Observed and perceived walkability among young adults in San Francisco: spatial divergence, neighborhood inequality, and self-rated health.

Walkability is a common built environment measure for guiding health-supportive planning. However, built environment metrics do not necessarily capture resident experiences of neighborhood walkability. This study examines observed audit-based walkability and resident-perceived walkability in San Francisco as complementary but distinct measures of neighborhood walkability and examines their spatial relationships with neighborhood sociodemographic characteristics and young adult self-rated health. Data come from the 2014-2020 Bay Area Young Adult Health Panel Study, a probabilistic stratified sample of young adults aged 18-32 and census block-level neighborhood audits. We constructed composite observed and perceived walkability measures, generated continuous spatial surfaces using kriging, and estimated both global and local associations using multiscale geographically weighted regression. Observed and perceived walkability showed divergent spatial patterns and relationships with self-rated health, socioeconomic conditions, and racial/ethnic composition. The observed walkability (R2 = 0.60) model explained more variance than the perceived model (R2 = 0.24), suggesting that structural neighborhood inequalities are more directly captured by observable built environment measures. Perceived walkability, however, reflected broader lived experiences, including everyday mobility. Our findings suggest that walkable built environments in infrastructural terms do not consistently align with pedestrian experience or better health, underscoring the need to integrate experiential data into equitable urban health and planning research.