Are Canadian Bridges Safe?

The Francis Scott Key Bridge collapse in Baltimore a few months ago raised serious questions about the safety of Canadian bridges in Canadian media. A massive cargo ship struck a minor pier, causing the entire structure to crumble seconds later.

The National Transportation Safety Board (NTSB) is investigating the probable cause. The final report and recommendations will take over a year to complete. Still, the preliminary findings suggest that the ship lost power at the worst possible moment—far too close to the bridge to stop or even steer clear of the pier.

If confirmed, this would represent an extraordinary “black swan event”—a scenario where everything went wrong at the most critical moment.

What Does 'Safe' Even Mean?

Understandably, the public wants reassurance. The thought of driving over a bridge at night and experiencing a sudden collapse is terrifying. But before we attempt to answer if Canadian bridges are “safe,” we must first define what safe means.

Defining Safety in Practical Terms

Safe does not mean risk-free. In the physical world, no activity is entirely free from risk. An accident doesn’t automatically mean that the activity is unsafe. Likewise, an accident-free record doesn’t guarantee safety either.

Safety, therefore, must be measured statistically. Once we understand the likelihood of an event, we can develop risk management strategies to make structures statistically safer.

Perception vs. Reality of Safety

Consider driving:

• Riding a motorcycle is 16 times more likely to result in a serious accident than driving a car.
• Contrarily, commercial air travel is statistically much safer than driving.

But here’s the thing: most of us don’t hesitate to grab our car keys and hit the road daily, while plenty of people still get nervous about boarding a plane.

Why? We don't base our sense of safety on data but on our perception. We judge safety based on our feelings, which sometimes makes us bad at assessing risks appropriately.

However, we must understand that safety is not the absence of risk; it’s the management and reduction of risk to an acceptable level. We must, therefore, judge the safety of an activity or the occurrence of an event on the idea of risk management. This is the best we can do to measure safety objectively.

Bridges and Risk Management

All bridges spanning major waterways are at risk of being struck by ships. In Canada, our bridge codes are conservative, and pier impact governs much of the design philosophy.

What is Structural Robustness?

In modern times, we design our bridges to withstand impact by considering robustness. In engineering terms, robustness refers to a structure's ability to remain stable after an extreme and unexpected event, such as an explosion or a ship impact.

Canadian bridge codes account for these risks but don’t guarantee survival under every scenario—especially with modern cargo ships weighing 150,000 tonnes.

To put it into perspective, a 100,000-tonne cargo ship traveling at standard speed can exert an impact force equivalent to 30 million pounds—roughly the weight of a medium-sized building.

The Economic Balance in Design

Economically, it would be impossible to design a bridge that could resist any potential disaster, though physically, it is not too difficult. Like most things, the money supply is the most significant barrier to possibilities. Why haven't we been back to the moon? There are many reasons, but the primary one is that the US government will not invest the massive budget they once did.

Therefore, in practice, an actual bridge is designed to provide a balance between these two principles:

• Engineering Robustness: Bridge design to increase the ability to survive extreme impacts.
• Economic feasibility: To ensure that the projects remain cost-effective.

Takeaway: Bridge design focuses on achieving structural robustness while maintaining economic balance, guided by probabilistic safety measures.

Windsor Corridor: A Strategic Hotspot

Canada’s most densely populated and economically significant region is the Windsor Corridor, running between Windsor and Québec City. The corridor is home to nearly half of Canada’s population; therefore, the country's industrial, commercial, and transportation activities are assumed to be centered in it.

Geography and Economic Importance

The St. Lawrence River and Great Lakes form Canada's major marine transportation network, connecting the Atlantic Ocean to important inland centers in Montreal, Toronto, and Windsor.

These waterways are desperately needed for transporting raw materials, industrial goods, and exports. Without the St. Lawrence River, Atlantic Canada would most probably have been the industrial heartland of the country instead of Southern Ontario and Quebec.

Network of Bridges Under Pressure

The Windsor Corridor also features Canada's highest concentration of bridges, from grand structures like the Jacques Cartier Bridge to more minor crossings connecting communities across waterways.

This concentration comes with increased exposure to marine traffic risks, including cargo ships, tankers, and freighters that operate under tight schedules and ply narrow waterways daily.

Smaller Connector Bridges

Many bridges in this corridor are older structures designed years ago according to older design codes.

Because many of the vulnerabilities are recognized, many older bridges are currently under retrofitting projects that aim to enhance their robustness and resilience against impacts.

Retrofitting measures include but are not limited to:

• Reinforcing bridge piers and supports.
• Structural members upgrade to present-day design codes.
• An instrumentation upgrade is needed to detect stresses at an early stage.
• Bridge pier impact deflection structures

Although retrofitting is a high-cost and logistically challenging endeavor, it is an investment that must be made to maintain the dependability of these crucial aging structures.

Takeaway: Retrofitting the older bridges is the basic principle to ensure safety and resilience within high-traffic waterways like the Windsor Corridor.

The Verdict: Are Canadian Bridges Safe?

After looking at the data, I will cross any bridge in Canada without any qualms.

Why?

• Strict Protocols for Ships: Ships that navigate the waters in Canada are mandated to follow very high safety rules, much like aviation pilots are supposed to adhere strictly to flight rules.
• Technology and Training: Monitoring systems with advanced technology, float plans, and real-time monitoring have minimized risks.
• Proven Safety Records: Most pier strikes are not catastrophic.

When compared statistically, crossing a Canadian bridge by car, bike, or on foot is considered safe. The likelihood of a bridge collapse is incredibly rare.

Takeaway: While no structure can be risk-free, Canada’s bridges are built and maintained to meet very high safety standards, and the highly trained boat captains piloting our waters.

Final Thoughts

The Francis Scott Key Bridge tragedy is a sobering reminder that anything could happen. Yet, we have to understand that it is a sporadic event—a convergence of failures that were unlikely to begin with coming together at the worst possible moment.

Today's engineering, technological systems, and protocols make our bridges remarkably safe. But absolute safety will always be unattainable—engineering is about managing risks. A larger perspective is worth considering as we reflect upon this bridge tragedy.

Indeed, the probability of being involved in a vehicle accident is magnitudes higher than experiencing a bridge collapse. Compared to the stringent criteria pilots or boat captains adhere to, the acquisition process of a driver's license reveals the shockingly low demand that drivers must meet. Surprisingly, the figures seem to highlight a far more urgent concern—the safety of drivers.

Is it high time that greater attention and resources are dedicated to improving driver training and licensing standards to reduce the depressing statistics associated with road transportation?