1. Postdoctoral Research Associate, Nebraska Transportation Center, Univ. of Nebraska-Lincoln, 262K Prem S. Paul Research Center at Whittier School, Lincoln, NE 68583-0851. ORCID: .
2. Distinguished Professor and Director, Auburn University Transportation Research Institute, Auburn Univ., Auburn, AL 36849.
3. Professor, College of Civil Engineering, Hunan Univ., Changsha 410082, China (corresponding author). ORCID: .