Steve Reschke Discusses the Benefits of 3D Transportation Models
He incorporates three-dimensional (3D) roadway modeling into a variety of transportation projects across Michigan and the United States Midwest. He has extensive experience in developing and reviewing 3D models for transportation projects, including serving as an official 3D model reviewer for the Michigan Department of Transportation. He takes a holistic modeling approach for every project, by modeling roadway, utility, and structural elements to create a coordinated design that minimizes conflicts in construction.
Steve received a Bachelor of Science in Civil Engineering from the University of Michigan and has a strong background in roadway survey, design, and construction. He has more than 15 years of experience providing services to government clients at the state, municipal, and local levels. Steve currently serves as a senior project manager in Tetra Tech’s Brighton, Michigan office.
How do 3D models support transportation projects?
A 3D model is a virtual representation of the proposed design. It is much more than a pretty picture—it is a precise engineered model providing exact coordinates and elevations throughout the entire project. This allows for accurate review of design elements such as visually checking sight distances, obtaining detailed earthwork quantities, and identifying and fixing potential grading issues.
Various aspects of the project often are led by different designers, making close coordination between disciplines essential for a successful project. We model a wide variety of transportation assets in 3D, including roads, bridges, and utilities to support seamless coordination during design. Design is often a fluid process that is constantly changing, so 3D models are a terrific way to check things such as bridge underclearances, water main covers, and catch basin rim elevations. We once modeled proposed traffic signal poles to check for clearances from nearby electric transmission lines.
I just discussed the benefits of 3D models in design, but the benefits to construction may be even greater. Technology advancement now enables construction to do more with 3D models than ever before thanks to the growth in digital construction and automated machine guidance (AMG). These models allow construction to see the design intent for the entire project—something that is not possible with traditional plan sets.
How is 3D model construction delivery different from traditional delivery?
Traditional design-to-construction delivery consists of paper or PDF plan sets. Roadway plan sets usually include typical cross-sections, alignment, removal, construction, profile sheets, and other types of sheets depending on the project type. These sheets are created by simplifying the 3D models used in design. Traditional plan sets have limitations on the amount of information that can be conveyed and often require contractors to infer design intent.
To help address some of the shortcomings of traditional deliverables, 3D models are now provided for construction in addition to the plan sets. These 3D model deliverables are usually non-contractual, so contractors must take ownership of the models if they decide to use them. We have participated in pilot projects where 3D deliverables were contractual deliverables. It is only a matter of time until 3D models will be contractual deliverables on all projects, and traditional plan sets become things of the past.
How do transportation projects benefit from 3D models?
First, projects designed in 3D are typically more ready for construction. 3D models allow for improved accuracy and review of the proposed project, so problems can be solved in design before becoming problems in construction.
Second, 3D models create great visualizations of the project for stakeholders, including non-technical stakeholders. This can range from identifying and resolving potential impacts with utility companies to showing nearby residents the look and feel of the new roadway.
Last (and most important), using 3D models and AMG technology in construction results in greater efficiencies, as it reduces construction mistakes, time, and cost. Construction staking on projects can be reduced, if not eliminated. The quality of the final product is also likely to be better as the model provides more information about construction than traditional plans. Because of this, roads no longer need to be built from grade elevations staked every 25 or 50 feet but can use AMG technology instead.
There are also some potential long-term uses of 3D models for transportation clients. 3D models can be great vehicles for preserving record information, such as underground utility information, and asset management, providing a digital twin of the project. These 3D models can be leveraged for improved long-term maintenance of the project area.
Can you give some examples of how Tetra Tech helps clients innovate using 3D models?
Yes! The I-696 project in Michigan was a pilot project that used contractual model deliverables. The design of an 8-mile-long depressed freeway was successfully completed in less than four months to meet an accelerated schedule. A project of this magnitude would typically take one to two years using traditional plan set deliverables.
Another example is a high-profile boulevard project that used 3D models to record as-built utility information during a two-year construction schedule. This information will be used for future projects along the corridor, providing high confidence in the location of utilities and their depths.
A final example is developing a 3D digital twin model of a signature tied arch bridge in downtown Detroit. Not only did this provide substantial benefits during design, but the model also was used to house applicable construction documentation, such as shop drawings, testing reports, and pictures. This model will assist the bridge owner in the long-term maintenance and management of the bridge.