1. Department of Civil Engineering, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-8639, Tehran, Iran.
2. Institute of Transportation Studies, University of California, Davis, One Shields Avenue, Davis, CA 95616.
3. Department of Civil Engineering and Traffic Engineering Research Center, Sharif University of Technology, Azadi Avenue, P.O. Box 11365-8639, Tehran, Iran.
4. Department of Civil and Environmental Engineering and Institute of Transportation Studies, University of California, Davis, One Shields Avenue, Davis, CA 95616.