High Speed 2 Phase 1 is a huge mass transit project requiring massive amounts of earthworks – approximately 25 million cubic meters of material was earmarked for excavation. Determining how to reuse material and minimize waste could greatly reduce the carbon emissions produced by mass haul vehicles, but traditional geotechnical assessment methods were not up to the task. By combining digital data management and advanced geotechnical applications, Mott MacDonald developed a collaborative geoBIM assessment technique based on a 3D representation of the construction site. This analysis provided critical insight into material reuse across the project, greatly reducing waste and carbon emissions, supporting HS2’s 50% carbon reduction commitment.