Abstract: Low-altitude public air routes constitute a new type of infrastructure supporting the large-scale operation of the low-altitude economy. The design of sustainable operation mechanisms during the operational phase is directly relevant to the sustainable development of this emerging sector. Motivated by the practical demands of large-scale low-altitude operations, drawing on Lefebvre's spatial production theory and the sustainable operation experiences of surface transportation and civil aviation air traffic management, this paper systematically examines the design logic of sustainable operation mechanisms from three dimensions: infrastructure specificity, the conditions and boundaries for the compensated use of airspace resources, and multi-actor interest dynamics. At the infrastructure level, through a full life-cycle comparison between air routes and ground roads across planning, construction, and operation phases, the study reveals the deep institutional isomorphism between low-altitude routes and surface roads, while analyzing the paradigmatic challenges in cost accounting, property rights delineation, and pricing fundamentals arising from the shift of “construction materials” from predominantly tangible physical elements toward a deep coupling of physical infrastructure with digital components. At the resource attribute level, it demonstrates the conditions and boundaries for the compensated use of low-altitude airspace through five dimensions: scarcity, technical feasibility of excludability, measurability of externalities, allocative function of price signals, and institutional foundations. At the actor level, it reveals the differentiated value aspirations and interest tensions among government, enterprises, and the public. On this basis, the study constructs a three-tier sustainable operation logic encompassing cost recovery, market allocation, and redistribution, and outlines a phased implementation pathway aligned with industry development stages, providing an institutional design framework for the transition of low-altitude public air routes from government-led infrastructure construction to government-authorized, market-based sustainable operation.

Key words: Low-altitude Economy, Airspace Resources, Low-altitude Public Air Routes, Sustainable Operation Mechanism, Spatial Production Theory