1. Assistant Professor, Dept. of Civil Engineering, Univ. of North Dakota, 243 Centennial Dr. Stop 8115, Upson II Room 260, Grand Forks, ND 58202-8115 (corresponding author).
2. Professor, Dept. of Civil Engineering, 2118 Fiedler Hall, Kansas State Univ., Manhattan, KS 66506.
3. Bureau Chief (Retired), Bureau of Materials and Research, Kansas Dept. of Transportation, 5235 NW 44th St., Topeka, KS.
4. Bureau Chief, Bureau of Materials and Research, Kansas Dept. of Transportation, 2300 Van Buren, Topeka, KS 66611.