Advances in 3D modeling of Existing Subsurface Utilities

3D design for highway and other transportation projects is ramping up in a significant way. However, almost all projects using this new technology still rely upon 2D mapping and occasional cross-sections or point locations for the depictions of existing underground utilities. The reason for this is simple; there has been no 3D utility information consistently and comprehensively available. Although the x,y data is pervasive, and reliable when ASCE 38 ("Standard Guideline for the Collection and Depiction of Existing Subsurface Utility Data") is utilized, the z values have been spotty and singular, or totally estimated from mostly unreliable sources or no sources at all. A convergence of improved geophysics developed by various international and national research programs (ORFEUS-EU; Mapping the Underworld - UK; Strategic Highway Research Program -USA) are combining with new ASCE concepts on z-value risk management attribution to address this problem. Florida DOT has instigated a trial program to utilize these technologies and concepts on a variety of highway projects. This paper will detail the technologies, processes, and risk management aspects of 3D mapping of non-visible assets, and results so far of the successful project deliverables for the Florida DOT. It will discuss remaining challenges and issues, and the potential to leverage clash detection programs based upon good data versus bad.