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be plotted on the basis of explicitly quantified values. This allows the quantification of properties of ‘preferred’ (‘connective’ or ‘griddy’) networks (Chapter 2). The second demonstration has used ‘complexity analysis’ to characterise network patterns based on their differentiation of route structure. The graphic device of the hetgram has been used to distinguish and graduate a spectrum of complexity from ‘characteristic’, typically unplanned networks to more regular, typically planned layouts. Both of these analyses home in on – and provide quantification for – the properties of traditional street patterns, whose structures neo-traditional planners might wish to emulate. These are united with the third and final demonstration of ‘characteristic’ structure, which combines a relatively high degree of complexity and a medium to high level of relative connectivity. The analysis suggests the recognition of particular kinds of structure – identified as characteristic structure – which equates with typical traditional street pattern structure. Figure 6.13 demonstrates that a whole host of traditional street patterns from Bayswater to Babylon possess this identifiable kind of characteristic structure – this combination of connectivity and complexity – that sets them apart from either pure geometric grids or pure trees. This means that instead of placing this structure into some ‘hybrid’ or ‘other’ category – a rag-bag with a disparate array of weird and wonderful patterns that would never see the light of day as street patterns – we can recognise the characteristic structure as the quintessential ‘streetpattern-shape’. In other words, when urban designers call for ‘more connective’ layouts, or for ‘less standardised traditional-like’ layouts, they may well be pointing to a kind of structure that in fact is not some elusive amorphous entity, but a very specific type of structure, whose properties can be pinned down – to a specific combination of complexity and relative connectivity. This means that, where appropriate, ‘preferred’ layouts can be expressed in terms of specific route-structural properties, rather than having to rely on elusive terms like ‘inter-connected’ or having to resort to depicting a stereotypical pattern on plan. As noted at the end of Chapter 4, patterns are not monolithic, but are articulated assemblies of elements. Taken together, this chapter and Chapter 5 have demonstrated a direct (and quantifiable) connection between the character of the routes and the whole route structure. Connector streets reside in connector networks (grids); culs-de-sac fit together to make