1.Linear, Radial and Grid Iron Layout Patterns

Cities exist for many reasons, and the diversity of urban forms depends on the complex functions that cities perform.




Cities serve as centers of government. 1. For example, the emergence of the great nation-states of Europe between 1400 and 1800 led to the creation of new capital cities . 2. One of the examples being Washington, D.C., which displays the monumental buildings, radial street pattern, and large public spaces typical of capital cities. AGGLOMERATION POPULATION TYPE








The urban life style is quite complex. Cities created when large number of people live together, in a specific geographic location. Leading to the Creation of urban areas. With the growth of cities, infrastructure starts to malfunction.

Temporary settlement

3-100

Villages

100-5,000

Towns or Polis

5,000-2,00,000

Metropolis

2,00,000-10million

Megalopolis

10million-500million




The settlements grew into villages, villages transformed into cities.




The cities are dynamic in nature.




The growth of the city was irregular, responsive to the changes.




Form depended on:1. Structure of the land. 2. Pattern in which land was distributed.




The cities that are the result of transformation of villages, show superimposition of geometrical layout over existing irregular ones.




Motives of city builder.

The form of the city is influenced by:1.

Geography

2.

Depend on the impact of natural environment.

3.

Social, political, economic forces.

4.

Period of development.

5.

Trade practiced.




Cities are physical artifacts inserted into a preexisting natural world, and natural constraints must be respected if a settlement is to survive and prosper.




Cities must conform to the landscape in which they are located.




Climate influences city form. For example, streets have been aligned to take advantage of cooling breezes, and arcades designed to shield pedestrians from sun and rain.




The architecture of individual buildings often reflects adaptations to climatic characteristics.




Cities must have a healthy water supply, and locations along rivers and streams, or near underground watercourses, have always been favored.




City location and internal structure have been profoundly influenced by natural transportation routes. 1. Cities have been sited near natural harbors, on navigable rivers, or along land routes determined by regional topography.


The physical elements of the city can be divided into three categories: 1. Networks 2. Buildings 3. Open spaces NETWORKS 1. Every modern city contains an array of pathways to carry flows of people, goods, water, energy, and information. Transportation networks are the largest and most visible of these. 2. Ancient cities relied on streets, most of them quite narrow by modern standards, to carry foot traffic and carts. 3. The modern city contains a complex hierarchy of transportation channels, ranging from ten-lane freeways to sidewalks. 4. American cities display the low-density sprawl characteristic of auto-centered urban development.

NETWORKS 5. Modern cities rely on complex networks of utilities. a. When cities were small, obtaining pure water and disposing of wastes was not a major problem. b. But cities with large populations and high densities require expensive public infrastructure. American and European cities began to install adequate sewer and water systems.

BUILDINGS 1. Buildings are the most visible elements of the city, the features that give each city its unique character. a. Residential structures occupy almost half of all urban land, with the building types ranging from scattered single-family homes to dense highrise apartments. b. Commercial buildings are clustered downtown and at various sub centers, with skyscrapers packed into the central business district. c.

Industrial buildings come in many forms ranging from large factory complexes in industrial districts to small workshops.

2. City planners engage in a constant search for the proper arrangement of these different types of land use, paying particular attention to the compatibility of different activities, population densities, traffic generation, economic efficiency, social relationships, and the height and bulk of buildings.

OPEN SPACES 1. Open space is sometimes treated as a leftover, but it contributes greatly to the quality of urban life. 2. Hard spaces such as plazas, malls, and courtyards provide settings for public activities of all kinds. 3. Soft spaces such as parks, gardens, lawns, and nature preserves provide essential relief from harsh urban conditions and serve as space for recreational activities. 4. These amenities increasingly influence which cities will be perceived as desirable places to live.

EVOLUTION OF TOWN PLANNING PATTERNS


Apart from orthogonal layout of the city, there was another essence of city planning prevalent in the ancient cities, i.e. A. Coordination among urban buildings and spaces. B. Standardization of built forms.
This gives variation in the extent of city planning, some being planned more intensely than others.
Apart from these principles, the connotations of mode of governance, the kingship, goals and concepts, aspirations of the ancient world also influenced the city form.
The urbanism experienced in ancient European continent was quite different form the rest of the world.


Town planning and planned forms of the ancient world can be divided into following categories: 1. ORGANIC: cities whose growth occurred without any discernible direction or coordination. direction or 2. GRID: a. refers to orthogonal layouts. b. Cities in which there is a formal and organized arrangement of building and spaces. 3. DIAGRAM CITIES: a. refers to inflexible cities. b. Planned for the present as a precise diagram of some pre conceived ideas. c. Based on the single minded vision of some pre determined individual or institution of how the world should function ideally. 4. GRAND MANNER: planning in which buildings and spaces are arranged in a manner to display grandeur and coherence.


Earliest cities had two basic components of planning which governed most of the urban planning parameters:1. COORDINATION AMONG BUILDINGS AND SPACES IN THE CITY: this can be understood under the following categories: a. Arrangement of buildings. b. Monumentality and formality of layout. c. Orthogonality. d. Other forms of geometric order. e. Accessibility and visibility.

2. STANDARDIZATION AMONG CITIES: a. Standardization in terms of urban architectural forms, and their orientation. b. Standardization of spatial layout.


SCALE OF PLANNING: a. Scale of planning is complex and multi faceted. b. There are degrees of planning or presence of ordinal scale. c. Some cities are more planned than others. d. More planned refers to degree of coordination or standardization. For e.g. orthogonal planned cities are more than simple arrangement and coordination of buildings. e. More planned refers to the extent of planning, involving rigorous efforts.

EXAMPLES OF ANCIENT CITY PLANNING


Is the grandest example of idealized urban planning of the ancient Mediterranean world.
City’s regularity was facilitated by its level site near a mouth of the Nile. It was based on the Hippodamian or grid plan.
City plan was not creative but very practical.
The plan consisted of orthogonal streets, with sea being the main landscaping element. 1. The main street known as CANOPIC connected the gate of the moon to the west with the gate of the sun in the east. 2. It then extended eastward, along a road, up to canopus. 3. Orthogonal to the CANOPIC was the “Street Street of the SOMA” SOMA 4. At the termination of these streets were dockyards or major waterways.


The major urban area was the city forum with city services, surrounded by compact, rectilinear grid of streets, wrapped in a wall for defense.
To reduce travel time, two diagonal streets crossed the square grid passing through the central square.
Sewage disposal, transportation, water supply was aided by the river flowing through the city.

TOWN PLANNING OF THE MEDIEVAL PERIOD


Early medieval town was dominated by church or monastery & castle of lords.
For protective measures, towns were sited in irregular terrain, occupying hill tops or islands.
Towns assumed informal & irregular character.
Church plaza became a market place.
Roads generally radiated from church plaza& market plaza to gates with secondary lateral roadways connecting them.
Castle was surrounded by wall & moat as a protective elements. Irregular pattern in planning was devised to confuse enemies; as enemies unfamiliar with town.
Open spaces, streets, plazas developed as an integral part of site.Streets were used for pedestrian while wheels were restricted to main roads.

CITIES IN 12TH AND 13TH CENTURY
The city of middle ages grew within the confines of the walls.
While the population was small, there was space in the town, but when it increased the buildings were packed more closely and the open spaces filled.
Result was intolerable congestion, lack of hygiene and pestilence CITIES IN THE 14TH AND 15TH CENTURY
During the Renaissance, systematic study of the shaping of urban space.
City itself were a piece of architecture that could be given an aesthetically pleasing and functional order.
Parts of old cities were rebuilt to create elegant squares, long street vistas, and symmetrical building arrangements.
Responding to advances in firearms during the fifteenth century, new city walls were designed with large earthworks to deflect .
Cities were built according to rules, specifying an orderly grid of streets with a central plaza, defensive wall, and uniform building style.


Baroque city result of the emergence of great nation-states between 1600 and 1750.
Ambitious monarchs constructed new palaces, courts, and bureaucratic offices.
The grand scale was created in urban public spaces: a. long avenues, b. radial street networks, c. monumental squares, geometric parks and gardens.
Examples of this era include :Washington, D.C and Versailles.


Baroque principles of urban design were used by Baron Haussmann in his restructuring of Paris between 1853 and 1870. a. Haussmann carved broad new thoroughfares through the tangled web of old Parisian streets,. b. Linking major subcenters of the city with one another .




Initially proposed by Soria Y Mata




Expand the city along the spine of transport. transport.




The Linear City concept is a Conscious Form Of Urban Development with Housing And Industry Growing Along The Highway Between existing cities and contained by the continuous open space of the rural countryside.




A key building block to the construction of large cities was the development of fast mass transit systems capable of transporting passengers across vast distances that not only separated neighborhoods within a city but, between cities themselves.




When this type of development was proposed, the fast moving trolleys of the late 19th Century maintaining speeds of about 30 kms per hour, resulted in Linear Cities of less than 30 kms in length.




The essence of city planning is not distance but time of travel.




Reduce congestion within city.




Bring country to the city and city to the country.




The growth of the city was possible from any direction.




Length of the city based on needs.




Linearity defined by straight road.




Width of city based on pedestrian movement.




Road network grid like and simple.




City connected through railroads acting as the spine of the city.


Only 1/4th of the total area of the city could be built; leaving the rest for open spaces and parks. The maximum allowable coverage was 20%




The sectors of a linear city would be: 1. Purely segregated zone for railway lines 2. Zone for communal and production enterprises, with related scientific, technical and educational institutions. 3. A green belt or buffer zone, including a band of social institutions. 4. A band of residential buildings and a children's band and a park zone. 5. An agricultural zone with gardens and farms.




As the city expanded, additional sectors would be added to the end of each band, so that the city would become even longer without growing wider.

PLANNING PRINCIPLES


Central roadway,railroad with gridded slabs for houses and working areas on both sides.
While designing one thing should be kept in mind that from every point of the linear city, a new community could arise

















The expansion of such a city is possible from any direction along the communication channel. New town could be added at an angle to the main line, where topography permits. Soria Y Mata neglected the influence of automobile on city planning. The major drawback of this planning principle was that the city was not zoned. Also there was no centre or functional node thus the interaction between the residents were less. The city became monotonous.




Geographical possibility of spreading in all directions.




Site leveled.




Inner outer ring roads linked by radiating roads.




Core has the business area.




Industrial area interspersed within the residential.




Periphery has green belts.
















Solution to the problem of radial planning. Green wedges of agriculture field radiating from the centre. Alternating with residential localities served by railway lines. Finger shaped plan Great hand resting over the city. Power lines, telecom lines and mass rapid transit lines follow the bones, arteries, veins and the nerves of the fingers. Between those fingers, was found the green land of Demark.

PLANNING OF COPENHAGEN, \DENMARK








gridiron plan is a type of city plan in which streets run at right angles to each other, forming a grid. built with blocks divided by a grid of straight streets, running north-south and east-west block was subdivided by small lanes.




Infrastructure cost for regular grid patterns is generally higher than for patterns with discontinuous streets.




Street width (ROW) influences the amount of land that is devoted to streets, which becomes unavailable for development and therefore represents an opportunity cost.




Street length influences proportionately the amount of street components that have to be constructed such as pavement, curbs and sidewalks, storm sewers.




Pavement width influences the cost by affecting the amount of materials and labour required to provide a finished road surface




Modern city planning can be divided into two distinct but related types of planning. 1.

Visionary City Planning proposes radical changes in the form of the city, often in conjunction with sweeping changes in the social and economic order.

2.

Institutionalized City Planning is lodged within the existing structures of government, and modifies urban growth processes in moderate, pragmatic ways. It is constrained by the prevailing alignment of political and economic forces within the city.

3.




In the twentieth century, Le Corbusier, Frank Lloyd Wright, Paolo Soleri, and dozens of other architects have designed cities.




Although few have been realized in pure form, they have influenced the layout of many new towns and urban redevelopment projects.




In his "Contemporary Contemporary City for Three Million People" of 1922 and "Radiant City" of 1935, 1935 Le Corbusier advocated 1. A high-density urban alternative, 2. With skyscraper office buildings and mid-rise apartments placed within park-like open spaces. 3. Different land uses were located in separate districts, forming a rigid geometric pattern with a sophisticated system of superhighways and rail transit.




Frank Lloyd Wright envisioned a decentralized low-density city. 1. 2. 3. 4.




The Broadacre City plan of 1935 is a large grid of arterials spread across the countryside. With most of the internal space devoted to single-family homes on large lots. Areas are also provided for small farms, light industry, orchards, recreation areas, and other urban facilities. A network of superhighways knits the region together, so spatially dispersed facilities are actually very close in terms of travel time.

In utopian plans planners and architects have generated a complex array of urban patterns which lead to formulation of ideas and inspiration.




The form of the city is determined primarily by thousands of private decisions to construct buildings, within a framework of public infrastructure and regulations administered by the city governmental institutions.




City planning actions can have enormous impacts on land values.




The goal of city planning is to intervene in order to protect widely shared public values such as health, safety, environmental quality, social equality, and aesthetics.




The roots of city planning lie in an array of reform efforts of the late nineteenth century: the Parks movement, the City Beautiful movement.




The zoning of land became, and still is, the most potent instrument available to city planners for controlling urban development.




The other important elements of existing city planning are subdivision regulations and environmental regulations.




Subdivision regulations require that land being subdivided for development be provided with adequate street, sewers, water, schools, utilities, and various design features.




Since the late 1960s, environmental regulations have exerted a stronger influence on patterns of urban growth by restricting development in floodplains, on unstable slopes, on earthquake faults, or near sensitive natural areas.




Businesses have been forced to reduce smoke emissions and the disposal of wastes has been more closely monitored.




Overall, the pace of environmental degradation has been slowed, but certainly not.