyond the capability of a single machine. They often consist of thousands of computers which require ...

, local

internet service providers An Internet service provider (ISP) is an organization that provides a myriad of services related to accessing, using, managing, or participating in the Internet. ISPs can be organized in various forms, such as commercial, community-owned, non ...

as well as the

protocols Protocol may refer to: Sociology and politics * Protocol (politics), a formal agreement between nation states * Protocol (diplomacy), the etiquette of diplomacy and affairs of state * Etiquette, a code of personal behavior Science and technology ...

and other basic software required for the system to function (does not include specific websites, although may include some widely used web-based services, such as

social network service A social networking service (SNS), or social networking site, is a type of online social media platform which people use to build social networks or social relationships with other people who share similar personal or career content, interests ...

s and web search engines) *

Communications satellite A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a Transponder (satellite communications), transponder; it creates a communication channel between a source transmitter and a Rad ...

s * Undersea cables *Major private, government or dedicated telecommunications networks, such as those used for internal communication and monitoring by major infrastructure companies, by governments, by the military or by emergency services, as well as

national research and education network A national research and education network (NREN) is a specialised internet service provider dedicated to supporting the needs of the research and education communities within a country. It is usually distinguished by support for a high-speed backb ...

s *

Pneumatic tube Pneumatic tubes (or capsule pipelines, also known as pneumatic tube transport or PTT) are systems that propel cylindrical containers through networks of Tubing (material), tubes by Gas compressor, compressed air or by partial vacuum. They are use ...

mail distribution networks

Solid waste management

* Municipal garbage and recyclables collection *Solid waste

landfill A landfill is a site for the disposal of waste materials. It is the oldest and most common form of waste disposal, although the systematic burial of waste with daily, intermediate and final covers only began in the 1940s. In the past, waste was ...

s *Solid waste

incinerators Incineration is a waste treatment process that involves the combustion of substances contained in waste materials. Industrial plants for waste incineration are commonly referred to as waste-to-energy facilities. Incineration and other high ...

and plasma gasification facilities * Materials recovery facilities *

Hazardous waste Hazardous waste is waste that must be handled properly to avoid damaging human health or the environment. Waste can be hazardous because it is Toxicity, toxic, Chemical reaction, reacts violently with other chemicals, or is Corrosion, corrosive, ...

disposal facilities

Earth monitoring and measurement networks

Meteorological Meteorology is the scientific study of the Earth's atmosphere and short-term atmospheric phenomena (i.e. weather), with a focus on weather forecasting. It has applications in the military, aviation, energy production, transport, agriculture ...

monitoring networks * Tidal monitoring networks *

Stream gauge A stream gauge, streamgage or stream gauging station is a location used by hydrologists or environmental scientists to monitor and test terrestrial bodies of water. Hydrometric measurements of water level surface elevation (" stage") and/or v ...

or fluviometric monitoring networks *

Seismometer A seismometer is an instrument that responds to ground displacement and shaking such as caused by quakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The out ...

networks *

Earth observation satellite An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit, including spy satellites and similar ones intended for non-military uses such as environmental monitoring, me ...

s * Geodetic benchmarks *

Global Positioning System The Global Positioning System (GPS) is a satellite-based hyperbolic navigation system owned by the United States Space Force and operated by Mission Delta 31. It is one of the global navigation satellite systems (GNSS) that provide ge ...

Spatial Data Infrastructure A spatial data infrastructure (SDI), also called geospatial data infrastructure, is a data infrastructure implementing a framework of geographic data, metadata, users and tools that are interactively connected in order to use spatial data in an eff ...

References

Bibliography

* Larry W. Beeferman, "Pension Fund Investment in Infrastructure: A Resource Paper", Capital Matter (Occasional Paper Series), No.3 December 2008 * A. Eberhard, "Infrastructure Regulation in Developing Countries", PPIAF Working Paper No. 4 (2007) World Bank * M. Nicolas J. Firzli & Vincent Bazi, “Infrastructure Investments in an Age of Austerity : The Pension and Sovereign Funds Perspective”, published jointly in Revue Analyse Financière, Q4 2011 issue, pp. 34– 37 and USAK/JTW 30 July 2011 (online edition) * Georg Inderst, "Pension Fund Investment in Infrastructure", OECD Working Papers on Insurance and Private Pensions, No. 32 (2009) * * *

External links

Body of Knowledge on Infrastructure Regulation

Next Generation Infrastructures international research programme

Report Card on America's Infrastructure
{{Rail tracks Construction Technology development Infrastructure