super apple
A superblock is an area of urban land that is bounded by arterial roads" and is the size of several typical-sized urban blocks. Within the superblock, the local road network, if any, is designed to serve local needs only.
Within the broad concept of a superblock, several typologies emerge based primarily on the internal road networks within the superblock, their historical context, and whether they are autocentric or pedestrian-centric. The context in which superblocks are studied or conceived gives rise to various definitions.
An internal street network characterized by dead ends&action=edit&redlink=1 "Dead end (street) (not yet drafted)") is typical of car-centric suburban development mainly in Western countries throughout the century. The definition of the Oxford Dictionary of Architecture and Landscape Architecture is based on this typically suburban conception:
Although the goal of such superblocks is generally to minimize traffic within the superblock by directing it to arterial roads, the effect in many cases has been to entrench automobile dependence" by limiting permeability&action=edit&redlink=1 "Permeability (spatial transportation planning) (not yet drafted)") for pedestrians and cyclists.
Superblocks may also contain a network of orthogonal internal streets, including those based on a "grid" or quasi-grid plan. This typology prevails in Japan and China, for example. Chen defines the urban morphology of the supergrid and the superblock in that context as follows:
Superblocks can also be retroactively overlaid on the pre-existing grid plan by changing the traffic rules and streetscape of internal streets within the superblock, as in the case of Barcelona superblocks. Each superblock has nine city blocks, with speed limits on internal roads reduced to 10-20 km/h, no traffic allowed and circulation possible only on perimeter roads.[17].
In the Soviet Union and post-Soviet states, a construction industry technical term is "mass residential." (in Russian: , Zhyloi massiv). According to the definition, a residential mass consists of several residential neighborhoods (city blocks) that are associated by an architectural design (concept).[18] In several cities of post-Soviet countries, several urban neighborhoods have names like massiv or masyv and appeared in the second half of the century with the rapid expansion of cities. In Central and Eastern Europe, which was once in the Warsaw Pact, several cities have residential areas filled with affordable housing of multi-story buildings known as panelák (panel building). Panel buildings of similar architectural type can be erected as a residential quarter of the city or as a larger residential area as a mass.
The superblock concept has been applied retroactively in the La Ribera and Gracia neighborhoods of Barcelona, both with a network of narrow and irregular streets, since 1993. In these two cases it translated into an increase in trips on foot (more than 10%) and by bicycle (>15%) and in a higher level of commercial activity and services.[19].
The superblocks are superimposed on the famous grid plan designed by Ildefonso Cerdá at the turn of the century for the Ensanche district.[17] Each superblock comprises nine city blocks, in which internal traffic flows have been modified to prohibit through traffic and speed limits on internal roads have been reduced. After entering a superblock from a perimeter street, vehicles can only circumnavigate one city block and return again to the same perimeter street, meaning that local access to garages and businesses is maintained, but making passage impossible. 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.[20].
It is planned to further reduce the speed to 10 km/h and eliminate on-street parking by building more off-street parking. This aims to make internal streets safer for pedestrians and create more space for games, sports and cultural activities such as open-air cinemas.[20].
The concept was initially driven by a redesign of the city's bus network that consolidated bus routes into a simpler orthogonal network, with more frequent services. With many streets free of buses as a result, the idea of creating superblocks was formulated to reduce traffic, reduce the high levels of air and noise pollution in the city and reallocate space to pedestrians and cyclists. Superblocks have received criticism and resistance from some residents, who have complained about the drastic increase in distance for some previously short car trips and the increase in traffic on arterial perimeter roads.[21] From an economic point of view, the Catalan business mapping observatory (EIXOS) showed trends that non-routine businesses would feel obliged to the perimeter of superblocks to keep specialized businesses sufficiently active (higher value of the premises). Conversely, the blocks Interiors within them would inevitably converge into a lower quality network of food and beverage stores and supermarkets (lower commercial value of the properties).[22][23] The adaptation of the Barcelona superblock concept to other cities has been explored.[24].
Superblocks have been the predominant mode of urban land use planning in Japan, even being described as the "sine qua non of Japanese urban design".[25] present in all medium and large cities in Japan to a greater or lesser degree. Cities are typically organized around a system of wide arterial roads, which often approximate a grid and are flanked by generous sidewalks, and an orthogonal network of narrow internal streets, which typically function as shared zones without sidewalks. The grid plan layout of Japanese cities such as Kyoto and Nara dates back to the 19th century, which in turn was derived from Chinese grid models. The superblock system was primarily created in the early to mid-century by physically widening arterial roads, overlapping the supergrid and superblock structure in a physical sense. This contrasts with the Barcelona model in which the superblock model was imposed through the change of traffic signage rather than the physical expansion of streets. Furthermore, they contrast with the Western autocentric models described above, as they are generally characterized by highly walkable and bikeable street networks, featuring high-density mixed-use development, and supported by a highly effective and efficient public transportation system.
Largely resulting from planning controls linking building height to street width, Japanese superblocks are typically characterized by a 'hard shell' of tall buildings with commercial uses along the main perimeter roads, with a 'soft shell' of low-rise residential use in the centre.[27].
The spatial structure of superblocks can also be analyzed, according to a taxonomy detailed by Barrie Shelton,[26] through the classification of roads as 'global', with arterial roads being those that allow travel through the city, 'local' roads, which provide local access to buildings within the superblock, and 'glocal' roads, which can cross the entire superblock, allowing through travel and, in many cases, neighboring superblocks. However, glocal roads differ from global roads in that they are narrow, have lower speed limits, and are not part of the "supergrid" structure. Shelton also describes the sidewalks of global road arteries as functioning as streets themselves, or "sidewalk streets," functioning similarly to local streets.
Substructure
From a geoprocessing perspective, there are two complementary ways to model city blocks:
• - with sidewalks: using a direct geometric representation of the usual concept of city blocks. Not only sidewalks, but also interior alleys, common gardens, etc. Some parts of the street, such as a street greenway, isolated and without a related lot, can also be represented as a block without sidewalks.
• - without sidewalks: represented by a polygon obtained by the external edge of the union of a set of touching parcels") (adjacent illustration).
A block without sidewalks is always within a block with sidewalks. The geometric subtraction of a "block without sidewalks" from a "block with sidewalks" contains the sidewalk, the alley, and any other non-lot substructure.