With the rapid development of bridge construction, environmental concerns have become increasingly prominent. Low-carbon, green, and sustainable bridge engineering has emerged as an inevitable trend. A comprehensive carbon emission calculation system is key to achieving low-carbon bridges. This study proposes a rapid calculation and analysis system for bridge carbon emissions (Building Information Modeling–Life Cycle Assessment, BIM-LCA). This system, using the bridge information model as a carrier, calculates and manages data on material consumption, machinery, transportation, and energy throughout the bridge’s life cycle. It then calculates the carbon emissions for each stage. This system simplifies the complex and cumbersome data collection and analysis processes found in traditional methods while also making the carbon emissions across the full bridge life cycle more accessible and visible. Being applicable to all types of bridges, this system can provide insights and a basis for decision-making in the early design stages and during construction and operation to support carbon reduction. Ultimately, it promotes low-carbon, environmentally friendly, and sustainable bridge engineering development.

Transportation infrastructure construction generates substantial greenhouse gas emissions, yet construction-phase emissions from small- and medium-span concrete bridges remain difficult to quantify at the design stage. This study develops a data-driven framework for carbon accounting and prediction using 58 urban concrete bridges in Guangdong Province, China, comprising 23 hollow slab girder bridges and 35 concrete box girder bridges. Construction-phase emissions were quantified using process-based life cycle assessment and inventory analysis. Three prediction approaches—Kriging, Kriging–support vector machine, and sequential sampling–ISC–Kriging—were evaluated across low-, medium-, and high-dimensional variable spaces. Material production dominated the carbon footprint, accounting for 84.7% of emissions from hollow slab bridges and 82.0% from box girder bridges. Average unit-volume emissions were 499.81 and 686.78 kg CO₂e/m³, respectively. The sequential sampling–ISC–Kriging model achieved the best performance in the high-dimensional space (R² = 0.920), and its error for the independent case bridge was 5.65%. These findings show that integrating structural, construction, and transportation variables can support early-stage carbon estimation and comparison of low-carbon bridge alternatives.