Association between street greenery and walking behavior in older adults in Hong Kong

Built environment interventions, such as creating green and walkable neighborhoods have increasingly been recognized as an effective approach to promote physical activity and health for older adults. However, evidence of the associations of urban greenery and older adults' physical activity is still inconclusive, partially due to the difficulty to estimate eye-level urban greenery exposure. To address this gap, we assessed street greenery by Google Street View (GSV) images with machine learning techniques and associated it with walking behavior for 10,700 and 1083 Hong Kong older adults (aged 65 or above) respectively. Neighborhood socioeconomic status, individual factors, and other built environment characteristics were controlled for in the analysis. We found that street greenery assessed by GSV was positively associated with both the odds of engaging in walking and total walking time of the older adults. Our findings suggest that urban planners and policymakers should maximize residents' greenery exposure by considering the accessibility and visibility of urban greenery from pedestrian and human-scale perspectives.