An Evaluation Method of 3D Pavement Imaging Systems for Cracking Identification Capability Using a Verification Board

3D pavement imaging has become the mainstream technology adopted by highway agencies for automated pavement condition evaluation. The high-resolution and high-accuracy imaging systems collect 3D pavement image data that enables cracking distress identification at a fine granularity to support the agencies' maintenance and rehabilitation planning. However, there is currently no standard procedure for the evaluation of the systems' image data quality and performance in cracking distress identification. The objective of this study is to propose a simplified methodology for evaluating the cracking identification capability of a 3D pavement imaging system using a manufactured verification board with known dimensions. This board was designed with linear gaps representing different ranging from 1 mm to 5 mm. The evaluation method utilizes objective indicators and consistent procedures to evaluate the system's crack identification capability in terms of (1) crack detectability for different crack widths, (2) crack width measurement error, and (3) the overall image quality. A case study was conducted to demonstrate the feasibility of the proposed method by performing a sample evaluation using test images of the scanned board, collected by different 3D imaging systems, and a ground reference image of the board, which was obtained using "FARO Arm Quantum S" scanner, with an accuracy of +/- 30 mu m and minimum point spacing of 20 mu m. This paper presents the preliminary findings of the case study and the proposed standardized procedure of crack identification evaluation using the verification board. This study is sponsored by the ongoing NCHRP 01-60 research project.