Introduction & Objective: Achieving sustainability in multi-modal public transport systems depends heavily on the precise alignment of the street network's geometric configuration with the operational layer of transit fleet distribution. Due to its heterogeneous morphology, the Mashhad metropolis faces the structural challenge of "spatial mismatch." The present study aims to quantitatively evaluate the topological adaptability of the street network with public mobility infrastructure across macro, meso, and micro scales.

Methodology: This applied, descriptive-analytical research utilizes Space Syntax modeling (DepthmapX software) to extract geometric variables, including the advanced Normalized Angular Integration (NAIN) index, and Geographic Information Systems (GIS) to overlay operational layers. The statistical population encompasses the entire street network of Mashhad and the 800-meter pedestrian catchments of five strategic rapid transit interchange stations.

Results: At the macro scale, rail corridors align strongly with axes exhibiting high "Global Choice" values. At the meso scale, applying the normalized index revealed a morphological paradox: the western planned fabric suffers from internal block isolation (structural value 8430) and car-dependency, whereas the eastern organic fabric shows high capillary entanglement (structural value 9598), possessing immense potential for micro-transit despite currently functioning as a "transit desert." At the micro scale, apart from Mellat Park station, which benefits from structural synergy (local integration 134.81), stations such as Shariati and Tabarsi experience severe "spatial friction" due to physical barriers.

Conclusion: The linear, corridor-centric development of mass transit infrastructure, without improving the permeability of local fabrics, significantly distorts the efficiency of the mobility system. Enhancing system resilience requires a paradigm shift from a passive Transit-Adjacent Development (TAD) approach to Transit-Oriented Development (TOD), alongside the geometric regeneration of the first- and last-mile travel catchment.