<p>Expressways are critical infrastructure in facilitating economic connectivity and regional development. However, the construction and maintenance of expressways significantly induce resource consumption and environmental impacts. China, with the largest expressway network globally, serves as an important case for assessing expressway-related material metabolism and associated environmental impacts. Although previous studies have examined the material metabolism of road systems, systematic assessments of expressway material metabolism and associated resource consumption and environmental impacts at the national scale remain limited. Here, we conducted a quantitative study using dynamic material flow analysis (MFA) and life cycle assessment (LCA) to explore the material metabolism and environmental impacts of China’s national expressway network from 2005 to 2035. National expressways accumulated 8.9 gigatons (Gt) material stocks, dominated by sand and gravel (76%). Pavement comprised 44% of stocks, while bridges and culverts contributed 30%. Further, notable regional disparities in stocks and efficiency reflected economic, strategic, and geographic variations. Enhanced maintenance and recycling have reduced the demand of virgin materials. In 2023, material savings amounted for approximately 61 megatons (Mt), representing a 20-fold increase compared to 2010. Although sand and gravel constitute the majority of material stocks, life cycle greenhouse gas (GHG) emissions are overwhelmingly driven by energy intensive materials like cement, steel, and asphalt. Findings highlight the critical role of sustainable material management in supporting China’s infrastructure development and climate goals.</p>