Development of a Neighbourhood Walkability Index for Porto Metropolitan Area. How Strongly Is Walkability Associated with Walking for Transport?

The creation of walkable communities constitutes a cost-effective health promotion strategy, as walking is an accessible and free intervention for increasing physical activity and health. In this cross-sectional ecological study, we developed a walkability index for the Porto Metropolitan Area and we validated it by assessing its association with walking for transportation. Neighborhood walkability was measured using a geographic information system and resulted from the weighted sum of residential density, street connectivity, and a destination-based entropy index. The index was categorized into quintiles of increasing walkability. Among the 1,112,555 individuals living in the study area, 28.1% resided in neighborhoods in the upper quintile of walkability and 15.8% resided in the least walkable neighborhoods. Adjusted regression models revealed that individuals residing in the most walkable neighborhoods are 81% more likely to report walking for transportation, compared with those from the least walkable neighborhoods (odds ratio: 1.81; 95% confidence intervals: 1.76-1.87). These results suggest that community design strategies to improve walkability may promote walking behavior.