Comprehensive Impact Assessment of Sustainable Transport Interventions on Urban Quality of Life and Health Risks: A System Dynamics-Based Case Study of Shenzhen

Abstract

Background: Rapid urbanization and motorization in megacities have led to severe challenges, including traffic congestion, air pollution, and public health risks, which collectively degrade the urban quality of life. This study aims to comprehensively assess the long-term impacts of different sustainable transport interventions on urban quality of life and health risks.Methods: We developed an integrated System Dynamics (SD) model that couples four subsystems: Transport, Environment, Health, and Quality of Life (TEHQ). Using Shenzhen, China, as a case study, we simulated the system’s behavior from 2025 to 2045 under four scenarios: Business as Usual (BAU), Public Transit Priority (PT-First), New Energy Vehicle Promotion (NEV-Push), and an Integrated Intervention scenario. Key performance indicators, including a composite Quality of Life (QoL) index and a Health Risk Index, were used for evaluation.Results: Under the BAU scenario, traffic congestion, pollution exposure, and health burden continue to worsen over time, while the quality of life index shows a declining trend in the later period. Compared with BAU, the PT-First scenario shows the strongest improvement in traffic efficiency, whereas the NEV-Push scenario performs better in reducing pollution-related health burden. The Integrated scenario achieves the most balanced overall performance across mobility, environmental, and health dimensions, resulting in the highest improvement in the composite QoL index and the largest reduction in excess mortality. These findings suggest that combined interventions are more effective than single-policy approaches in improving long-term urban sustainability.Conclusions: Single-dimensional transport policies have clear limitations and trade-offs. An integrated governance approach that combines supply-side optimization (e.g., developing public transit) with demand-side management (e.g., promoting NEVs and managing private car use) is the most effective strategy for achieving a sustainable, healthy, and livable urban future. The findings provide crucial insights for policymakers in megacities to formulate holistic and synergistic transport policies.