1. Assistant Professor, Dept. of Civil Engineering, Texas A&M Univ., 503F CE/TTI Building, 3136 TAMU, College Station, TX 77843-3136.
2. Graduate Research Assistant, Dept. of Civil Engineering, Texas A&M Univ., 501H CE/TTI Building, 3136 TAMU, College Station, TX 77843-3136.
3. Director, Dept. of Civil Engineering, Institute for Transport Technology, Univ. of Stellenbosch, Stellenbosch, South Africa 7600.
4. Student Worker, Dept. of Civil Engineering, Texas A&M Univ., 503 CE/TTI Building, 3136 TAMU, College Station, TX 77843-3136.