1. School of Economics and Finance, University of Hong Kong, Pokfulam Road, Hong Kong
2. Department of Geography, University of Hong Kong, Pokfulam Road, Hong Kong
3. Department of Transportation Technology & Management, National Chiao Tung University 1001 Ta Hsueh Road, Hsinchu, 30010, Taiwan
4. Department of Civil Engineering, University of Hong Kong, Pokfulam Road, Hong Kong