1. School of Transportation and Logistics, Southwest Jiaotong University, Chengdu 610031, China
2. National United Engineering Laboratory of Integrated and Intelligent Transportation, Southwest Jiaotong University, Chengdu 610031, China
3. KU Leuven Mobility Research Center-CIB, KU Leuven, Celestijnenlaan 300-box 2422, Leuven 3001, Belgium