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Pittsburgh tunnel widening

Started by Gnutella, May 07, 2015, 02:44:58 PM

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Gnutella

"There's no way to widen the tunnels!"

Bullshit! Bull-fucking-shit! Scream it from the rooftops: BUUUUULLLLLSHIIIIITTTTT!!!









If anything, there's no excuse for Pittsburgh's shitty highways anymore.


Zeffy

I think the better excuse is that there is not enough money to do such a thing. Tunnel work is beyond expensive.
Life would be boring if we didn't take an offramp every once in a while

A weird combination of a weather geek, roadgeek, car enthusiast and furry mixed with many anxiety related disorders

Gnutella

Quote from: Zeffy on May 07, 2015, 04:02:20 PM
I think the better excuse is that there is not enough money to do such a thing. Tunnel work is beyond expensive.

Eh, if Boston can get $16B for the "Big Dig," and Seattle can get $1B to bury the Alaskan Way Viaduct, then Pittsburgh ought to get $1B to enlarge the Fort Pitt Tunnel.

Gnutella

Shit, I just realized I put this topic on the wrong board. Somebody move it, please. :(

Pete from Boston


Quote from: Gnutella on May 07, 2015, 04:05:07 PM
Quote from: Zeffy on May 07, 2015, 04:02:20 PM
I think the better excuse is that there is not enough money to do such a thing. Tunnel work is beyond expensive.

Eh, if Boston can get $16B for the "Big Dig," and Seattle can get $1B to bury the Alaskan Way Viaduct, then Pittsburgh ought to get $1B to enlarge the Fort Pitt Tunnel.

Boston got $10.5 billon from the Federal government.  Massachusetts continues to pay the remaining $15 billion or so.  These numbers on a $2.5 billion estimate are an object lesson in why "let's just dig/expand a tunnel" is not approached lightly. 

ARMOURERERIC

I think a 3rd reversible HOT tube, even at a nearby location will be the better option for the FT Pitt

Gnutella

Quote from: Pete from Boston on May 07, 2015, 06:11:46 PM

Quote from: Gnutella on May 07, 2015, 04:05:07 PM
Quote from: Zeffy on May 07, 2015, 04:02:20 PM
I think the better excuse is that there is not enough money to do such a thing. Tunnel work is beyond expensive.

Eh, if Boston can get $16B for the "Big Dig," and Seattle can get $1B to bury the Alaskan Way Viaduct, then Pittsburgh ought to get $1B to enlarge the Fort Pitt Tunnel.

Boston got $10.5 billon from the Federal government.  Massachusetts continues to pay the remaining $15 billion or so.  These numbers on a $2.5 billion estimate are an object lesson in why "let's just dig/expand a tunnel" is not approached lightly. 

I understand that, but the Big Dig was also much more complex. It basically involved burying a large interchange plus six miles of eight- to 10-lane Interstate highway (four to five lanes per tube) under downtown Boston and part of Boston Harbor. On the other hand, the Fort Pitt Tunnel is just a pair of tubes that are two thirds of a mile long, and it'd only need to be expanded to six lanes (three lanes per tube). The difference in scale between the projects would make cost overruns both less likely and less severe for the Fort Pitt Bridge than the Big Dig. The Fort Pitt Tunnel handles more than 100,000 vehicles per day, so expansion really ought to be considered.

rickmastfan67

Quote from: ARMOURERERIC on May 07, 2015, 06:32:54 PM
I think a 3rd reversible HOT tube, even at a nearby location will be the better option for the FT Pitt

Outbound needs an extra lane, no and's, if's, or but's.  It's a nightmare in rush hour for traffic to get from I-279 and the Downtown on ramp over to the thru lanes.  I-279 traffic needs to have itself at least one dedicated lane.

I can count on one hand how many times in the past 10 years that I've been able to get into the Ft. Pitt Tunnels from I-279's lanes without haven't to play the 'stop and go roulette' that it requires almost all the time except overnight.

NE2

Quote from: ARMOURERERIC on May 07, 2015, 06:32:54 PM
I think a 3rd reversible HOT tube, even at a nearby location will be the better option for the FT Pitt
It's called the Wabash Tunnel.
pre-1945 Florida route log

I accept and respect your identity as long as it's not dumb shit like "identifying as a vaccinated attack helicopter".

rickmastfan67

Quote from: NE2 on May 07, 2015, 11:08:22 PM
Quote from: ARMOURERERIC on May 07, 2015, 06:32:54 PM
I think a 3rd reversible HOT tube, even at a nearby location will be the better option for the FT Pitt
It's called the Wabash Tunnel.

And it's not even really wide enough for two lanes of traffic, even though it's stripped for such.

ARMOURERERIC

I am aware of the Wabash tunnel, but I had something a little more robust in mind.

BigRedDog

Would widening the tunnel mean widening the bridge? And, if so, is that easily done? I'm curious what ideas you guys have.

rickmastfan67

Quote from: BigRedDog on May 08, 2015, 12:29:52 AM
Would widening the tunnel mean widening the bridge? And, if so, is that easily done? I'm curious what ideas you guys have.

Widening the bridge?  Nope.  That part isn't needed.  It's already 4 lanes on each deck.  If they just eliminate one of the two lanes to/from the Carson Street exit on the Southside of the bridge, they can easily give the extra lane to traffic going into/out of the tunnel.

ARMOURERERIC

I envisioned HOT or reversible lanes coming in from at least 79 and splitting off halfway down greentree hill going through an elevated structure and tunnel that was at an angle more direct towards Smithfield St Bridge with direct access to large multi story parking facilities near station square and pedestrian access to the T.  The lanes would continue along the south shore and cross the river rejoining 376 near the old J&L bend

Gnutella

Quote from: BigRedDog on May 08, 2015, 12:29:52 AM
Would widening the tunnel mean widening the bridge? And, if so, is that easily done? I'm curious what ideas you guys have.

Existing interface between Fort Pitt Bridge and Fort Pitt Tunnel


Proposed interface between Fort Pitt Bridge and Fort Pitt Tunnel (crude rendering)


BAM! :clap:

briantroutman

An engineering study back in 2002 recommended expanding the tunnels to four lanes in each direction (via new bores) and also closing the Carson ramps to simplify access from the tunnels to the bridge.

Here's the Post-Gazette article discussing the study.

BigRedDog

I like the idea as mentioned in the PG article. Removing the Carson ramps would alleviate all of the crazy weaving that occurs. Going outbound across the Ft. Pitt bridge and into the tunnel would be so smooth.

Here's my follow up for the inbound. Will there be a problem with only having one lane to continue onto the Ft. Duquesne Bridge, as it is currently? And, if so, is there an "easy" fix?

JawnwoodS96

Quote from: BigRedDog on May 09, 2015, 02:15:16 AMHere's my follow up for the inbound. Will there be a problem with only having one lane to continue onto the Ft. Duquesne Bridge, as it is currently? And, if so, is there an "easy" fix?
As far as I know, 376E-->279N isn't that much of a headache; the main problem mainly consists of outbound traffic (Especially coming from Liberty Ave, interstates shouldn't be so inadequate to have stop signs).
Major interstates driven: i64, i264(VA), i66, i68, i70, i270(DC & OH), i71, i74, i75, i275 (Cin), i76, i376, i476, i77, i79, i279, i579, i80, i480 (OH), i81, i83, i283, i85, i185(GA), i285, i485, i90, i95, i295(VA & NJ), i495, i695(MD), i99

Go Steelers, Pirates, and Penguins!

jeffandnicole

Quote from: Gnutella on May 08, 2015, 04:04:19 PM
Quote from: BigRedDog on May 08, 2015, 12:29:52 AM
Would widening the tunnel mean widening the bridge? And, if so, is that easily done? I'm curious what ideas you guys have.

Existing interface between Fort Pitt Bridge and Fort Pitt Tunnel


Proposed interface between Fort Pitt Bridge and Fort Pitt Tunnel (crude rendering)


BAM! :clap:

Your potential design is clearly the obvious way to go about doing it.  However, you also have to find a way to support the additional lane.  You need a structure design that will somehow keep that upper roadway over the lower roadway.  Since both roadways are widened, you need to extend the piers in such a way where there can support the roadways, without interfering with the roadways.  That is where the problems would come in.

iBallasticwolf2

Quote from: briantroutman on May 08, 2015, 04:13:54 PM
An engineering study back in 2002 recommended expanding the tunnels to four lanes in each direction (via new bores) and also closing the Carson ramps to simplify access from the tunnels to the bridge.

Here's the Post-Gazette article discussing the study.

I think it would be a good idea, as well as closing the Carson street ramps. I would say alot of I-376 in the Pittsburgh area is highly functionally obsolete, especially with the strange and abnormal interchanges and *Gulp, left exits and entrances
Only two things are infinite in this world, stupidity, and I-75 construction

JawnwoodS96

I-376 from I-79 to PA 791 is not built to interstate standards, correct. However, it's hardly the only expressway in the Pittsburgh area with left exits/on ramps (I-79 and PA 28 are a couple of examples).
Major interstates driven: i64, i264(VA), i66, i68, i70, i270(DC & OH), i71, i74, i75, i275 (Cin), i76, i376, i476, i77, i79, i279, i579, i80, i480 (OH), i81, i83, i283, i85, i185(GA), i285, i485, i90, i95, i295(VA & NJ), i495, i695(MD), i99

Go Steelers, Pirates, and Penguins!

Gnutella

Quote from: jeffandnicole on May 09, 2015, 05:56:05 PM
Quote from: Gnutella on May 08, 2015, 04:04:19 PM
Quote from: BigRedDog on May 08, 2015, 12:29:52 AM
Would widening the tunnel mean widening the bridge? And, if so, is that easily done? I'm curious what ideas you guys have.

Existing interface between Fort Pitt Bridge and Fort Pitt Tunnel


Proposed interface between Fort Pitt Bridge and Fort Pitt Tunnel (crude rendering)


BAM! :clap:

Your potential design is clearly the obvious way to go about doing it.  However, you also have to find a way to support the additional lane.  You need a structure design that will somehow keep that upper roadway over the lower roadway.  Since both roadways are widened, you need to extend the piers in such a way where there can support the roadways, without interfering with the roadways.  That is where the problems would come in.

Each bridge deck would be widened to the outside, so there'd be no interference between the two of them. What would be required is the replacement of two complex bridge piers, however. The good news is, it's not logistically impossible. There's enough room between the existing tunnel-side pier and Carson Street to build a new pier that can handle three lanes on each level, and there's enough room between the existing bridge-side pier and Station Square Drive to do the same. Even the ramp piers wouldn't interfere.


Quote from: BigRedDog on May 09, 2015, 02:15:16 AM
I like the idea as mentioned in the PG article. Removing the Carson ramps would alleviate all of the crazy weaving that occurs. Going outbound across the Ft. Pitt bridge and into the tunnel would be so smooth.

Here's my follow up for the inbound. Will there be a problem with only having one lane to continue onto the Ft. Duquesne Bridge, as it is currently? And, if so, is there an "easy" fix?

If the ramps to and from Carson Street are removed altogether, then inbound Parkway West traffic should get a supplementary big green sign that reads, "TO PA 837 East | Carson Street | South Side | Follow U.S. 19 Truck North/PA 51 North | EXIT 69A." (I envision reconfiguring that interchange to a modified "directional T.")

Unfortunately, there is no easy fix to the I-279 connection between the Fort Pitt and Fort Duquesne Bridges. It passes through a historically significant area (the site of Fort Pitt), and a lot of people are already salty that it cuts off Point State Park from downtown Pittsburgh, so there'd more than likely be overwhelming NIMBY resistance to any reconfiguration of the connection. In fact, there'd probably be a faction in favor of eliminating the connection altogether, regardless of how much traffic it handles. You know the type: In their zeal to make their cities as pretty as possible, there's absolutely no room for anything with a utilitarian purpose, regardless of how necessary it is. (Ironically, they don't consider rail overpasses to be a psychological barrier the way they do highway overpasses.)


Quote from: JawnwoodS96 on May 09, 2015, 03:31:11 PMAs far as I know, 376E-->279N isn't that much of a headache; the main problem mainly consists of outbound traffic (Especially coming from Liberty Ave, interstates shouldn't be so inadequate to have stop signs).

Then again, the outbound bottleneck would resolve itself altogether if the Carson Street off-ramp was eliminated, since the root of the problem is four lanes of traffic compressing into a two-lane tunnel. If the tunnel was expanded to three lanes and the Carson Street off-ramp was reduced to one lane, then the bottleneck would be alleviated during off-peak hours at least. In that scenario, there'd have to be a sign for each of the two lanes coming down off the Fort Duquesne Bridge: One over the left lane that reads, "I-376 | Monroeville | Carnegie | Airport | 1/4 MILE | LEFT LANE ONLY," and one over the right lane that reads, "EXIT 69B | PA 837 | Carson Street | West End | South Side | 1/2 MILE | EXIT ONLY."

As for the stop sign at the end of the Liberty Avenue on-ramp, there really is nothing that can be done about that because traffic is already on the bridge at that point. If anything, the ramps to and from Liberty Avenue could be eliminated, and everybody wanting to enter downtown Pittsburgh would be directed to Fort Duquesne Boulevard.

Unfortunately, I-376 past downtown Pittsburgh and the I-279 connector between the Fort Pitt and Fort Duquesne Bridges are going to be substandard regardless. When I gripe about substandard Interstates in Pittsburgh, I'm talking about how obsolete I-376 is away from downtown, because that's where they can actually be brought up to standard. All it requires is somebody at PennDOT District 11 to grow some balls.


Quote from: iBallasticwolf2 on May 09, 2015, 09:27:51 PM
I think it would be a good idea, as well as closing the Carson street ramps. I would say alot of I-376 in the Pittsburgh area is highly functionally obsolete, especially with the strange and abnormal interchanges and *Gulp, left exits and entrances

Sometimes it doesn't pay to be a pioneer. Pennsylvania had hundreds of miles of highway built before 1956 that were grandfathered into the Interstate Highway System. At the time they were built, there were no "Interstate standards" for them to be built to. Making matters worse in Pittsburgh is the tunnels constricting the highways, and even railroad bridges that don't have enough room between the piers to allow for expansion. Basically, two things have to happen first for the Parkway West portion to be expanded properly: expansion of the Fort Pitt Tunnel, and replacement of two W&LE Railroad bridges. The Parkway East can wait if necessary, but the Parkway West is quickly becoming a protracted bottleneck.


Quote from: JawnwoodS96 on May 10, 2015, 12:19:24 AM
I-376 from I-79 to PA 791 is not built to interstate standards, correct. However, it's hardly the only expressway in the Pittsburgh area with left exits/on ramps (I-79 and PA 28 are a couple of examples).

Minor correction: It's built to Interstate standards west of here and east of here, but not in between.

froggie

Widening the existing tunnels is not an option.  You'd have to shut down one portal entirely in order to do it.  Likely why the 2002 study mentioned upthread recommended new tunnel bores.

Henry

Quote from: froggie on May 11, 2015, 01:06:22 PM
Widening the existing tunnels is not an option.  You'd have to shut down one portal entirely in order to do it.  Likely why the 2002 study mentioned upthread recommended new tunnel bores.

Which really is the only way to widen a tunnel anyway.
Go Cubs Go! Go Cubs Go! Hey Chicago, what do you say? The Cubs are gonna win today!

Gnutella

Quote from: froggie on May 11, 2015, 01:06:22 PM
Widening the existing tunnels is not an option.  You'd have to shut down one portal entirely in order to do it.

:banghead:

I mean, just breeze right on by the pictures in the first post of this topic that prove otherwise!






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