1. 150 Crothers Engineering Hall, Civil and Environmental Engineering Department, South Dakota State University, Box 2219, Brookings, SD 57007.
2. Office of Road Design, South Dakota Department of Transportation, 700 East Broadway, Pierre, SD 57501.
3. 100 Crothers Engineering Hall, Civil and Environmental Engineering Department, South Dakota State University, Box 2219, Brookings, SD 57007.