Why are they building Phase II all at once?

[pithecanthropus]

It's obvious why Phase I of the Expo Line, or any new rail transit line needs to be built, as far as possible, all at once. For the route to be useful at all, it needs to run at least some distance and stop at several stations. The original MOS of the Red Line between Union Station and Westlake was the target of considerable derision, at the time, as a "train to nowhere".

Now, though, since the first segment of the Expo Line is in operation, why do we have to wait for all of the next segment to be completed before we can use any of it? Recently there have been traffic warnings about Expo construction work in downtown Santa Monica, when no trains will run there until at least 2016, in short aggravating people now for something they won't be able to use for years yet. Instead, why not concentrate all the work at the current terminus, for now between Culver City and Palms, and open Palms Station in one year rather than three? When that's done, then move on to the next segment, to Westwood/Overland--and so on. It seems like a wasted opportunity to demonstrate concrete progress to the public, and to open the system up to new markets sooner rather than later. Is there a sound engineering reason that they needed to plan the project as they have done? For example, would it be too difficult to concentrate all the necessary workers and equipment in the typical length between stations?

Of course I may be biased since Palms Station will be my station if I'm still living at this address when it does open.

[masonite]

That would be extremely inefficient and expensive. It is like if a house was being built for your family. You would say just build one room for your family to live in and then finish another room. You'd call out the roofer, electrician, plumber, drywaller, etc. just to finish that room and then call them out again to finish another room and so on and of course each room would have to be independent and couldn't rely on systems located in other rooms.

For Phase 2, they really need the maintenance facility and that will be in Santa Monica. They also need new cars as the system is nearly maxed out and those won't be delivered for several years. Basically the answer is no. I think the only way this could be a phased opening is if in 2016 there is a problem in Downtown Santa Monica and it opens to Bergamont Station, although I would think that would be very unlikely.

[Gokhan]

I would love to have the Palms Station open, as I live only within 5 minutes of walk from it. However, it really wouldn't speed it up that much if they opened the line in segments. Perhaps at most six months or so.

On top of that, it would be a lot more expensive, inconvenient (from a construction point of view), and problematic.

Phase 1 was opened in segments and we are still having serious problems with operating the line as a result. Culver City segment usually has trains stalling or trains docked at the wrong platform, preventing departures and arrivals. On top of that, there is a speed restriction in the at-grade segment because of defective parts in the frog. Opening the line in segments ruins the testing and start-up, which ruins the revenue operations.

[crzwdjk]

The thing is, a line that is twice as long doesn't take twice as long to build, if you have twice as many workers. Of course, it means you need to pay all of the construction costs all at once, rather than spreading them over a longer period, which is why Expo was broken up into phases in the first place. The one other possibility is if some segments of the line are "easier" to build than others, but Expo Phase II has bridges pretty evenly distributed throughout its length, and those are likely to be the critical path to opening. I suppose they could've done just the surface segment in Santa Monica, but would that really be useful to anyone?
Since there's no funding constraint for Phase II and there's no segment that's "easier" or faster to build, there's no reason to break the project up into phases and incur the extra costs and testing complexity that that would entail.

[Gokhan]

True -- everything is already being built in parallel anyway.

Besides, Phase 2 EIR didn't study any minimum operating segment (MOS), meaning they cannot legally open the line in segments even if they wanted and could. Therefore, it's basically a moot issue. In contrast, Phase 1 had three MOSs (Vermont, Crenshaw, and La Cienega) studied in the EIR.

[bobdavis]

In many ways, building in an urban area is a royal pain, but one of the advantages is that work can progress in several locations because the street network provides access for workers and materials. Compare this with building the Union Pacific west from Omaha 150 years ago. Everything had to come from "back east" and be schlepped along an ever extending supply line as work progressed. Out in my area, the Gold Line Foothill Extension project has work going on in several locations.

[pithecanthropus]

Thank you all for the interesting and informative answers.

If I hadn't forgotten about the Bergamot maintenance yard, I probably wouldn't have needed to ask.

ETA: It's been my impression that there aren't many good books for the interested layman about how transit projects are put together, in contrast to some other fields of engineering like aerospace. Even without knowing multivariate calculus (or even second year algebra), you can learn quite a lot about how rockets and spacecraft work, and a little of how the designers of those systems have to balance out the desired quality attributes against the constraints under which the rocket has to operate. With transit projects, not so much. I don't deny that you can find a lot of project documentation on the websites of transit agencies, but a narrative explanation in book form would be a lot handier.

[matthewb]

Apr 1, 2013 21:32:07 GMT -8 pithecanthropus said:

Thank you all for the interesting and informative answers.

If I hadn't forgotten about the Bergamot maintenance yard, I probably wouldn't have needed to ask.

ETA: It's been my impression that there aren't many good books for the interested layman about how transit projects are put together, in contrast to some other fields of engineering like aerospace. Even without knowing multivariate calculus (or even second year algebra), you can learn quite a lot about how rockets and spacecraft work, and a little of how the designers of those systems have to balance out the desired quality attributes against the constraints under which the rocket has to operate. With transit projects, not so much. I don't deny that you can find a lot of project documentation on the websites of transit agencies, but a narrative explanation in book form would be a lot handier.

I know you're mostly interested in construction, but as you mentioned talking about the design of a system vs. its attributes (albeit in the context of rockets), Human Transit is a good website: www.humantransit.org/

Presumably the book is good, too, but I haven't read it. From what I've gotten from reading most of the posts on the website, it's about how the physical properties of cities determine the kind of service that's feasible to provide, and how there are intrinsic trade offs between network efficiency and coverage. The author also focuses quite a bit on how the properties of a system (service frequency, separation from general automobile traffic, level boarding through multiple doors, ticket sales on the platform, etc.) can be separate from the technology used (rail vs. tires).

Maybe there's a market opportunity for someone to write a similar book for a popular audience about how to plan a large scale transit construction project once the mode and route is determined.

[bobdavis]

I'd probably be interested in buying a book on building a transit system (I think they was one published many years ago about the first segment of the New York subway system), but I would guess that the market would be rather limited. It's a lot easier to sell "spy thrillers" or "bodice-ripper romances" than real-world accounts of construction projects, unless they're really dramatic, like Hoover Dam or Golden Gate Bridge.

[culvercitylocke]

Or the Gateway Arch (I do have a book on that construction!)

[Gokhan]

If they can't get the new LRVs on-time and they are rather short of spare LRVs, they can probably do a quick environmental assessment (EA) to open the line to Palms, Westwood, or Sepulveda only. They would only need 0 - 1 more trains to do so. Palms Station can easily be operated with the existing 6 trains and they can go up to Sepulveda with only 1 more train.