City block
A city block, residential block, urban block, or simply block is a central element of urban planning and urban design.
A city block is the smallest group of buildings that is surrounded by streets, not counting any type of thoroughfare within the area of a building or comparable structure. City blocks are the space for buildings within the street pattern of a city, and form the basic unit of a city's urban fabric. City blocks may be subdivided into any number of smaller land lots usually in private ownership, though in some cases, it may be other forms of tenure. City blocks are usually built-up to varying degrees and thus form the physical containers or "streetwalls" of public space. Most cities are composed of a greater or lesser variety of sizes and shapes of urban block. For example, many pre-industrial cores of cities in Europe, Asia, and the Middle East tend to have irregularly shaped street patterns and urban blocks, while cities based on grids have much more regular arrangements.
By extension, the word "block" is an important informal unit of length equal to the distance between two streets of a street grid.
Grid plan
In most cities of the
Since the spacing of streets in grid plans varies so widely among cities, or even within cities, it is difficult to generalize about the size of a city block. Oblong blocks range considerably in width and length. The standard block in Manhattan is about 264 by 900 feet (80 m × 274 m). In
Many
Structure variations
The concept of city block can be generalized as a superblock or sub-block.
Superblock
A superblock, or super-block, is an area of urban land that is bounded by
Definitions and typologies
Within the broad concept of a superblock, various typologies emerge based primarily on the internal road networks within the superblock, their historical context, and whether they are auto-centric or pedestrian-centric. The context in which superblocks are being studied or conceived gives rise to varying definitions.
An internal road network characterised by
“The Supergrid is a large-scale net of wide roads that defines a series of cells or Superblocks, each containing a network of narrower streets.”[4]
Superblocks can also be retroactively superimposed on pre-existing grid plan by changing the traffic rules and streetscape of internal streets within the superblock, as in the case of Barcelona's superilles (Catalan for superblocks). Each superilla has nine city blocks, with speed limits on the internal roads slowed to 10–20 km/h, through traffic disallowed, and through travel possible only on the perimeter roads.[5]
In Soviet Union and post-Soviet states, a technical term out of construction industry is "residential massíve" (Russian: Жилой массив, Zhyloi massiv). According to the definition, a residential massíve consists of several of residential quarters (city blocks) that are associated by one architectural design (concept).[6] In a number of cities in post-Soviet countries, several city neighborhoods have names like massiv or masyv and appeared in the second half of the 20th century with the rapid expansion of cities. In Central Eastern Europe, which was once in the Warsaw Pact, several cities have residential areas filled with inexpensive housing of multi-story buildings known as panelák (panel buildings). Panel buildings of similar architectural type may be erected as one residential city quarter or bigger residential area as massíve.
History and usage
Superblocks in North America, Brazil, the United Kingdom, and Australia
Most notably, however, the largest superblocks in contemporary cities are used by university and college campuses[
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; 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
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,
Superblocks have been proposed as a potential solution to road space prioritisation and increased pedestrian flows in the CBD of Melbourne, Australia. The City of Melbourne's 2018 Transport Discussion Paper: City Space suggests, based on the example of Barcelona's superilles, that “‘Superblocks’ could be applied in Melbourne to make streets in the central city safer, greener, more inclusive and more vibrant.”
Barcelona's super·illes
The superblock concept has been applied retroactively in Barcelona's La Ribera and Gràcia districts, which both have a medieval street network with narrow and irregular streets, since 1993. In these two cases it resulted in an increase of journeys on foot (over 10%) and by bicycle (>15%) and in a higher level of commercial and service activity.[13]
Superblocks, or super·illes in the native Catalan, are being superimposed in the Eixample District's famous Ildefons Cerdà-designed late 19th century grid plan.[5] Each superilla comprises nine city blocks, or illes, in which the internal traffic flows have been altered to disallow through traffic, and speed limits on internal roads reduced. After entering a superilla from a perimeter road, vehicles are only able to circumnavigate one city block and return out to the same perimeter road again, meaning that local access to garages and businesses is maintained, but making it impossible to cut through to the other side. Speed limits have also been reduced to 20 km/h initially. It was estimated that this could be implemented city-wide for less than €20 million, simply by changing traffic signals.[14]
It is planned to further reduce speeds to 10 km/h and remove on-street parking by building more off-street car parks. This is intended to make the internal streets safer for pedestrians and create more space for playing games, sports, and cultural activities such as outdoor cinemas.[14]
The concept was initially spurred by a redesign of the city's bus network that consolidated bus routes into a simpler orthogonal network, with more frequent services.
Superblocks in Japan
Superblocks have been the prevalent mode of urban land use planning in Japan, even being described as the "
Resulting largely from planning controls which link building height with street width, Japanese superblocks are typically characterised by a ‘hard shell’ of tall buildings with commercial uses along the perimeter arterial roads, with a ‘soft yolk’ of low-rise residential use in the centre.[21]
The spatial structure of superblocks can also be analysed, per a taxonomy detailed by Barrie Shelton,[20] through the classification of roads as ‘global’, being the arterial roads which provide for cross-city travel, ‘local’ roads, which provide local access to buildings within the superblock, and ‘glocal’ roads, which may cross the entire superblock, allowing through travel, and in many instances into neighbouring superblocks. Glocal roads differ from global roads however, in that they are narrow, have lower speed limits, and do not form part of the ‘supergrid’ structure. Shelton also describes the sidewalks of the global arterial roads as functioning as streets in themselves, or ‘sidewalk streets’, operating in a similar manner to the local streets.
Sub-structure
In a
- with sidewalks: using a direct geometric representation of the usual concept of city blocks. Not only sidewalks, but also inner alleys, common gardens, etc. Some street parts, such as a street greenway, isolated and with no related lot, can be also represented as a block without sidewalks.
- without sidewalks: represented by polygon obtained by the external border of the union of a set of touching land lots (illustration opposite).
Always a block without sidewalks is within a block with sidewalks. The geometric subtraction of a block without sidewalks from block with sidewalks, contains the sidewalk, the alley, and any other non-lot sub-structure.
Perimeter block
A perimeter block is a type of city block which is built up on all sides surrounding a central space that is semi-private. They may contain a mixture of uses, with commercial or retail functions on the ground floor. Perimeter blocks are a key component of many European cities and are an urban form that allows very high urban densities to be achieved without high-rise buildings.[22]
Uses
As an informal unit of distance
In North American English and Australian English, the word "block" is used as an informal unit of distance.[23] For example, someone giving directions might say, "It's three blocks from here".
Online
There have been online innovations and websites such as MSNBC-owned EveryBlock, which uses geo-specific feeds from neighborhood blogs, Flickr, Yelp, Craigslist, YouTube, Twitter, Facebook and other aggregated data to give readers a picture of what is going on in their town or neighborhood down to the block.[24]
See also
- Census block
- Grid plan
- Manhattan distance
- Urban design
- Urban planning
References
- ^ ISBN 978-0-419-22110-4.
- ^ cityofchicago.org
- ISBN 978-0-19-172648-4.
- hdl:2123/17986.
- ^ a b Bausells, Marta (2016-05-17). "Superblocks to the rescue: Barcelona's plan to give streets back to residents". The Guardian. Retrieved 2018-04-14.
- ^ Understanding about residential massíve. Round calendar planning of residential massíve development by urban-planned complexes (Понятие о жилых массивах. Календарные планы застройки жилых массивов градостроительными комплексами).
- ^ Postaria, Ronika (31 May 2021). "Superblock (Superilla) Barcelona—a city redefined". Cities Forum.
- S2CID 220915328.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ "The Pedestrian Pocket Book: A New Suburban Design Strategy - Calthorpe Associates". www.calthorpe.com. Retrieved 12 September 2017.
- ^ ISBN 978-0-415-94874-6.)
{{cite book}}
: CS1 maint: multiple names: authors list (link - ^ "Superquadras de Brasília foram pensadas para serem espaços públicos, diz antropóloga". Agencia Brasil. 2 March 2020. Retrieved 4 January 2023.
- ^ Commission for Architecture and the Built Environment http://www.cabe.org.uk/case-studies/vauban
- ^ "Barcelona Metropolis - Salvador Rueda - Sustainable Urban Expansions: the Legacy of the Cerdà Plan". lameva.Barcelona.cat. Retrieved 12 September 2017.
- ^ a b c "Superblocks, Barcelona Answer to Car-Centric City – Cities of the Future". Cities of the Future. 2016-07-21. Retrieved 2018-04-14.[permanent dead link]
- ^ "Barcelona's Car-Taming Superblock Plan Faces a Backlash". CityLab. Retrieved 2018-04-14.
- ^ Nogué, David (23 April 2023). "Superilla: la pacificació del comerç?". L'Econòmic. Retrieved 29 May 2023.
- ^ "David Nogué: "Els polígons industrials amb comerç són més competitius"". Ràdio Comerç (in Catalan). 29 January 2022. Retrieved 29 May 2023.
- PMID 35614932.
- ISBN 9780415554398.
- ^ ISBN 9780415554398.
- ^ Popham, Peter (1985) Tokyo: the City at the End of the World. Tokyo: Kodansha International, p. 48, cited in Shelton, Barrie (2012) Learning from the Japanese city : looking East in urban design. Abingdon, Oxon: Routledge, p. 8.
- ^ Edwards, Brian: "The European perimeter block" in Courtyard Housing: Past, Present and Future, Taylor & Francis, 2004
- ^ Imagination: The Science of Your Mind's Greatest Power, by Jim Davies
- ^ "Web Publishing Roll-Up: Rise and Advise". CMSWire.com. Retrieved 12 September 2017.
Further reading
- Jacobs, Jane (1961). The Death and Life of Great American Cities. Random House.
- The Great American Grid: Block Size Dimensions Archived 2019-11-03 at the Wayback Machine