This dissertation addresses limitations in existing affordability frameworks, proposing an expandable framework to incorporate critical components like health costs. Focusing on Los Angeles County, it examines the impacts of public transit on location affordability, emphasizing accessibility factors and socio-demographic influences on property values. The study validates public transit's role in reducing private vehicle reliance and its minimal impact on air pollution, particularly notable with bus services. Central to the research is the development of the H+T+H Index, integrating housing, transportation, and health costs to enhance predictability in location cost changes. Interdisciplinary in nature, the study contributes to urban planning, public policy, and environmental science by offering insights into complex relationships within urban dynamics, setting a new direction for future research integrating advanced technologies.