How does the layout of a city affect its performance? And what are the opportunities and challenges of spatial evidence in policy? We discussed these issues at a roundtable held last week at Centre for Cities with urban planning consultancy Space Syntax.
Space Syntax studies the impact that the physical layout of cities has on the social, organisational and economic performance of urban areas. Developed by researchers at The Bartlett (University College London’s global faculty of the built environment), this theory is used to give streets an ‘accessibility’ score, denoting how well a street is linked to the wider layout of a city (e.g. if it is a dead end, its score would be low). Streets are then plotted on a map using different colours for different levels of accessibility – with red meaning more accessible streets and cold colours like blue representing less accessible ones.
The physical fabric of a place has an impact on its performance. One of the examples discussed on the day was the comparison between Ashford, Kent, which has grown over a number of centuries, and the new town of Skelmersdale in West Lancashire. The two cities have different layouts and this has consequences in terms of city centre accessibility and land use. In Ashford, most streets are interlinked with one another, creating an accessible town centre (figure 1). In contrast, the centre of Skelmersdale is characterized by fragmented streets with many more dead ends (figure 2). These separated movements make the city centre inaccessible.
The accessibility of streets affects land use. Ashford town centre is more accessible, and has a combination of retail and catering businesses, commercial activities and offices, houses and services, all in close proximity (figure 3). In contrast, land use in Skelmersdale town centre is much more fragmented (figure 4). The Concourse Shopping Centre dominates the town centre while offices, houses and services are broadly segregated in three different parts.
The wider body of research shows that the layout of a city has an impact on a wide range of issues such as crime, social inclusion, poverty, and health. Understanding that impact – and better communicating the implications to policy-makers – has the potential to bring about positive change to the everyday lives of the people who live and work in urban areas. In conjunction with the researchers at UCL, we will be doing more work in the coming months on the implications of spatial design for policy makers at the local and national level.