Superblock
Superblocks were popular during the early and mid-20th century, arising from modernist ideas in architecture and urban planning. A superblock is much larger than a traditional city block, with greater setback for buildings, and is typically bounded by widely spaced, high-speed, arterial or circulating routes rather than by local streets. Superblocks are often found in suburbs, planned cities, or are the result of urban renewal of the mid-20th century, where a street hierarchy has replaced the traditional grid. In a residential area of a suburb, the interior of the superblock is typically served by cul-de-sac or looped streets. Superblocks can also be found in central city areas, where they are more often associated with institutional, educational, recreational and corporate rather than residential uses.
Urban planner Clarence Perry argued for use of superblocks and related ideas in his "neighborhood unit" plan, which aimed to organize space in a way that is more pedestrian-friendly and provided open plazas and other space for residents to socialize. The same intention to facilitate pedestrian movement and socializing is captured by an influential 1989 conceptual design of a Pedestrian Pocket (see diagram). It is, similarly, a superblock composed of nine normal city blocks clustered around a light rail station and a central open space. Its circulation pattern consists primarily of a dense pedestrian network which is complementary to but independent from the car network. Access by car is provided by means of three loops. This superblock differs from Perry’s concept in that it makes it impossible for cars to traverse it rather than very difficult; it is car-impermeable.
In the 1930s, superblocks were often used in urban renewal public housing projects in American cities. In using superblocks, housing projects aimed to eliminate back alleys, which were often associated with slum conditions.
Superblocks are also used when functional units such as rail yards or shipyards, inherited from the 19th and early 20th centuries, are too big to fit in an average city block. A contemporary function which reflects ancient practices that also requires larger than typical blocks is the sports stadium or arena. Just as the Coliseum in ancient Rome, sports complexes require superblocks. The Jeld Wen Field stadium in Portland, for example, takes up six normal city blocks as does the equally large Greensboro Coliseum in North Carolina. Other contemporary institutions, establishments or functions that use superblocks are: city halls like Government Center, Boston and Toronto City Hall; regional general hospitals or specialized medical centres; convention and exhibition centers, such as Exhibition Place in Toronto and the Boston Convention and Exhibition Center; and downtown enclosed Shopping Malls such as Eaton Centre in Toronto, echoing the large gallerias of the 19th century. Cultural complexes, such as the Lincoln Centre in New York City, often occupy a superblock achieved through the consolidation of regular city blocks. A recent superblock user is the merchandise distribution centre, which can range in area from one to ten city blocks.
Most notably, however, the largest superblocks in contemporary cities are used by university and college campuses such as Massachusetts Institute of Technology, the University of Illinois at Chicago, the City College of New York, Columbia University and the University of Alberta in Edmonton. The "campus" impact on the city block structure is quite prominent particularly in small university towns such as Waterloo, Ontario or Ithaca, New York where the university superblock counts for a sizeable portion of the total city area. Campuses, in general, are fully walkable and sociable environments within the superblock structure. On some university campuses the extensive and exclusive pedestrian path network at grade is supplemented with below grade paths. New Urbanists would argue that separating circulation modes effectively kills the social interaction that bolsters urban areas.
Additional users of the superblock concept are large national or multinational corporations who constructed campuses in the late 1900s and 2000s. Examples of superblock campuses include Google in Mountain View, California; IBM in Somers, New York; and Apple and Hewlett-Packard in San Jose, California. Another well-known commercial superblock is the World Trade Center site in New York City, where several streets of Manhattan's downtown grid were removed and de-mapped to make room for the center.
Social and housing agencies in the U.S., Canada and the UK used the superblock model for large housing projects such as Regent Park in Toronto and Benny Farm in Montreal, Canada. In New York City, the Stuyvesant Town private market, residential development superblock takes up about 18 normal city blocks and provides a large green amenity for its residents and neighbours. It uses crescent (loop) rather than cul-de-sac streets inside the superblock and an extensive network of paths that provide excellent connectivity within the block and to the neighbouring areas (see drawing).
Where the superblock is used for housing projects like Stuyvesant Town, the advantages sought are an improved separation of vehicular and pedestrian circulation, enhanced tranquility and reduced accident risk within the neighbourhood. In 2003, Vauban (a rail suburb of Freiburg,Germany) was constructed with similar goals. Its layout consists mainly of a superblock with a central pedestrian spine and a few narrow looped and cul-de-sac streets. The British new town of Milton Keynes is built around a grid of one-kilometre square superblocks (see drawing).
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