From transport hubs to sustainable hubs: a long-term network framework for resilience in U.S. aviation

This study assesses the long-term evolution of transport hubs in the U.S.-centred aviation network operated by U.S. carriers from a sustainable hub perspective. By constructing flow-weighted and carbon-weighted networks from 1971 to 2024, we evaluate how historically formed hub structures perform across three interconnected dimensions: carbon efficiency, network efficiency and structural resilience. We find that (1) the U.S.-centred aviation network has not followed a linear or stable pathway toward improved hub sustainability, but is instead characterised by persistent trade-offs among carbon efficiency, network efficiency, and structural resilience; (2) hub-and-spoke structures have strengthened network efficiency, but have also concentrated carbon burdens at key nodes, revealing an embedded tension between connectivity and emissions; and (3) spatial heterogeneity and scenario analysis show that no single intervention improves all three dimensions, calling for coordinated technological, structural, and redundancy-based measures. These results provide insights for low-carbon spatial planning and resilience-oriented governance in aviation systems.