Automatic Pavement‐Distress‐Survey System

Abstract

An automatic pavement‐distress‐survey system that uses laser, video, and image processing techniques has recently been developed. This system consists of a survey vehicle and a data‐processing system. The survey vehicle can measure cracking, rutting, and longitudinal profile simultaneously, without contact, rapidly and accurately. The data‐processing system can convert the measured data automatically into formats that can be used in the pavement data bank. As for cracking, cracks over 1 mm wide can be measured, and it is easy to output the various parameters calculated from length, width, direction, position and number of cracks. The cracking processor uses a unique line‐finding algorithm that can extract a crack in a noisy road image by analysis of projection curves. This algorithm is implemented in special‐purpose high‐speed hardware. In this hardware, up to 512 32‐bit microprocessors execute in parallel. This system allows automatic crack recognition that has conventionally only been performed by humans.