The highway construction industry’s use of digital terrain models (DTMs) has dramatically improved production and efficiency. Highway designers and consultants, however, have confronted obstacles in their efforts to use DTMs effectively. Specifically, the rapid proliferation of and advances in DTM technology have made it difficult to consistently prepare construction-ready DTMs for inspectors and contractors. That is, while designers incorporate the necessary level of detail into their DTMs to complete a design, when DTM files are handed over to inspectors or contractors, they require significant adjustments or reformatting to render them usable, or they are scrapped entirely. Editing and reformatting DTMs is time-consuming and hinders project execution. State departments of transportation (DOTs) vary in their documented guidance on the development and handover of DTMs to construction.
Various approaches exist for file management protocols, survey practices, and plan production methods. Some states push the control of the model to design consultants and have them work with the contractors for transition to construction. Some states also document their degree of liability in regard to the accuracy and use of the DTM in construction. Conversely, there are also states that provide no guidance regarding the use of DTMs in construction.
The objective of this synthesis is to document current strategies and identify existing barriers to effective use of DTMs during and in transition to the construction phase of highway projects.
Information will be gathered through literature review, a survey of DOTs, and interviews with selected agencies for the development of case examples. Knowledge gaps and suggestions for research to address those gaps will be identified.
Information Sources (Partial):
• Utah DOT (2018). “UDOT Model Based Design and Construction (MBDC) Guidelines.”
• Bell, P. (2018). “Civil Integrated Management and the Use of 3D Data Models for Construction Inspection.” New York State DOT.
• Page, M. and Lukes, G. (2018). “UDOT’s Digital Job Site: Model Based Design and Construction.”
• Lukes, G. and McDowell, J. (2017). “Intelligent Design and Construction Guidance Document.” Utah Department of Transportation Preconstruction Division.
• “Construction-Ready Digital Terrain Models.” SPR 19-576 Funded by the Kentucky Transportation Cabinet and Federal Highway Administration.