Robert L. Schmitt, P.E., is Professor of Civil Engineering at the University of Wisconsin, Platteville. He has worked as a consultant on major construction projects and served on technical committees for the American Society of Civil Engineers, the Associated General Contractors, and the Wisconsin DOT.

Clifford J. Schexnayder, P.E., has worked with major heavy/highway construction contractors as field engineer, estimator, and corporate chief engineer. He served as a consultant to the Autoridad del Canal de Panama and is a Member of the National Academy of Construction and the Beavers.

Aaron Cohen, CPC, is a product manager at InEight building estimating and project management software solutions and teaches courses on heavy construction methods at Arizona State University. He was previously president of Apollo Trenchless, Inc., specializing in the trenchless construction of underground utility projects.

Herbert L. Nichols, Jr. (deceased), was a private excavation consultant and author of numerous books and manuals on the topic.

David A. Day, P.E. (deceased), was a civil engineering and construction consultant. He was a Life Member of the National Society of Professional Engineers and the American Society of Civil Engineers, where he helped to start the Underground Technology Conference.