There are a few products available that allow the linking of a 3D CAD model to a shedule (Primavera or Microsoft Scheduler). These applications are commonly referred to as 4D tools. The tools are being applied more often to architectural and large scale construction projects rather than highway projects, but it is only a matter of time before the tools are available. Below is a screen shot from a model of an under street section of the Fulton Transit Center in NYC.

The window on the bottom is a schedule that has been imported, the 3D model is made up of discreet elements that match schedule activities. Once the 3D elements are linked to the schedule, the application can play back the construction sequencing as an animation, showing the date and the percent complete on that date for each activity. The model view is an interactive window that can be moved to any view, or to any of a list of saved views.

The tool is useful for planning and construction design teams to see the incremental design in 3D and evaluate the sequencing of the construction visually.