Development of a Method for Assessing Metrological Traceability in 3D Pavement Texture Measurements

Abstract

Three-dimensional (3D) pavement texture measurement plays a significant role in helping engineers calculate pavement performance–related parameters, such as the international roughness index (IRI), texture depth (TD), and rutting depth index (RDI). However, in terms of measurement, no matter how accurate a measurement instrument is, measurement bias inevitably exists, creating a difference between the true values and the measured values. To solve this problem, a standardization method named metrological traceability has been proposed to standardize measurements by tracing the measured values to the national metrological standard. Metrological traceability is indispensable to the measurement field, and it is used in standardization for the 3D measurement of electronic elements and machine parts. Nevertheless, in the study of pavement, there is still a lack of metrological traceability for 3D pavement texture measurement. This study is dedicated to realizing metrological traceability for 3D pavement texture measurement. A metrological traceability chain for 3D pavement texture measurement is proposed, the key processes of the metrological traceability chain are described, and the measurement uncertainty is evaluated. In the metrological traceability chain, a high-accuracy system named the 3D Pavement Texture Meter based on the Interference Fringe (3D-PTMIF) is proposed as a tool for calibration with standard samples of pavement texture depths (SSPTDs). Then, common 3D pavement texture meters are calibrated with the SSPTDs. The results show that 3D pavement texture measurement can be standardized with the proposed metrological traceability chain. In terms of measurement, no matter how accurate a measurement instrument is, measurement bias inevitably exists, creating a difference between the true values and the measured values. To solve this problem, a standardization method named metrological traceability has been proposed to standardize measurements by tracing the measured values to the national metrological standard. Metrological traceability, which is used in standardization for the measurement, is indispensable to the measurement field. In the study of pavement, there is still a lack of metrological standards for 3D pavement texture measurement. This study aims to provide standards for 3D pavement texture measurement. In order to achieve this goal, a metrological traceability chain for 3D pavement texture measurement is proposed. The results show that 3D pavement texture measurement can be standardized with the proposed metrological traceability chain.