Abstract
Two skid testers, one a two-wheel and the other a single wheel design, were used in an extensive field test program to determine effects of specific variables on skid-resistance measurement. Primary attention was given to the effects of pavement wetting and trailing dynamics. Temperature effects were studied both in the field and on an indoor circular track apparatus. repeatability was studied to separate the effects of random errors from those of systematic errors in testing. The magnitude of each error source was determined.