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Comment by donkeyd | Hacker News Reader

This seems like an easy excuse for what happened here. If you can't maintain those 450 bridges, then don't keep 450 bridges. Remove 150 of them and maintain the other 300. You can't just ignore 450 bridges and hope nothing goes wrong because you can't afford to maintain 450 bridges.

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Oh yeah, just knocking down 150 bridges is a very easy decision that's going to go over extremely well with the local population, certainly not political suicide as well as a massive, expensive project in its own right. It's not like all those bridges existed for good reason, and just getting rid of them wouldn't have massive impact on an extremely large number of things about the city.

They absolutely need better maintenance. It's been a safety hazard for most of my life. But the solutions are not easy.

> Oh yeah, just knocking down 150 bridges is a very easy decision that's going to go over extremely well with the local population, certainly not political suicide as well as a massive, expensive project in its own right.

I knew this response was coming. However, doing nothing isn’t an option. I also never said it’d be easy. If you can’t afford 450 bridges, you need less bridges or more money. You can’t just ignore the problem.

It turns out not only is not doing anything an option, it’s the option that has been selected.

I'm amused that people are willing to contextualize this bridge failure within what is essentially the entire 20th century economic history of Pittsburgh; and then act like that history somehow excuses the complete failure of local governments over that same time period to either repair or eliminate unsafe infrastructure. It's honestly nothing short of absurd.

No one is honestly expecting the local governments throughout the Pittsburgh metropolitan area to eliminate 150 bridges (or some other arbitrarily large number) by 2023... They expected the local governments (and the state and federal governments) to behave competently and never let it get to this point. The decline of Pittsburgh as an industrial hub started over half a century ago... They've had plenty of time to address things like this in that context.

The fact that keeping infrastructure safe is "political suicide" or "costs too much money" is essentially the entire problem - and it's a problem that is not at all unique to Pittsburgh.

One can wish that the city spent less time and money building new sports stadiums, spent more time and money investing in infrastructure, yet still acknowledge that the political reality on the ground makes doing so hard to near-impossible.

I guess for me, the fact that the political reality makes infrastructure "hard" is profoundly obvious... And, while the specific details may change with the city, that reality is quite common throughout the US (even the relatively specific economic conditions discussed earlier in the context of Pittsburgh are not really that unique)...

Pretending like this type of infrastructure decline is somehow unique to Pittsburgh, which, at least implicitly, the top level comment does, does a great disservice to actually finding solutions to the problems with that "political reality on the ground" - and not just in Pittsburgh.

That's fair. I do also agree that it seems obvious, but given the number of the people in this thread and elsewhere suggesting that fixing it would just simply be so easy, it doesn't seem like that's the case for many others.

I didn't read the OP as saying "nowhere else has infrastructure problems" but "bridges are a particularly acute problem in Pittsburgh for these reasons." I would certainly agree that suggesting this kind of issue is unique to Pittsburgh would be misguided.

That's also fair. I think my initial reading of the top comment, and some of the replies, was overly assumptive; and my take on the nature of the cause was a direct result of my already pessimistic view of contemporary American political structures.

> The fact that keeping infrastructure safe is "political suicide"

Is this a good reason why politics should always include term limits? It would prevent anyone from NOT doing something that is in the good for the constituents, but is seen as "political suicide". Since no one can be in politics long term, you might as well make the tough decisions.

>"However, doing nothing isn’t an option."

Cynically, it actually is for a cash strapped municipality. If they lack the money for proper maintenance - but can afford the bare minimum amount of caretaking - they certainly cannot afford the cost to dismantle the bridge. They will go with bandaid solutions virtually every single time.

There's no need to dismantle, it can just be closed if it's deemed unsafe.

This particular bridge's condition was rated as poor but not unsafe.

And then get screwed with lawsuit costs and payouts. But that's a can they can kick down the road.

Yes, it is something that should be done, and yes, it won't be easy. Your comment reflected absolutely none of that, and even was arguing against me saying that it would be extremely difficult, so it did in fact seem like you were saying that this is a simple fix. Heck, you didn't even say "figure out how many bridges you can afford," but simply "remove 150 of them."

I think the other option is to just restrict the weight limit on these and change bus routes.

There is a lot to be learned from this. It’s contemporary to talk about the boom/bust cycles of fracking towns out west. Building a bridge or a nuclear power station is a much bigger commitment than simply building the structure and getting it operational. It outlasts political memory.

I lived in Pittsburgh and remember one way bridges (like a fast path for morning rush hour, but screw getting home) and lots of sort of ad hoc things. They never had a fire wipe the place out and allow for some replanning or long term planning. Worse, if you were to try to knock some things down, there is a huge emotional reaction to it (the out field walls to Forbes field are still there, two stadiums later) I remember the city tax being fairly high as well, in many places I think increased mass transit (usually costs taxes) plus some tolls or something to discourage use on some bridges (read: another tax to use the bridge you were taxed to build) would make sense. Probably a federal bail out or mass closing of bridges are the only options. You are right, it’s not easy.

Pittsburgh itself has actually knocked down quite a few bridges over the last 30 years. The suburbs have not as they just run out of money.

I'm from up route 28 before I moved into the city, PennDOT certainly is always doing quite a bit of work. 100% agree that there's been changes to bridges over the years. But nothing on the scale of "knock down a third of the bridges with no replacement."

I agree, I haven't lived in the 'Burgh for a long time, but its geography is basically, lots of little hills and a few big ones. Everywhere you look, you are staring at a hill. And you are on a hill. Plus rivers. A lot of bridges (and tunnels) are needed out there for basic navigation.

It could well be better to knock some down in an organized way. If the alternative is to have committees and referendums and posturing until nature decides which ones to take.

The devil is in the details. What's "an organized way" if not "committees and referendums"? Even just the traffic impact studies alone to figure out what would happen when taking out each bridge, let alone that very often they'd impact each other and so you'd also need to figure out what happens with traffic for combinations of bridges, seems like a daunting and expensive task to me.

Phase it. You don't have to nominate every bridge and start simultaneously. Like you say. Choose a few, remove those, then re-evaluate what traffic looks like now.

I wouldn't expect anyone, even the OP, to suggest undertaking 150 demolitions simultaneously.

That still doesn't help you decide which bridges.

When you go to Pittsburgh for the first time, you will learn that the city has 450 bridges because they're necessary, and you can't just go eliminating a third of them

They can, in fact, maintain the bridges. You might not know this from a brief look at a newspaper article.

What happened is that the bus was too heavy for the bridge. It's PennDOT's fault.

Look up the weight of a bus. Look up the average weight of an American. Look up PennDOT rider numbers. Do the math. They were three tons over on a 26 ton limit.

"Three‐axle 60‐ft articulated buses are the next most common transit bus in service [in the USA], comprising about 10% of the fleet. The curb weights for these buses currently range between approximately 38,000 and 50,000 pounds, and fully‐loaded weights range from approximately 56,000 to 65,000 pounds." (page iii)[1]

Fully loaded weights for 3-axle US buses from the linked report's executive summary are 28 to 32.5 tons, empty range from 19 to 25 tons. So a not-fully loaded 3-axle bus was very likely over the 26 ton limit.

Three axle buses should not have been on that bridge. Would be interesting to see if that route was changed recently from 2-axle to 3-axle service.

[1] https://onlinepubs.trb.org/onlinepubs/tcrp/docs/TCRPJ-11Task...

From the Post-Gazette article there was a driver and two passengers on the bus, so it might not have been over limit this time but sounds like it would have been at other times on that route.

https://www.post-gazette.com/local/city/2022/01/28/pittsburg...

I used to walk under that bridge quite a bit, hopefully no one was under it when it collapsed (it doesn't sound like they suspect there was, but I guess it could potentially be hard to tell).

oh wow, i hadn't even noticed that it was a three axle

i've been making this argument on skepticism that a two axle bus should have been on that bridge. the standard patransit two axle fleet bus, a cummins isl (which is more than half their fleet) is 2 tons shy of max load when empty, and average american weight breaks load at bus half full.

that's the 61b. when i lived in pittsburgh it was often packed to the gills. i have a hard time imagining that that has changed.

you're right. if it was a 3 axle, that's very significant. hell, an empty three axle (i think they use man sg 220 gawr, which is ~30 tons curb weight) would likely be too much. i'm glad you pointed this out; thank you.

> i have a hard time imagining that that has changed.

Fun trivia, https://www.portauthority.org/system-map/ shows stats on this. It doesn't support deep linking, but I went to the outbound stop just after the bridge, and it says

In FY2021:

Average Weekday Ons: 0.32

Average Weekday Offs: 5.1

Pre-pandemic ridership for CY2019:

Average Weekday Ons: 1.00

Average Weekday Offs: 37.00

It has dropped by quite a bit since the pandemic. The 61A has a daily ridership of 1,643 and the 61B has 1,312.

those are indeed much lower numbers than i had expected

that said, the other person pointing out that it's a three axle bus makes me relatively confident that the fleet contains no domain-relevant busses that had any business going over that bridge in the first place

it's worth noting that when i was growing up, patransit tried to send heavy construction trucks across the larimer bridge. one of the crew members stopped them at the last minute when they saw the bridge and called it in (this is way before pocket internet,) and good thing - basically this would have happened, and in that case, it's a probably five or so story drop onto an active highway. would have been a catastrophe.

What was the limit when the bridge was new?

The limit has been 26 tons for almost 20 years now.

I don't know what the limit was originally, but PATransit should be able to accomodate bridge limits within two decades.

So, what do you propose? Knocking them down? Put fences? Which are you going to do that on? Are you going to fend off all the people using those bridges for destroying their commute? None of those options are cheap either. Even selecting the bridges to keep/not keep takes time and effort and thus money.

In the town where I’m from in Germany, exactly this happened: a major bridge was unsafe - one of two major roads leading to the crossing of the river rhine. It was closed and torn down, replacement will take a few years. In Berlin, one major river crossing was closed because it was unsafe, then torn down and replaced. Another was severely impacted and partially closed, it’s now replaced with a temporary bridge. Full replacement is expected in a decade or so. People adapt. Life goes on. It’s better than having the bridge collapse with people on it.

This very thing occurred in PGH with the Greenfield Bridge[0]. This caused significant disruption because the bridge spans a major highway to the eastern suburbs. Of course, the infrastructure issues with that bridge were rather obvious, since chunks of concrete would fall on to the highway (necessitating netting to be installed).

[0] http://greenfieldbridge.otmapgh.org/

Anything is better than people on a collapsing bridge, obviously. But you can only fence it off when you know its too bad. Checking that can be very expensive. So if you just don't know which of 450 bridges are bad, what do you do? Fence them all of and spark at least outrage? Safest option. Finding out what to do is already expensive

You can start off with warning signs. I doubt bridges would collapse if pedestrians or bicyclists use them but sings could fend traffic off.

Second, the size of the vehicle is important. Larger vehicles like trucks get these poor bridges lifespan shortened drastically. Trucks and busses could be rerouted on safe bridges and so on.

I generally am not afraid of bridges because they have convinced me that they're safe but if a bridge were to collapse under me and I'd make it out alive I'd probably have a bridge phobia.

Here's a tweet with a picture from December of 2018 of the bridge that collapsed today, showing a large steel beam rusted completely through.

So you could start with the lowest hanging fruit, the bridges that are in such bad condition that people post pictures of them on Twitter.

Here's the tweet you were referring to, I think: https://twitter.com/gpk320/status/1078885655634157569

How did people in that town pay for tearing down and replacing the bridge?

The problem Pittsburgh encounters is even demolition costs money. Can't squeeze blood from a stone.

The solutions are easier in a growing city than a declining one.

I know of a relatively small bridge in rural Ohio that simply has barriers placed in front of it. It's still walkable.

They did the same with an old wooden bridge near where I grew up. In the early 80s, you could still drive across it. Later they closed it and barricaded it. Eventually in the 2000s, they preserved it and built a park around it.

Of course, this bridge only carried about 10 cars a day, mostly as a novelty, prior to closing. It's an entirely different animal to close a bridge in a major city.

> It's an entirely different animal to close a bridge in a major city.

Minneapolis/St. Paul managed to adapt when the busiest bridge in the state collapsed.

I know of a couple of medium-sized bridges in upstate NY that have completely collapsed and the state has just abandoned them, with some barriers thrown in front and that's it. Funnily enough they still show up as routes on Google Maps, but OSM has them removed. I decided to leave it as is to fight the Google mapping monopoly power.

They could install micro-tolls ie ezpass and charge everyone a use fee.

Make some free. Let the communities who need them pay for them.

Some unsafe bridges have in fact been closed. Fetterman has a campaign video from 2016 of him driving around to several of them. https://twitter.com/JohnFetterman/status/1487099733978095622

Pittsburgh lost over half of it's population over a 40 year stretch starting in the 70s. Blaming them in the past for not being able to tell the future doesn't make a lot of sense.

When they built these bridges, it probably seemed pretty reasonable

If you can't afford to maintain them, how are you going to afford to remove them?

Can the value of the scrap pay for the cost of removal?

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