1. Professor, College of Transportation Engineering, Chang’an Univ., Middle-section of Nan’er Huan Rd., Xi’an 710064, China.
2. Purchasing Agent, Xuzhou XCMG Excavator Machinery Co. Ltd., 39 Gaoxin Rd., Xuzhou 221132, China.
3. Professor, John A. Reif, Jr. Dept. of Civil and Environmental Engineering, New Jersey Institute of Technology, 323 Dr. MLK Jr. Blvd., Newark, NJ 07102.
4. Assistant Research Scientist, China Urban Sustainable Transport Research Center, China Academy of Transportation Science, No. 240 Huixinli, Chaoyang District, Beijing 100029, China (corresponding author).
5. College of Transportation Engineering, Chang’an Univ., Middle-section of Nan’er Huan Rd., Xi’an 710064, China.