<p>The overall sustainability of transportation systems is shaped by the dynamic interplay of economic, environmental, and social factors. While system dynamics modeling has been employed to analyze transportation policies, this research offers novel insights into the intricate mechanisms driving sustainability. By developing system dynamics models of transportation systems, we have identified several key findings. First, the economic dimension is significantly influenced by transportation system efficiency. Second, the environmental dimension is affected by the adoption of eco-friendly vehicles and energy conservation measures, which also influence efficient pricing and prioritization strategies. Third, the social dimension is shaped by both the effectiveness and the operational efficiency of the transportation system. Furthermore, scenario analyses involving infrastructure improvements, the adoption of environmentally sound vehicles, and public transport expansion reveal disproportionately large benefits across all three sustainability dimensions. Consequently, this research contributes actionable insights for policymakers seeking to optimize transportation system sustainability by fostering a deeper understanding of these complex dynamics. The positive outcomes of these proposed scenarios were confirmed to be robust through a comprehensive sensitivity analysis, strengthening their practical applicability.</p>