Robotics And Drones Could Save America’s Bridges

Robotics and drones could replace visual inspections of infrastructure such as bridges and highways, providing far greater accuracy and quantitative results.

Infrastructure Inspection Guidelines

  • Federal and State guidelines for manual inspection of bridges are about fifty years old, with methods that are subjective.
  • About 15 years ago, the Federal Highway Administration admitted “For more than 30 years, inspectors relied largely on visual inspections to evaluate the condition of bridges.”
  • FHWA also said new Nondestructive Evaluation technologies “increasingly are sought to solve difficult inspection challenges that are beyond the capability of normal visual inspections.”

Aging is a natural process, and it brings about situations that require action.

For instance, most of America’s highways and bridges were built in the 1950s, and are now old and crumbling. Years of bearing the weight of relentless and growing traffic have taken their toll. Many of our bridges are in dire need of repair. Some require outright replacement.

It is self-explanatory that to attend to a problem, one needs to know what the problem is, and this requires inspection.

Federal Guidelines on Inspection

In the case of bridges, the inspection process is another major problem area. This is chiefly due to the fact that the industry has failed to move with the times. It is frankly ironic that in an age of technology, America still sticks to using manual methods of inspecting bridges. To make matters worse, federal and state guidelines for manual inspection of bridges are about thirty years old, and the methods still remain significantly subjective.

About 15 years ago, the Federal Highway Administration admitted “For more than 30 years, inspectors relied largely on visual inspections to evaluate the condition of bridges.” FHWA also admitted that Nondestructive Evaluation technologies were not being used as widely as they should be, with the realization “New NDE technologies increasingly are sought to solve difficult inspection challenges that are beyond the capability of normal visual inspections.”

On the instruction of Congress, FHWA set up a Nondestructive Evaluation Validation Center  in 1998, to engage in researching the accuracy of the bridge inspection process. In the course of its study, the center found that manually conducted in-depth Inspections may, in fact, miss detecting many types of deficiencies. History shows that disasters happened because problems went undetected.

The collapse of Interstate 35W Bridge over Mississippi River during rush hour on August 1, 2007, which killed 13 people, injured 145 and destroyed 111 vehicles, was later attributed to a serious flaw in the original bridge design. Manual inspections never caught this because focusing on design aspects are outside the scope of manual inspections. The bridge was weakest at the point it should have been the strongest, and everyone was blissfully unaware of a disaster waiting to happen.

American author Stewart Brand said, “Once a new technology rolls over you, if you’re not part of the steamroller, you’re part of the road.” 

Monitoring Structural Health

Structural health monitoring has its place in the infrastructure toolbox, and bridges in the National Bridge Inventory are inspected every 2 years.

However, many of the structural health monitoring services used are antiquated, being older than 50 years, are too costly and subjective, being manual, and  provide inadequate data. In fact, state and federal transportation agencies spend millions of dollars to manually inspect bridges and determine their stress points, and to subsequently schedule repairs – a process involving countless billable man-hours, which is subjective and vulnerable to human limitations.

And because of this, lives and property are unnecessarily compromised.

By implementing modern technology and robotics, the same inspections can be conducted with far greater accuracy and quantitative results. These will lead to safer travelling for the people who need to use those bridges regularly.

To address this problem, smaller firms such as Florida-based Infrastructure Preservation Corp., have introduced modern technologies utilizing customized robotics and drones. These methods are convenient and speedy, and provide accurate and quantitative data to help the US Department of Transportation better allocate assets.

Robotics are able to detect issues earlier on in the infrastructure life-cycle. Asset owners, therefore, are able to make repairs early, and extend the service life of the structure and save billions in untimely replacements.

Inspection with Robotics and Drones
Drone Inspection Credit: Infrastructure Preservation Corp.

Large asset management firms, which have traditionally handled bridge repairs can profit immensely from these new technologies. But it essentially requires a flexible attitude and a total shift in perception, because “billable man hours” have to be replaced with technology that provides a better deliverable to their customer, safer and for a lower cost.

On the other hand, IPC has taken modern technology and matched it with custom built robotics that enable quantitative results within current DOT budgets. This allows the asset owners and DOT to better allocate assets to extend the service life of critical infrastructure assets.

Recently, IPC inspected a small bridge in Florida using BridgeScan™, a tool to determine the condition of aging bridge decks. The larger engineering firm which was awarded the contract to repair the bridge, suspected a problem, but the Department of Transportation did not have enough data to warrant repairs. The data provided by IPC identified several issues which had not even been suspected, and it resulted in more projects for the engineering firm.

This totally proves the fallacy that large engineering firms harbor, that they will lose revenue by giving up billable hours, and using technology instead for inspections.

BridgeScan™ is IPC’s bridge inspection service.

Those who realize the value of technology, are, in fact, able to shore up their earnings because data-driven low-cost drone and robotic inspections invariably reveal hidden problems that lead to more repair projects. The firms can therefore engage their engineers and technical staff on enhanced maintenance work on bridges and enhance profits in totally unanticipated ways. Besides, isn’t it supposed to be about public safety.

President of IPC, Doug Thaler says, “I believe structural health monitoring is good for bridges that have been deemed functionally obsolete and are scheduled for replacement. If issues are bad enough they may need to be monitored daily to insure the health of the structure and the safety of the public.

“Technology today allows us to develop very sophisticated condition assessments. We just need state and federal governments to evaluate and adopt them.”

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