Technology in Bridge Inspection Can Extend Lifespan

A nation’s treasure is buoyed by the existence of healthy infrastructure. On the flip side, a bridge collapse is a monstrous and unjustifiable loss of national treasure, apart from the ensuing loss of innocent lives and unwarranted loss of property.

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 said new Nondestructive Evaluation technologies “increasingly are sought to solve difficult inspection challenges that are beyond the capability of normal visual inspections.”

Very often, technology is bypassed in the crucial task of bridge inspections, and archaic inspection methods still hold sway. The result can only be a disaster waiting to happen.

And disasters do happen with no notice.

The latest collapse of a bridge that received global attention, was a 200-meter stretch of a highway bridge in Genoa, Italy, which gave way during a violent storm on August 14, 2018, killing 38 people, injuring at least 15 others, and rendering 10-20 more people missing, while destroying 35 cars and a number of trucks, which dropped 45 meters to the railway below. Subsequent investigations into the disaster exposed severe under-spending on aging infrastructure over the years, even though heavy tolls were collected from road users.

US is Different

US authorities are spending colossal budgets every year, on inspection, repair and maintenance of aging bridges, but with little result.

Despite gobbling down precious tax payer dollars, many bridges continue to be in a state of grave deterioration. Red flags are rustling urgently, even as maintenance work gets done. The primary problem is inaccurate diagnoses and insufficient data of bridge conditions obtained from obsolete inspection methods. And it is self-explanatory, that unless a correct diagnosis is made, the cure is not going to be effective, whatever the money spent on repair and maintenance.


“This begs the question, when preventive maintenance is lighter on the nation’s purse than replacing parts of bridges, why isn’t more care given to the process of maintenance, which starts with bridge inspection?”


What appears to be the problem is the lack of a cohesive approach among USDOT senior officials in the different states, in responding to the brewing crisis in the bridge inspection industry.

Some, like the Bridge Inspection DOT Lead in South Dakota, Chief Bridge Engineer Steve Johnson, says, “We are always looking to incorporate new technology into bridge inspections, whether it is Nondestructive Testing, or using new technology.” His assertiveness is significant. “In our state, the inspectors I am familiar with, they really like to use the latest technology,” he adds. “They are always suggesting new technology so yes, they like to use new technology, absolutely.”

On the other hand, Justin Bruner, Chief, Bridge Asset Management Section, Pennsylvania DOT, said, “We are only interested in using technology when it is appropriate. On the larger structures, it makes a lot of sense.”

Technology in Inspection

To counter the current muddled situation, small firms such as Florida-based Infrastructure Preservation Corporation, have introduced modern technologies utilizing customized robotics and drones.

Robotics are able to detect issues early in the infrastructure lifecycle. 

Asset owners, therefore, are able to carry out repairs early, extending the service life of the structure and saving billions in untimely replacements. The same inspections that are currently being done manually, can be done with greater accuracy, and with quantitative results, by using modern technology and robotics.

IPC engages nondestructive technology (NDT) in robotic systems that are able to identify deterioration in concrete and other structural material at the initial stages.

With the results it receives, IPC is able to provide an action plan for repairs before deterioration spreads and compromises the safety of bridges.

Material deterioration, fatigue, vibrations, foundation integrity issues, design flaws and consistent loads and overloads on bridges weaken their serviceability and lifespan. Extreme weather conditions add to the problem. Intense heat can warp concrete and steel while salting of bridges in harsh winters will corrode steel. Conventional technologies can only expose these problems when they are apparent to the naked eye, which is too late to prevent a disaster.

Robotic devices are able to provide precise quantitative data for an entire bridge, not just for sections of it. And the data provided is decisive enough to expose any problem minutely. It clues in on anything irregular, even before the issue becomes a problem.

Empowering Inspectors

This is where the knowledge and years of experience of bridge inspectors, can make a difference. Accurate data provides the opportunity for inspectors to make real-time assessments, identifying exact locations and sizes of irregularities. Armed with their skills and expertise, inspectors are able to analyze the information received and decide how to proceed with repair and maintenance.

When I interviewed the president of Infrastructure Preservation Corporation, Doug Thaler as to why technology like this has not been adopted for bridge inspection globally, his response was, “With the condition of infrastructures worldwide, it is only a matter of time.”

Thaler explains that modern technology and robotics provide more quantitative data for less money and exceed requirements of Federal Highway Administration (FHWA) and American Association of State Highway and Transportation Officials (AASHTO), the two agencies that set the standards for these inspections.

“Typically, and unfortunately change only takes place after a catastrophe,” he says. “After the I-35 collapse of 2007 in the US, new regulations were released. You will see the same in Italy after the recent collapse.”

With inspections done the same way for over 50 years by a handful of companies, it’s about time to let fresh air in.

Says Thaler, “The asset owners themselves need to be at the forefront of legislating the changes. Also, local heads of USDOT districts have the authority to pull any work away from current asset managers in the interests of the public. Those who don’t want a catastrophe striking on their watch, will start exerting their authority before it’s too late.”

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