But what aspects of “walkability” are tied to better health? Is it the mix of uses, the connected street grid, the density of housing, or all of the above? It’s an important question to understand if we want to design places that encourage healthier habits.
Researchers at St. Michael’s Hospital in Toronto set out to determine what features of urban neighborhoods lead to more activity and thus better health outcomes. Their study of Toronto-area residents, published in the peer-reviewed science and medical journal PLOS-ONE, examined the link between four built environment factors and people’s health records and transportation habits.
Researchers started by looking at street connectivity, population density, residential density (which measures occupied housing units), and “availability of walkable destinations” (a measure of non-residential uses).
They found that street connectivity was not an especially strong predictor of active transportation habits, but the other three factors were. Basically, if you live in a dense area, you are more likely to walk and bike often, and you’re even more likely to get physical activity if there are a lot of destinations close to your house.
The team found that both residential density and the presence of walkable destinations were strongly predictive of residents’ transportation habits, and that walking and biking trips per person seem to be linked most strongly to residential density. Even in low-residential-density areas with a high number of destinations, people were unlikely to walk or bike.
More often than not, however, the places that were densely settled also had a high number of destinations. And while both factors make pretty good predictors of how much activity residents get, the combination of the two — places that are both dense with residences and full of other types of uses — is especially powerful. Street connectivity was found to be a weaker predictor of travel behavior than the other measures, but was also strongly correlated with density and number of attractions.