This Alabama Department of Transportation (ALDOT) video of I-20 & I-59 in Birmingham, AL is a great example of using multiple technologies to create accurate 3D models for the design of interstates and interchanges. The use of Building Information Modeling (BIM) is the strength of new, leaner design and construction techniques such as Virtual Design and Construction (VDC) and Integrated Project Delivery (IPD). This approach provides an intelligent 3D model that functions as a collaborative hub for engineers, constructors and planners throughout the entire life of a transportation infrastructure project. Data can be added, extracted and analyzed by all stakeholders for making key decisions. BIM offers the potential to deliver a better product at a lower cost and rise above the competition as an industry leader.
Prior to the design phase, a topographic survey is needed of the existing project area that represents true project conditions. A LiDAR point cloud of the collected data files provides accurate measurements and depictions of the roadway and roadside assets such as lamp posts, curbs, storm drains, guardrails, signs, overpass and underpass clearances, and surrounding vegetation that are translated into a 3D model.
For the Birmingham project, over 1,100 potential construction and design clashes were identified, saving ALDOT 20 times more than the original investment. The ability to use and reuse the data across many departments presents an overall cost savings throughout the lifecycle of the project. Data collected for the model for one project will be preserved and used for data management and maintenance projects without having to recollect the area.
LandAir Surveying Company, mentioned in the video, created the existing structures and utilities models from the laser scanned data and is a strategic partner of ACA. LandAir’s BIM capabilities combined with ACA’s state-of-the-industry Mobile LiDAR and Aerial LiDAR capabilities create the most advanced precision mapping products for transportation projects in the Southeast.