A yearly report on bad bridges by the American Road and Transportation Builders Association (ARTBA) stated that nationwide, over fifty thousand bridges were found to be deficient.
It’s no surprise that our infrastructure is literally falling apart. If you’ve ever taken a short road trip, you’ll notice most bridges and roadways look as though they have been deteriorating for years. It’s not limited to just a few states; it’s a nationwide problem. States that have cold winters being hit the hardest.
Small fixes can make a big difference. Even a fresh coat of paint can help; as rust erodes a bridge and concrete crumbles, the closer the structure comes to needing a complete replacement.
As bridge concrete deteriorates, chunks fall onto stretches of roadway, damaging the surface and cars below. All of this leads to added consumer cost for operating a vehicle, from insurance claims to maintenance. Having lived in Michigan for many years of my life, I can tell you first hand that crumbling roads and bridges cause many problems from vehicle damage and even accidents.
The Federal Highway Administration estimates an annual investment of $20.5 billion is needed over the next 16 years to repair and replace our bridges. On a slightly happier note, the number of bridges needing repair dropped by 2,785 last year.
However, at that pace of improvement, it will be a generation before the last insufficient bridge is addressed. The average lifespan of a highway bridge is 50 to 70 years, with newer bridges that were built to higher standards expected to achieve the latter number.
Why Are Bridges Failing
Another issue which only exacerbates our growing problem of bridge failure is overuse. Fifty years ago when most of our current bridges and overpasses were being built, they were designed for vehicles which weighed an average of 3,200 lbs. However, in 2019 those scales have tipped to nearly 4,000 pounds.
Additionally, as semi-trucks have gotten major boosts in power, they are able to tow significantly more. Now, being able to carry more and having a safer vehicle which may weigh more is not a bad thing. In fact, it helps keep people safer and transportation costs lower. But the fact remains, the bridges built in the 1940s and ’50s were not designed to support an additional 800 pounds per vehicle.
How Safe Are Bridges
One in ten bridges are structurally deficient. This means the bridge has a significant defect that requires reduced weight or speed limits. (It does not necessarily mean the bridge is unsafe.) Another 14 percent of the nation’s 607,380 bridges are considered “functionally obsolete,” meaning they are no longer suited to their current task because of overuse or a lack of safety features.
In 2015, an overpass collapsed on I-75 in Cincinnati, Ohio as it was being dismantled. It remains to be seen if the collapse was due to the age and condition of the span or was an unfortunate demolition accident. Regardless, it emphasizes the risks we face.
More well known was the collapse of the I-35 West Mississippi River Bridge in Minneapolis in 2007. Thirteen people were killed and 145 injured. The bridge was deemed structurally deficient in 1990, though after investigation, the collapse was attributed to a design flaw that was exacerbated by an increase in bridge load over time.
How Do We Fix The Problem
This influx of vehicles, plus shoddy maintenance, has taxed our system to the brink of collapse. There’s no doubt our bridges are in dire need of repair and replacement, but how we tackle that challenge will be paramount in our journey as a country to once again become an innovator in infrastructure design and development.
There have been many ideas recently about how to best attack a problem of this magnitude. While it will come down to individual bridge requirements, some designers are proposing next level multi-use bridge designs, where a bridge would be used as much more than just a way to cross water or treacherous terrain.
Instead, they would act as a part of the landscape, featuring cafes, waterfalls, walking-only levels and high-speed self-driving lanes to increase traffic flow and reduce backups while improving safety.
In 2016 commercial design firm OMA + OLIN won the contract to build Washington D.C.’s 11th Street Bridge which will encompass many of the aspects we’ve talked about. They aim to integrate the Capitol Hill neighborhood with communities east of the Anacostia River.
The goal of the project, spearheaded by project director Scott Kratz, is to re-envision a bridge that, beyond conveying pedestrian traffic, would generate inspiration and human connection. “By following a community-driven and vetted process, the Bridge Park can become a useful example of how the public and private sectors can invest in and create world-class public space in an equitable manner,” Kratz said in a statement last November.
The 11th Street Bridge is not the world’s first multipurpose bridge, that honor goes to China’s Tianjin Eye which features a giant ferris wheel. It’s paving the way for more ingenious designs that can better unify communities.
Bridges Moving Forward
Now is the time to plan for the next fifty years of infrastructure design. Will we be leaders or followers? It’s tough to get people (especially those in government) to make changes quickly so we can adapt for the future. However, if we don’t address our failing bridges and other infrastructure soon, we’ll have a lot more to worry about than vehicle pollution concerns.