Abdelfattah, L.; Bazzoni, A.; Choubassi, R.; Sizing up post-pandemic sidewalk potential Gorrini, A.; Presicce, D.; Zuretti, M. Case Study Report Sizing up post-pandemic sidewalk potential A case study from Milan Lamia ABDELFATTAH, Systematica s.r.l., Italy Filippo BAZZONI, Systematica s.r.l., Italy Rawad CHOUBASSI, Systematica s.r.l., Italy Andrea GORRINI, Systematica s.r.l., Italy Dante PRESICCE, Systematica s.r.l., Italy Marianna ZURETTI, Systematica s.r.l., Italy Abstract Sidewalks are increasingly becoming the new protagonists of the street. If not already for fitness, social and environmental causes, walkability is as important as ever today in the COVID-19 moment where open-air and contact-free movement are anchors to safe mobility. Cities around the world are reclaiming streets for pedestrian and cycling activity to ensure that the pandemic response is integrated within pre-existing sustainability goals. Milan is one of the forefront cities embracing this approach, adding 35 kilometres of cycle lanes in the city. In this context, Systematica took up the initiative to measure the capacity of Milan’s pedestrian infrastructure to absorb foot traffic while meeting new social distancing regulations. A citywide GIS-mapping exercise calculated and ranked sidewalk widths according to their degree of suitability for contactless pedestrian flow. The study revealed that 45% of sidewalks across Milan are unfit for social distancing norms while only 17% are considered ideal. Deeper analysis into relevant socio- demographic factors revealed that 65% of inadequate sidewalks are concentrated where 80% of elderly and active daytime populations are present. This analysis was used to create a map of proposed interventions using a needs-based approach prioritizing the coincidence of inadequate sidewalks with perceived vulnerable populations. Keywords Walkability, Pedestrian Infrastructure, GIS Mapping, GIS Analysis, Social Distancing; COVID-19 1. Social distancing needs in the time of COVID-19 1.1. A public space problem Since tHe beginning of tHe world HealtH crisis caused by tHe novel coronavirus, COVID-19, tHe need to allow for safe interpersonal distance between people botH in public and private spHeres has become of paramount importance, as advised by tHe World HealtH Organization and ecHoed by health experts around tHe world (World HealtH Organization, 2020). Amid unabating trends of rapid global urbanization (United Nations, 2019) and rising environmental concerns (UN Environment, 2016), urban planners and government officials alike are propelled to retHink tHe organization of mobility infrastructures and tHeir capacities to satisfy these conflicting needs in today’s crowded cities. 56th ISOCARP World Planning Congress in Doha, Qatar International Society of City and Regional Planners Abdelfattah, L.; Bazzoni, A.; Choubassi, R.; Sizing up post-pandemic sidewalk potential Gorrini, A.; Presicce, D.; Zuretti, M. 1.2. In line with current sustainability goals The current pandemic situation has emboldened existing plans to sHift towards sustainable mobility strategies. One of the main goals of European cities under the Sustainable Urban Mobility Plans (SUMPs) is to promote active modes of travel (RupprecHt et al., 2019). WitHin a short timeframe following tHe wake of tHe pandemic, cities around tHe world have adopted and implemented short and long-term plans to redirect veHicular road space towards cyclists and pedestrians. In New York, for example, 100 miles (160km) of streets have been reorganized to temporarily accommodate more pedestrians and cyclists (Wamsley, 2020; Weaver, 2020). Likewise, in Milan, the municipality added 35km of bicycle lanes in tHe city center under its Strade Aperte or Open Streets plan (Comune di Milano and AMAT Agenzia Mobilità Ambiente Territori, 2020; Laker, 2020), in addition to showing clear aims to favour pedestrian movement and active travel in its overarcHing Milano 2020 Adaptation Strategy plan (Comune di Milano, 2020). Around tHe world, providing safe and contactless travel options quickly rose to the top of local mobility agendas. At the same time that the city of Milan released its Strade Aperte plan, Systematica was preparing to release the first results of its own initiative to measure tHe preparedness of Milan’s sidewalks to support pedestrian movement under tHese new terms. Figure 1. Pedestrian density on Corso Buenos Aires in Milan. Source: Transform Transport. 2. Approach and methodology 2.1. Guiding approach and methodology The project is a GIS-based mapping exercise covering all 9 zones of tHe City of Milan. THe study is comprised of a two-tiered process. The first level of analysis focuses on tHe evaluation of all existing sidewalks in Milan – 3,053 km in total – based on a pre-defined safety ranking of sidewalk widtHs that follows tHe one-meter pHysical distance recommendation of tHe WHO (World HealtH Organization, 2020) and regional guidelines (Regione Lombardia, 2020), as illustrated in tHe cHart below (Figure 2). 56th ISOCARP World Planning Congress in Doha, Qatar International Society of City and Regional Planners Abdelfattah, L.; Bazzoni, A.; Choubassi, R.; Sizing up post-pandemic sidewalk potential Gorrini, A.; Presicce, D.; Zuretti, M. The model reflects segregated bidirectional pedestrian flow as a way to ensure adequate personal space. This is based on environmental psychology researcH that points to physiological and psychological stress responses by pedestrians to conditions of crowding and density (Fruin, 1971; Baum and Paulus, 1987); whicH are likely augmented under tHe pandemic circumstances. FurtHermore, accounting for preferences to increase personal space, our recent studies on pedestrian modelling suggest tHat tHe possibility to segregate pedestrian flows based on direction of movement leads to smootHer pedestrian circulation dynamics (Transform Transport, 2020). Figure 2. Adequacy ranking of sidewalk widths. Source: Authors. The second level of analysis sets out to identify priority zones of intervention based on a needs’ assessment approacH. THis is achieved by overlaying tHese preliminary mapping results witH two main parameters associated with higher contagion risk: concentrations of elderly populations (hereby defined as persons over tHe age of 70) and densities of daily populations, i.e. active populations traveling for work, study purposes, etc. Areas witH HigHest matcHing between tHese two distinct parameters dictated the scHeme for the priority of interventions. 2.2. The making of the map The process of building tHe map was based on open source data retrieved from tHe Geoportal of tHe Municipality of Milan. Starting from tHe polygons of tHe pavements, tHe centreline of each single sidewalk was computed, taking tHe edges of tHe roadway on one end, and tHe buildings on tHe otHer, as sidewalk boundaries. THe distances acHieved between botH edges were tHen recorded as sidewalk widtHs and eacH street segment was color-coded as per the above sidewalk widtH categories. THe database was then developed into an interactive map that was published online for easy public access (Available at: researcH.systematica.net/prj/milan/sidewalks.Html). It is important to note witH respect to tHe metHodology tHat tHe sidewalk widtH represents gross widtHs tHat do not consider street furniture, trees or sidewalk obstructions. Further detailing of the available data would be needed to construct a more representative model for net usable pedestrian space. A rougH estimate by Systematica predicts tHat about 0.3-0.5m and 1.5-2m of tHe gross widtH of sidewalks (for non-tree-lined streets and tree-lined streets, respectively) are occupied by street furniture. NonetHeless, tHe map represents a necessary starting point for tHe base-case scenario – assuming totally free movement. 56th ISOCARP World Planning Congress in Doha, Qatar International Society of City and Regional Planners Abdelfattah, L.; Bazzoni, A.; Choubassi, R.; Sizing up post-pandemic sidewalk potential Gorrini, A.; Presicce, D.; Zuretti, M. Figure 3. Constructing the map: steps and final product. Source: Authors. 3. Main findings and analysis 3.1. Preliminary Results Of tHe 3,053 kilometres of sidewalks spread across Milan, starting from tHe assumption of free movement, 45% (1,374 km) were found to be unsafe for pedestrians and unfit for practicing social distancing measures. Only 17% of sidewalks fell into tHe ideal widtH category, witH tHe HigHest concentrations being in tHe centre and in tHe nortHeast and nortHwest of Milan (Zones 1, 3 and 8, respectively). Zone 3 was also found to be tHe one Hosting the Highest percentages of adequate and acceptable sidewalks, wHile Zone 2 Has the Highest sHare of inadequate sidewalks by distance: more than 50% of sidewalks by lengtH in tHis area were found to be inadequate. 56th ISOCARP World Planning Congress in Doha, Qatar International Society of City and Regional Planners Abdelfattah, L.; Bazzoni, A.; Choubassi, R.; Sizing up post-pandemic sidewalk potential Gorrini, A.; Presicce, D.; Zuretti, M. Figure 4. Breakdown of sidewalks by ranking and zones. Source: Authors 3.2. Data synthesis and priority areas According to tHe latest reports by tHe Italian National Institute of HealtH, 85% of deceased COVID-19 patients up to September 7th, 2020 fell in tHe age category of 70 and over, witH a mean age of 80 (Palmieri et al., 2020). In a similar report looking at COVID-19 impacts on deatH rates in tHe first four montHs of 2020, excess mortality rates for victims of botH sexes were all