Response-type roughness measuring devices, now commonly used throughout the world to monitor the condition of low volume roads, require careful calibration to ensure the accuracy of their measurements. Yet there is no consensus regarding the most appropriate instrumentation for such calibration. A recent world bank publication, reporting the findings of a series of experiments in a number of countries, proposed a hierarchy of roughness measuring instruments, the most accurate of which (termed class i) might be used for the calibrationof response-type instruments (most of which are termed class iii). Included among these class i instruments is the face dipstick, an inexpensive high-resolution profiling device whose features commend itfor application on low-volume roads, but whose applicability for such use has not yet been properly demonstrated. By comparing two class i profiling instruments for potential use in road roughness calibration, accepting the classification scheme established by the world bank, it was found that the face dipstick, in its manual form, is a fast, accurate, and cost-effective alternative to other methods, including the rod-and-level method. This paper appears in transportation research record no. 1291, Fifth international conference on low-volume roads, may 19-23, 1991, raleigh, north carolina, volume 2.
Abstract