A Scalable Methodology Towards a European Noise-Barrier Database: The Case of Andalusian Highways (Spain)

Environmental noise is increasingly recognized as a major environmental and public health challenge, with road traffic identified as the dominant source of acoustic pollution across Europe. In this context, noise mitigation is directly linked to sustainable development goals related to human health and urban sustainability. Noise barriers are among the most widely implemented mitigation strategies; however, their spatial distribution and adequacy remain poorly documented, limiting their effectiveness for sustainable territorial planning. This study develops the first georeferenced database of highway noise barriers in Andalusia (Spain) and applies a reproducible, transdisciplinary geospatial workflow integrating field surveys, remote-sensing tools, and Geographic Information Systems (GIS). A total of 110 barriers were mapped, classified by material, geometry, and surrounding land use, and analyzed in relation to sensitive receptors, including dwellings, schools, and hospitals. Results show that only 1.6% of the Andalusian highway network is currently protected by noise barriers, with strong territorial disparities: over 50% of all structures are concentrated along coastal metropolitan corridors, while extensive inland areas remain unprotected. Misalignments were also detected between barrier placement and officially reported high-exposure segments, indicating limited correspondence between infrastructural deployment and planning-designated priority areas. Beyond generating a comprehensive regional dataset, the proposed methodology provides a scalable basis for national and European initiatives seeking to harmonize the mapping and assessment of noise-mitigation infrastructures. By offering an open-access, transferable framework, this work contributes to a more equitable distribution of environmental protection measures and supports policy professionals, environmental managers, and planners in advancing healthier and more sustainable urban and transport systems.