Rethinking Streets: a study of streetspace allocation metrics and street networks in London

This research investigates streetspace allocation metrics for all streets in London providing quantitative evidence about a key parameter of street design citywide. A new methodology to quantify streetspace allocation is introduced using a geocomputational approach that allows both the processing of high-resolution topographic data over a large geographic extent and enables replicability for other cities. The correlation between streetspace allocation metrics and street network centrality at distinct scales is investigated across different geographic areas. These variables are then examined using cluster analysis to identify a typology of streets based on streetspace allocation and centrality. The results provide the framework for a design scenario study of inner London applying shortest-path analysis under an active travel prioritisation perspective. Streetspace statistics for London confirm the predominance of space allocated for vehicular transport over pedestrian uses. Most streets display standard "residential" street metrics, coinciding with traditional street classification schemes. Also, this serves to demonstrate quantitatively the spatially efficient organisation of the London street system with few wider distributors and many narrower local streets. In addition, through the combined examination of the streets' allocation and configurational metrics, it is possible to identify a new sub-type of local streets. The spatial arrangement of the streets segments types follows a centre-periphery pattern: wider and higher centrality streets are clustered at the city centre and show relative larger streetspace designated to pedestrians, corresponding with higher levels of estimated activity. On a prescriptive streetspace model of Inner London, the streetspace allocation of critical pathways is modified to illustrate how strategic scale street properties affect and are affected by design scale street parameters. The fine-grain physical metrics analysed here, not only can be useful to tackle a wide range of contemporary street related questions from urban environmental quality to the adoption of new technologies but also offer alternative analytical methods for street research, planning and design