Public transport promotes walking

The quality of public transit, and the degree it is integrated into a community, significantly
affects travel activity. As service quality improves and communities become more transitoriented, residents tend to own fewer vehicles, drive less and rely more on alternative modes (walking, cycling and public transit) than they otherwise would (ICF 2008; Litman 2007).

Walking to public transit: steps to help meet physical activity recommendations.

PubMed - NCBI: "Americans who use transit spend a median of 19 minutes daily walking to and from transit; 29% achieve > or =30 minutes of physical activity a day solely by walking to and from transit. In multivariate analysis, rail users, minorities, people in households earning <$15,000 a year, and people in high-density urban areas were more likely to spend > or =30 minutes walking to and from transit daily."