Fern Hollow Bridge should have been closed years before it collapsed

For context, there were 42,391 structurally deficient bridges in 2023.[0]

16 of the worst are in LA county and several see 300k trips daily, including one carrying the 405.[1]

0. PDF https://artbabridgereport.org/reports/2023-ARTBA-Bridge-Repo...

1. https://artbabridgereport.org/state/ranking/top-bridges

EDIT: States with the least % of SD bridges: AZ, NV, TX, DE, and UT.

WV and IA have the most at almost 20% SD bridges respectively. (1 in 5!)

EDIT2: Raw data https://www.fhwa.dot.gov/bridge/nbi/ascii.cfm

Same stuff for the Genoa, Italy bridge (Ponte Morandi). Everyone running on that would feel vibrations and "repairs" were just lipstick on a ugly face, until it finally collapsed, with 43 dead.

Surprisingly, or not so, no one was found guilty, not even the inspectors that didn't report the ongoing damages, just because "it would be too costly to rebuild it, and profits of the highway company (1) in charge of it would be zero".

(1) the company name is Atlantia, fully owned at the time by the Benetton family, yes those of the sweater chain

Many western countries in general do not care for routine maintenance of infrastructure / buildings / water lines / busses.

Norway has to be among the worst.

It is not fun and glorious for a political administration to set aside $$$$ every year that will just go to people doing boring work that the voters will not be impressed with.

You dont see politicians "Under my administration we painted XX buildings, we did need maintenance of YY bridges, we replaced ZZ parts of the railway that would become problematic with time.

Rather: "Under my administration we opened up a new large hospital (because the other had near 0 maintannce for decades), we built 2 new bridges etc"

If you knew all this, would you have avoided driving over the bridge? Would you have wanted the local government to close it indefinitely awaiting repairs?

Let's say it would collapse with 100% certainty randomly in the next three years, and you're in the danger area for 2 minutes, with a 20% chance of fatality (in fact, nobody died). That's still around a one in 4 million chance any given trip kills you, about the same as 30 miles of driving for the average American driver.

Most people would accept that level of risk. Perhaps not to save a couple of minutes on the journey, but if everyone was redirected to another route at rush hour, it might cost each commuter 10-20 minutes.

A handful of newsworthy bridge collapses per decade across the US doesn't seem so bad. Instead of negligence, perhaps that indicates an appropriate level of maintenance and risk tolerance, and an appropriate human price to add to the 500,000 other road deaths over the same period.

For those interested in the official NTSB report:

Collapse of the Fern Hollow Bridge Pittsburgh, Pennsylvania January 28, 2022

Highway Investigation Report HIR-24-02 released: February 21, 2024

PDF (136 pages): https://www.ntsb.gov/investigations/AccidentReports/Reports/...

Predictions and pre vs post accident is an interesting subject.

Which bridge that is currently in operation should be closed next?

(Not a dunk on the article, which brilliantly addresses the difficulty of knowing in advance vs making real world changes. Practical Engineering is an awesome YouTube channel!)

It really is supremely fortunate that the collapse took place in the early morning when few people were about. I've walked under that bridge many times, it's a lovely recreational footpath through the heart of Frick Park, and more than once I've clambered up the hillside under the bridge for fun.

An interesting takeaway is that a simple task like cleaning the drainage grates and preventing them from being clogged probably would have saved the bridge. The bridge has a prescribed drainage path, and with the grates clogged the water drains and pools in other places, accelerating the corrosion.

I used to walk across this bridge every day. You could feel whole bridge shake when heavy vehicles would drive over it (Lived in Reagent Square 2017 - 2019). I remember one morning I was trapped on the bridge for an hour in traffic on my drive to school because the city of Pittsburgh could not afford to keep the roads plowed.

Very thankful that nobody was hurt when it collapsed, and as other people have pointed out it is representative of all of the infrastructure that many cities have but can no longer afford to maintain or replace.

This is why I think nuclear power is a bad idea. Paying back a multibillion dollar investment takes decades. Operating costs eat into profits. The financial incentive is to run them as cheaply as possible for as long as possible. In a place where there’s a strong work ethic and good maintenance history that might be fine. Look around at your infrastructure before climbing on the nuclear bandwagon.

> No one holds a press conference and cuts a big ribbon at the end of a bridge inspection or structural retrofit.

maybe they should. maybe we could celebrate repair like we do new construction. there’s a comfort in knowing we’ve been put good again that’s worth signifying.

Not an engineer, found the video on this fascinating and very approachable. It sounds like the NTSB report did a surprisingly good job of addressing the multiple mistakes and failures that led to the bridge collapse.

But to the bigger point made near the end, without a person in the loop who both appreciates the meaning held within the inspection reports AND having the power to act on that information, we still remain vulnerable to the complexity of our own social systems becoming too inefficient to handle problems like this.

To prevent this from happening in the future, I would give the inspectors the right to immediately close a bridge when it got to be this bad. If the owner forcibly reopened it, they would lose any insurance coverage on it (be totally liable for consequences).

This is all interesting, but misses the point: the bridge collapsed due to a social (management, responsibilities, organization, ...) failure. Investigating the engineering story distracts from that, both in the video and apparently effectively as there is a NTSB investigation and not mentioning if any organizational review if the same rigor.

The article goes incoherent in the first paragraph:

"...collapsed without warning. ...And this bridge had been listed as being in ‘poor condition’ for over a decade. "

I just spent the last 4 years living in a series of countries that Americans would call ‘3rd world’. Places where proper funding of infrastructure, let alone inspections are so far below US metrics of adequate, they’d legitimately scare you.

Bridges and overpasses that exist until they break and the people die. People call out to God for justice! But all that infra is then rebuilt the same way if it’s rebuilt / when it’s rebuilt.

Something something American tech people have forgotten just how amazing the US is because they don’t realize how good it is. They take too much for granted. They have the safety to be snarky on the internet.

Get a passport and go for a walk.