Demetrius Tonias, P.E., is an award-winning author of numerous works pertaining to civil engineering, in general, and transportation engineering in particular. As a member of the Adjunct Engineering Faculty of Union College, Mr. Tonias taught a variety of courses ranging from Bridge and Highway Engineering to Infrastructure Management Systems to refresher courses for the E.I.T. and PE professional licensing examinations. In addition to engineering design experience, Mr. Tonias is an accomplished software developer with extensive experience in the development of civil engineering computer applications.

Jim J. Zhao, P.E., Chief Bridge Engineer with Nolan Associates, Inc, (Ellicott City, MD). In charge of bridge design and overall project management. Mr. Zhao is experienced in design, teaching, and research in structural engineering and serves on the ASCE-ACI joint committees on "Concrete Bridge Design" and on "Prestressed Concrete Design." He is also the President of the Structural Engineering Institute, ASCE Maryland Chapter. Is the author of two books on Bridge Design and one on Risk Management.