This was the pilot bridge replacement project for the Pennsylvania Turnpike Commission’s (PTC) Bridge Information Modeling (BIM) and Digital Delivery Program, which included developing a 3D model. The existing bridge was a single-span steel beam bridge, and we proposed a two-span composite prestressed spread box-beam bridge. This project was part of a $1.5 million open-end engineering services contract.

RETTEW used Civil3D, Inventor, Revit, and other Autodesk software to develop 3D modeling of both the roadway and the bridge. Standard 2D plan sets were still part of the deliverables, but the plans were derived from the 3D model, and the 3D structure model replaced standard 2D structure plans as part of the contract documents. RETTEW coordinated with both PTC and the Pennsylvania Department of Transportation (PennDOT) throughout design engineering to develop a review process for the 3D model, since ownership of the bridge would be turned over to PennDOT after construction. RETTEW was also responsible for evaluating and providing feedback on PTC’s draft engineering and technology standards for the BIM and Digital Delivery Program, and for evaluating revisions to the standard contract documents and bidding process to address inclusion of the 3D model.