Integrating economic, environmental, and social sustainability metrics: Assessment of cross-modal passenger transportation

Transportation sustainability assessments face a critical methodological gap: while economic and environmental factors are routinely quantified, social sustainability metrics remain unstandardized and often overlooked. Current evaluation frameworks such as the Benefit-Cost Analysis (BCA) primarily emphasize long-term economic projections while underestimating non-monetary impacts, and Multi-Criteria Decision Analysis (MCDA) lacks standardized guidelines for cross-modal comparisons. This research addresses these limitations by developing a Holistic Impact Measurement (HIM) methodology that evaluates transportation sustainability during the operational phase across all three dimensions—economic, environmental, and social per person per trip. The methodology monetizes sustainable impacts to provide a unified measurement framework, particularly highlighting the significance of agency costs and subsidies. This study compares door-to-door travel options between specific origins and destinations utilizing current transportation infrastructure in Massachusetts, with case studies ranging from 1 to 60 miles. Through stakeholder engagement, systematic metric selection, and detailed multi-modal case studies, the findings demonstrate that public transit and active transportation offer superior sustainability performance, especially for shorter trips. A sensitivity analysis further examines how varying stakeholder priorities and policy interventions influence outcomes. The HIM methodology offers transportation planners and policymakers a complementary tool to existing approaches, enabling more comprehensive evaluation of transportation investments by providing a structured snapshot of immediate operational impacts on a per-person, per-trip basis. • Developed a Holistic Impact Measurement (HIM) to evaluate impacts of transport modes. • Considered the current state of transportation infrastructure at the operational stage. • Established sustainability metrics on impacts quantifiable and influenceable by policy. • Applied HIM to case studies and quantified impacts such as emissions, health effects. • Sensitivity analyses revealed how changes impact sustainability and policy decisions.