It would definitely be an improvement if more elevated stations were partially enclosed, trainshed style instead of platform canopies only. A good example that comes to mind that I've personally seen is the Quai de la Gare M6 Metro station in Paris:

http://images.cdn.fotopedia.com/flic...6480-image.jpg
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I would speculate that with platform heaters, this would stay relatively tolerable, even on the coldest of days - because if we know one thing that's true about Chicago, its the damn wind man!

They don't need to fit four tracks into it, they would likely bore two tunnels one for each track anyhow. Get a little bigger TBM and you can just run two tracks down each tunnel, problem solved...

Chicago's soil is horrible for tunneling. Not as bad as, say, Miami, but pretty bad nonetheless. The more stuff you try to cram underground, the more complex the excavation is and the more crazy mitigation stuff you have to do (utility relocation, ground freezing, underpinning, tunnel jacking, etc). Just read about the Big Dig... it's a lesson in how NOT to build underground structures, unless you have a $12bn budget.

It's all a moot point anyway. With an option to build a 4-track elevated, why would a more expensive 4-track subway even be under consideration? I don't understand why saving two blocks of Wrigleyville and a few feet off the back of some 1920s commercial buildings along Broadway is worth another $700million in construction costs or so. Spend that money and get us the Brown Line subway to Jeff Park, or a functioning Gray Line, or a citywide BRT network.

The Big Dig was in Boston, not Chicago. Chicago is mostly a dream to tunnel under, because there's blue clay at -40. It's so simple that the State and Dearborn subways were dug with knives.

The subway was put on the table because of the complexities of rebuilding the embankment between Wilson and Loyola. Since the stations are in the middle, you can't easily or cheaply do half at a time.

That isn't all that dissimilar to Clark/Lake or Merchandise Mart.

True. Have to admit a bit more stylish though.

No doubt. They'd never do it, but I could absolutely see a similar canopy being placed on many of the Loop stops.

Reminds me of the original design for Fullerton and Belmont before value-engineering struck.

http://img16.imageshack.us/img16/357...969e20133e.jpg

As Mr. D said its actually not that bad to tunnel under Chicago. Just look at the original subways and the massive Chicago Tunnel Company Network. It was even safe to do by hand. Chicago's soil is just a bit more difficult to build foundations in because extremely heavy loads tend to sink in the clay and mud here if not distributed properly.

The main advantage to building a 4 track subway would be having the exact same number of tracks as a four track elevated, but underground where the infrastructure can go 100+ years without being completely rebuilt. Elevated structures are only designed to last 40-60 years even though Chicago has managed to maintain several of its elevated lines for more than twice that time. Essentially the main advantage of a subway tunnel is that it lasts forever with very little maintenance. Its an investment in our future, more money now a hell of a lot less money later.

CDOT begins South Lakefront Corridor Transit Study
 

http://www.cityofchicago.org/city/en...nsitstudy.html


http://www.cityofchicago.org/content..._factsheet.pdf

I am amazed that this thread is getting the most traffic these days, especially since there is next to nothing interesting going on in Chicago area mass transit, and there is next to nothing that will ever happen in the forseeable future.

If it were LA, it would be far more exciting--a mayor who makes trips to Washington and brings home the bacon, gets projects underway, and you can actually see new construction before your very eyes. But this mental masturbation thing we have going on over here just serves no purpose other than to get one excited over things that may never be.

Am I the only one who is literally getting bored of the ongoing process in Chicago of publishing a study, then shelving it; publishing a study, then shelving it; rinse and repeat. I realize the the Federal Government has to pass a transportation funding bill and all, but you guys do realize that 90% of this fluff that you keep talking about will never happen, right?

^ Great, we can finally study an improvement over the current predominant mode of south lakefront transit:

http://tedsingh.com/wp-content/uploa...let-impala.jpg
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Really? Wow, good thing wise ol' TUP is here to let us in on the ways of the world since the rest of us are idiots who think things magically appear just because we imagine them ...

The South Lakefront Study wouldn't necessarily involve any serious capital projects.

As for the other projects, they need to be pretty well along if not "shovel-ready" to get included in the next transportation funding act.

^ Fine, then, carry on the mental masturbation.

Because that is what the last 10 pages of this thread have essentially been.

I just don't see the point in planning and speculating (and, frankly, caring) when there are zero dollars in the pipeline. At least with buildings there is a chance that something will happen with private financing.

IMO, I think the focus of this thread should be "how can the city get more funding for transit and transit projects?" instead of "lets speculate on another mass transit expansion idea that I came up with last night that will never happen".

Anyhow, I'm done here, that's all I had to say..

Hate to break it to you, but NOTHING on this board ever amounts to anything. The reason people discuss plans instead of funding is that, well, funding is rather hopeless right now and talking about speculative physical development is a lot more interesting to most people than talking about speculative numbers. I don't recall people discussing at length numbers on how to get the Spire built, for example.

Except for what is reported as actually news, everything on this board is, as you so coarsely put it, "mental masturbation" and amounts to absolutely no productive use of any of our time and we participate not because we think it will amount to anything, but because it's fun to imagine and work through ideas. If you have some other self-delusion you'd rather discuss, then start discussing it - I don't see the point of you arrogantly taking the piss out of the discussion here.

I'm sorry if you somehow thought otherwise.

^^^ I don't know about you, but whenever I say something on this board it immediately happens in real life...

Transit funding advocacy is sorely lacking in Chicago, though--we don't really have an equivalent of Greater Greater Washington or something like that. We have a lot of quasi-official bodies and nonprofits that work on the issue, but the political culture here makes reform very difficult. It would really be great to have some sort of online springboard for reform, and to break what Aaron Renn called the "racket" attitude--complaining about the CTA like it's the weather (which, despite our hedonism in this forum, is really the predominating attitude in Chicago).

I'm not sure is SSP is the best place for that kind of discussion--a lot of people here are either citizens interested in the built environment or have some engineering background, and personally I feel out of my depth when discussing funding mechanisms and public policy with any kind of intricacy. Also, much of the last four pages was debate over planning that's currently on--funding might not be secured, but the process is slowly moving forward. From what I understand, it's hard to ask for money for major capital projects if you have little idea what you'll be doing with it.

Anyway, it's good to see the south lakefront study moving forward--I've taken Metra to work over the last two days rather than the #2 and it was a pleasure; I look forward to seeing what (pragmatic, not-capital intensive) ideas they come up with.

My god--Chicago suddenly sprouted a new subway under Lawrence Avenue which feeds into the new four-track subway under Broadway! It will be useful for transferring to the new four-track mainline above, which was rerouted under Clinton Street in order to connect with the new vactrain to Omaha!

It's funny how commonplace that is. I think most people seem to forget that we have a fantastic transit system, one of the best on the continent. I wouldn't choose to live in Chicago without it. Of course it has problems, but so do the systems in NY and DC.

Hooray for Chicago transit.