The Silent Threat to America’s Bridges: How AI and ‘Portable MRIs’ Are Fighting Back

Nearly 49 billion trips are taken across U.S. bridges every single day. But a hidden danger is growing, one that doesn’t announce itself with dramatic collapses like the Francis Scott Key Bridge – but with a slow, insidious weakening caused by extreme heat. As temperatures climb to record highs, the very foundations of our transportation infrastructure are under unprecedented stress, and a new wave of technology is emerging to meet the challenge.

The Heat is On: Why Bridges Are Increasingly Vulnerable

Unlike the immediate devastation of floods or tornadoes, extreme heat acts as a silent killer, gradually degrading bridges over time. Bridge materials, like steel and concrete, expand and contract with temperature fluctuations. While engineers have accounted for this movement, today’s record-breaking temperatures are pushing these structures beyond their original design limits. “The hotter it gets compared to what typically it is, the more danger you have,” explains Paul Chinowsky, a professor emeritus of civil engineering at the University of Colorado Boulder.

The consequences can range from inconvenient – a swing bridge stuck in the open or closed position due to swollen steel joints, as seen in Chicago in 2018 – to potentially catastrophic. Concrete expansion can lead to cracking, exposing internal metal components to corrosion. The 2022 collapse of a concrete bridge in China and the emergency foil-wrapping of London’s Hammersmith Bridge serve as stark warnings of what can happen when heat overwhelms infrastructure.

A Nation’s Aging Infrastructure: A Perfect Storm

This vulnerability comes at a particularly precarious time. According to a 2025 report by the American Society of Civil Engineers, almost half of the 600,000+ bridges in the U.S. have exceeded their 50-year design lifespan. While many can be maintained for longer, roughly one in three requires significant repair or replacement. The American Road and Transportation Builders Association estimates a $373 billion funding gap over the next decade to address these needs. Heat-induced damage only exacerbates the problem, accelerating deterioration and driving up maintenance costs.

Hussam Mahmoud, a professor at Vanderbilt University, has found that heat is prematurely aging steel-girder bridges, particularly through the accelerated malfunction of expansion joints. These joints, crucial for accommodating movement, are increasingly stressed by frequent expansion and the accumulation of debris. Even minor defects, while not immediately dangerous, require costly repairs and can disrupt commerce, as demonstrated by the recent hours-long closure of a swing bridge in South Carolina, delaying rescue efforts during a boating accident.

Beyond the Hammer Tap: The Rise of AI-Powered Bridge Inspection

Traditional bridge inspections are time-consuming and often require lane closures, creating logistical headaches. Suyun Ham, an engineering professor at the University of Texas at Arlington, recognized these limitations firsthand during his early career. His solution? A mobile, AI-powered scanning system – essentially a “portable MRI” for bridges. This innovative approach promises faster, more frequent, and less disruptive inspections.

Ham’s system, towed by a pickup truck, utilizes a suite of technologies: mechanical wave generation to detect internal flaws, ground-penetrating radar to image subsurface structures, GPS for precise location data, and GoPros to document surface conditions. The data collected is then analyzed using artificial intelligence to identify cracks, voids, and other anomalies. “Just like it is difficult to heal a human patient with stage-four cancer, it’d be too late to repair a bridge when there are a lot of defects,” Ham explains.

From Lab to Field: Refining the Technology and Looking Ahead

The Texas Department of Transportation has already deployed Ham’s technology to inspect dozens of bridges, reporting significant time savings and improved safety for inspectors. However, the system is still evolving. Ham and his team are actively refining the AI algorithms, creating a “manufacturing hub of artificial defects” in their lab to train the system to accurately identify different types of damage. They’re simulating corrosion and cracks to improve the machine’s diagnostic capabilities.

While the current system can’t detect stress caused by heat alone – only the physical damage it creates – the data collected will be invaluable for future bridge design. By analyzing patterns of damage in bridges built with different materials and methods, regulators can develop more heat-resilient infrastructure. The American Society of Civil Engineers’ Infrastructure Report Card provides further insight into the state of U.S. infrastructure and the challenges ahead.

The Future of Infrastructure Monitoring

The work of Ham and others signals a broader shift towards proactive, data-driven infrastructure management. Expect to see increased adoption of AI, machine learning, and advanced sensor technologies in bridge inspection and monitoring. Drones equipped with thermal imaging cameras will likely play a larger role, providing a cost-effective way to identify areas of heat stress. Furthermore, the integration of real-time data from these systems with predictive analytics could allow for preventative maintenance, minimizing disruptions and extending the lifespan of our bridges.

The challenge isn’t just technological; it’s also financial and logistical. Scaling up these technologies requires significant investment and collaboration between government agencies, research institutions, and the private sector. But the cost of inaction – the potential for catastrophic failures and economic disruption – is far greater. What are your predictions for the future of bridge infrastructure and the role of AI in ensuring its safety and resilience? Share your thoughts in the comments below!