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2. Federal Highway Administration, U.S. Department of Transportation. Traffic Monitoring Guide, Washington, D.C., 1985.
3. Liu G X, Sharma S C, Luo J Z. Traffic Data Needs for Saskatchewan Highways and Transportation. Research Report of Saskatchewan Highways and Transportation, Regina, Saskatchewan, Canada, 2001.
4. American Association of State Highway and Transportation Officials. Guidelines for Traffic Data Programs, Washington, D.C., 1992.
5. American Society for Testing and Materials. Standard Practice E1442, Highway Traffic Monitoring Standards, Philadelphia, PA, 1991.