Influence of transportation accessibility and built environment on loneliness and social support

Loneliness is a global epidemic that influences mental and physical well-being. Loneliness and other mental well-being indicators, such as social network size, social cohesion, and emotional and social support, are often interlinked, but the underlying mechanisms and coping strategies may differ. This study explores the role of distinct and overlapping demographic, transportation accessibility, and built environment factors on two outcomes – self-reported loneliness and perceived lack of social and emotional support across U.S. counties. Data from the U.S. Environmental Protection Agency (EPA)’s Smart Location Database and the County Health Ranking and Roadmap 2025 were used in this study. Transportation accessibility and built environment factors were aggregated from the census block group level to the county level. Two multiple linear regression models were developed, one for each outcome. Built environment factors significantly influence the percentage of adults feeling lonely and reporting a lack of social and emotional support. Pedestrian network density and multimodal network density significantly influence loneliness but are not significantly correlated with social and emotional support. The employment diversity index is associated negatively with the percentage of adults feeling lonely. The findings serve as valuable insights to help address the issues of loneliness and enhance the quality of life.