1. Ph.D. student, Highway Division, Dept. of Civil and Environmental Engineering, Amirkabir Univ. of Technology, Tehran 15914, Iran (corresponding author).
2. Associate Professor, Dept. of Civil and Environmental Engineering, Amirkabir Univ. of Technology, Tehran 15914, Iran.
3. Associate Professor, Dept. of Civil Engineering, Iran Univ. of Science and Technology, Tehran 16846, Iran.