1. Assistant Professor, Construction Engineering and Management Dept., Faculty of Engineering, Zagazig Univ., Egypt; presently, Visiting Assistant Professor, Civil and Environmental Engineering Dept., Univ. of Cincinnati, Cincinnati, OH 45219.
2. Associate Professor, Construction Division, School of Civil Engineering, Purdue Univ., 1284 Civil Building, West Lafayette, IN 47907.
3. Professor, Transportation and Infrastructure Systems Engineering Area, School of Civil Engineering, Purdue Univ., 1284 Civil Building, West Lafayette, IN 47907.