1. Department of Urban Engineering, Urban and Transportation Research Center, Chung-Ang University, Ansung City, Kyung-Gi Do, 456-756, Republic of Korea
2. Department of Transportation Engineering, Hanyang University, Ansan City, Kyung-Gi Do, 425-791, Republic of Korea
3. Urban and Transportation Research Center, Chung-Ang University, Ansung City, Kyung-Gi Do, 456-756, Republic of Korea