Leveraging roadless areas to close strict protection gaps in the EU

Strictly protected areas are critical to biodiversity conservation, yet only 4% of the EUs land currently meets this designation, falling short of the 10% target outlined in the EU Biodiversity Strategy for 2030. Roadless areas, i.e., portions of land 1 km farther from linear infrastructure, are increasingly recognized for their ecological value and potential role in closing this gap. Using OpenStreetMap data and environmental gradients derived from climate, soil, and topographic layers, we identified the extent of EU roadless areas and assessed their conservation value based on their capacity to complement the existing strict protection network in terms of environmental representativeness. We found that 11.5% of EU land is roadless, with only 18.9% of this already under strict protection. Integrating all roadless areas would raise strict protection coverage to 12.7% and improve representation of abiotic environmental space from 78.8% to 94.4%. However, most roadless areas are extremely fragmented and redundant with respect to their abiotic features. While roadless areas offer a critical opportunity to expand the strict protection network, they cannot solely meet conservation goals. A balanced strategy that includes restoration, coordination across governance levels, and prioritization based on other biodiversity features is essential to effectively meet EU conservation commitments.