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The Fused Grid is a street network pattern first proposed in 2002 and subsequently applied in Calgary, Alberta (2006) and in Stratford, Ontario (2004). It represents a synthesis of two well known and extensively used network concepts: the "grid" and the "Radburn" pattern, derivatives of which are found in most city suburbs. Both concepts were self-conscious attempts to organize urban space for habitation. The grid was conceived and applied in the pre-automotive era of cities starting circa 2000 BC and prevailed until about 1900 AD. The Radburn pattern emerged in 1929 about thirty years following the invention of the internal combustion engine powered automobile and in anticipation of its eventual dominance as a means for mobility and transport. Both these patterns appear throughout North America. "Fused" refers to a systematic recombination of the essential characteristics of each of these two network patterns.〔Fanis Grammenos and Gordon Lovegrove, 2015. Remaking the City Street Grid – A Model for Urban and Suburban Development, McFarland Publishers, Jefferson, NC, - ISBN 978-0-7864-9604-4〕〔Fanis Grammenos and Chris Pidgeon, Fused Grid Planning in a Canadian City, Wharton Real Estate Review, Spring 2005 University of Pennsylvania〕〔Fanis Grammenos et Al. Hippodamus Rides to Radburn- A new Model For the 21 century, Journal of Urban Design, Vol. 13. No. 2, 163–176, June 2008〕 ==Terminology and history== Modern urban planners generally classify street networks as either organic and planned. Planned networks tend to be organized according to geometric patterns, while the organic networks are believed to emerge from spontaneous, unorganized growth. Architectural historian Spiro Kostof writes that "The word 'grid' is a convenient, and imprecise, substitute for 'orthogonal planning'. 'Gridiron' in the US implies a pattern of long narrow blocks, and 'checkerboard' a pattern of square blocks."〔Spiro Kostof, 1991: ''The City Shaped'', Thames and Hudson Ltd., London〕 In addition to the right angle being a key characteristic, a second attribute of equal importance is its imputed openness and unconstrained expandability. Loosely interpreted, the term "grid" can be applied to plans such as the Vitruvian octagonal plan for an ideal city, resembling a spider web, or to plans composed of concentric circles. These are all grids in that a regularly spaced armature leaves recurring openings and that they could, conceivably, expand outward. The emergence of the pure, rectilinear, orthogonal grid, or Hippodamian grid, is explained by the natural tendency of people to walk in a straight line, particularly in the absence of obstacles and on level land.〔Spiro Kostof, 1991 The City Shaped, Thames and Hudson Ltd., London, Ch X〕 This intuitive explanation leaves the question of pre-grid and post grid non-rectilinear city patterns to be better understood, particularly those on plane territory such as Marrakech. Another potential influence may have been exerted by the second frequent user of city streets – horses. Horses also tend to move in a straight line, particularly at trotting, canter or galloping pace. When horses serve a city and draw chariots singly or in pairs, or, similarly, carts for a variety of transportation and processional functions, straight line travel becomes imperative; turns force a sluggish pace and cumbersome manoeuvres that reduce their efficiency of movement. The need for speed accentuates with city size; distances to the public functions at the centre increase and, consequently, the need for quick access intensifies. Speed in turn implies straight lines. It is plausible that the drivers for rectilinear layouts may have been man’s horses, mules and carts as much as man himself, spurred by the growth of settlements. The creation of the Radburn pattern is attributed to Clarence Stein but has a lineage of ideas that preceded it in Raymond Unwin and Barry Parker’s work that included the use of cul-de-sac and crescent street types. In contrast to the scarcity of records that obscures the original rationale for the grid, the reasons for the Radburn pattern has been articulated clearly in Stein’s writings and those of his predecessors.,〔Stein, C. (1957). Towards new towns for America. Cambridge, MA:MIT Press〕〔Raymond Unwin, Town Planning in Practice (London: Fisher Unwin, 1909) 393〕 "Radburn" (after a place in New Jersey) now denotes a street network configuration. It signifies a departure from the strict orthogonal geometry and regularity of the grid and a distinct approach to laying out new districts. As a system, it can be described more accurately as a "cellular" network that has a characteristic hierarchy of streets as distinct from identical streets intersecting at regular intervals. Its derivatives and idiosyncratic imitations are often characterized as "cul-de-sac and loop" patterns highlighting the distinguishing street types that are used systematically in this network. A second term equally uncharacteristic is "suburban". This association of a pattern with a location is inaccurate and unintentionally misleading: entire early cities such as Cairo and Fez are structured on this pattern whose newer suburbs follow the grid reversing the urban/suburban relationship. "Suburban" is also devoid of geometric descriptors of the pattern. These shorthand expressions conceal the variety of patterns that emerged in the 20th century that are decidedly neither grids nor "Radburn"〔Michael Southworth and Peter Owens, 1993: The evolving Metropolis: Studies of Community, Neighbourhood, and Street From at the Urban Edge, JAPA 59,3:271-288〕 and the "system" aspect of the pattern. The "loop and lollipop" label may be a more applicable descriptor of later interpretations of the Radburn model that appear to lack structure and to overlook key elements of the original concept such as its emphasis on pedestrian priority, for example. The pattern’s systematic use of the cul-de-sac and loop is decidedly linked to automotive mobility as a means of controlling and guiding its flow. The Radburn pattern is a complex system; more than a series of identical orthogonal city blocks in a linear progression. It rests on a functional program plus an intentional picturesque aesthetic: it avoids straight lines, limits four-way intersections and shuns repetitive blocks all of which enhance its picturesque imagery.〔Frederick Howe, The Garden Cities of England, Scribner’s Magazine, July 1912〕 To facilitate the discussion, the name "Radburn-like" or "Radburn-type" will be used in the subsequent sections. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Fused grid」の詳細全文を読む スポンサード リンク
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