Mapping the space between buildings using Open Street Map Obi Thompson Sargoni, Hannah Gumble, Nicolas Palominos The Bartlett Centre for Advanced Spatial Analysis, University College London Defining Streets (a manifesto) In urban areas buildings should be accessible by foot or wheelchair. The spaces between buildings should provide space and infrastructure suitable to these modes. Digital representations of this infrastructure should help indicate the extent to which this objective is met. Streets and Sustainability The sustainable mobility paradigm1 creates demand for spatial information by emphasising the links between land use and transport planning. For example, the link and place function2 categorisation of urban roads highlights the role of roads as places in themselves, increasing the need to understand public space design and features of the urban realm encompassed in the space “between buildings”3. Furthermore, emerging transport innovations are increasing the demand for diverse high- resolution geographic information. The introduction of single rider vehicles (micromobility) and increased transport network connectivity through mobility-as-a-services (MaaS) platforms exemplify such innovations. The resulting diversified use of streetspace creates competing demands, motivating the need to measure streetspace. 1. Banister, D. "The sustainable mobility paradigm." Transport policy 15.2 (2008) 2. Jones, P., Boujenko, N., & Marshall, S. (2007). “Link & Place—A guide to street planning and design” Landor. 3. Gehl, Jan. “Life between buildings”. Vol. 23. New York: Van Nostrand Reinhold, 1987 4. Aderson, J et al. ‘Corporate Editors in the Evolving Landscape of OpenStreetMap’ ’, ISPRS International Journal of Geo-Information, 8(5), p. 232 Streets in Open Street Map OSM recommends a hierarchy for defining pedestrian routes. The overarching tag “highway”=”footway” should be applied to all pedestrian specific routes. The more specific “footway”=“sidewalk” tag identifies routes along sidewalks/pavements. Geometries with this tag map the ‘pavement centre line’. Alternatively, road centre line geometries can be assigned the “sidewalk”= “both|left|right|no” tags, indicating the availability of pedestrian infrastructure without adding geometries to show its location. Whilst a street can be represented by a one-dimensional road centre line geometry, understanding a ‘place’ effectively requires capturing activities across two and three dimensions. Furthermore, one-dimension representations are insufficient for assessing increasingly contested urban street space allocation. Only pavement centre line geometries, associated with the tag “footway”=“sidewalk”, extend the one-dimensional representation of streets by distinguishing between sides of the road. We make an initial assessment of the availability of pavement centre line geometries in OSM using a sample of 99 cities worldwide and compare this to the coverage of all ‘footways’ and of road centre lines (RCL) with ‘sidewalk’ tags. For each city we calculate the coverage of footways and sidewalk tagged geometries by dividing the total length of these geometries by twice the total length of the walkable road network, also downloaded from OSM. obi.sargoni.18@ucl.ac.uk hannah.gumble.17@ucl.ac.uk n.palominos@ucl.ac.uk Walkable Road Centre Line Geometries Pavement Centre Lines Road Centre Lines with Sidewalks ["highway"]["area"!~"yes"] ["highway"!~"abandoned|bus_guideway|construction| cycleway|motor|planned|platform| proposed|raceway|pedestrian|footway"] [“footway”!~ “sidewalk”] ["foot"!~"no"]["service"!~"private"] “footway”=“sidewalk” “sidewalk”= “both|left|right”] Access Movement Public Realm The spaces ‘between’ buildings. Pavement Centre Lines: ‘Sidewalks’ Walking routes: ’Footways’ Function Infrastructure Mapping Region N Cities Footways Coverage Pavement Centre Line Coverage Road Centre Line with Sidewalks Coverage US + Canada 57 0.124 0.084 0.042 Europe 18 0.181 0.023 0.063 Brazil 10 0.