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Originally Posted by themaguffin
I think there are a few big obstaciles in widening that portion of the parkway.
The rail bridge is one of them, but it's obviously been done in other cities... probably way back when other cities properly built their highways.
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Other cities didn't start building highways extensively until after Dwight Eisenhower implemented the Interstate highway system and all the design and engineering standards they entailed.
Quote:
Originally Posted by themaguffin
A very expensive issue for expansion would be the office tower closest to the parkway there. I don't see how it could stay.
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Just expand the right of way on the south (eastbound) side of the highway. I measured, perpendicularly to the highway, the distance between the office complex on the north (westbound) side and the water tower on the south side, and I got 245', which is more than enough for an eight-lane, 146'-wide right of way, plus two one-lane ramps with shoulders. Here's the view:
It's also worth noting that no residential property would have to be acquired to reconfigure the interchange and widen the highway through it. Only two businesses and a handful of parking spaces at two other businesses would have to be acquired. That's a lot less expensive than tearing down an office tower.
Further west toward the Wheeling & Lake Erie Railroad Bridge, there is a bit of a squeeze between a frontage road on the north side of the highway and somebody's backyard on the south side, but that can be rectified either by realigning part of the frontage road or acquiring part of the (large) backyard. Here's what I'm talking about
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Obviously this issue would have to be resolved somehow, but other than that, there's literally no residential property between I-79 and the Fort Pitt Tunnel that'd be at risk even if the Parkway West was expanded to eight lanes, and not much commercial or industrial property either, for that matter. The only significant obstacles are the Wheeling & Lake Erie Railroad Bridge between the Carnegie (Exit 66) and Green Tree/Mt. Lebanon (Exit 67) interchanges, and the size of the Fort Pitt Tunnel portals. If those two things can be rectified, then widening the Parkway West and reconfiguring the interchanges should actually be pretty easy despite all the talk for decades about how "it can't be done."
Quote:
Originally Posted by themaguffin
Beyond that, after widening ramps could be redone with it, including removing the assinine f'd up people getting on as people are exiting... within feet of each other. If you're leveling land and expanding, ramps have to be redone, so it's not a challenging fix.
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That's where a
SPUI comes in. It's an interchange that can handle high volumes of traffic efficiently without requiring a huge footprint. It'd also keep all the traffic on the main thoroughfare, instead of having to drive through a residential area to get to the eastbound on-ramp. Other interchanges that can be rebuilt this way include the Edgewood/Swissvale (Exit 77), Forest Hills/Wilkinsburg (Exit 78), Churchill (Exit 80A) and Monroeville/Plum (Exit 84). Even the U.S. 22/U.S. 30 interchange (Exit 60) could be reconfigured as such if a "stack" interchange is too expensive.
Quote:
Originally Posted by themaguffin
I don't see this happening and additionally, where would the lane be configured on the other side? Is it possible. It might be helpful, if money existed, to expand almost for another lane (big enough for emergancies) and would make it so wide that closed in feeling that slows people down would not happen.
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Quote:
Originally Posted by Wiz Khalifa
I don't think this can even be done with the way the tunnels are dug at an angle, with the bridge side portals being nearly stacked above one another and the west side portals being side-by-side. I could be wrong though, either way it would be an exorbitantly expensive project.
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Quote:
Originally Posted by PITairport
If such an extreme rebuild of the Ft Pitt Tunnel were to happen, then I would like to see it be re-bored to be 4 lanes in each direction to match the capacity of the bridge. Not only do the Carson St ramps not need two lanes to/from the Ft. Pitt Bridge, but even having one exit only lane is overkill. Those ramps only handle 6,000 cars a day. Traditional ramps should be sufficient. If that's not possible, they could go altogether for all I care; Carson St. already has access to the West End and Smithfield St. Bridges.
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I believe it's possible to expand the tunnel portals; the expansion just has to happen away from the centerline of the tunnel. Here's a crude graphic I put together illustrating a modified interface between the Fort Pitt Bridge and a six-lane Fort Pitt Tunnel:
A tunnel portal that's three lanes wide with 12' shoulders on each side would be 60' wide, which is the approximate length of the lines I drew to illustrate the openings to the tunnel portals. As long as the tunnel walls closer to the centerline stay in place, the tunnel walls away from the center line can be expanded outward without having to get creative.
You can also see that it'd be pretty easy to drop one lane from the eastbound on-ramp and the westbound off-ramp to make room for the third lane in each direction. I'd still rather keep the ramps because traffic can get directly from the westbound Fort Pitt Bridge to Carson Street, and from Carson Street to the eastbound Fort Pitt Bridge, without having to go through downtown Pittsburgh or the West End Circle. The geometry of the eastbound on-ramp might have to be reconfigured slightly to accommodate a third westbound lane under it, though, but that's about the only complication I can see on the bridge.
Quote:
Originally Posted by themaguffin
Ideally, it would be at least six lanes from the tunnel all the way to the split (to the old and new airports), but I don't see it widening west of Robinson.
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It's only two miles from the airport split to U.S. 22/U.S. 30, and there's enough room on both sides of the highway to expand it to six lanes without acquiring any property, so it's very doable.
Quote:
Originally Posted by themaguffin
But 2 lanes with horrific ramps makes for a mess. It also limits the ability to move around wrecks and forces 2 lanes to be one lane with the right lane always be a ramp.
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This is one of many reasons why I'm in favor of expanding capacity on the Parkways East and West. Not only are many of the ramps dangerous, but each highway is so far over capacity right now that even if T extensions to Pittsburgh International Airport and Monroeville reduced traffic by 20%, and the South Beltway reduced traffic by another 10%, they'd still both be over capacity. Besides, cars are more efficient at highway speeds than they are in stop-and-go traffic.
For the record, though I'd like to see both the Parkways East and West upgraded eventually, I consider the Parkway West to be a higher priority than the Parkway East. The Parkway East can be a longer-term project, but it's time to get serious about the Parkway West at the very least.
Quote:
Originally Posted by Wiz Khalifa
The Bates "loop" is the only way to get from the parkway east to the PTC, Hazelwood, and Southside Works without confusing detours. There's no good reason to eliminate this ramp. If anything, this interchange should be expanded so that you can also get on the parkway westbound directly from second ave.
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I understand the function of the loop, but that could be taken care of with a modified SPUI setup. Here's a crude example of what I had in mind:
The problem with an eastbound off-ramp is the same as it is with the eastbound on-ramp: not much space between the Parkway East and Second Avenue, especially after adding 12' interior and exterior shoulders to the Parkway East in order to meet Interstate standards. (The right of way for a six-lane Interstate is 122' wide, versus 146' wide for an eight-lane Interstate.) A portion of Second Avenue would have to be realigned, and the eastbound off-ramp would have to tunnel under not only the Parkway East, but the Great Allegheny Passage as well.
As for the westbound loop ramp, it could be eliminated simply by allowing left turns. All the ramps would meet at a certain point on Bates Street which would have signalized traffic control. The point at which the ramps meet could conceivably be moved slightly north on Bates in order to create more space between the intersections of the ramps and the intersection with Second Avenue.
Quote:
Originally Posted by Wiz Khalifa
Oh and there already aren't enough ways for drivers in Oakland and the East End to get on to the parkway east towards Monroeville. If you get rid of that Squirrel Hill ramp, then all of that traffic is going to be pushed onto either Bates st. or S. Braddock ave, which are already handling well beyond their designed capacity during the evening rush. Somethings gotta give.
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I should have been more clear; an eastbound on-ramp is obviously important at the Squirrel Hill/Homestead interchange, but that entire interchange and all the intersecting streets around it need to be completely reconfigured.
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Originally Posted by PITairport
Actually I think a huge improvement in this area is to rebuild the westbound I-376 overhead Grant St. ramps. This exit is the only thing preventing I-376 westbound from being 3 lanes through downtown. I -376 east is already 3 lanes if you include the ramp from I-279.
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I see what you're saying about the eastbound ramp from the Fort Duquesne and Portal Bridges to the Parkway East, but I took a closer look at the Grant Street interchange, and it looks to me like reconfiguring the westbound off-ramp and adding a third lane would leave no room for the westbound on-ramp. You'd either have to eliminate it or end up with another stubby on-ramp, which is one of the main problems with the Parkways East and West in the first place.
Quote:
Originally Posted by PITairport
But having it tie in to that area of the turnpike would really limit the access to the eastern terminus of the Southern Beltway, as you need to make your way to the Monroeville or Irwin interchanges. I prefer using the eastern arm of the MFE as the 4th segment of the Southern Beltway to the Parkway east as currently envisioned, but have it continue just a few more miles to meet with the turnpike on the north side of the Monroeville interchange.
Something like this, drawn in light green on this image of the full MFE in Pittsburgh:
This would also provide an alternate north-south bypass around Pittsburgh if tied into the Turnpike in this manner.
Everything else you said I agree with. |
That makes sense now that I look at the satellite imagery. For a second I thought that your proposed extension would just barrel through a bunch of residential areas, but then I saw that there's very little development anywhere near Thompson Run. Some residential property would have to be acquired near the Pennsylvania Turnpike, and also in Turtle Creek near the Tri-Boro Expressway, but otherwise it looks like a clear shot. And a partial interchange with the Turnpike wouldn't require too much space, which is good.
One unresolved dilemma, though, is the possibility for direct movements between U.S. 30 and the South Beltway in the vicinity of the Westinghouse Bridge and the Tri-Boro Expressway.
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