This study develops a conceptual framework to assess sustainable mobility system design, addressing methodological gaps in the analysis of non-deterministic system behaviour. Using the Analysis-Projection-Synthesis (APS) approach in conjunction with the Vester Sensitivity Model, the system is evaluated across 22 global variables: infrastructure, technology, fuel and energy security, institutional capacity, spatial dynamics, accessibility, mobility services, accident resilience, investment, operating costs, economic development, environmental pollution, safety, enabling conditions, cultural values, aesthetics, mobility awareness, participatory culture, justice, political power, rural-urban dynamics, and human well-being. The extensive system scrutiny (projection and synthesis) simulated with the help of Vester Sensitivity Model shows the global variables (Economic development, Mobility service, Enabling condition) leverages the scrutinized system to sustainable mobility. However, for the designed system to be sustainable, current mobility system requires transformation to service centric design fuelled by renewable energy sources which needs to be enabled through behaviour correction of mobility user. The system reaches its saturation in every 15-simulation round which is bound in the negative feedback cycle indicating it can be qualified as self-regulating system. The study presents the conceptual methodological position where empirical grounding is left for future research on a contextual basis.