1. Asst. Prof. of Civ. Engrg., Jordan Univ. of Sci. and Tech., Irbid, Jordan
2. Prof. of Civ. Engrg., Civ. Engrg. Building, Purdue Univ., West Lafayette, IN 47907
3. Transp. Engr., Sub‐Saharan Africa Transp. Program, World Bank, 1818 St. N.W., Washington, DC 20433