So, you’re a highway inspector and you are tasked with inspecting a bridge. Roadway – OK. Structure and supports – check. But how about the top? What if you are evaluating the soaring trusses of a bridge like the Tappen Zee over the Hudson, or any bridge with structures that reach far above the lanes of traffic. For that matter, how do you see all parts of the inside of a tunnel? A retaining wall? A high mast light?
The answer for the Federal Highway Administration in recent months, has been to employ Unmanned Aerial Systems, also known as drones. During the past year, increasing numbers of state departments of transportation are considering using UASs as well, taking their cues from states like Minnesota which, since adopting UAS, has seen a 40% savings in inspection costs and improved data quality. The drones are able to “see’ and deliver data from difficult-to-access bridge elements such as confined spaces, high wall abutments, steep slopes and piers under traffic.
Financial and safety improvements are also noted by UAS users, who observe how UAS can collect data without having to raise or lower inspectors to various parts of bridges and structures using traditional methods like under-bridge inspection vehicles, ladders, lifts and ropes. UAS also results in less large equipment use, which in turn means reductions in not only road and lane closures, but also in overall inspection time and costs.
DOTs are additionally able to collect infrared and 3D modeling bridge and topographic mapping details, and can identify concrete delamination using this wave-of-the-future structural inspection tool.