Aging Bridge Infrastructure: Maintenance, Material Selection and Performance

Bridges continue to be a vital part of U.S. infrastructure, enabling the ongoing flow of people, goods and services across the country. However, many of these structures were designed for traffic volumes, load demands and environmental conditions that no longer reflect current realities.  

As usage intensifies and infrastructure ages, the limitations of a repair-after-failure strategy become clear. A more effective path forward requires a proactive mindset: one that prioritizes routine maintenance, strategic preservation and long-term planning. Shifting to an ongoing maintenance approach can help extend the service life of bridges and improve the productivity of public investments.  

The Reality of Aging Bridge Infrastructure in the United States

In a 2025 study, the American Society of Civil Engineers (ASCE) notes that a significant portion of the nation’s bridge inventory was designed and constructed under assumptions that no longer align with present-day demands (2025 Report Card). Traffic volumes have increased, freight loads are heavier and design standards from the past did not anticipate the cumulative stress imposed by modern logistics networks.  

Simultaneously, environmental conditions have become more variable. Greater exposure to evolving weather conditions, moisture, chemicals and severe weather events has accelerated wear patterns on bridges that were once considered gradual and manageable. 

Along with these combined pressures, there are a variety of additional pitfalls:

• Corrosion, fatigue and material breakdown are active issues that require continuous monitoring and intervention.  
• Even with well-structured maintenance programs, unplanned events such as extreme weather and vessel or vehicle impacts remain ongoing risks.  

Adding to these challenges is a history of underinvestment, which has delayed essential maintenance and allowed minor issues to progress into more complex and costly problems. As a result, many bridge-owning agencies are balancing rehabilitation needs with limited budgets and rising public expectations for reliability and safety. 

In the2025 Report Card for America’s Infrastructure, bridges received an overall C rating because 49.1% were in “fair” condition, exceeding the 44.1% in “good” condition (ASCE, 2025). While the lifespan of bridges varies widely based on materials and maintenance, the average age of bridges across the U.S. is 47 years, and many were originally designed for 50-year spans. Therefore, addressing these realities requires disciplined approach to long-term planning.

As Bridges in good and fair condition keep aging, two outcomes are possible:

• a. Bridges continue to age, leading to further degradation and replacement. 
• b. Bridges are proactively maintained and repaired for longevity. 

Option a. is simple and cost-free in the short term, yet vastly more costly in the long run, while option b. offers a valuable opportunity because maintaining bridges is less expensive than repairing or replacing bridges in poor condition. 

It is important to recognize that material selection matters as bridges age. The American Iron and Steel Institute (AISI) notes that the “structural advantages of using steel include its high strength, durability and light weight, which mean lighter foundations and lower erection costs. Steel’s strength also makes it highly resistant to extreme natural disasters, such as earthquakes” (AISI Steel Bridges, 2026). Their study found that in studies of California earthquakes that destroyed transportation infrastructure, 96% of steel bridges were completely undamaged, including those over 50 years old. 

Why Preventive Bridge Maintenance Matters

A preventive approach to bridge maintenance is fundamentally more cost-effective than reacting to issues as they occur. When deterioration is addressed early, agencies can preserve structural integrity and avoid the far higher costs associated with emergency response or full replacement.  

Preservation strategies, including routine inspections, targeted repairs and protective treatments, slow the progression of damage, allowing bridges to remain in service longer with fewer disruptions. Similarly, well-timed rehabilitation efforts can restore performance and capacity without the need for complete reconstruction, which carries significantly greater financial and operational impact. 

Additional benefits of preventive maintenance:

• Ability to plan for budget cycles, labor availability and traffic management 
• Maintain safety standards for drivers, passengers and pedestrians using bridges and walkways 
• Predictable cycles of inspection and repairs with reduced probability of failure or emergencies help with risk management and budgeting 

These strategies are most effective when they are integrated into a broader lifecycle approach. Measures such as corrosion protection, deck replacement and structural reinforcement can be implemented incrementally to maintain performance over time, while bridge material upgrades can further enhance durability and reduce future maintenance demands.  

Early decisions regarding design and materials will significantly influence a bridge’s long-term management and resilience. 

Material Selection and Lifecycle Value in Bridge Construction

Choosing materials is a key decision in bridge design, affecting initial construction costs as well as ongoing maintenance, repairs and longevity. A lifecycle-focused approach evaluates how materials perform under real-world conditions by balancing durability, adaptability and long-term investment value rather than prioritizing upfront cost alone. 

Here are five important factors to consider when planning for long-term performance: 

1. Lifecycle Cost vs. Initial Cost

Lower initial costs can be attractive during procurement, but they often shift the financial burden downstream in the form of more frequent repairs, accelerated deterioration or earlier replacement. For example, selecting materials like steel beams and steel plates that support longer service intervals and more predictable maintenance cycles enables a more disciplined capital planning strategy. By investing in durability and performance at the outset, agencies can reduce the likelihood of emergency repairs, limit disruptions to the traveling public and better stabilize long-term budgets.

Helpful resource: The National Steel Bridge Alliance (NSBA), a division of the AISC, offers design and technical resources for steel bridge construction.

2. Speed Repair and Reduced Disruption

Maintenance and rehabilitation are technical challenges as well as operational obstacles for roadways. Steel repairs can often be staged and executed in phases, reducing the need for extended closures and allowing bridges to remain operational during rehabilitation periods. For high-traffic corridors and critical infrastructure routes, minimizing downtime is a significant advantage. It aids from a logistical standpoint and reduces the broader economic impact on the surrounding communities associated with restricted access or detours.

What does this look like in action?

Time was of the essence when a massive mudslide caused the original concrete Pfeiffer Canyon Bridge in California to collapse. Caltrans knew they needed a long-term solution, so they designed a single-span steel plate girder bridge spanning 315 feet, with three 14-foot-deep steel I-girders, eliminating structural vulnerability to future landslides.

Within just three days of receiving an order for 800 tons of steel plate, Nucor shipped the materials, and the custom steel bridge was opened to the public in eight months, significantly ahead of the estimated timeline of nearly eight years.

Learn more about the steel that made it happen: see the case study.

3. Reparability vs. Replacement

Equally important is how a structure can be maintained over time. Steel bridge architecture offers a high degree of repairability, enabling targeted, efficient interventions as conditions change. Individual components can be reinforced, plated, welded or selectively replaced without requiring large-scale reconstruction compared to bridges primarily made of concrete and timber. This incremental approach allows owners to address issues as they arise, extending the life of the structure while avoiding the cost and complexity of full replacement. 

A fast fix for long-lasting durability: steel repairs on the Big Mac Bridge

The Daniel Carter Beard Bridge (also called the “Big Mac” Bridge for its golden arches) was originally built in the 1970s and connects Cincinnati, OH and Newport, KY on I-471 over the Ohio River. In November 2024, a fire caused significant damage to the steel superstructure and deck, requiring girder and deck replacement, with initial estimates putting the repair and reopening at 8 months.  

However, the Ohio DOT knew this project would have a major impact on traffic patterns, so they worked with a local emergency fabricator, Stupp Bridge, that partners with material manufacturers to procure supplies faster. Because of their prior work with Nucor Steel Brandenburg, Stupp requested that they proactively roll Grade 50 slab, and Nucor prioritized the order, recognizing that it was an emergency situation for major bridge repairs. 

Due to these partnerships, the first steel girder was delivered to the jobsite in less than two months (which often takes a year on typical construction timelines), and the bridge reopened to the public just 100 days after the initial incident.  

Read the full article in Modern Steel Construction.

4. Adaptability for Future Demands

Long-term performance also depends on a structure’s ability to adapt. Over time, bridges need to accommodate varying traffic volumes, freight loads and updated design standards. Steel structures can be modified or strengthened to meet these evolving demands, whether through section reinforcement, system upgrades or road widening efforts. This adaptability allows owners to extend the functional life of existing assets rather than replacing them entirely, preserving prior investment while responding to future needs.

5. Sustainability Considerations

Sustainability factors further emphasize the importance of choosing materials carefully. Steel is fully recyclable without loss of quality, and Nucor uses electric arc furnace (EAF) technology, a circular steelmaking process, to produce low-embodied carbon steel. 

Additionally, the ability to repair and extend the life of a structure reduces the need for new material production, lowering overall resource consumption and embodied carbon over time. In this context, sustainability is not limited to how a material is produced but also to how effectively it supports long-term use, maintenance and reuse over its life cycle. 

Discover the circularity story of the Goethals Bridge, where the original steel truss bridge was demolished and recycled into new EAF steel to be made into future bridges and other infrastructure. 

Overall, these factors indicate that material selection is not simply a design choice; it reflects a long-term approach to infrastructure investment and supporting a circular economy. 

How to Extend the Life of Steel Bridges

Lengthening the service life of bridges requires a targeted, performance-driven approach. With the right strategies, many structures can continue to operate safely and efficiently. 

According to the American Road and Transportation Builders Association, “1 in 3 U.S. bridges needs repair or replacement” (ARTBA Bridge Report, 2025). One of the most effective approaches is targeted structural rehabilitation. Rather than replacing entire structures, engineers can address specific areas of concern, such as reinforcing members, repairing localized damage or replacing aging components that no longer meet performance requirements. This method allows owners to preserve much of the original structure while restoring strength and reliability where needed most. In many cases, strengthening existing members can also increase load capacity, enabling bridges to accommodate heavier traffic and evolving usage without full reconstruction. 

Material upgrades play a key role in this process. Replacing or supplementing existing elements with modern, high-performance materials allows structures to meet current standards while improving long-term durability. 

• High-performance structural steels, such as ASTM A709 HPS50W and HPS70W steel plate, are designed to provide enhanced strength and better overall performance in demanding environments.  
• Incorporating high-strength low-alloy steel into new projects or rehabilitation efforts can extend service life while reducing future maintenance requirements.