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Urban, city, and town planning integrates land use planning and transport planning to improve the built and social environments of communities. Regional planning deals with a still larger environment, at a less detailed level.

Urban planning can include urban renewal, by adapting urban planning methods to existing cities suffering from decay and lack of investment.

History

As an organized profession, urban planning has only existed for the last 60 years. However, most settlements and cities show forethought and conscious design in their layout and functioning.

Agriculture and other techniques facilitated larger populations than the very small communities of the Paleolithic. It may have caused stronger, more coercive governments at the same time. The pre-Classical and Classical ages saw a number of cities laid out according to fixed plans, though many tended to develop organically.

Designed cities were characteristic of the totalitarian Mesopotamian, Harrapan, and Egyptian civilizations of the third millennium BCE.

Distinct characteristics of urban planning from remains of the cities of Harappamarker, Lothalmarker and Mohenjo-daromarker in the Indus Valley Civilization (in modern-day northwestern Indiamarker and Pakistanmarker) lead archeologists to conclude that they are the earliest examples of deliberately planned and managed cities. The streets of these early cities were often paved and laid out at right angles in a grid pattern, with a hierarchy of streets from major boulevards to residential alleys. Archaeological evidence suggests that many Harrapan houses were laid out to protect from noise and enhance residential privacy; also, they often had their own water wells for probably both sanitary and ritual purposes. These ancient cities were unique in that they often had drainage systems, seemingly tied to a well-developed ideal of urban sanitation.

Urmarker, located near the Euphrates and Tigrismarker rivers in modern day Iraqmarker also had urban planning in later periods. The Greek Hippodamus (c. 407 BC) is widely considered the father of city planning in the West, for his design of Miletusmarker; Alexander commissioned him to lay out his new city of Alexandriamarker, the grandest example of idealized urban planning of the Mediterranean world, where regularity was aided in large part by its level site near a mouth of the Nile.

The ancient Romans used a consolidated scheme for city planning, developed for military defense and civil convenience. The basic plan is a central forum with city services, surrounded by a compact rectilinear grid of streets and wrapped in a wall for defense. To reduce travel times, two diagonal streets cross the square grid corner-to-corner, passing through the central square. A river usually flowed through the city, to provide water, transport, and sewage disposal.Many European towns, such as Turinmarker, still preserve the remains of these schemes. The Romans had a very logical way of designing their cities. They laid out the streets at right angles, in the form of a square grid. All the roads were equal in width and length, except for two. These two roads formed the center of the grid and intersected in the middle. One went East/West, the other North/South. They were slightly wider than the others. All roads were made of carefully fitted stones and smaller hard packed stones. Bridges were also constructed where needed. Each square marked by four roads was called an insula, the Roman equivalent of modern city blocks. Each insula was square, with the land within each insula divided. As the city developed, each insula would eventually be filled with buildings of various shapes and sizes and would be crisscrossed with back roads and alleys. Most insulae were given to the first settlers of a budding new Roman city, but each person had to pay to construct their own house. The city was surrounded by a wall to protect the city from invaders and other enemies, and to mark the city limits. Areas outside of the city limits were left open as farmland. At the end of each main road, there would be a large gateway with watchtowers. A portcullis covered the opening when the city was under siege, and additional watchtowers were constructed around the rest of the city’s wall. A water aqueduct was built outside of the city's walls.

The collapse of Roman civilization saw the end of their urban planning, among many other arts. Urban development in the Middle Ages, characteristically focused on a fortress, a fortified abbey, or a (sometimes abandoned) Roman nucleus, occurred "like the annular rings of a tree" whether in an extended village or the center of a larger city. Since the new center was often on high, defensible ground, the city plan took on an organic character, following the irregularities of elevation contours like the shapes that result from agricultural terracing.


The ideal of wide streets and orderly cities was not lost, however. A few medieval cities were admired for their wide thoroughfares and other orderly arrangements, but the juridical chaos of medieval cities (where the administration of streets was sometimes hereditary with various noble families), and the characteristic tenacity of medieval Europeans in legal matters, prevented frequent or large-scale urban planning until the Renaissance and the enormous strengthening of all central governments, from city-states to the kings of France, characteristic of that epoch. Florence was an early model of the new urban planning, which rearranged itself into a star-shaped layout adapted from the new star fort, designed to resist cannon fire. This model was widely imitated, reflecting the enormous cultural power of Florence in this age; "[t]he Renaissance was hypnotized by one city type which for a century and a half— from Filarete to Scamozzi— was impressed upon utopian schemes: this is the star-shaped city". Radial streets extend outward from a defined center of military, communal or spiritual power. Only in ideal cities did a centrally-planned structure stand at the heart, as in Raphael's Sposalizio of 1504 (illustration); as built, the unique example of a rationally-planned quattrocento new city center, that of Vigevanomarker, 1493-95, resembles a closed space instead, surrounded by arcading. Filarete's ideal city, building on hints in Leone Battista Alberti's De re aedificatoria, was named "Sforzinda" in compliment to his patron; its twelve-pointed shape, circumscribable by a "perfect" Pythagorean figure, the circle, takes no heed of its undulating terrain in Filarete's manuscript. And, all this occurred in the cities, but ordinarily not in the industrial suburbs characteristic of this era (see Braudel, The Structures of Everyday Life), which remained disorderly and characterized by crowded conditions and organic growth.In the 1990s, the University of Kentuckymarker voted the Italian town of Todimarker as ideal city and "most livable town in the world", the place where man and nature, history and tradition come together to create a site of excellence. In Italy, other examples of ideal cities planned according to scientific methods, are: Urbinomarker, Pienzamarker, Ferraramarker, San Giovanni Valdarnomarker, San Lorenzo Nuovomarker.

Many cities in Central American civilizations also planned their cities, including sewage systems and running water. In Mexicomarker, Tenochtitlan, was the capital of the Aztec empire, built on an island in Lake Texcoco in what is now the Federal District in central Mexico. At its height, Tenochtitlan was one of the largest cities in the world, with close to 250,000 inhabitants.

Shibammarker in Yemenmarker features over 500 tower houses, each one rising 5 to 11 storeys high, with each floor being an apartment occupied by a single family. The city has some of the tallest mudbrick houses in the world, with some of them being over 100 feet high (over 30 meters).

In developed countries (Western Europe, North America, Japanmarker and Australasia), planning and architecture can be said to have gone through various stages of general consensus in the last 200 years. Firstly, there was the industrialised city of the 19th century, where control of building was largely held by businesses and the wealthy elite. Around 1900, there began to be a movement for providing citizens, especially factory workers, with healthier environments. The concept of garden cities arose and several model towns were built, such as Letchworthmarker and Welwyn Garden Citymarker, the world's first garden cities, in Hertfordshiremarker, UK. However, these were principally small scale in size, typically dealing with only a few thousand residents.

It wasn't until the 1920s that modernism began to surface. Based on the ideas of Le Corbusier and utilising new skyscraper building techniques, the modernist city stood for the elimination of disorder, congestion and the small scale, replacing them instead with preplanned and widely spaced freeways and tower blocks set within gardens. There were plans for large scale rebuilding of cities, such as the Plan Voisin (based on Le Corbusier's Ville Contemporaine), which proposed clearing and rebuilding most of central Paris. No large-scale plans were implemented until after World War II however. Throughout the late 1940s and 1950s, housing shortages caused by wartime destruction led many cities to subsidize housing blocks. Planners used the opportunity to implement the modernist ideal of towers surrounded by gardens. The most prominent example of an entire modernist city is Brasiliamarker, constructed between 1956 and 1960 in Brazilmarker.

Reaction

By the late 1960s and early 1970s, many planners realized that modernism's clean lines and lack of human scale also sapped vitality from the community. The symptoms were high crime rates and social problems.

Modernism ended in the 1970s when the construction of the cheap, uniform tower blocks ended in most countries, such as Britain and France. Since then many have been demolished and replaced by more conventional housing. Rather than attempting to eliminate all disorder, planning now concentrates on individualism and diversity in society and the economy. This is the post-modernist era.

Minimally-planned cities still exist. Houstonmarker is a large city (with a metropolitan population of 5.5 million) in a developed country, without a comprehensive zoning ordinance. Houston does, however, restrict development densities and mandate parking, even though specific land uses are not regulated. Also, private-sector developers in Houston use subdivision covenants and deed restrictions to effect land use restrictions resembling zoning laws. Houston voters have rejected comprehensive zoning ordinances three times since 1948. Even without traditional zoning, metropolitan Houston displays large-scale land use patterns resembling zoned regions comparable in age and population, such as Dallas. This suggests that nonregulatory factors such as urban infrastructure and financing, may be at least as important as zoning laws.

Sustainable development and sustainability

Sustainable development and sustainability influence today's urban planners. Some planners say that modern lifestyles use too many natural resources, polluting or destroying ecosystems, increasing social inequality overheating urban heat islands, and causing climate changes. Many urban planners therefore advocate sustainable cities.

However, sustainable development is a recent, controversial concept. Wheeler, in his 1998 article, defines sustainable urban development to be "development that improves the long-term social and ecological health of cities and towns." He then sketches a 'sustainable' city's features. These include compact, efficient land use, less automobile use yet with better access, efficient resource use, less pollution and waste, the restoration of natural systems, good housing and living environments, a healthy social ecology, a sustainable economy, community participation and involvement and preservation of local culture and wisdom.

As they always have, urban planners try to implement widely accepted social policies and programs. Sustainability must be widely supported by society before planning can realistically modify actual institutions and regions. Real implementations are often complex compromises.

Aspects of planning

Urban aesthetics



In developed countries, there has been a backlash against excessive human-made clutter in the visual environment, such as signposts, signs, and hoardings. Other issues that generate strong debate among urban designers are tensions between peripheral growth, housing density and new settlements. There are also debates about the mixing tenures and land uses, versus distinguishing geographic zones where different uses dominate. Regardless, all successful urban planning considers urban character, local identity, respects heritage, pedestrians, traffic, utilities and natural hazards.

Planners can help manage the growth of cities, applying tools like zoning and growth management to manage the uses of land. Historically, many of the cities now thought the most beautiful are the result of dense, long lasting systems of prohibitions and guidance about building sizes, uses and features. These allowed substantial freedoms, yet enforce styles, safety, and often materials in practical ways. Many conventional planning techniques are being repackaged using the contemporary term smart growth.

There are some cities that have been planned from conception, and while the results often don't turn out quite as planned, evidence of the initial plan often remains. (See List of planned cities)

Safety



Historically within the Middle East, Europe and the rest of the Old World, settlements were located on higher ground (for defense) and close to fresh water sources . Cities have often grown onto coastal and flood plains at risk of floods and storm surges. Urban planners must consider these threats. If the dangers can be localised then the affected regions can be made into parkland or green belt, often with the added benefit of open space provision.

Extreme weather, flood, or other emergencies can often be greatly mitigated with secure emergency evacuation routes and emergency operations centres. These are relatively inexpensive and unintrusive, and many consider them a reasonable precaution for any urban space. Many cities will also have planned, built safety features, such as levees, retaining walls, and shelters.

In recent years, practitioners have also been expected to maximize the accessibility of an area to people with different abilities, practicing the notion of "inclusive design," to anticipate criminal behaviour and consequently to "design-out crime" and to consider "traffic calming" or "pedestrianisation" as ways of making urban life more pleasant.

Some city planners try to control criminality with structures designed from theories such as socio-architecture or environmental determinism. Refer to Foucault and the Encyclopedia of the Prison System for more details. These theories say that an urban environment can influence individuals' obedience to social rules and level of power. The theories often say that psychological pressure develops in more densely developed, unadorned areas. This stress causes some crimes and some use of illegal drugs. The antidote is usually more individual space and better, more beautiful design in place of functionalism.

Oscar Newman’s defensible space theory cites the modernist housing projects of the 1960s as an example of environmental determinism, where large blocks of flats are surrounded by shared and disassociated public areas, which are hard for residents to identify with. As those on lower incomes cannot hire others to maintain public space such as security guards or grounds keepers, and because no individual feels personally responsible, there was a general deterioration of public space leading to a sense of alienation and social disorder.

Jane Jacobs is another notable environmental determinist and is associated with the "eyes on the street" concept. By improving ‘natural surveillance’ of shared land and facilities of nearby residents by literally increasing the number of people who can see it, and increasing the familiarity of residents, as a collective, residents can more easily detect undesirable or criminal behaviour. However, this is not a new concept. This was prevalent throughout the middle eastern world during the time of Mohamad. It was not only reflected in the general structure of the outside of the home but also the inside. (refer to various religious texts and archaeological sites)

The "broken-windows" theory argues that small indicators of neglect, such as broken windows and unkempt lawns, promote a feeling that an area is in a state of decay. Anticipating decay, people likewise fail to maintain their own properties. The theory suggests that abandonment causes crime, rather than crime causing abandonment.

Some planning methods might help an elite group to control ordinary citizens. Haussmann's renovation of Paris created a system of wide boulevards which prevented the construction of barricades in the streets and eased the movement of military troops. In Romemarker, the Fascists in the 1930s created ex novo many new suburbs in order to concentrate criminals and poorer classes away from the elegant town.

Other social theories point out that in Britain and most countries since the 18th century, the transformation of societies from rural agriculture to industry caused a difficult adaptation to urban living. These theories emphasize that many planning policies ignore personal tensions, forcing individuals to live in a condition of perpetual extraneity to their cities. Many people therefore lack the comfort of feeling "at home" when at home. Often these theorists seek a reconsideration of commonly used "standards" that rationalize the outcomes of a free (relatively unregulated) market.

Slums

The rapid urbanization of the last century caused more slums in the major cities of the world, particularly in developing countries. Planning resources and strategies are needed to address the problems of slum development. Many planners are calling for slum improvement, particularly the Commonwealth Association of Planners. When urban planners work on slums, they must cope with racial and cultural differences to ensure that racial steering does not occur.

Slum were often "fixed" by clearance. However, more creative solutions are beginning to emerge such as Nairobimarker's "Camp of Fire" program, where established slum-dwellers promise to build proper houses, schools, and community centers without government money, in return for land on which they have been illegally squatting on for 30 years. The "Camp of Fire" program is one of many similar projects initiated by Slum Dwellers International, which has programs in Africa, Asia, and South America.

Urban decay

Urban decay is a process by which a city, or a part of a city, falls into a state of disrepair and neglect. It is characterized by depopulation, economic restructuring, property abandonment, high unemployment, fragmented families, political disenfranchisement, crime, and desolate urban landscapes.

During the 1970s and 1980s, urban decay was often associated with central areas of cities in North America and Europe. During this time, changes in global economies, demographics, transportation, and policies fostered urban decay. Many planners spoke of "white flight" during this time. This pattern was different than the pattern of "outlying slums" and "suburban ghettos" found in many cities outside of North America and Western Europe, where central urban areas actually had higher real estate values.

Starting in the 1990s, many of the central urban areas in North America have been experiencing a reversal of the urban decay, with rising real estate values, smarter development, demolition of obsolete social housing and a wider variety of housing choices.

Reconstruction and renewal



Areas devastated by war or invasion challenge urban planners. Resources are scarce. The existing population has needs. Buildings, roads, services and basic infrastructure like power, water and sewerage are often damaged, but with salvageable parts. Historic, religious or social centers also need to be preserved and re-integrated into the new city plan. A prime example of this is the capital city of Kabulmarker, Afghanistanmarker, which, after decades of civil war and occupation, has regions of rubble and desolation. Despite this, the indigenous population continues to live in the area, constructing makeshift homes and shops out of salvaged materials. Any reconstruction plan, such as Hisham Ashkouri's City of Light Development, needs to be sensitive to the needs of this community and its existing culture and businesses.

Urban Reconstruction Development plans must also work with government agencies as well as private interests to develop workable designs.

Transport

Although an important factor, there is a complex relationship between urban densities and car use.


Transport within urbanized areas presents unique problems. The density of an urban environment increases traffic, which can harm businesses and increase pollution unless properly managed. Parking space for private vehicles requires the construction of large parking garages in high density areas. This space could often be more valuable for other development.

Good planning uses transit oriented development, which attempts to place higher densities of jobs or residents near high-volume transportation. For example, some cities permit commerce and multi-story apartment buildings only within one block of train stations and multilane boulevards, and accept single-family dwellings and parks farther away.

Notes

References

  • Atmospheric Environment Volume 35, Issue 10, April 2001, Pages 1717-1727. "Traffic pollution in a downtown site of Buenos Aires City"
  • (A standard text for many college and graduate courses in city planning in America)
  • Hoch, Charles, Linda C. Dalton and Frank S. So, editors (2000). The Practice of Local Government Planning, Intl City County Management Assn; 3rd edition. ISBN 0-87326-171-2 (The "Green Book")
  • T. R. Oke (1982). "The energetic basis of the urban heat island". Quarterly Journal of the Royal Meteorological Society 108: 1–24.
  • Matheos Santamouris (2006). Environmental Design of Urban Buildings: An Integrated Approach.
  • Tunnard, Christopher and Boris Pushkarev (1963). Man-Made America: Chaos or Control?: An Inquiry into Selected Problems of Design in the Urbanized Landscape, New Havenmarker: Yale Universitymarker Press. (This book won the National Book Award, strictly America; a time capsule of photography and design approach.)
  • Wheeler, Stephen (1998). "Planning Sustainable and Livable Cities", Routledge; 3rd edition.


Further reading



External links




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