PHOTO-INTERPRETATION OF PAVEMENT SKID RESISTANCE IN PRACTICE

A standard texture classification procedure has been formulated that views the pavement surface as a geometric structure expressed by 6 parameters: height, width, angularity, distribution, harshness of projections above the matrix, and harshness of the matrix itself. The function of the classification method is primarily to identify pavement surfaces and to correlate textures with the accumulated test results and experience of skid testing devices. A simple stereophotographic technique was used. Regression analyses of photo-interpreted skid numbers and skid trailer test results indicated that the coefficient of correlation ranged from 0.8 to 0.9. Examples are reported of the method's applications for examining the reason for pavement slipperiness, for obtaining skid resistance information in locations where skid test vehicles cannot operate, for investigating the skid resistance of laboratory samples of pavement textures, for easing the work load of skid trailers engaged in skid resistance surveillance, and for determining the need for correcting deficient pavement skid resistance.