Supplementing Current Visual Highway Bridge Inspections with Gigapixel Technology

Developing an efficient bridge condition evaluation procedure is economically critical to a state highway department; however, any adopted bridge condition approach needs to be accurate. A state highway department typically conducts a bridge condition evaluation by visual inspection on a 24-month cycle. During the evaluation, a bridge inspector visually inspects bridge components to derive a bridge condition rating on a 0–9 scale; a 0 value represents failure. The intrinsic weakness in a visual inspection system is the nonuniformity in the process due to the subjective nature of the approach. This paper proposes an approach to supplement visual bridge inspections by implementing gigapixel technology to promote quality assurance and control in a state bridge management system. The discussed approach supplements the visual inspection of a bridge with panoramic images to be later reviewed by a trained group of bridge engineers. This trained group of bridge engineers is enlisted in the inspection review process to promote uniformity in the bridge rating process. Additionally, the presented approach creates a bridge panorama that can be cataloged as a permanent bridge condition record in a state DOT’s structural health monitoring system. The presented approach uses gigapixel technology to create high-resolution panoramas that can be reviewed by an engineer using Google Earth tools. The hardware needed for gigapixel technology is inexpensive, but can greatly improve conditional bridge rating consistency between bridge sites.