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FHWA/EDC News: Highway Agencies Using 4D and 5D

3D Engineered Models: Schedule, Cost and Post-Construction

While the transportation industry started building 3D engineered models to develop highway designs as far back as the 1990s, today’s uses for 3D modeling also include schedule and cost management, asset management and as-built records. 

Using a 4D engineered model to incorporate scheduling information can help stakeholders gauge how jobs such as utility installation, grading and paving can affect a project schedule. Using 5D modeling links the scheduling component to cost data, allowing stakeholders to see how changes can affect a project’s overall cost and schedule. Post-construction survey data can be used to crease accurate as-built drawings of projects and update asset management systems.

Highway agencies have used 4D models to deliver both large and small projects. Major projects that incorporated 4D modeling include the San Francisco–Oakland Bay Bridge East Span replacement in California, the Alaskan Way Viaduct replacement in Washington and the I-95 New Haven Harbor Crossing corridor improvement project in Connecticut.