Science & Technology

Urban Planning

rban planning and redevelopment is aimed at fulfilling social and economic objectives that go beyond the physical form and arrangement of buildings, streets, parks, utilities, and other parts of the urban environment. Urban planning takes effect largely through the operations of government and requires the application of specialized techniques of survey, analysis, forecasting, and design. It may thus be described as a social movement, as a governmental function, or as a technical profession. Each aspect has its own concepts, history, and theories. Together they fuse into the effort of modern society to shape and improve the environment within which increasing proportions of humanity spend their lives: the city.

The development of urban planning

Early history

There are examples from the earliest times of efforts to plan city development. Evidence of planning appears repeatedly in the ruins of cities in China, India, Egypt, Asia Minor, the Mediterranean world, and South and Central America. There are many signs: orderly street systems that are rectangular and sometimes radial; divisions of a city into specialized functional quarters; development of commanding central sites for palaces, temples, and what would now be called civic buildings; and advanced systems of fortifications, water supply, and drainage. Most of the evidence is in smaller cities, built in comparatively short periods as colonies. Often the central cities of ancient states grew to substantial size before they achieved governments capable of imposing controls. In Rome, for example, the evidence points to no planning prior to late applications of remedial measures.

For several centuries during the Middle Ages, there was little building of cities in Europe. There is conflicting opinion on the quality of the towns that grew up as centres of church or feudal authority, of marketing or trade. They were generally irregular in layout, with low standards of sanitation. Initially, they were probably uncongested, providing ready access to the countryside and having house gardens and open spaces used for markets and fairs or grazing livestock. But, as the urban population grew, the constriction caused by walls and fortifications led to overcrowding and to the building of houses wherever they could be fitted in. It was customary to allocate certain quarters of the cities to different nationalities, classes, or trades, as in cities of East Asia in the present day. As these groups expanded, congestion was intensified.

The physical form of medieval and Renaissance towns and cities followed the pattern of the village, spreading along a street, a crossroad, in circular patterns or in irregular shapes--though rectangular patterns tended to characterize some of the newer towns. Most streets were little more than footpaths--more a medium for communication than for transportation--and even in major cities paving was not introduced until 1184 in Paris, 1235 in Florence, and 1300 in Lübeck. As the population of the city grew, walls were often expanded, but few cities at the time exceeded a mile in length. Sometimes sites were changed, as in Lübeck, and many new cities emerged with increasing population--frequently about one day's walk apart. Towns ranged in population from several hundred to perhaps 40,000 (London in the 14th century). Paris and Venice were exceptions, reaching 100,000.

Housing varied from elaborate merchant houses to crude huts and stone enclosures. Dwellings were usually two to three stories high, aligned in rows, and often with rear gardens or inner courts formed by solid blocks. Windows were small apertures with shutters, at first, and later covered with oiled cloth, paper, and glass. Heating improved from the open hearth to the fireplace and chimney. Rooms varied from the single room for the poor to differentiated rooms for specialized use by the wealthy. Space generally was at a premium. Privacy was rare and sanitation primitive.

During the Renaissance, however, there were conscious attempts to plan features, such as logistically practical circulation patterns and encircling fortifications, which forced overbuilding as population grew. As late as the 1860s, the radial boulevards in Paris had military as well as aesthetic purposes. The grand plan, however, probably had as its prime objective the glorification of a ruler or a state. From the 16th to the end of the 18th century, many small cities and parts of large cities were laid out and built with monumental splendour. The result may have pleased and inspired the citizens, but it rarely contributed to the health or comfort of their homes or to the efficiency of manufacturing, distribution, or marketing.

The planning concepts of the European Renaissance were transplanted to the New World. In particular, Pierre l'Enfant's plan for Washington, D.C. (1791), illustrated the strength and weakness of these concepts; it was a plan ably designed to achieve monumentality and grandeur in the siting of public buildings but was in no way concerned with the efficiency of residential, commercial, or industrial development. More prophetic of the layout of U.S. cities was the rigid, gridiron plan of Philadelphia, designed by William Penn (1682), with a layout of streets and lots (plots) adaptable to rapid changes in land use but wasteful of land and inefficient for traffic. The gridiron plan travelled westward with the pioneers, since it was the simplest method of dividing surveyed territory. Its special advantage was that a new city could be planned in the eastern offices of land companies and lots sold without buyer or seller ever seeing the site.

The New England town also influenced later settlement patterns in the United States. The central commons, initially a cattle pasture, provided a focus of community life and a site for meetinghouse, tavern, smithy, and shops. It became the central square in county seats from the Alleghenies to the Pacific and remained the focus of urban activity. Also from the New England town came the tradition of the freestanding, single-family house. Set well back from the street and shaded by trees, it had an ornamental front yard and a working backyard and became the norm of American residential development. This was in contrast to the European town house, with its party wall and tiny fenced backyard.