1. Research Associate, Materials and Pavements Division, Texas Transportation Institute, The Texas A&M Univ. System, 3135 TAMU, College Station, TX 77843-3135.
2. Research Engineer, Materials and Pavements Division, Texas Transportation Institute, The Texas A&M Univ. System, 3135 TAMU, College Station, TX 77843-3135.
3. Professor, Dept. of Road and Traffic Engineering, Tongji Univ., 1239 Siping Rd. Shanghai, 200092, P. R. China.