A spatially explicit comparison of walkability within city-centre and suburban contexts in Helsinki, Finland

Walking and high-quality walking environments are essential for sustainable and healthy cities. Walkability depends on both objective environmental features and perceived aspects. However, less is known about how the interplay between objective and perceived walkability influences walking behaviour across different urban contexts. We conducted a spatially explicit comparison of walkability and walking routes between a city centre representing inner-city walking fabric and a suburb comprising transit and automobile urban fabrics in Helsinki, Finland. Our objective walkability index consisted of floor space ratio, functional mix, and accessibility variables, while the perceived quality index included safety, comfort, and enjoyment variables retrieved from public participatory GIS data reflecting citizens’ perceptions. We also compared the characteristics of hotspots of people's reported routes for utilitarian and recreational walking, incorporating additional variables, namely green and blue index, which consisted of the NDVI and shoreline length. We found that prerequisites for walking significantly differed between city-centre and suburban contexts. In the city centre, objective and perceived walkability were high in the commercial centre, whereas in the suburb, they rarely overlapped. Suburban centres had a lower degree of perceived walkability than the city centre, but these areas were widely used for utilitarian and recreational walking. In the city centre, perceived protection was higher in utilitarian walking hotspots, which were also associated with higher building density, functional mix, and objective walkability index. Conversely, in the suburb, perceived protection was higher in recreational hotspots, associated with higher urban permeability, NDVI, and shoreline length. High perceived enjoyment, i.e., pleasant sensory experiences, induced both utilitarian and recreational walking across urban fabrics. Our results underline the importance of including citizen perceptions in walkability planning. With more limited mobility options, suburban walkability is crucial for fair mobility. Such contextual features of walkability need to be better addressed in future studies and planning practices.