A single source of truth is critical for information exchanges in rail and urban large complex projects involving diverse disciplines—from highways, structures, and architecture to dry and wet utilities. It allows enhanced real-time coordination and supports sustainability through carbon tracking. This case study will discuss how SYSTRA adopted this approach for large-scale, industrial, city infrastructure projects spanning more than 45 square kilometers and housing 90,000 people. We'll showcase how this approach empowered global task teams from France, India, Saudi Arabia, and Dubai to transcend geographical barriers, enabling real-time coordination that drove the creation of complex designs. We'll also show how we used in-house tools like eLODY (Model Checker), PABLO (digital twin), and CARBON TRACKER (derived from Autodesk Platform Services) to streamline design delivery, ensuring adherence to ISO 19650 information management standard for superior project outcomes for all stakeholders.