Comprehensive Pittsburgh-area transportation discussion (Erie, Lebanon: house, construction, university)

[Craziaskowboi]

Since we talk a lot about transportation on this message board, I figure it'd be convenient to have one at-large topic pertaining to all sorts of transportation -- roads and highways, bridges, light rail, freight rail, buses, airports, bike trails, boats, etc.

Anyway, here's proof that PennDOT has big plans for the Parkway West. Check out the width of the right of way under the Ridge Road overpass:



Notice how there's a little bit of grass near the eastbound exterior shoulder, and a whole lot of grass near the westbound exterior shoulder. That's no accident. PennDOT has left room under the overpass for eight travel lanes, an acceleration lane, a deceleration lane, two interior and exterior shoulders, and a median barrier. Per AASHTO requirements, all travel lanes and exterior shoulders on Interstates have to be 12' wide, and the interior shoulders also have to be 12' wide on Interstates with six or more lanes. Median barriers have to be at least 2' thick and reinforced. This gives us the following equation for eight lanes, one acceleration lane, one deceleration lane, two interior and exterior shoulders, and a median barrier:

12' + 12' + 12' + 12' + 12' + 12' + 12' + 2' + 12' + 12' + 12' + 12' + 12' +12' +12' = 170'

Envision the shoulders as BLUE and the median barrier as RED in the equation above in order to see the cross-section of the planned highway. Now here's a distance measure from one overpass pier to the other:



As you can see, the distance measured is the exact amount of room needed for the setup that I described.

About half a mile west of the Ridge Road interchange is the U.S. 22/U.S. 30/PA 60 interchange. U.S. 22/U.S. 30 is a limited-access highway itself, but movement between it and the Parkway West involves an obsolete partial-cloverleaf interchange that does not meet AASHTO requirements for movement between two limited-access highways. More than likely, PennDOT will rebuild this as a stack interchange in the future, with acceleration and deceleration lanes extending for half a mile to the east, and under the Ridge Road overpass.

The only obstacles in the way of PennDOT widening the Parkway West right now are the following:


1. The design of the existing overpasses at the U.S. 22/U.S. 30/PA 60 and Green Tree/Mt. Lebanon interchanges are identical, with piers constricting the right of way underneath them. These overpasses were more than likely built in the 1960's, which means that they're at or near the end of their engineered lifespans.

2. The Wheeling & Lake Erie (W&LE) Railroad has two bridges that span the Parkway West with piers constricting the right of way underneath them. The bridge near the Carnegie interchange is about 1,000' long, and the bridge near the Fort Pitt Tunnel is about 500' long. Both would need to be rebuilt in order to create extra space.

3. The Fort Pitt Tunnel can only fit four lanes, and it needs to fit at least six lanes in order not to create a dangerous bottleneck if the rest of the Parkway West is widened to eight lanes.


If work is done on any of these things, especially the overpasses since they're the easiest to fix, then consider it another step toward widening the Parkway West.

Anyway, this is a free-for-all transportation topic, so feel free to post or discuss any news or ideas about different transportation improvement projects here, whether they be highways, rail, bikes, or anything else.

[LIRefugee]

Here is an interesting article put out by the University of Toronto in 2010 describing attempts to address issues with traffic congestion. Here is the concluding paragraph:

Originally Posted by University of Toronto

These findings suggest that both road capacity expansions and extensions to public transit are not appropriate policies with which to combat traffic congestion. This leaves congestion pricing as the main candidate tool to curb traffic congestion.

The article obviously goes into more detail and is a very dry read, being an academic article and all, but it does find that adding highway lanes also adds a commensurate amount of highway traffic, thereby offering no congestion relief whatsoever.

[Craziaskowboi]

Originally Posted by LIRefugee

Here is an interesting article put out by the University of Toronto in 2010 describing attempts to address issues with traffic congestion. Here is the concluding paragraph:



The article obviously goes into more detail and is a very dry read, being an academic article and all, but it does find that adding highway lanes also adds a commensurate amount of highway traffic, thereby offering no congestion relief whatsoever.

What many (most?) people don't realize is, the Parkway West is so far over capacity that if other modes of transportation were built from downtown Pittsburgh to the west that cut the amount of traffic in half, it'd still be over capacity. That means it needs to be widened regardless of whether or not other modes of transportation are built, and regardless of whether or not another house is built west of I-79. It's been nearly 60 years, and capacity on the Parkway West has never been expanded, which is ridiculous. I fully support extending the T to the airport -- I'd route it through the West End and Crafton -- but even that won't help alleviate congestion on the Parkway West enough to leave it as it is.

[LIRefugee]

Originally Posted by Gnutella

What many (most?) people don't realize is, the Parkway West is so far over capacity that if other modes of transportation were built from downtown Pittsburgh to the west that cut the amount of traffic in half, it'd still be over capacity. That means it needs to be widened regardless of whether or not other modes of transportation are built, and regardless of whether or not another house is built west of I-79. It's been nearly 60 years, and capacity on the Parkway West has never been expanded, which is ridiculous. I fully support extending the T to the airport -- I'd route it through the West End and Crafton -- but even that won't help alleviate congestion on the Parkway West enough to leave it as it is.

The point of the article above is that even if you increased the capacity of the parkway, you would wind up with an increase in traffic that would result in the same overcapacity issue. The conclusion to draw from that is that expansion of freeways is pointless if you're are trying to relieve congestion (i.e. the usage is over capacity). In addition to that, expansion of mass transit also does not relieve highway congestion, so all the usual suggestions wouldn't work. So sayeth the research article.

[JoeP]

3. The Fort Pitt Tunnel can only fit four lanes, and it needs to fit at least six lanes in order not to create a dangerous bottleneck if the rest of the Parkway West is widened to eight lanes.

I think that could be resolved with a fly over ramp to the west for 2 lanes. One, the west end should be a viable alternative to the tunnel.

But regarding the parkway, I read a PG article noting many things routinely discussed and it doesn't look good. It's disgusting that major changes weren't done decades ago.

I tried to find the article and guess what, find a much older one...

The Pittsburgh Press - Google News Archive Search

[FreightTrainRunning]

Widening the Parkway West, including the Fort Pitt tunnels and Bridge, would cost billions of tax dollars, would take years and years of construction and as was pointed out, really wouldn't cut down on congestion in the long run anyway. Explain to me why this is a good idea?

[Craziaskowboi]

Originally Posted by JoeP

It's disgusting that major changes weren't done decades ago.

That's because Pittsburgh was effectively thrown away by the United States back in the 1980's. Good luck getting federal funding for a city that most people believed didn't deserve to exist anymore.

[Craziaskowboi]

Originally Posted by GeneW

Widening the Parkway West, including the Fort Pitt tunnels and Bridge, would cost billions of tax dollars, would take years and years of construction and as was pointed out, really wouldn't cut down on congestion in the long run anyway. Explain to me why this is a good idea?

Because a) the design of the highway is dangerous, b) I'm talking about improving an existing highway, as opposed to building a new one, and c) other cities have nice highways. Extending the T to the airport won't magically make the Parkway West not suck.

[FreightTrainRunning]

Originally Posted by Gnutella

Because a) the design of the highway is dangerous, b) I'm talking about improving an existing highway, as opposed to building a new one, and c) other cities have nice highways. Extending the T to the airport won't magically make the Parkway West not suck.

Can you explain how improving the highway won't cost billions?

[stburr91]

Originally Posted by LIRefugee

The point of the article above is that even if you increased the capacity of the parkway, you would wind up with an increase in traffic that would result in the same overcapacity issue. The conclusion to draw from that is that expansion of freeways is pointless if you're are trying to relieve congestion (i.e. the usage is over capacity). In addition to that, expansion of mass transit also does not relieve highway congestion, so all the usual suggestions wouldn't work. So sayeth the research article.

I think it's the congestion charge supporters that muddy the waters by purposefully confusing the issue between adding capacity, and reducing congestion.