Quantifying agglomeration productivity in long-term infrastructure planning

Current understanding of and approaches to devising and selecting infrastructural and ultimately land-use interventions for better urban economic performance are often of limited capacity in providing long-term ‘place-based’ blueprints. These have been best framed by Sir David Higgins, the former Chair of HS2 Limited, as a need for an overall national transport strategy for and against which individual interventions can be constructed and appraised. These issues are also echoed in the Productivity Insights Network’s Infrastructure and Regional and City Productivity Debates evidence reviews. These reviews have specifically highlighted a number of gaps in our understanding and framing of the wider effects and role of infrastructure, particularly that of mobility and transport, on the productivity prospects of the UK cities. Difficulties in directly determining and measuring precise improvements in overall GVA as a result of particular transport infrastructure interventions and a lack of mechanisms/tools that would enable a more longer-term oriented planning of infrastructure targets have specifically been highlighted.

The present study focuses on aspects relating to the interrelation of the effects of urban connectivity, agglomeration, and morphology on efforts seeking to increase urban and regional output through transport interventions in a UK context. We attempt to assess the feasibility of quantifying a sense of productivity premium that may be associated with the spatial organization and connectivity of small area neighborhoods and their demographic profiles within cities. Using the Sheffield council area as a testbed, this project examines ways to quantify productivity potentials, albeit not in monetary terms, in long-term planning for land-use and transport infrastructure within an agglomeration-compatible framework.