1. Grad. Research Asst. and Doctoral Candidate, Dept. of Civ. Engrg., The Univ. of Texas at Austin. Austin, Tex.
2. Asst. Prof. of Civ. Engrg., The Univ. of Texas at Austin, Austin, Tex.
3. Prof. of Civ. Engrg. and Dir., Center for Highway Research, The Univ. of Texas at Austin, Austin, Tex.