2Carl-Gustaf Wallman. Friction Measurement Methods and the Correlation between Road Friction and Traffic Safety [ R ] . Swedish National Roadand Transport Research Institute (VTI), 2001.
3James C, J J Henry. Evaluation of IFI Calibration Procedures for New and Existing Devices [R] .Canada: Transportation Development Centie, 2001.
4Liviu Bursanescu. Automated Pavement Distress Data Collection and Analysis: a3-DApproach [C] .Ontario, Canada: International Conference on Recent Advances in 3- D Digital Imaging and Modeling,1997.
5Leif Sjoegren. State of the art: Automatic Crack Measurement of Road Surfaces [R] .Swedish National Road and Transport Research Institute(VTI), 2002.
6Robert Lytton. Determination of Asphalt Concrete Pavement Structural Properties by Nondestructive Testing [ R ] . Washington D. C, USA:NCHRP Project 10-27, Transportation Research Board, 1989.
7S Rasmussen, J A Krarup. Non-contact Deflection Measurement at High Speed [C] .Lisbon, Portugal: The 6^rd International Conference on the Bearing Capacity of Roads, Railways and Airfields, 2002.
8Joseph Budras. A Synopsis on the Current Equipment Used for Measuring Pavement Smoothness [ R ] . USA: Federal Highway Administration,2001.
9Perem, R W Kohn. LTPP Manual for Profile Measurements - Operational Field Guidelines Version 3.1 [R] .USA: Federal Highway Administration, 1999.