AARoads Forum

National Boards => Bridges => Topic started by: davewiecking on January 28, 2022, 08:15:02 AM

Title: Forbes Avenue Pittsburgh bridge collapse
Post by: davewiecking on January 28, 2022, 08:15:02 AM
At about 6:50 AM today. https://www.post-gazette.com/local/city/2022/01/28/pittsburgh-bridge-collapse-forbes-braddock-avenue-point-breeze-squirrel-hill/stories/202201280075

https://www.google.com/maps/@40.4395152,-79.8993553,401m/data=!3m1!1e3
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: bwana39 on January 28, 2022, 09:41:55 AM
The ironies are many.

Biden is coming to Pittsburgh TODAY to discuss infrastructure.

It collapsed during a low traffic time period.

The bus only had a driver and two passengers.

The realquestion we should ask is WHY did it fail?
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: DeaconG on January 28, 2022, 09:56:54 AM
At about 6:50 AM today. https://www.post-gazette.com/local/city/2022/01/28/pittsburgh-bridge-collapse-forbes-braddock-avenue-point-breeze-squirrel-hill/stories/202201280075

https://www.google.com/maps/@40.4395152,-79.8993553,401m/data=!3m1!1e3

You're the first posting that even bothered to name the bridge or the area, I spent 5 minutes on CNN trying to figure out where the hell it was-then said "never mind, AA Roads is on it" and you were on point!
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: 1995hoo on January 28, 2022, 10:07:25 AM
At about 6:50 AM today. https://www.post-gazette.com/local/city/2022/01/28/pittsburgh-bridge-collapse-forbes-braddock-avenue-point-breeze-squirrel-hill/stories/202201280075

https://www.google.com/maps/@40.4395152,-79.8993553,401m/data=!3m1!1e3

You're the first posting that even bothered to name the bridge or the area, I spent 5 minutes on CNN trying to figure out where the hell it was-then said "never mind, AA Roads is on it" and you were on point!

Heh, I was getting annoyed at CNN for not saying anything more than "near Frick Park," so I looked at Google Maps, found the park, and turned on the traffic display. That made it pretty clear where it had to be. I wonder why they wouldn't say which street—desire not to cause spectators to congregate, maybe?
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: jmacswimmer on January 28, 2022, 10:18:35 AM
At about 6:50 AM today. https://www.post-gazette.com/local/city/2022/01/28/pittsburgh-bridge-collapse-forbes-braddock-avenue-point-breeze-squirrel-hill/stories/202201280075

https://www.google.com/maps/@40.4395152,-79.8993553,401m/data=!3m1!1e3

You're the first posting that even bothered to name the bridge or the area, I spent 5 minutes on CNN trying to figure out where the hell it was-then said "never mind, AA Roads is on it" and you were on point!

Heh, I was getting annoyed at CNN for not saying anything more than "near Frick Park," so I looked at Google Maps, found the park, and turned on the traffic display. That made it pretty clear where it had to be. I wonder why they wouldn't say which street—desire not to cause spectators to congregate, maybe?

I pinpointed it using the exact same method.

I also saw a tweet mentioning the area smelled like natural gas post-collapse, so yes they probably do want to keep as many people away as possible.

Besides Forbes Ave over the bridge itself, Google is indicating Braddock Ave is closed as well between PA 8 & I-376.

?ref_src=twsrc%5Egoogle%7Ctwcamp%5Eserp%7Ctwgr%5Etweet
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: Roadgeekteen on January 28, 2022, 10:20:22 AM
Perfect opportunity for Biden to hammer home the importance of fixing our infrastructure.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: kevinb1994 on January 28, 2022, 10:21:29 AM
I did read that the gas line has been shut off. So that’s good news.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: bwana39 on January 28, 2022, 10:38:56 AM
Perfect opportunity for Biden to hammer home the importance of fixing our infrastructure.


I agree totally. That said, places like Pennsylvania and Iowa who have historically neglected their infrastructure will have larger needs and may very well preempt the things places like the mid-south and southwest need.

The bridge that failed was just over 50 years old. In the scope of things, not that old.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: MASTERNC on January 28, 2022, 10:45:01 AM
GSV shows deterioration off the roadway on the sides.

Given this is one of many bridges that spans a deep gap below in Pittsburgh (the one over the Parkway East that was just replaced is one example), this will likely cause some alarm (as well as emergency inspections of similarly tall bridges).
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: webny99 on January 28, 2022, 11:13:55 AM
Wow, that's a pretty significant artery to/from Pittsburgh too. The trail underneath the bridge actually has Street View, shown here (https://www.google.com/maps/@40.4391788,-79.9003246,3a,90y,344.02h,95.58t/data=!3m7!1e1!3m5!1sAF1QipNLthLj6biCNJjNOzz1E14mvIna0c_8geVbUMcg!2e10!3e11!7i5760!8i2880!5m1!1e1).

Here's a better (worse?) picture:

And look at this, from over three years ago:
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: kernals12 on January 28, 2022, 11:35:46 AM
This is probably a case of overuse of road salt.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: empirestate on January 28, 2022, 11:47:33 AM
This is very near my former home in Regent Square, so naturally I crossed this bridge many times. It did always feel a little bouncy, didn't it? Or am I just confirmationing that bias?

As to the vagueness of the reports (which frustrated me also), I've found that's pretty common just in general conversation. When I meet someone who says they're also from New York, it can be like pulling teeth to find out where exactly they're from. ("Oh, it's a small town, you probably never heard of it.") News-wise, you'll see similar things with the reporting of weather events and the like. I'm not sure it's the result of intentional obfuscation in most cases.

In any case, this will result in some very unpleasant detours. (Which color detour is designated for this eventuality?)  :hmm:
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: 1995hoo on January 28, 2022, 11:50:13 AM
....

As to the vagueness of the reports (which frustrated me also), I've found that's pretty common just in general conversation. When I meet someone who says they're also from New York, it can be like pulling teeth to find out where exactly they're from. ("Oh, it's a small town, you probably never heard of it.") News-wise, you'll see similar things with the reporting of weather events and the like. I'm not sure it's the result of intentional obfuscation in most cases.

....

(http://coachrandom.mrinitialman.com/Comics/Sem_1/california.gif)
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: kevinb1994 on January 28, 2022, 11:53:12 AM
In any case, this will result in some very unpleasant detours. (Which color detour is designated for this eventuality?)  :hmm:
I suppose that the Blue Route (not the one in SEPA) will see the largest use.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: formulanone on January 28, 2022, 12:09:19 PM
I'm surprised a span that long and wide was rated for only 26 tons.

A close call all the way around.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: catch22 on January 28, 2022, 12:53:41 PM
GSV from the path underneath the bridge.  My wife and I were in Pittsburgh last September and crossed this bridge a couple of times.

https://goo.gl/maps/PTPrVKdvUEzWyAbr9
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: davewiecking on January 28, 2022, 01:30:38 PM
At about 6:50 AM today. https://www.post-gazette.com/local/city/2022/01/28/pittsburgh-bridge-collapse-forbes-braddock-avenue-point-breeze-squirrel-hill/stories/202201280075

https://www.google.com/maps/@40.4395152,-79.8993553,401m/data=!3m1!1e3

You're the first posting that even bothered to name the bridge or the area, I spent 5 minutes on CNN trying to figure out where the hell it was-then said "never mind, AA Roads is on it" and you were on point!

I got a WaPo alert on my iPad that mentioned Forbes Road over a park, and as others have noted, opened up Google Maps and searched for a bridge over a park. The closed road (marked "until 2024") confirmed the location. Shocked at zero coverage on any of the network morning shows, but CNN had a report. Absolutely amazing nobody was seriously hurt. Snow delays had many people home that otherwise might have been out and about.

I've read that this bridge was rated poor; the rusted cross braces noted in the 3 year old tweet posted by webny99 probably didn't fix themselves.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: jeffandnicole on January 28, 2022, 02:02:37 PM
I'm surprised a span that long and wide was rated for only 26 tons.

A close call all the way around.

Because of the condition underneath.  Maybe it's more surprising they still permitted vehicles up to 26 tons to drive on it.

Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: bwana39 on January 28, 2022, 02:32:27 PM
GSV from the path underneath the bridge.  My wife and I were in Pittsburgh last September and crossed this bridge a couple of times.

https://goo.gl/maps/PTPrVKdvUEzWyAbr9


Looking at the streetview, this bridge was pretty lightly built BEFORE the rust and other damage reduced the capacity even farther.  It appears to have been seriously underbuilt and heavily salted.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: tolbs17 on January 28, 2022, 03:03:09 PM
Fix ya bridges!

I-35W,

Florida pedestrian bridge,

And now this...
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: kernals12 on January 28, 2022, 03:20:50 PM
Fix ya bridges!

I-35W,

Florida pedestrian bridge,

And now this...
I-35w was due to a design flaw
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: Dirt Roads on January 28, 2022, 04:02:21 PM
GSV shows deterioration off the roadway on the sides.

Given this is one of many bridges that spans a deep gap below in Pittsburgh (the one over the Parkway East that was just replaced is one example), this will likely cause some alarm (as well as emergency inspections of similarly tall bridges).

Indeed, as will the fact that the Frick Park bridge is relatively young (built in 1970).
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: kalvado on January 28, 2022, 04:09:18 PM
Fix ya bridges!

I-35W,

Florida pedestrian bridge,

And now this...
I-35w was due to a design flaw
It is fairly easy to write off things as "design flaw", especially if the thing (I-35 bridge in Minneapolis) was in use "just" 40 years and most people involved in construction are retired, if still alive.  It is a bit more involved though.

Quote
Major safety issues identified in this investigation include insufficient bridge design firm quality control procedures for designing bridges, and insufficient Federal and State procedures for reviewing and approving bridge design plans and calculations; lack of guidance for bridge owners with regard to the placement of construction loads on bridges during repair or maintenance activities; exclusion of gusset plates in bridge load rating guidance; lack of inspection guidance for conditions of gusset plate distortion; and inadequate use of technologies for accurately assessing the condition of gusset plates on deck truss bridges.

And regarding inspections...
Quote
Each of the fracture-critical inspection reports from 1994–2006 did note the presence of rust, corrosion, and section loss on gusset plates


GSV shows deterioration off the roadway on the sides.

Given this is one of many bridges that spans a deep gap below in Pittsburgh (the one over the Parkway East that was just replaced is one example), this will likely cause some alarm (as well as emergency inspections of similarly tall bridges).

Indeed, as will the fact that the Frick Park bridge is relatively young (built in 1970).
That makes it 52 year young, and I thought that is more or less standard design lifetime...
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: SectorZ on January 28, 2022, 04:34:06 PM
Fix ya bridges!

Florida pedestrian bridge,

And now this...

The Florida bridge was an engineering failure, had nothing to do with fixing anything.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: LilianaUwU on January 28, 2022, 04:36:04 PM
This isn't the first time a bridge built in 1970 collapses. (https://en.wikipedia.org/wiki/De_la_Concorde_overpass_collapse)
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: Stephane Dumas on January 28, 2022, 04:41:39 PM
This isn't the first time a bridge built in 1970 collapses. (https://en.wikipedia.org/wiki/De_la_Concorde_overpass_collapse)

The Pierre-Laporte bridge is opened in 1970, it's still there but from what I read on this French site with the maintenance and all.
https://ici.radio-canada.ca/nouvelle/1855411/augmentation-couts-travaux-reparation-entretien-pont-pierre-laporte-quebec-infrastructures-mtq-expertise-interne-ingenieurs
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: J N Winkler on January 28, 2022, 05:24:04 PM
I'm surprised a span that long and wide was rated for only 26 tons.

A close call all the way around.

Because of the condition underneath.  Maybe it's more surprising they still permitted vehicles up to 26 tons to drive on it.

Since load-posting is a first step for bridges whose structural deficiencies are deemed critical, I expect the decision to post for 26 tons to be put under the microscope:  why not a lower weight, and why not close the bridge altogether?

And regarding inspections...

Quote
Each of the fracture-critical inspection reports from 1994–2006 did note the presence of rust, corrosion, and section loss on gusset plates

I think the gusset plate issue must have been a continuing blind spot.  It wasn't just a question of failure to choose an adequate thickness--the original design was checked using a method that assumes gusset plates will have all the strength required and thus can be ignored.  MnDOT commissioned finite element analysis of the bridge before it collapsed and, from what I can tell, it did not surface the gusset plates as a problem in a way that would have told MnDOT it needed to take urgent action to forestall the collapse.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: kkt on January 28, 2022, 05:49:38 PM
If the September inspection rated it "poor" is there a lower rating for "failure imminent, close the bridge today"?
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: Big John on January 28, 2022, 05:53:21 PM
If the September inspection rated it "poor" is there a lower rating for "failure imminent, close the bridge today"?

NBI: 4=poor, 3=serious, 2=critical, 1-failure imminent.  The failure imminent rating calls for a immediate closure.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: kkt on January 28, 2022, 07:50:33 PM
If the September inspection rated it "poor" is there a lower rating for "failure imminent, close the bridge today"?

NBI: 4=poor, 3=serious, 2=critical, 1-failure imminent.  The failure imminent rating calls for a immediate closure.

Thanks.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: noelbotevera on January 28, 2022, 08:51:21 PM
Hey, I drove over this bridge back in December! Kinda crazy that it didn't collapse on me while I passed over it.

I'm surprised that a relatively new bridge like this collapsed, but considered the sad state of infrastructure...
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: tolbs17 on January 28, 2022, 09:31:43 PM
Hey, I drove over this bridge back in December! Kinda crazy that it didn't collapse on me while I passed over it.

I'm surprised that a relatively new bridge like this collapsed, but considered the sad state of infrastructure...
And with that happening. Now I'm afraid to drive on the Alligator River Bridge because I feel like that one will collapse next; it's due for a replacement anyway.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: zzcarp on January 28, 2022, 11:20:47 PM
The questions I'd like answered is where was this bridge ranked on the list for a major rehab or replacement, and when was that maintenance scheduled (if applicable). We can call for more infrastructure funds, and, for a locally maintained bridge, if it's not ranked in the top several, it's not going to get replaced even if it rains federal money on the local government.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: roadman65 on January 28, 2022, 11:29:06 PM
Shouldn’t the recent transportation infrastructure cover this?
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: rickmastfan67 on January 28, 2022, 11:29:18 PM
Fixed thread title, as it's Forbes Avenue, not Forbes Road.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: SteveG1988 on January 29, 2022, 08:38:59 AM
Fix ya bridges!

Florida pedestrian bridge,

And now this...

The Florida bridge was an engineering failure, had nothing to do with fixing anything.

yup, it was built in an extremely stupid manner, a concrete truss... it would have never worked.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: MASTERNC on January 29, 2022, 09:17:46 AM
Replacement times were quoted as 1-2 years. With construction on the 376 bridge east of the Squirrel Hill Tunnel to start in 2025 (Forbes would be a natural alternative route), the clock is ticking.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: zzcarp on January 29, 2022, 10:52:49 AM
The questions I'd like answered is where was this bridge ranked on the list for a major rehab or replacement, and when was that maintenance scheduled (if applicable). We can call for more infrastructure funds, and, for a locally maintained bridge, if it's not ranked in the top several, it's not going to get replaced even if it rains federal money on the local government.
Shouldn’t the recent transportation infrastructure cover this?

The answer is apparently no (https://www.nbcnews.com/news/us-news/collapsed-pittsburgh-bridge-was-rated-poor-condition-rcna14010?cid=sm_npd_nn_tw_ma), the bridge was not a priority, and it wasn't going to have this federal infrastructure money targeted to it to replace it or make repairs.

Quote
But the bridge is not among the highway and bridge projects targeted for federal funding in the state's 2021 transportation improvement program.

City officials haven’t said why the bridge, built in 1970, wasn’t placed on the list for federal infrastructure funding.

The 447-foot, steel, rigid frame bridge had an overall 4 rating and was listed in poor condition, according to the Pennsylvania Department of Transportation. Ratings range from 0 to 9, with the highest number receiving an excellent score.

Specifically, the bridge was handed a pair of 4s for its deck and superstructure, but the substructure was rated 6, state transportation records show.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: roadman65 on January 29, 2022, 11:38:34 AM
To the smartass mod who keeps taking after FB Fact Check and trying to censor us ( I talked to one of the administrators to find out who you are but he couldn’t) I wasn’t being political or cracking a wise crack about the infrastructure bill, I was just asking why the commonwealth isn’t responding to the money aid that is entitled to them via our government for roads specifically?

I wasn’t poking fun at anyone specific nor making a typical Dan joke (that you seem to turn the other way at, that needs the owner himself to take action, but that’s another story) when I asked about why the funding wasn’t used.  You need to stay out of politics which is why you assume that. Also Mr. MOD keep your personal feelings out of this forum!
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: Scott5114 on January 29, 2022, 08:12:32 PM
To the smartass mod who keeps taking after FB Fact Check and trying to censor us ( I talked to one of the administrators to find out who you are but he couldn’t) I wasn’t being political or cracking a wise crack about the infrastructure bill, I was just asking why the commonwealth isn’t responding to the money aid that is entitled to them via our government for roads specifically?

I wasn’t poking fun at anyone specific nor making a typical Dan joke (that you seem to turn the other way at, that needs the owner himself to take action, but that’s another story) when I asked about why the funding wasn’t used.  You need to stay out of politics which is why you assume that. Also Mr. MOD keep your personal feelings out of this forum!

According to the server logs, the only moderation that has taken place in this thread is rickmastfan67 changing "Road" to "Avenue" in the thread title.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: J N Winkler on January 29, 2022, 09:13:32 PM
I am going to lay down a marker:  the eventual analysis of the collapse will focus on the Forbes Avenue viaduct being an early use of weathering steel in bridge construction, before the importance of drainage detailing was adequately understood.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: Bitmapped on January 30, 2022, 06:14:53 PM
I'm surprised a span that long and wide was rated for only 26 tons.

A close call all the way around.

Because of the condition underneath.  Maybe it's more surprising they still permitted vehicles up to 26 tons to drive on it.

Since load-posting is a first step for bridges whose structural deficiencies are deemed critical, I expect the decision to post for 26 tons to be put under the microscope:  why not a lower weight, and why not close the bridge altogether?

Weight-restricted bridges aren't particularly uncommon in Pennsylvania.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: ixnay on February 01, 2022, 08:10:27 AM
In any case, this will result in some very unpleasant detours. (Which color detour is designated for this eventuality?)  :hmm:
I suppose that the Blue Route (not the one in SEPA) will see the largest use.

 :rolleyes:
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: 74/171FAN on February 01, 2022, 08:13:02 AM
An emergency project for the bridge replacement has already been entered into PennDOT's CE Expert System (https://www.dotdom2.state.pa.us/ceea/ceeamain03.nsf/18c042d1dacb327c85256c010051898b/85257fc4007728ec852587db004f2595?OpenDocument).
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: ixnay on February 01, 2022, 08:16:28 AM
Hey, I drove over this bridge back in December! Kinda crazy that it didn't collapse on me while I passed over it.

I'm surprised that a relatively new bridge like this collapsed, but considered the sad state of infrastructure...
And with that happening. Now I'm afraid to drive on the Alligator River Bridge because I feel like that one will collapse next; it's due for a replacement anyway.

I crossed (as a passenger) that bridge on US 64 in 2007 on a Carolinas vacation (making my way up from Charleston to our next stop, the OBX).
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: ixnay on February 01, 2022, 08:17:35 AM
The Fern Hollow bridge is now immortalized on Wikipedia.

https://en.wikipedia.org/wiki/Fern_Hollow_Bridge
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: tolbs17 on February 01, 2022, 08:19:46 AM
https://pittsburgh.cbslocal.com/2022/01/31/penndot-investment-rebuild-fern-hollow-bridge/

For $25.3 million, that is almost expensive as widening a road from 2 lanes to 4 lanes.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: tolbs17 on February 01, 2022, 08:20:27 AM
The Fern Hollow bridge is now immortalized on Wikipedia.

https://en.wikipedia.org/wiki/Fern_Hollow_Bridge
Yes, and more was added to it. I see that photos were added.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: rickmastfan67 on February 01, 2022, 09:48:03 AM
They got out the Bus & one of the cars yesterday.
https://pittsburgh.cbslocal.com/video/6193776-port-authority-bus-hoisted-from-site-of-pittsburgh-bridge-collapse/
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: MCRoads on February 01, 2022, 10:03:11 AM
I am very immature, I immediately saw the name of the park and started laughing my but off.

In all seriousness though, I’m very curious to see what happened. Why was this bridge not higher on the priority list? Was the collapse able to be predicted from the last inspection? If so, why wasn’t the bridge closed? Guess I’ll just have to wait for the NTSB report.
Title: Re: Forbes Rd Pittsburgh bridge collapse
Post by: SGwithADD on February 02, 2022, 03:52:05 AM
This is very near my former home in Regent Square, so naturally I crossed this bridge many times. It did always feel a little bouncy, didn't it? Or am I just confirmationing that bias?

I used to live in Shadyside and this was one of three or four bridges I drove on most frequently. I seem to remember it bouncing as well, particularly while waiting through multiple light cycles around rush hour, but maybe I'm also experiencing some confirmation bias :spin:
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: jeffandnicole on February 02, 2022, 07:15:03 AM
This is very near my former home in Regent Square, so naturally I crossed this bridge many times. It did always feel a little bouncy, didn't it? Or am I just confirmationing that bias?

I used to live in Shadyside and this was one of three or four bridges I drove on most frequently. I seem to remember it bouncing as well, particularly while waiting through multiple light cycles around rush hour, but maybe I'm also experiencing some confirmation bias :spin:

Most bridges are flexible to deal with numerous changes including temperature fluctuations, and by their very nature will "bounce" a bit.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: empirestate on February 02, 2022, 09:48:33 AM
This is very near my former home in Regent Square, so naturally I crossed this bridge many times. It did always feel a little bouncy, didn't it? Or am I just confirmationing that bias?

I used to live in Shadyside and this was one of three or four bridges I drove on most frequently. I seem to remember it bouncing as well, particularly while waiting through multiple light cycles around rush hour, but maybe I'm also experiencing some confirmation bias :spin:

Most bridges are flexible to deal with numerous changes including temperature fluctuations, and by their very nature will "bounce" a bit.

Indeed, and that's what I would have told myself at the time. Now that this has happened, of course I'm going back and wondering why this one sticks out as being particularly bouncy.

It's like that common reaction people have when something calamitous happens: "See? This is why I never [do something that literally never occurred to me not to do until this calamity]."  :-P
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: Big John on February 02, 2022, 05:12:43 PM
If a bouncy bridge suddenly becomes un-bouncy, get away from the bridge ASAP.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: Ketchup99 on February 02, 2022, 05:24:59 PM
This was weird, really weird. I'm a student at CMU and I was on a 61 bus over that bridge, bound for Wilkinsburg, the day before. Later that day I was going to be on another one, with some friends, again to Wilkinsburg. It was a little jarring to see the bridge we'd been on the day before and would be on later that day just collapse into the ravine.

And if I'm being honest, I never even realized there was a bridge on Forbes Avenue there. I assume if we'd left a little earlier I would have noticed...
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: MCRoads on February 03, 2022, 11:56:40 AM
This is very near my former home in Regent Square, so naturally I crossed this bridge many times. It did always feel a little bouncy, didn't it? Or am I just confirmationing that bias?

I used to live in Shadyside and this was one of three or four bridges I drove on most frequently. I seem to remember it bouncing as well, particularly while waiting through multiple light cycles around rush hour, but maybe I'm also experiencing some confirmation bias :spin:

Most bridges are flexible to deal with numerous changes including temperature fluctuations, and by their very nature will "bounce" a bit.

The Rio Grande Gorge Bridge was super bouncy! It was a little unnerving to stand there, looking down, then suddenly an 18 wheeler goes by and you move 2-3 inches up and down, lol. My grandpa thought that was pretty cool. My grandma didn’t.

I think the most movement I have ever felt on a bridge was center span on the Royal Gorge bridge during a windy day. Had to be at least 50 mph gusts. During the really big gusts, the bridge felt like it was “jumping” up about 12-18 inches! That was really interesting. Saw a couple of hats fly into the gorge that day. Would actually kind of like to experience that again, it was a fun sensation.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: ixnay on February 04, 2022, 08:17:18 AM
(https://media.townhall.com/Townhall/Car/b/sk020422dAPR20220202094505.jpg)
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: mrsman on February 04, 2022, 02:40:01 PM
https://pittsburgh.cbslocal.com/2022/01/31/penndot-investment-rebuild-fern-hollow-bridge/

For $25.3 million, that is almost expensive as widening a road from 2 lanes to 4 lanes.

The video that played while hitting this link had a spokesperson from (I believe) the city department of transportation telling people to use the Parkway instead of side streets to make the connection between east and west sides of the park.  She also mentioned that they were working on adjusting singal timing in the area to handle different traffic patterns.  [I noticed that the left turn arrow from Braddock to Forbes towards the closed bridge was shown on the video, so hopefully they can work on eliminating that unnecessary signal phase while the bridge is closed, sometime soon.  They probably will.]

Some other random comments on this;

Of course with any road story, I do my own peaking around GSV and formulate some thoughts of my own on general issues beyond the collapse.

First, Forbes Ave on both sides of the park, west of Beechwood and east of Braddock,  is 1 driving lane in each direction with parking.  Between Beechwood and Braddock, there are two driving lanes in each direction.  The lanes appear narrow and there are also narrow bike lanes within the park.  It would seem that this would be a good candidate for some form of road diet to maintain one lane in each direction, an occasional passing lane in the park*, and protected bike lanes within the park.  So basically 3 lanes of traffic and two protected bike lanes within the right of way.  The ends of the route, basically the last few feet eastbound approaching Braddock and westbound approaching Beechwood should maintain existing lane assingnments so each direction gets its own lane eastobund.  Westbound two lanes will allow for a right turn only lane at Beechwood.  The arrangement will also make left turn pockets possible at Dallas Ave. 

The weird loop of Beechwood near Dallas also deserves a comment.  While I have some ideas for this section, the current arrangement does seem to handle the traffic flows pretty well.  THe Beechwood/Dallas intersection should be signalized and coordinated with the Forbes/Dallas intersection that is nearby.

* While not strictly necessary, i could see there being a need for occasionally passing slow moving vehicles in this long stretch.  A brief stretch of passing lane in the center in each direction could be provided as there would be room for three vehicle lanes.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: kernals12 on February 04, 2022, 06:24:58 PM
(https://media.townhall.com/Townhall/Car/b/sk020422dAPR20220202094505.jpg)
I don't think this bridge is going to be bought by an eccentric British tycoon and put on display in Devon.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: Ketchup99 on February 07, 2022, 10:27:56 PM
https://pittsburgh.cbslocal.com/2022/01/31/penndot-investment-rebuild-fern-hollow-bridge/

For $25.3 million, that is almost expensive as widening a road from 2 lanes to 4 lanes.

The video that played while hitting this link had a spokesperson from (I believe) the city department of transportation telling people to use the Parkway instead of side streets to make the connection between east and west sides of the park.  She also mentioned that they were working on adjusting singal timing in the area to handle different traffic patterns.  [I noticed that the left turn arrow from Braddock to Forbes towards the closed bridge was shown on the video, so hopefully they can work on eliminating that unnecessary signal phase while the bridge is closed, sometime soon.  They probably will.]

Some other random comments on this;

Of course with any road story, I do my own peaking around GSV and formulate some thoughts of my own on general issues beyond the collapse.

First, Forbes Ave on both sides of the park, west of Beechwood and east of Braddock,  is 1 driving lane in each direction with parking.  Between Beechwood and Braddock, there are two driving lanes in each direction.  The lanes appear narrow and there are also narrow bike lanes within the park.  It would seem that this would be a good candidate for some form of road diet to maintain one lane in each direction, an occasional passing lane in the park*, and protected bike lanes within the park.  So basically 3 lanes of traffic and two protected bike lanes within the right of way.  The ends of the route, basically the last few feet eastbound approaching Braddock and westbound approaching Beechwood should maintain existing lane assingnments so each direction gets its own lane eastobund.  Westbound two lanes will allow for a right turn only lane at Beechwood.  The arrangement will also make left turn pockets possible at Dallas Ave. 

The weird loop of Beechwood near Dallas also deserves a comment.  While I have some ideas for this section, the current arrangement does seem to handle the traffic flows pretty well.  THe Beechwood/Dallas intersection should be signalized and coordinated with the Forbes/Dallas intersection that is nearby.

* While not strictly necessary, i could see there being a need for occasionally passing slow moving vehicles in this long stretch.  A brief stretch of passing lane in the center in each direction could be provided as there would be room for three vehicle lanes.

A road diet on that part of Forbes doesn't seem like a very good idea to me. All of the lanes are pretty important, and it carries a lot of traffic. Consider that most traffic from Oakland and Squirrel Hill into the Parkway, into Wilkinsburg, and into Homewood all follow that stretch of Forbes.

No, it should be rebuilt with all four lanes - and the sooner, the better.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: rickmastfan67 on February 16, 2022, 06:04:13 AM
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: tolbs17 on February 16, 2022, 03:05:40 PM
I've seen big trucks ignore warning signs and they make bridges so vulnerable to collapse which will warrant a rehabilitation or replacement.

I like how warning signs are right next to bridges, but I prefer some to be right at the entrance of the road heading towards the bridge.
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: Mapmikey on February 16, 2022, 07:11:47 PM
I like how warning signs are right next to bridges, but I prefer some to be right at the entrance of the road heading towards the bridge.

This is standard practice in Virginia
Title: Re: Forbes Avenue Pittsburgh bridge collapse
Post by: 74/171FAN on March 08, 2022, 09:19:45 AM
PennDOT - District 11 News: Fern Hollow Bridge Design, Construction Advance in Pittsburgh (https://www.penndot.pa.gov/regionaloffices/district-11/pages/details.aspx?newsid=5678)