Green Line Reconfiguration

[citylover94]

Thats not accurate as you can transfer to the red line at South Station. The green line heads directly into the transitway and stops there so why would they still transfer at park?

 

[davem]

Quick post while I'm on the train. This wouldn't be deep, it would be very shallow, just below the surface. Same debth as the pike. The orange line has to be deeper, since it goes under the pike, so the green line would pass over it, before the line to Dudley takes a dive to get cross under the pike itself. The length to decend is enough: compare it to the length the trains take to dive under each other at Boylston, it's longer than that.

Yes, people on the Boylston subway would still transfer at park. But those on Huntington wouldn't, and with the Brookline connector that's a decent chunk of existing transfers. And its not like the plan is to make park and dtx obsolete, its just to spread the load and prevent more new services from using it, which this doesm

 

[Scalziand]

[youtube]https://www.youtube.com/watch?v=wlJgD4GuDVs[/youtube]

 

[cbrett]

So in summary, the silver line would continue to exist for the SL1 the SL2 and the Silver Line Gateway. Frankly, it will give it more legitimacy because it will be the only buses on the T system that use their own dedicated busway (i.e. the Transitway) warranting a color designation as opposed to now where half the silver line system does have some BRT components (SL1 and SL2) and the other half of the system (SL4 and SL5) is nothing more than a silver painted bus with a subway fare.

LRV and BRT can run in the Transitway together (and will need to if the South Station - Logan connection is to be maintained).

Thanks for the responses, I totally forgot about them needing to run busses for the airport and upcoming Chelsea line. Transitmass, I love your point about how converting the non-brt routes will make the Silver Line seem like much more legitimate brt, and agree 100%.

 

[cbrett]

Wouldn't Red-Blue, GLX to Porter, and the proposed (on here at least) GL spur to either Harvard or Kendall (via Grand Junction) reduce Park Street transfers too? Porter/Harvard connections could fall under the relatively reasonable pitch category and potentially implemented alongside this expansion, but likely wouldn't have the same load reduction capabilities as the crazier GL via Grand Junction to Kendall could. Either way, there is quite a lot in the pipeline to reduce Park Street congestion.

I'm by no means an expert, but a Boylston super station seems excessive IMO. Obviously the costs would be much lower for the Green Line, but judging by the massive pain in the ass Silver Line phase 3 was slated to be I still believe it's an uneccessary headache.

Also, I was doing some research on the Silver Line for a class today, and thought this was super interesting, considering the Green Line reconfiguration being discussed is basically a cheaper and better function replacement of the Silver Line's Phase 3 proposal.

In the year 2000, there were approximately 265,000 residents and 491,000 jobs located within a ½ mile radius of MBTA station stops with two-seat ride access to the Airport, South Boston Waterfront, and or Dudley Square via the existing Silver Line service. Completing Silver Line Phase III would boost those figures to approximately 655,000 residents and 753,000 jobs by 2030.

I got that from http://www.abettercity.org , and would imagine the numbers being dramatically increased by Seaport growth in the last 15 years. EDIT: I just realized the cited growth was "by 2030", which accounts for said growth. The point still stands that this would be a massive addition to the overall network.

 

[vanshnookenraggen]

Yes, people on the Boylston subway would still transfer at park. But those on Huntington wouldn't, and with the Brookline connector that's a decent chunk of existing transfers. And its not like the plan is to make park and dtx obsolete, its just to spread the load and prevent more new services from using it, which this doesm

So it boils down to who would benefit more with a direct South Station connection: Huntington Ave riders or Boylston St riders. I still think that Boylston St riders would benefit more and Huntington Ave riders can just transfer at Boylston rather than vise-versa.

 

[cbrett]

So it boils down to who would benefit more with a direct South Station connection: Huntington Ave riders or Boylston St riders. I still think that Boylston St riders would benefit more and Huntington Ave riders can just transfer at Boylston rather than vise-versa.

Should we really be routing a lot of current Green Line traffic away from GLX and towards the Seaport/South Station? I think it makes more sense to keep the most frequent service along the existing route, and instead route the E and Dudley that way. Aside from the E which is already the operational black sheep from splitting at Copley, you're also causing much less disturbance to the existing commuting patterns on the Boylston lines by routing the Huntington riders to South Station and the Seaport.

I also don't really see how one side benefits more than the other from the South Station connection, if anything I think the argument could be made for Huntington Riders being in greater need as there are fewer possible connections to Red via Huntington. (Spur to Harvard off of B, Indigo to South Station at Riverside for Boylston)

 

[Alon]

Alright I get what you are going for now. That's a pretty ingenious solution. But I have some issues.

1) The Orange Line tunnel is going to be a problem since it's so close to your new tunnel complex. The new stations and tunnels are going to have to be DEEP to get around the OL and the Pike right there. If the Dudley branch wasn't turning south then I'd say you could just go above the OL but with it you'd have to go DEEP and I don't know if your plan would be able to handle the grades needed.

If so then it shouldn't be built because it would complicate NSRL tunneling.

2) Given how many different services are running through here, and especially if you want to have a terminal platform, I think it might be better to have a bi level platform; something akin to West 4th St in NYC (less complex here). I'm mostly concerned about if there is a disabled train. One set of tracks will back up service in BOTH directions. Having two levels will allow trains to be held while merging when the Tremont tunnel goes from 4 to 2 tracks.

No. No, no, no, no, no, no. No.

The IND was a disaster, and its penchant for multilevel stations, full-length mezzanines, tunneling around and under an active subway, and flying junctions everywhere, is why. Superstations are incredibly expensive; just look at the billions spent on multilevel caverns in New York. To say nothing of the fact that if you're dipping underground anywhere east of Washington, you're making it harder to build the actually useful South Station-North Station connection, the one that focuses on the CBD and on the inner suburbs and not on airport access and a poor man's Vancouver West End.

EDIT: you mention disabled trains. As usual, organization before electronics before concrete. If the MBTA managers can't get MDBF to high enough levels that expensive redundancy is not required, they should be replaced with managers who can. There's no need to even go to normal first-world countries for that: there's a nearby domestic example, in New York, which has reliable enough equipment it does not need to plan its infrastructure around the assumption that trains will routinely break down in service.

 

[vanshnookenraggen]

To say nothing of the fact that if you're dipping underground anywhere east of Washington, you're making it harder to build the actually useful South Station-North Station connection, the one that focuses on the CBD and on the inner suburbs and not on airport access and a poor man's Vancouver West End.

Considering that the space for the NSRL was saved UNDER the Central Artery tunnels I don't see how building anything above them east of Washington St has any effect on the link.

 

[Alon]

Considering that the space for the NSRL was saved UNDER the Central Artery tunnels I don't see how building anything above them east of Washington St has any effect on the link.

The link needs to dip from the existing at-grade track to the space under the Central Artery. If it goes below grade right east of where the Orange Line crosses it, it can get there, but with a steep grade, I believe 3%. Anything that forces the link to begin farther east requires even steeper grade, or a portal that's much farther west, with a longer tunnel. The point here is that the Green Line reroute involves the Green Line running next to the NEC between Back Bay and Tremont. If it's just Back Bay-Tremont then it's not a big deal, but if tunneling continues farther east, especially with a multilevel complex that's hard to duck under, then it is problematic.

 

[vanshnookenraggen]

The link needs to dip from the existing at-grade track to the space under the Central Artery. If it goes below grade right east of where the Orange Line crosses it, it can get there, but with a steep grade, I believe 3%. Anything that forces the link to begin farther east requires even steeper grade, or a portal that's much farther west, with a longer tunnel. The point here is that the Green Line reroute involves the Green Line running next to the NEC between Back Bay and Tremont. If it's just Back Bay-Tremont then it's not a big deal, but if tunneling continues farther east, especially with a multilevel complex that's hard to duck under, then it is problematic.

Oh yes, sorry I thought you meant over by South Station. You are right.

 

[vanshnookenraggen]

Going off of what cbrett said, since we already have established traffic patterns it makes the most sense to build off of them instead of rerouting trains south and looping back to South Station. Also think about the track layout at Boylston St; Tremont St subway trains use the outside tracks which run past Park to Govt Center and beyond. D/E trains are already slated to take over the GLX routes. Boylston St subway trains terminate at Park (B) and North Station (C) so it wouldn't be a change to ask B/C riders to transfer at Boylston to continue east. An Essex St alignment has the least disruption to current traffic patterns with the most benefit.

I also don't really see how one side benefits more than the other from the South Station connection, if anything I think the argument could be made for Huntington Riders being in greater need as there are fewer possible connections to Red via Huntington. (Spur to Harvard off of B, Indigo to South Station at Riverside for Boylston)

If you go with the Bay Village alignment then only Huntington Ave riders get a direct connection to South Station. Anyone coming from Boylston St still needs to transfer at Park St or double back. For sake of argument lets say the E train goes to SBW

(B)/(C) riders have to go to Park and take Red Line to South Station and change again

(D) riders have to change at Bay Village.

(E) riders wanting to go to Park St have to change at Bay Village (or before)


A Boylston-Essex St alignment means that every service hits Boylston St station where you can continue north or east. If the Huntington Ave Subway extension is built then it may be best to add a new branch from Reservoir to SBW (R) via Boylston St:

(B)/(C) riders wanting to go to Park don't change, wanting to go to South Station can change at any Boylston St subway stations for (R)

(D)/(E) via Huntington riders to Park don't change, to go to SBW would change at Boylston for (R).


There are going to have to be transfers but the Essex St alignment allows the easiest way to transfer since all trains will run through one station and this will have the biggest impact on congestion at Park St.

 

[Nexis4jersey]

Is North-South tunnel partial built under the Artery?

 

[George_Apley]

So it boils down to who would benefit more with a direct South Station connection: Huntington Ave riders or Boylston St riders. I still think that Boylston St riders would benefit more and Huntington Ave riders can just transfer at Boylston rather than vise-versa.

But the two trunk lines would be so close together for the Back Bay stretch (that I think you're most concerned about) that it's almost a moot point. As Dave has said, riders originating in the Back Bay who want to go to SBW would just hop on the GL at Prudential or Back Bay, instead of Hines or Copley. An extra 3 minute walk, or a transfer at Boylston.

 

[vanshnookenraggen]

But the two trunk lines would be so close together for the Back Bay stretch (that I think you're most concerned about) that it's almost a moot point. As Dave has said, riders originating in the Back Bay who want to go to SBW would just hop on the GL at Prudential or Back Bay, instead of Hines or Copley. An extra 3 minute walk, or a transfer at Boylston.

Let me boil it down even more: if you are going to spend whatever billion dollars it will cost for all this why make it so not everyone can transfer at one station? Why make people walk in the first place if you are going to spend the money on transit? A single point of transfer is better than two or three transfers on different lines and in theory is cheaper (one station). I'm not trying to separate the lines so that riders have to chose between one or the other. I'm just trying to rework them so they go to the same place more efficiently while creating a new link to South Station that takes pressure off of Park St. I don't think a Bay Village alignment does that as you still force Boylston St subway riders to transfer at Park St. Do you really think someone is going to get off at Copley, walk to Back Bay and transfer just to get to South Station? No one would do that.

Also the way the Bay Village alignment is set up sends West Medford trains to SBW and I am highly skeptical that there will be such a demand that a dedicated subway line would need to be built. Keep in mind that riders coming from Union Sq/West Medford hit the major transfer stations before getting to Boylston St (North Station, Haymarket, Gov't Center, and Park St) which means anyone needing to transfer to get anywhere will do so before Boylston (or Bay Village). Any riders from the west and southwest have to transfer at Park St FIRST which causes the congestion problem. A superstation at Boylston allows more riders to transfer before Park St than does the Bay Village station.

 

[Alon]

Is North-South tunnel partial built under the Artery?

There's no North-South tunnel right now. However, the Big Dig reserved space under the Artery for a future four-track rail tunnel. It's dirt that has to be dug out, but there are no utilities, archeological sites, etc.

 

[davem]

Here are some of the thoughts that brought me to believe in the Bay Village connection. Remember, I was an avid Essex fanboy for years, and argued with F-Line about it a lot.

Project Goals (please tell me if you think they are different):
1) Avoid adding new traffic to Park and Gov't Center
2) Connect the Seaport to the Back Bay
3) Reactivate the Tremont Tunnel for Dudley light rail
4) Retire Copley Junction

The Essex street alignment does 2 very, very well, and 1 somewhat well. It does nothing for 3 and 4. Also, whatever line is rerouted to the Seaport doesn't get a Blue Line connection. There are also construction issues:
-PO Square provision is for inbound track only, unless an at-grade junction is constructed.
-The outbound track would probably separate reusing the old Arlington portal, requiring underpinning the green line tunnel and digging next to the burial ground.
-The new tracks would have to dive two levels down, below the abandoned tremont tunnel.
-The new station would be very deep, and would require underpinning Boylston station, the out of service junction, and the orange line.
-Essex is very narrow, the footprint of the new station would stretch from foundation to foundation of the existing buildings
-The historic buildings are susceptible to shifting, look at what just drilling an elevator shaft did to the church at Arlington.
-Undocumented utilities that would rival the Big Dig

The Bay Village routing does 1 a bit better than Essex, as if a train from Union/West Medford short turns it would do so at Bay Village, meaning that people don't get tossed off at the Brattle Loop.
It does 2 worse, because while Copley=Back Bay and Hynes=Prudential (access to the Hynes Convention Center is actually superior at Prudential, you don't have to go outside), there is no Arlington equivalent, and it misses Fenway and Kenmore.
Most importantly, it does 3, and 4. If you go via Essex, if you want to do 3 and 4 it's a completely unrelated project, while via Bay Village it's a tack-on. Although it's only a tangent benefit, you also get a one seat North-South connection.

To touch on the Red Line connection thing: yes, via Bay Village people coming through the Boylston tunnel would continue to transfer at Park. However at least one line that presently does would be routed to South Station, lightening the load. People coming from Union/West Medford who want to get to the Red Line would also transfer at Park. However if they are going to South Station or the Seaport, they are going to sit on their butts and ride an extra two stops. It has been proven time and time again people prefer a one seat ride to a transfer, even if it's longer. Not to mention, a hypothetical Union-Porter extension would make half that issue moot.


TL;DR, If your only goal is to connect the Seaport to the Back Bay, then going via Essex is superior. If your goal is to do the above, plus Dudley, retiring Copley Junction, easing construction issues, than Bay Village is superior, even if the routing is slightly more convoluted. Perfection should not be the enemy of the good.

Below is a copy of my Crazy Transit Map. I'm posting it because I think it does a good job of outlining the benefits of the Bay Village connection. Pretend you are using it to go to various destinations, I think you will see that overall transfers at Park do decrease, while also maintaining existing commuting patterns. For the sake of keeping this thread uncluttered, please refrain from discussing things not directly related to the Green Line:

 

[Transitmass]

^I agree totally with Davem and I also want to emphasize that Point 4- "Retiring the Copley Junction"- could be amended to read as "increasing capacity on Boylston tunnel."

I know I'm not stating anything new but one of the issues with the Boylston tunnel (besides the infamous capacity killing at grade junction before Copley) is that there are simply too many trains that are forced to travel down it. Now I know we could all debate at length what could be done to increase capacity short of adding a new tunnel. We could talk about dispatching on the surface segment, we could talk about CBTC and we could talk about enhancing the Worcester line with indigo service, etc. and all of those thing are relevant and important and will help. But at the end of the day I think the essence of the problem is that we cram too many trains down that tunnel for it to operate well. In short,[/I]We have a capacity problem[/I]

Alon, I know you are going to disagree with me on that point but I can say that it's not just me who says that. A lot of people have looked at the same issue carefully and considerately and have come to the same conclusion. That's why there are so many proposed solutions floating around (some of them crazy) that all attempt to solve this core issue of undercapacity. For example, we have that Wentworth professor who has recently given a presentation about sending the Blue line down Newbury Street to eat the D line and on the Transitmatters podcast one of the show's presenters has advocated that we turn the green line into heavy rail. While those are potential solutions (with many attendant issues) they pale in comparison to this proposed solution that does more for less with fewer downsides.

Ask a random local T rider and they'll likely say something to the effect of "the green line sucks." Now people say that for a lot of reasons but I think- while they may not know it- the reason it sucks to them is because we are asking the core infrastructure (i.e. the Boylston tunnel) to do more than it can and it fails. Fix this problem and we fix the green line.

The Bay Village alignment does this by taking the E trains out of the busiest part of the Boylston tunnel. The Essex street alignment does not. That to me makes the choice between the two clear.

 

[vanshnookenraggen]

I think I see where the disconnect is: I've always assumed that a Huntington Ave-Tremont extension would be built at the same time as an Essex St subway. So what you are proposing combines them into one project and one tunnel.

No question construction of one larger tunnel along the Pike/Bay Village would be cheaper and easier to build. With Essex, though, I wouldn't use the POS provisions but have a new slip using the old Boylston St portal which is back near Arlington (avoiding the burial ground). This would give you the space to dive as deep as you need. I still think this would have other benefits like an underground mezzanine that can be used by nonpaying pedestrians during winter months.

I see your reasoning now (though to be fair in my version the Copley Junction was the first to go by extending the Huntington Ave subway to Tremont St and this doesn't prevent a tunnel to Dudley mind you) and I do see the downsides to the Essex St alignment. That said I still stand by it.

 

[George_Apley]

To be clear: your Essex proposal also includes Tremont to Huntington connection?

In that case, the specific disagreement over the transitway connection between the two proposals makes more sense to me.