1. School of Traffic and Transportation, Beijing Jiaotong Univ., No. 3 of Shangyuancun, Haidian District, Beijing 100044, PR China.
2. Transportation Research Centre Beijing Urban Construction Design and Development Group Co., Ltd., No. 5, Fuchengmen Beidajie, Xicheng District, Beijing 100032, PR China.
3. Dept. of Urban and Regional Planning College of Urban and Environmental Sciences, Peking Univ., Beijing 100871, PR China (corresponding author).
4. Beijing Advanced Innovation Center for Future Urban Design, Beijing Univ. of Civil Engineering and Architecture, Beijing 100044, PR China.