Sustainable Urban Mobility Challenges: Multi-Dimensional Topological Fracture Typology of Pedestrian Travel Networks in 15-Minute Neighborhoods, a Case Study of Hefei

The 15-minute neighborhood paradigm has reshaped the evaluation system of urban pedestrian mobility, shifting pedestrian network assessment from single facility supply to holistic topological structural analysis. Structural fracture of pedestrian systems has thus become a prominent challenge restricting high-quality sustainable urban travel and neighborhood renewal. Existing studies mainly focus on macroscopic accessibility and geometric connectivity, lacking systematic multi-dimensional quantitative measurement and refined typological identification of network topological fractures. Taking 52 typical 15-min neighborhoods in Baohe District, Hefei as research samples, this paper constructs a four-dimensional topological fracture evaluation system, and conducts empirical analysis through correlation analysis, K-means++ clustering and micro topological feature mining. The results show that functional fracture and hierarchical fracture are weakly correlated and relatively independent (ρ = 0.068). Four distinct topological fracture types are classified, among which the Cognitive Disorientation type accounts for the largest proportion of 37.3%. Microscopic topological verification further reveals the formation mechanisms and spatial differentiation laws of various fracture patterns. This study provides a scientific typological basis and targeted topological intervention strategies for sustainable governance, classified regulation and optimized upgrading of urban pedestrian travel networks.