1. Department of Transportation, Chonnam National University, San96-1, Dunduck-dong, Yeosu-si, Jeollanam-do, South Korea.
2. Department of Transportation Engineering, University of Seoul, 90 Jeonnong, Dongdaemoon, Seoul, South Korea.
3. Department of Civil and Coastal Engineering, University of Florida, 470A Weil Hall, Gainesville, FL 32611.
4. Department of Engineering Technology, Missouri Western State University, 108 Wilson Hall, St. Joseph, MO 64506.