1. Dynatest International, Naverland 32, DK 2600 Glostrup, Denmark.
2. University of California Pavement Research Center, Department of Civil and Environmental Engineering, University of California, Davis, CA 95616.
3. Division of Pavement Management, California Department of Transportation, 5900 Folsom Boulevard, Sacramento, CA 95819.
4. University of California Pavement Research Center, University of California, Berkeley, 1353 South 46th Street, Building 452-T, Richmond, CA 94804.