1. School of Engineering; Sun Yat-Sen University; Guangzhou China
2. Guangdong Provincial Key Laboratory of Intelligent Transportation Systems; Guangzhou China
3. Guangzhou Public Transport Data Management Center; Guangzhou China
4. Department of Civil, Environmental and Geomatic Engineering; University College London; London U.K.
5. Department of Civil and Environmental Engineering; The Hong Kong Polytechnic University; Hong Kong
6. Department of Automatic Control, School of Information Science and Technology; Sun Yat-Sen University; Guangzhou China