Environmental impacts of development of railways in a road dominated infrastructure

• Combines spatial modelling and scenario analysis to assess conversion risk in natural areas. • Shows how proposed railways may redistribute conversion risk in a road-dominated system. • Achieves 79 % model accuracy, with population and rail proximity as dominant predictors. • Identifies overlap between railway-associated risk and Key Biodiversity Areas. • Provides policy guidance for biodiversity-sensitive transport planning in developing economies. Railway infrastructure plays a pivotal role in economic development, with well-documented environmental implications. However, emerging global agreements, and environmental policies introduce new dimensions that must be considered. The expansion of Brazil’s railway network has the potential to transform landscapes. This study evaluates the environmental effects of railway expansion, focusing on landcover conversion risk driven by proximity to infrastructure, population density, and agricultural potential. Spatial analysis and Random Forest modelling identified population and proximity to railways as the strongest contributors to landcover conversion risk revealing relevant environmental impacts, with overlap between estimated conversion risk and ecologically sensitive regions, and threatened species. While scenario-specific analyses highlight variations in potential impacts, the primary finding is: railways function as major drivers of landscape transformation, amplifying anthropogenic pressures on natural habitats. These results underscore the urgent need for proactive conservation planning to mitigate ecological impacts and ensure that infrastructure development aligns with global biodiversity goals.