Three-dimensional (3D) modeling in transportation construction is a mature technology that serves as the building block for the modern-day digital jobsite. The technology allows for faster, more accurate and more efficient planning and construction. As the benefits are more widely recognized, many in the U.S. highway industry will transition to 3D modeling over the traditional two-dimensional (2D) design process.
With 3D modeling software, design and construction teams can connect virtually to develop, test and alter project designs throughout the design and construction phases. Intricate design features can be viewed geospatially, or in a 3D view, from multiple perspectives, and simulations can be run to detect design flaws before construction begins. Data, exported from the 3D models, can be transferred to a global positioning system (GPS) machine control that guides and directs construction equipment like bulldozers and excavators. The connectivity allows workers to receive and work with the most accurate, up-to-date models even if mid-cycle design changes are made.
The combination of 3D modeling and GPS machine control helps State Departments of Transportation (DOTs) complete highway projects faster with improved quality and safety. As an example, GPS-enabled construction equipment can run all day and night with the guidance from 3D model data and achieve accurate grades on the first pass. The first-pass accuracy of GPS machine control equipment reduces waste and the misuse of resources by eliminating human error and the need for change order rework due to faulty designs.
The combined technologies of 3D modeling and GPS machine control can increase productivity by up to 50 percent for some operations and cut survey costs by up to 75 percent. Reduced idle time of equipment and rework cuts fuel consumption and the associated green house gas emissions by up to 40 percent.
With GPS machine control, many manual tasks can be completed automatically and with machine-like precision. Automation decreases the need for certain tasks like staking, stringing lines, drawing fill lines and setting grade stakes. Additionally, the reduced number of workers onsite increases project safety.
Using "intelligent" technology, including 3D models, GPS machine control and on-site laser-based positioning systems allow machine operators to monitor their constantly moving, real-time location. Machine operators can also conduct grades, cuts, and fills to a high level of precision either automatically or with the guidance of an onboard system. Automation, or machine control, is also used for effective portland cement concrete and hot mix asphalt paving.
With growing reception to 3D technology, the transfer and use of 3D model data in GPS machine control equipment has been successfully demonstrated and used in numerous states nationwide. The technology proves to be a cost effective method for accelerating highway pavement construction.