About the author William W. Hay is Professor Emeritus of Railway Civil Engineering at the University of Illinois and is a domestic and foreign railroad consultant. Prior to his academic career, he spent 16 years in the engineering and maintenance departments of several major railroads and the military railway service. Dr. Hay is author of Introduction to Transportation Engineering, Second Edition (Wiley 1977) He is an honorary member of the American Railway Engineering Associations, and served as Director of both the Roadmasters and Maintenance of Way Associations of America. He received his Ph.D. in civil engineering from the University of Illinois.