City

Downtown Pittsburgh at the confluence of the Monongahela and Allegheny rivers, which flow into the Ohio River

Town siting has varied through history according to natural, technological, economic, and military contexts. Access to water has long been a major factor in city placement and growth, and despite exceptions enabled by the advent of rail transport in the nineteenth century, through the present most of the world's urban population lives near the coast or on a river.[34]

Urban areas as a rule cannot produce their own food and therefore must develop some relationship with a hinterland that sustains them.[35] Only in special cases such as mining towns which play a vital role in long-distance trade, are cities disconnected from the countryside which feeds them.[36] Thus, centrality within a productive region influences siting, as economic forces would, in theory, favor the creation of marketplaces in optimal mutually reachable locations.[37]

Kluuvi, a city centre in Helsinki, Finland

The vast majority of cities have a central area containing buildings with special economic, political, and religious significance. Archaeologists refer to this area by the Greek term temenos or if fortified as a citadel.[38] These spaces historically reflect and amplify the city's centrality and importance to its wider sphere of influence.[37] Today cities have a city center or downtown, sometimes coincident with a central business district.

Cities typically have public spaces where anyone can go. These include privately owned spaces open to the public as well as forms of public land such as public domain and the commons. Western philosophy since the time of the Greek agora has considered physical public space as the substrate of the symbolic public sphere.[39][40] Public art adorns (or disfigures) public spaces. Parks and other natural sites within cities provide residents with relief from the hardness and regularity of typical built environments. Urban green spaces are another component of public space that provides the benefit of mitigating the urban heat island effect, especially in cities that are in warmer climates. These spaces prevent carbon imbalances, extreme habitat losses, electricity and water consumption, and human health risks.[41]

The L'Enfant Plan for Washington, D.C. combines a utilitarian grid pattern with diagonal avenues and a symbolic focus on monumental architecture.[42]

The urban structure generally follows one or more basic patterns: geomorphic, radial, concentric, rectilinear, and curvilinear. The physical environment generally constrains the form in which a city is built. If located on a mountainside, urban structures may rely on terraces and winding roads. It may be adapted to its means of subsistence (e.g. agriculture or fishing). And it may be set up for optimal defense given the surrounding landscape.[43] Beyond these "geomorphic" features, cities can develop internal patterns, due to natural growth or to city planning.

In a radial structure, main roads converge on a central point. This form could evolve from successive growth over a long time, with concentric traces of town walls and citadels marking older city boundaries. In more recent history, such forms were supplemented by ring roads moving traffic around the outskirts of a town. Dutch cities such as Amsterdam and Haarlem are structured as a central square surrounded by concentric canals marking every expansion. In cities such as Moscow, this pattern is still clearly visible.

A system of rectilinear city streets and land plots, known as the grid plan, has been used for millennia in Asia, Europe, and the Americas. The Indus Valley civilization built Mohenjo-Daro, Harappa, and other cities on a grid pattern, using ancient principles described by Kautilya, and aligned with the compass points.[44][24][45][46] The ancient Greek city of Priene exemplifies a grid plan with specialized districts used across the Hellenistic Mediterranean.

Aerial view of the Gush Dan metropolitan area in Israel, showing the geometrically planned[47] city of Tel Aviv (upper left), Givatayim to the east, and some of Bat Yam to the south.[48]

The urban-type settlement extends far beyond the traditional boundaries of the city proper[49] in a form of development sometimes described critically as urban sprawl.[50] Decentralization and dispersal of city functions (commercial, industrial, residential, cultural, political) has transformed the very meaning of the term and has challenged geographers seeking to classify territories according to an urban-rural binary.[22]

Metropolitan areas include suburbs and exurbs organized around the needs of commuters, and sometimes edge cities characterized by a degree of economic and political independence. (In the US these are grouped into metropolitan statistical areas for purposes of demography and marketing.) Some cities are now part of a continuous urban landscape called urban agglomeration, conurbation, or megalopolis (exemplified by the BosWash corridor of the Northeastern United States.)[51]

A recreation of Ancient Rome, the first city in the world to reach one million inhabitants

Jericho and Çatalhöyük, dated to the eighth millennium BC, are among the earliest proto-cities known to archaeologists.[58][65] However, the Mesopotamian city of Uruk from the mid-fourth millennium BC (ancient Iraq) is considered by most archaeologists to be the first true city, innovating many characteristics for cities to follow, with its name attributed to the Uruk period.[66][67][68]

In the fourth and third millennium BC, complex civilizations flourished in the river valleys of Mesopotamia, India,[69][70] China,[71] and Egypt. Excavations in these areas have found the ruins of cities geared variously towards trade, politics, or religion. Some had large, dense populations, but others carried out urban activities in the realms of politics or religion without having large associated populations.

Among the early Old World cities, Mohenjo-Daro of the Indus Valley civilization in present-day Pakistan, existing from about 2600 BC, was one of the largest, with a population of 50,000 or more and a sophisticated sanitation system.[72] China's planned cities were constructed according to sacred principles to act as celestial microcosms.[73]

The Ancient Egyptian cities known physically by archaeologists are not extensive.[24] They include (known by their Arab names) El Lahun, a workers' town associated with the pyramid of Senusret II, and the religious city Amarna built by Akhenaten and abandoned. These sites appear planned in a highly regimented and stratified fashion, with a minimalistic grid of rooms for the workers and increasingly more elaborate housing available for higher classes.[74]

In Mesopotamia, the civilization of Sumer, followed by Assyria and Babylon, gave rise to numerous cities, governed by kings and fostered multiple languages written in cuneiform.[75] The Phoenician trading empire, flourishing around the turn of the first millennium BC, encompassed numerous cities extending from Tyre, Cydon, and Byblos to Carthage and Cádiz.

In the following centuries, independent city-states of Greece, especially Athens, developed the polis, an association of male landowning citizens who collectively constituted the city.[76] The agora, meaning "gathering place" or "assembly", was the center of the athletic, artistic, spiritual, and political life of the polis.[77] Rome was the first city that surpassed one million inhabitants. Under the authority of its empire, Rome transformed and founded many cities (Colonia), and with them brought its principles of urban architecture, design, and society.[78]

In the ancient Americas, early urban traditions developed in the Andes and Mesoamerica. In the Andes, the first urban centers developed in the Norte Chico civilization, Chavin and Moche cultures, followed by major cities in the Huari, Chimu, and Inca cultures. The Norte Chico civilization included as many as 30 major population centers in what is now the Norte Chico region of north-central coastal Peru. It is the oldest known civilization in the Americas, flourishing between the 30th and 18th centuries BC.[79] Mesoamerica saw the rise of early urbanism in several cultural regions, beginning with the Olmec and spreading to the Preclassic Maya, the Zapotec of Oaxaca, and Teotihuacan in central Mexico. Later cultures such as the Aztec, Andean civilizations, Mayan, Mississippians, and Pueblo peoples drew on these earlier urban traditions. Many of their ancient cities continue to be inhabited, including major metropolitan cities such as Mexico City, in the same location as Tenochtitlan; while ancient continuously inhabited Pueblos are near modern urban areas in New Mexico, such as Acoma Pueblo near the Albuquerque metropolitan area and Taos Pueblo near Taos; while others like Lima are located nearby ancient Peruvian sites such as Pachacamac.

Jenné-Jeno, located in present-day Mali and dating to the third century BC, lacked monumental architecture and a distinctive elite social class—but nevertheless had specialized production and relations with a hinterland.[80] Pre-Arabic trade contacts probably existed between Jenné-Jeno and North Africa.[81] Other early urban centers in sub-Saharan Africa, dated to around 500 AD, include Awdaghust, Kumbi-Saleh the ancient capital of Ghana, and Maranda a center located on a trade route between Egypt and Gao.[82]

Vyborg in Leningrad Oblast has existed since the 13th century.

Old town of Utrecht, Netherlands

The Free imperial cities of the Holy Roman Empire in 1648

A map of Haarlem in the Netherlands, created around 1550, shows the city completely surrounded by a city wall and defensive canal, with its square shape inspired by the shape of Jerusalem.

In the remnants of the Roman Empire, cities of late antiquity gained independence but soon lost population and importance. The locus of power in the West shifted to Constantinople and to the ascendant Islamic civilization with its major cities Baghdad, Cairo, and Córdoba.[83] From the 9th through the end of the 12th century, Constantinople, the capital of the Eastern Roman Empire, was the largest and wealthiest city in Europe, with a population approaching 1 million.[84][85] The Ottoman Empire gradually gained control over many cities in the Mediterranean area, including Constantinople in 1453.

In the Holy Roman Empire, beginning in the 12th century, free imperial cities such as Nuremberg, Strasbourg, Frankfurt, Basel, Zurich, and Nijmegen became a privileged elite among towns having won self-governance from their local lord or having been granted self-governance by the emperor and being placed under his immediate protection. By 1480, these cities, as far as still part of the empire, became part of the Imperial Estates governing the empire with the emperor through the Imperial Diet.[86]

By the 13th and 14th centuries, some cities become powerful states, taking surrounding areas under their control or establishing extensive maritime empires. In Italy, medieval communes developed into city-states including the Republic of Venice and the Republic of Genoa. In Northern Europe, cities including Lübeck and Bruges formed the Hanseatic League for collective defense and commerce. Their power was later challenged and eclipsed by the Dutch commercial cities of Ghent, Ypres, and Amsterdam.[87][88] Similar phenomena existed elsewhere, as in the case of Sakai, which enjoyed considerable autonomy in late medieval Japan.

In the first millennium AD, the Khmer capital of Angkor in Cambodia grew into the most extensive preindustrial settlement in the world by area,[89][90] covering over 1,000 km² and possibly supporting up to one million people.[89][91]

In the West, nation-states became the dominant unit of political organization following the Peace of Westphalia in the seventeenth century.[92][93] Western Europe's larger capitals (London and Paris) benefited from the growth of commerce following the emergence of an Atlantic trade. However, most towns remained small.

During the Spanish colonization of the Americas, the old Roman city concept was extensively used. Cities were founded in the middle of the newly conquered territories and were bound to several laws regarding administration, finances, and urbanism.

The growth of the modern industry from the late 18th century onward led to massive urbanization and the rise of new great cities, first in Europe and then in other regions, as new opportunities brought huge numbers of migrants from rural communities into urban areas. England led the way as London became the capital of a world empire and cities across the country grew in locations strategic for manufacturing.[94] In the United States from 1860 to 1910, the introduction of railroads reduced transportation costs, and large manufacturing centers began to emerge, fueling migration from rural to city areas.

Some industrialized cities were confronted with health challenges associated with overcrowding, occupational hazards of industry, contaminated water and air, poor sanitation, and communicable diseases such as typhoid and cholera. Factories and slums emerged as regular features of the urban landscape.[95]

In the second half of the 20th century, deindustrialization (or "economic restructuring") in the West led to poverty, homelessness, and urban decay in formerly prosperous cities. America's "Steel Belt" became a "Rust Belt" and cities such as Detroit, Michigan, and Gary, Indiana began to shrink, contrary to the global trend of massive urban expansion.[96] Such cities have shifted with varying success into the service economy and public-private partnerships, with concomitant gentrification, uneven revitalization efforts, and selective cultural development.[97] Under the Great Leap Forward and subsequent five-year plans continuing today, China has undergone concomitant urbanization and industrialization and become the world's leading manufacturer.[98][99]

Amidst these economic changes, high technology and instantaneous telecommunication enable select cities to become centers of the knowledge economy.[100][101][102] A new smart city paradigm, supported by institutions such as the RAND Corporation and IBM, is bringing computerized surveillance, data analysis, and governance to bear on cities and city dwellers.[103] Some companies are building brand-new master-planned cities from scratch on greenfield sites.

The Dublin Fire Brigade in Dublin, Ireland, extinguishing a severe fire at a hardware store in 1970

Cities typically provide municipal services such as education, through school systems; policing, through police departments; and firefighting, through fire departments; as well as the city's basic infrastructure. These are provided more or less routinely, in a more or less equal fashion.[133][134] Responsibility for administration usually falls on the city government, but some services may be operated by a higher level of government,[135] while others may be privately run.[136] Armies may assume responsibility for policing cities in states of domestic turmoil such as America's King assassination riots of 1968.

The traditional basis for municipal finance is local property tax levied on real estate within the city. Local government can also collect revenue for services, or by leasing land that it owns.[137] However, financing municipal services, as well as urban renewal and other development projects, is a perennial problem, which cities address through appeals to higher governments, arrangements with the private sector, and techniques such as privatization (selling services into the private sector), corporatization (formation of quasi-private municipally-owned corporations), and financialization (packaging city assets into tradeable financial public contracts and other related rights). This situation has become acute in deindustrialized cities and in cases where businesses and wealthier citizens have moved outside of city limits and therefore beyond the reach of taxation.[138][139][140][141] Cities in search of ready cash increasingly resort to the municipal bond, essentially a loan with interest and a repayment date.[142] City governments have also begun to use tax increment financing, in which a development project is financed by loans based on future tax revenues which it is expected to yield.[141] Under these circumstances, creditors and consequently city governments place a high importance on city credit ratings.[143]

The Ripon Building, the headquarters of Greater Chennai Corporation in Chennai, is one of the oldest city governing corporations in Asia.

Governance includes government but refers to a wider domain of social control functions implemented by many actors including non-governmental organizations.[144] The impact of globalization and the role of multinational corporations in local governments worldwide, has led to a shift in perspective on urban governance, away from the "urban regime theory" in which a coalition of local interests functionally govern, toward a theory of outside economic control, widely associated in academics with the philosophy of neoliberalism.[145] In the neoliberal model of governance, public utilities are privatized, the industry is deregulated, and corporations gain the status of governing actors—as indicated by the power they wield in public-private partnerships and over business improvement districts, and in the expectation of self-regulation through corporate social responsibility. The biggest investors and real estate developers act as the city's de facto urban planners.[146]

The related concept of good governance places more emphasis on the state, with the purpose of assessing urban governments for their suitability for development assistance.[147] The concepts of governance and good governance are especially invoked in emergent megacities, where international organizations consider existing governments inadequate for their large populations.[148]

La Plata in Argentina is based on a perfect square with 5196-meter sides, and was designed in the 1880s as the new capital of Buenos Aires Province.[149]

Urban planning, the application of forethought to city design, involves optimizing land use, transportation, utilities, and other basic systems, in order to achieve certain objectives. Urban planners and scholars have proposed overlapping theories as ideals for how plans should be formed. Planning tools, beyond the original design of the city itself, include public capital investment in infrastructure and land-use controls such as zoning. The continuous process of comprehensive planning involves identifying general objectives as well as collecting data to evaluate progress and inform future decisions.[150][151]

Government is legally the final authority on planning but in practice, the process involves both public and private elements. The legal principle of eminent domain is used by the government to divest citizens of their property in cases where its use is required for a project.[151] Planning often involves tradeoffs—decisions in which some stand to gain and some to lose—and thus is closely connected to the prevailing political situation.[152]

The history of urban planning dates to some of the earliest known cities, especially in the Indus Valley and Mesoamerican civilizations, which built their cities on grids and apparently zoned different areas for different purposes.[24][153] The effects of planning, ubiquitous in today's world, can be seen most clearly in the layout of planned communities, fully designed prior to construction, often with consideration for interlocking physical, economic, and cultural systems.

Urban society is typically stratified. Spatially, cities are formally or informally segregated along ethnic, economic, and racial lines. People living relatively close together may live, work, and play in separate areas, and associate with different people, forming ethnic or lifestyle enclaves or, in areas of concentrated poverty, ghettoes. While in the US and elsewhere poverty became associated with the inner city, in France it has become associated with the banlieues, areas of urban development that surround the city proper. Meanwhile, across Europe and North America, the racially white majority is empirically the most segregated group. Suburbs in the West, and, increasingly, gated communities and other forms of "privatopia" around the world, allow local elites to self-segregate into secure and exclusive neighborhoods.[154]

Landless urban workers, contrasted with peasants and known as the proletariat, form a growing stratum of society in the age of urbanization. In Marxist doctrine, the proletariat will inevitably revolt against the bourgeoisie as their ranks swell with disenfranchised and disaffected people lacking all stake in the status quo.[155] The global urban proletariat of today, however, generally lacks the status of factory workers which in the nineteenth century provided access to the means of production.[156]

Clusters of skyscrapers in Xinyi Planning District, the centre of commerce and finance of Taipei, the capital of Taiwan

Historically, cities rely on rural areas for intensive farming to yield surplus crops, in exchange for which they provide money, political administration, manufactured goods, and culture.[35][36] Urban economics tends to analyze larger agglomerations, stretching beyond city limits, in order to reach a more complete understanding of the local labor market.[157]

As hubs of trade, cities have long been home to retail commerce and consumption through the interface of shopping. In the 20th century, department stores using new techniques of advertising, public relations, decoration, and design, transformed urban shopping areas into fantasy worlds encouraging self-expression and escape through consumerism.[158][159]

In general, the density of cities expedites commerce and facilitates knowledge spillovers, helping people and firms exchange information and generate new ideas.[160][161] A thicker labor market allows for better skill matching between firms and individuals. Population density enables also sharing of common infrastructure and production facilities; however, in very dense cities, increased crowding and waiting times may lead to some negative effects.[162]

Although manufacturing fueled the growth of cities, many now rely on a tertiary or service economy. The services in question range from tourism, hospitality, entertainment, and housekeeping to grey-collar work in law, financial consulting, and administration.[97][163]

According to a scientific model of cities by Professor Geoffrey West, with the doubling of a city's size, salaries per capita will generally increase by 15%.[164]

Paris is one of the best-known cities in the world.[165]

Nepalese dancers at Edmonton Heritage Festival, in Alberta, Canada, an example of the cultural diversity of a city

Cities are typically hubs for education and the arts, supporting universities, museums, temples, and other cultural institutions.[25] They feature impressive displays of architecture ranging from small to enormous and ornate to brutal; skyscrapers, providing thousands of offices or homes within a small footprint, and visible from miles away, have become iconic urban features.[166] Cultural elites tend to live in cities, bound together by shared cultural capital, and themselves play some role in governance.[167] By virtue of their status as centers of culture and literacy, cities can be described as the locus of civilization, human history, and social change.[168][169]

Density makes for effective mass communication and transmission of news, through heralds, printed proclamations, newspapers, and digital media. These communication networks, though still using cities as hubs, penetrate extensively into all populated areas. In the age of rapid communication and transportation, commentators have described urban culture as nearly ubiquitous[22][170][171] or as no longer meaningful.[172]

Today, a city's promotion of its cultural activities dovetails with place branding and city marketing, public diplomacy techniques used to inform development strategy; attract businesses, investors, residents, and tourists; and to create shared identity and sense of place within the metropolitan area.[173][174][175][176] Physical inscriptions, plaques, and monuments on display physically transmit a historical context for urban places.[177] Some cities, such as Jerusalem, Mecca, and Rome have indelible religious status and for hundreds of years have attracted pilgrims. Patriotic tourists visit Agra to see the Taj Mahal, or New York City to visit the World Trade Center. Elvis lovers visit Memphis to pay their respects at Graceland.[178] Place brands (which include place satisfaction and place loyalty) have great economic value (comparable to the value of commodity brands) because of their influence on the decision-making process of people thinking about doing business in—"purchasing" (the brand of)—a city.[176]

Bread and circuses among other forms of cultural appeal, attract and entertain the masses.[109][179] Sports also play a major role in city branding and local identity formation.[180] Cities go to considerable lengths in competing to host the Olympic Games, which bring global attention and tourism.[181] Paris, a city known for its cultural history, is the site of the next Olympics in the summer of 2024.[182]

The atomic bombing of Hiroshima on 6 August 1945 devastated the city and led to Imperial Japan's surrender and the end of World War II.

Warsaw Old Town after the Warsaw uprising with 85% of the city destroyed

Cities play a crucial strategic role in warfare due to their economic, demographic, symbolic, and political centrality. For the same reasons, they are targets in asymmetric warfare. Many cities throughout history were founded under military auspices, a great many have incorporated fortifications, and military principles continue to influence urban design.[183] Indeed, war may have served as the social rationale and economic basis for the very earliest cities.[59][60]

Powers engaged in geopolitical conflict have established fortified settlements as part of military strategies, as in the case of garrison towns, America's Strategic Hamlet Program during the Vietnam War, and Israeli settlements in Palestine.[184] While occupying the Philippines, the US Army ordered local people to concentrate in cities and towns, in order to isolate committed insurgents and battle freely against them in the countryside.[185][186]

During World War II, national governments on occasion declared certain cities open, effectively surrendering them to an advancing enemy in order to avoid damage and bloodshed. Urban warfare proved decisive, however, in the Battle of Stalingrad, where Soviet forces repulsed German occupiers, with extreme casualties and destruction. In an era of low-intensity conflict and rapid urbanization, cities have become sites of long-term conflict waged both by foreign occupiers and by local governments against insurgency.[156][187] Such warfare, known as counterinsurgency, involves techniques of surveillance and psychological warfare as well as close combat,[188] and functionally extends modern urban crime prevention, which already uses concepts such as defensible space.[189]

Although capture is the more common objective, warfare has in some cases spelled complete destruction for a city. Mesopotamian tablets and ruins attest to such destruction,[190] as does the Latin motto Carthago delenda est.[191][192] Since the atomic bombings of Hiroshima and Nagasaki and throughout the Cold War, nuclear strategists continued to contemplate the use of "counter-value" targeting: crippling an enemy by annihilating its valuable cities, rather than aiming primarily at its military forces.[193][194]

Aqueduct of Segovia in Segovia, Spain

Public utilities (literally, useful things with general availability) include basic and essential infrastructure networks, chiefly concerned with the supply of water, electricity, and telecommunications capability to the populace.[228]

Sanitation, necessary for good health in crowded conditions, requires water supply and waste management as well as individual hygiene. Urban water systems include principally a water supply network and a network (sewerage system) for sewage and stormwater. Historically, either local governments or private companies have administered urban water supply, with a tendency toward government water supply in the 20th century and a tendency toward private operation at the turn of the twenty-first.[126][lower-alpha 3] The market for private water services is dominated by two French companies, Veolia Water (formerly Vivendi) and Engie (formerly Suez), said to hold 70% of all water contracts worldwide.[126][230]

Modern urban life relies heavily on the energy transmitted through electricity for the operation of electric machines (from household appliances to industrial machines to now-ubiquitous electronic systems used in communications, business, and government) and for traffic lights, street lights, and indoor lighting. Cities rely to a lesser extent on hydrocarbon fuels such as gasoline and natural gas for transportation, heating, and cooking. Telecommunications infrastructure such as telephone lines and coaxial cables also traverse cities, forming dense networks for mass and point-to-point communications.[231]

Gautrain at O. R. Tambo International Airport in Johannesburg

TransJakarta in Indonesia is the longest bus rapid transit system in the world.

Baana, a shared-path rail trail in Helsinki

Because cities rely on specialization and an economic system based on wage labor, their inhabitants must have the ability to regularly travel between home, work, commerce, and entertainment.[232] City dwellers travel by foot or by wheel on roads and walkways, or use special rapid transit systems based on underground, overground, and elevated rail. Cities also rely on long-distance transportation (truck, rail, and airplane) for economic connections with other cities and rural areas.[233]

City streets historically were the domain of horses and their riders and pedestrians, who only sometimes had sidewalks and special walking areas reserved for them.[234] In the West, bicycles or (velocipedes), efficient human-powered machines for short- and medium-distance travel,[235] enjoyed a period of popularity at the beginning of the twentieth century before the rise of automobiles.[236] Soon after, they gained a more lasting foothold in Asian and African cities under European influence.[237] In Western cities, industrializing, expanding, and electrifying public transit systems, and especially streetcars enabled urban expansion as new residential neighborhoods sprung up along transit lines and workers rode to and from work downtown.[233][238]

Since the mid-20th century, cities have relied heavily on motor vehicle transportation, with major implications for their layout, environment, and aesthetics.[239] (This transformation occurred most dramatically in the US—where corporate and governmental policies favored automobile transport systems—and to a lesser extent in Europe.)[233][238] The rise of personal cars accompanied the expansion of urban economic areas into much larger metropolises, subsequently creating ubiquitous traffic issues with the accompanying construction of new highways, wider streets, and alternative walkways for pedestrians.[240][241][242][174] However, severe traffic jams still occur regularly in cities around the world, as private car ownership and urbanization continue to increase, overwhelming existing urban street networks.[137]

The urban bus system, the world's most common form of public transport, uses a network of scheduled routes to move people through the city, alongside cars, on the roads.[243] The economic function itself also became more decentralized as concentration became impractical and employers relocated to more car-friendly locations (including edge cities).[233] Some cities have introduced bus rapid transit systems which include exclusive bus lanes and other methods for prioritizing bus traffic over private cars.[137][244] Many big American cities still operate conventional public transit by rail, as exemplified by the ever-popular New York City Subway system. Rapid transit is widely used in Europe and has increased in Latin America and Asia.[137]

Walking and cycling ("non-motorized transport") enjoy increasing favor (more pedestrian zones and bike lanes) in American and Asian urban transportation planning, under the influence of such trends as the Healthy Cities movement, the drive for sustainable development, and the idea of a carfree city.[137][245][246] Techniques such as road space rationing and road use charges have been introduced to limit urban car traffic.[137]

Stock exchanges, characteristic features of the top global cities, are interconnected hubs for capital. Here, a delegation from Australia visits the London Stock Exchange.

A global city, also known as a world city, is a prominent centre of trade, banking, finance, innovation, and markets.[273][274] Saskia Sassen used the term "global city" in her 1991 work, The Global City: New York, London, Tokyo to refer to a city's power, status, and cosmopolitanism, rather than to its size.[275] Following this view of cities, it is possible to rank the world's cities hierarchically.[276] Global cities form the capstone of the global hierarchy, exerting command and control through their economic and political influence. Global cities may have reached their status due to early transition to post-industrialism[277] or through inertia which has enabled them to maintain their dominance from the industrial era.[278] This type of ranking exemplifies an emerging discourse in which cities, considered variations on the same ideal type, must compete with each other globally to achieve prosperity.[181][174]

Critics of the notion point to the different realms of power and interchange. The term "global city" is heavily influenced by economic factors and, thus, may not account for places that are otherwise significant. Paul James, for example argues that the term is "reductive and skewed" in its focus on financial systems.[279]

Multinational corporations and banks make their headquarters in global cities and conduct much of their business within this context.[280] American firms dominate the international markets for law and engineering and maintain branches in the biggest foreign global cities.[281]

Large cities have a great divide between populations of both ends of the financial spectrum.[282] Regulations on immigration promote the exploitation of low- and high-skilled immigrant workers from poor areas.[283][284][285] During employment, migrant workers may be subject to unfair working conditions, including working overtime, low wages, and lack of safety in workplaces.[286]

Modern global cities, like New York City, often include large central business districts (CBDs) that serve as hubs for economic activity. A panorama of Manhattan, the world's largest central business district, is shown with prominent buildings highlighted by number, February 2018.

1. Riverside Church
2. Deutsche Bank Center
3. 220 Central Park South
4. Central Park Tower
5. One57
6. 432 Park Avenue
7. 53W53
8. Chrysler Building
9. Bank of America Tower
10. 4 Times Square
11. The New York Times Building
12. Empire State Building
13. Manhattan West
14. a: 55 Hudson Yards, b: 35 Hudson Yards, c: 10 Hudson Yards, d: 15 Hudson Yards
15. 56 Leonard Street
16. 8 Spruce Street
17. Woolworth Building
18. 70 Pine Street
19. Four Seasons Hotel New York Downtown
20. 40 Wall Street
21. 3 World Trade Center
22. 4 World Trade Center
23. One World Trade Center

Cities increasingly participate in world political activities independently of their enclosing nation-states. Early examples of this phenomenon are the sister city relationship and the promotion of multi-level governance within the European Union as a technique for European integration.[268][287][288] Cities including Hamburg, Prague, Amsterdam, The Hague, and City of London maintain their own embassies to the European Union at Brussels.[289][290][291]

New urban dwellers are increasingly transmigrants, keeping one foot each (through telecommunications if not travel) in their old and their new homes.[292]

Cities participate in global governance by various means including membership in global networks which transmit norms and regulations. At the general, global level, United Cities and Local Governments (UCLG) is a significant umbrella organization for cities; regionally and nationally, Eurocities, Asian Network of Major Cities 21, the Federation of Canadian Municipalities the National League of Cities, and the United States Conference of Mayors play similar roles.[293][294] UCLG took responsibility for creating Agenda 21 for culture, a program for cultural policies promoting sustainable development, and has organized various conferences and reports for its furtherance.[295]

Networks have become especially prevalent in the arena of environmentalism and specifically climate change following the adoption of Agenda 21. Environmental city networks include the C40 Cities Climate Leadership Group, the United Nations Global Compact Cities Programme, the Carbon Neutral Cities Alliance (CNCA), the Covenant of Mayors and the Compact of Mayors,[296] ICLEI – Local Governments for Sustainability, and the Transition Towns network.[293][294]

Cities with world political status as meeting places for advocacy groups, non-governmental organizations, lobbyists, educational institutions, intelligence agencies, military contractors, information technology firms, and other groups with a stake in world policymaking. They are consequently also sites for symbolic protest.[161][lower-alpha 4] South Africa has one of the highest rate of protests in the world. Pretoria, a city in South Africa had a rally where 5 thousand people took part in order to advocate for increasing wages to afford living costs.[297]

The World Bank headquarters in Washington, D.C.

The World Assembly of Mayors at the Habitat III conference in Quito

The United Nations System has been involved in a series of events and declarations dealing with the development of cities during this period of rapid urbanization.

• The Habitat I conference in 1976 adopted the "Vancouver Declaration on Human Settlements" which identifies urban management as a fundamental aspect of development and establishes various principles for maintaining urban habitats.[298]
• Citing the Vancouver Declaration, the UN General Assembly in December 1977 authorized the United Nations Commission Human Settlements and the HABITAT Centre for Human Settlements, intended to coordinate UN activities related to housing and settlements.[299]
• The 1992 Earth Summit in Rio de Janeiro resulted in a set of international agreements including Agenda 21 which establishes principles and plans for sustainable development.[300]
• The Habitat II conference in 1996 called for cities to play a leading role in this program, which subsequently advanced the Millennium Development Goals and Sustainable Development Goals.[301]
• In January 2002 the UN Commission on Human Settlements became an umbrella agency called the United Nations Human Settlements Programme or UN-Habitat, a member of the United Nations Development Group.[299]
• The Habitat III conference of 2016 focused on implementing these goals under the banner of a "New Urban Agenda". The four mechanisms envisioned for effecting the New Urban Agenda are (1) national policies promoting integrated sustainable development, (2) stronger urban governance, (3) long-term integrated urban and territorial planning, and (4) effective financing frameworks.[302][303] Just before this conference, the European Union concurrently approved an "Urban Agenda for the European Union" known as the Pact of Amsterdam.[302]

UN-Habitat coordinates the U.N. urban agenda, working with the UN Environmental Programme, the UN Development Programme, the Office of the High Commissioner for Human Rights, the World Health Organization, and the World Bank.[299]

The World Bank, a U.N. specialized agency, has been a primary force in promoting the Habitat conferences, and since the first Habitat conference has used their declarations as a framework for issuing loans for urban infrastructure.[301] The bank's structural adjustment programs contributed to urbanization in the Third World by creating incentives to move to cities.[304][305] The World Bank and UN-Habitat in 1999 jointly established the Cities Alliance (based at the World Bank headquarters in Washington, D.C.) to guide policymaking, knowledge sharing, and grant distribution around the issue of urban poverty.[306] (UN-Habitat plays an advisory role in evaluating the quality of a locality's governance.)[147] The Bank's policies have tended to focus on bolstering real estate markets through credit and technical assistance.[307]

The United Nations Educational, Scientific and Cultural Organization, UNESCO has increasingly focused on cities as key sites for influencing cultural governance. It has developed various city networks including the International Coalition of Cities against Racism and the Creative Cities Network. UNESCO's capacity to select World Heritage Sites gives the organization significant influence over cultural capital, tourism, and historic preservation funding.[295]