Comparison of Roughness Calibration Equipment - with a View to Increased Confidence in Network Level Data

摘要

With the advent of key performance indicators and performance specified maintenance contracts (PSMC), both in New Zealand and abroad, the accuracy, repeatability and reproducibility of roughness data is coming under increased scrutiny. Continuity of the service provider and their equipment has proven to assist in obtaining repeatable results. However, in some circumstances a change in the service provider has lead to a significant change in the average overall network figures, which appears largely unsubstantiated to the road controlling authority (RCA). Roughness is measured in network surveys using either profilometers or response type road roughness measuring systems (RTRRMS). Responsibility for calibration of the equipment resides with the service provider. Checks are often performed throughout the duration of the survey to ensure the vehicle stays within accepted bounds, specifically for RTRRMS. It is usual to have the vehicle run over the same section of road and compare the results with those obtained from previous runs. This provides the road controlling authority with some assurance of data repeatability, but does not provide assurance that the machine was correctly calibrated to begin with. For calibration it is necessary to provide a reference roughness. This provides the road controlling authority with confidence that the equipment is calibrated correctly prior to the roughness survey being undertaken on their network. There are a variety of instruments available for calibration level surveys, each with different levels of accuracy and precision. This research assesses and evaluates the accuracy of these different instruments, which range from low to high cost methods, for establishing the reference roughness on selected calibration sites.