1. Asst. Prof., Transp. Plng. Dept., Egyptian Nat. Inst. of Transport, P.O. Box 34 Abbassia, Cairo, Egypt; formerly, Visiting Fulbright Scholar, Dept. of Civ. Engrg. (Transp.), Univ. of Texas at Austin, Austin, TX 78712-1076.
2. Assoc. Prof., Dept. of Civ. Engrg., (Traffic and Transp.), Al-Azhar Univ., Nasr Road, Nasr City, Cairo, Egypt.
3. Asst. Prof., Dept. of Civ. Engrg., (Transp.), Ain Shams Univ., 1 Al-Saryat Street, Abbassia, Cairo, Egypt.