Road-expansion risk predicts future hotspots of tropical deforestation

Roads act as conduits for human incursions and hence underlay many of humanity’s impacts on nature, including deforestation, wildfires, and natural-resource overexploitation. Unfortunately, existing roadmaps often drastically underestimate the true extent of road networks, and future predictions of road-related impacts rely on incomplete and outdated data, undermining development planning and conservation decision-making. Here we develop a multivariate “road-expansion risk” index to identify areas prone to road building and therefore vulnerable to road-related environmental impacts. Using a massive road dataset—137 million 1-ha raster cells drawn from three different sources arrayed across the Amazon and Congo basins and insular Asia-Pacific region—we predict road-prone locations via a statistical model that integrates a range of biophysical, socioeconomic, and administrative data. This highly integrative, large-scale approach allowed us to identify areas likely to experience future road building and regions that may contain unmapped roads. This dataset contains the 'road-expansion risk index' layers described in Engert et al. (2025, PNAS) for both the pantropical and continental-scale models. Road-expansion risk index (RER) layers are divided by continental region (Asia-Pacific, Brazilian Amazon, Congo Basin) for accessibility and provided in the original projected coordinate system in which it was created. The methods used to create the road-expansion risk index and its utility are reported in Engert et al. (2025, PNAS). J.E. Engert, C.M. Souza, F. Kleinschroth, F.Y. Ishida, S.P. Costa, J. Botelho, & W.F. Laurance, Road expansion risk predicts future hotspots of tropical deforestation, Proc. Natl. Acad. Sci. U.S.A. 122 (52) e2502426122, https://doi.org/10.1073/pnas.2502426122 (2025).