I’m still trying to figure out walkability—specifically, whether cities in the UK, where participatory and convivial art walking is, as social scientists say, salient, are more walkable than the city where I live, and whether that might be one reason those art walking forms are so important. The authors of this study—and I hope they explain what the “Whitehall II Study” is, or was, because I have no idea—begin by defining walking as “a form of transport, with physical activity a healthy ‘side-effect’” (2). They note that studies of the connections between urban form and physical activity have been studied, but those studies have focused on North America and Australia, rather than the United Kingdom, and that London’s urban form—its age and the way its growth has been restrained by a greenbelt—has a form that is different from the cities that have been studied in the past (2).
“Walking is associated with physical environmental attributes such as greater diversity in land use (land use mix), greater street connectivity, and higher residential density,” the authors state (2). Greater land use mix is important because it enables “better access to services and employment” and induces “shorter within-neighbourhood travel by foot when a range of destinations is located near residences” (2). In such neighbourhoods, walking is likely to be more efficient than motorized transportation (2). Street connectivity, on the other hand, “relates to the feasibility of walking from one point to another: the more connected the streets, the more direct the route through the neighbourhood and the greater the walkability” (2). Finally, higher residential density creates “a more walkable environment by providing a critical mass of walkers seen by other people who are, in turn, encouraged by safety in numbers to walk as well” (2). That kind of density does not exist where I live, which means there is no “critical mass of walkers” whose example encourages others to walk—except in the park and along the creek. However, the authors continue, “physical environmental attributes should not be measured in isolation because they do not always reflect one another, and may be insifficient individually to promote physical activity” (2). For instance, greater street connectivity may not encourage walking if people lack a variety of places to visit—if, in other words, the land mix is not particularly high (2).
“Walkability indices are designed to reflect these various elements by capturing the multiple attributes of a place for which there is evidence for a positive association with walking or cycling,” the authors tell us (2). That’s interesting, but of course I find myself wondering about negative associations with walking: what makes places unwalkable, rather than what makes them walkable. A variety of such indices has been developed, but residential density, street connectivity and land use mix “are salient across populations and form the basis of a majority of indices” (2). They note that the typical land uses that “are included in the land use mix component” are heterogenous, consisting of residential, commercial, institutional and recreational uses (2). The evidence for positive associations between walkability and walking, they state, comes mostly from outside Europe and is therefore not appropriate to a city like London (2). Nevertheless, European research on this issue is “generally concordant” with non-European studies (2), although walkability remains “understudied in European cities” (3).
“Investigating associations between neighbourhood physical environments and walking also requires consideration of the spatial scale: how the neighbourhood is operationalised to capture exposures in an area that is sensitive to walking,” the authors continue (3). They suggest that most adults consider one kilometre a walkable distance, and they will “perceive areas within this distance from home to be a part of the neighbourhood” (3). However, that doesn’t mean that a one-kilometre circle around someone’s house constitutes their neighbourhood, because that measurement takes no account of areas that are inaccessible to pedestrians (3). Thus, administrative areas “constitute the most common operationalisation of neighbourhood in investigations between physical environments and walking” because they “are ‘ready-made’ and often have aggregated environmental measurements available” (3). “Whilst not ideal, the use of administrative areas as the spatial units of a walkability index provides independence from the study participants for whom associations with walking are examined: walkability is not limited to the potentially narrow range of participants’ neighbourhoods,” they state (3). For that reason, their research uses administrative areas as its basis in order “to build a walkability index for London,” using data from the Whitehall II Study to measure associations between walkability and walking (3). Their hypothesis was “that there would be a gradual radial decay in walkability of London from the centre to the periphery, reflecting reductions in residential dwelling density and street connectivity,” and that there would be a “positive association between walkability and time spent walking per week,” particularly in areas with greater land use mix (3).
Whitehall II, they explain, “is an ongoing longitudinal study of civil servants to examine the social determinants of health” (3). It has been going on since 1985 (3). Part of the questionnaire that participants answer asks about physical activity, including the “frequency and duration of walking over the past 4 weeks” (4). The duration and frequency of walking combined constituted walking volume (4). “Walkability indices for London were produced at three spatial scales of contiguous administrative areas (i) 21,140 output areas, (ii) 633 census area statistics (CAS) wards and (iii) 33 local authorities,” the authors tell us. “At each scale, three walkability models were constructed . . . containing the fixed components of residential dwelling density and street connectivity. In addition, each contained a land use mix component that included a different set of land uses” (4). Each successive model included more land uses (4).The city was mapped extensively in order to calculate street connectivity and residential density (4-5).
I skipped over the methodology section of the article—I don’t have the statistical background for it—and landed on the study’s results. The authors’ hypothesis that walkability would be highest in the centre of the city and lower elsewhere proved to be accurate (not surprisingly) (7, 9). To their knowledge, “this study is the first to construct and test a walkability index for the European city of London based on indices developed in non-European contexts,” the authors state. “The significant association between walkability and walking that remained even after adjustment for individual-level sociodemographic factors and for area deprivation represents a novel finding, and one that confirms the validity of the walkability tool constructed in the context of London, UK” (8). People without cars were more likely to walk, perhaps because they lacked other means of transportation, but it’s also possible that in areas with high residential density, street connectivity, and land use mix, people have less of a need for a car (8). However, it seems that people tended to walk more in neighbourhoods that were more walkable (9). However, the authors acknowledge that the study didn’t determine which land uses included in the land-use mix were related to walkability (9). In addition, because participants did not report where they walked, just how much, it’s possible they were walking outside of their neighbourhoods (10).
“In the context of the most populous city in Europe, the significant association between walkability and walking . . . highlights the potential importance of the physical environment of the neighbourhood in eliciting physical activity in individuals and thereby promoting public health at a population level,” the authors conclude. “The most basic walkability index model constructed here may offer urban planners and public health professionals a simple tool in building and maintaining healthy neighbourhoods” (10).
The connections between residential density, street connectivity, and land-use mix, on one hand, and walkability and walking, on the other, suggests that certain kinds of urban environments—densely populated places with high levels of street connectivity and a diverse land-use mix—are likely to be more walkable than urban environments that lack those features. Most of the city where I live isn’t densely populated, levels of street connectivity are low, and the land-use mix tends not to be complex; therefore, that city is less walkable than, say, central London. That seems obvious. I still wonder, though, about how walkable places create cultures of walking—attitudes towards walking that see it as normal and typical rather than eccentric—and whether such cultures of walking might encourage people to participate in art walking practices that push back against functional forms of walking in favour of walking that is more mythogeographic or psychogeographic. I am beginning to see how I might bolt this research together to make an argument, but I think I’m going to need a few more pieces before I’m confident about making those connections.
Works Cited
Stockton, Jemima C. Oliver Duke-Williams, Emmanuel Stamatakis, Jennifer S. Mindell, Eric J. Brunner, and Nicola J. Shelton. “Development of a Novel Walkability Index for London, United Kingdom: Cross-sectional Application to the Whitehall II Study. ” BMC Public Health, vol. 16, no. 416, pp. 1-12. DOI: 10.1186/s12889-016-3012-12.
