Although rail transport is widely recognised for its low operational emissions, the environmental impact of infrastructure construction and maintenance has the potential to offset these benefits. In the context of global climate targets, a comprehensive life-cycle perspective on greenhouse gas (GHG) emissions from railway projects becomes essential. However, practical implementation in early planning is constrained by limited data availability, despite its significant influence on long-term emissions. This study systematically analyses the data requirements of existing assessment frameworks and evaluates their compatibility with real-world planning data through a case study. As a result, significant discrepancies between methodological requirements and actual data conditions in early planning are identified. Although infrastructure inventories were available early on in the case study project, they lacked the material-level granularity needed for accurate emission quantification. Construction, maintenance, operation and end-of-life data were largely absent or poorly documented, requiring assumptions. The research emphasises methodological trade-offs between comprehensiveness, data accuracy and practical feasibility. It addresses the discrepancies between theoretical GHG accounting models and practical application, offering insights for practitioners, policymakers and researchers. The research identifies opportunities to improve assessment methods, data availability and standardisation in early-stage GHG balancing, to enhance the integration of environmental performance into early decision making.
Frey et al. (Fri,) studied this question.