Urbanization and transportation issues have become critical concerns for urban planners, developers, administrators, and practitioners. Efficient public passenger transportation is essential for mobility, economic growth, and sustainability. As urbanization continues to reshape South African cities such as Tshwane, innovative solutions are increasingly necessary. This study employs a System Dynamics (SD) modelling approach to analyses and improve the passenger transportation system in Tshwane. By integrating key factors such as population growth, travel demand, infrastructure development, and policy interventions, the model provides a comprehensive framework for evaluating transportation dynamics over time. The SD simulations reveal that, without intervention, traffic congestion in Tshwane could rise by 30% over the next decade. However, enhancements in rail services such as increased railcar production, smart scheduling, and multimodal integration could reduce road usage by 20%, decrease commuter travel time by 8%, increase rail usage by 25%, and lower peak-hour congestion by 15%. These improvements are also projected to raise the public transport modal share by 10%. The model identifies policy leverage points that support strategic decision-making, including scalable rail investment and coordinated planning. This holistic approach highlights the complex interactions between infrastructure, behavior, and policy, and serves as a cost-effective, low-risk tool for testing long-term strategies. Future research should focus on integrating multi-modal transport systems and extending the model to other metropolitan areas in South Africa to enhance its applicability and impact.