Red Line Extension to Arlington Heights

[okin15]

The minuteman ROW def makes the most sense from an urbanization point of view, but I wonder if an extension using part of the Rt 2 ROW is at all feasible or desirable. The big advantages are:

1. From Lake Street and on, the ROW has extra capacity, enough for both the train and the construction most likely
2. tunneling here would face minimal opposition when compared to tunneling and running heavy rail near existing houses
3. building a garage along the line somewhere in Lexington would be easy
4. would greatly reduce the pressure on Alewife garage and the surrounding street-system, both of which are over-capacity at most times of the day.
5. also connects to Belmont which is a relatively dense area, though less so on that edge.
6. Would reach 128 and the businesses at the 128/rt2 intersection much more easily

Disadvantages are significant as well:

1. I assume grades are too steep to climb the big hill without some cutting
2. tunneling to reach Lake Street would be costly and encounter wetlands
3. walkable ridership would be much lower unless significant TOD was approved in Arlington and Belmont, possibly creating more, rather than less traffic.

 

[JeffDowntown]

The minuteman ROW def makes the most sense from an urbanization point of view, but I wonder if an extension using part of the Rt 2 ROW is at all feasible or desirable. The big advantages are:

1. From Lake Street and on, the ROW has extra capacity, enough for both the train and the construction most likely
2. tunneling here would face minimal opposition when compared to tunneling and running heavy rail near existing houses
3. building a garage along the line somewhere in Lexington would be easy
4. would greatly reduce the pressure on Alewife garage and the surrounding street-system, both of which are over-capacity at most times of the day.
5. also connects to Belmont which is a relatively dense area, though less so on that edge.
6. Would reach 128 and the businesses at the 128/rt2 intersection much more easily

Disadvantages are significant as well:

1. I assume grades are too steep to climb the big hill without some cutting
2. tunneling to reach Lake Street would be costly and encounter wetlands
3. walkable ridership would be much lower unless significant TOD was approved in Arlington and Belmont, possibly creating more, rather than less traffic.

Your item 3 of the disadvantages basically says this would be a very expensive train that serves almost no one. The Rt 2 walkshed is hideously thin.

 

[TheRatmeister]

Arlington's density in these areas isn't dissimilar from Newton, Brookline, or Milton

Arlington is about 4x as dense as Milton.

walkable ridership would be much lower unless significant TOD was approved in Arlington and Belmont, possibly creating more, rather than less traffic.

Understatement of the century. Rt 2 completely bypasses the centers of Arlington, Belmont, and Lexington, essentially eliminating the possibility of significant walk-up traffic. Any ridership would need to be from highway adjacent TOD, and people generally don't like living right next to highways, for good reason.

 

[kdmc]

Instead of RLX, what if the GL-D was extended to Porter and then in center-running transit lanes (shared with the 77) along Mass Ave up to Arlington Center?

 

[Riverside]

A Green Line extension from Union Square along the Minuteman ROW has sometimes seemed more fit-for-purpose for Arlington to me -- better match for the Newton-like density (though see below), and better able to interface with the surface environment with grade crossings. But, I think last time I/someone else looked, it seemed unclear that there was enough width to fit both an LRT ROW and a bike path. (Center-running lanes on Mass Ave are also interesting, but that would be a lot of traffic lights + intersections to negotiate.)

That being said, I think the density is not actually what it looks like at first glance. Below are some modified screenshots of @Teban54's amazing population density map, in which I've removed color from tracts that are less dense than the tracts around the Newton Highlands and Newton Centre stations (which I've colored gold); the green and increasingly darker blue tracts are more and increasingly dense. All screenshots at the same zoom and scale.

As we can see, Arlington is actually significantly denser than the Green Line's sections of Newton. It is more comparable to Watertown and the north-of-Pike Newton neighborhoods, and not far off from Roslindale/West Roxbury. And the southern half of Arlington is basically on par with Quincy. Now, I'm not saying that such density demands heavy rail, but I do think it's worth highlighting.

~~~

Last summer, @ritchiew raised the idea of extending to Arlington via Mass Ave (potentially bypassing Alewife), and I think the justification holds:

A Red Line extension to Arlington Heights should include a stop at Lake Street and Mass Ave. Call it East Arlington Station. That point is in the middle of the most population dense part of Arlington, and would be about a mile from Davis, Alewife, or Arlington Center. This would require not following the Minuteman path, at least for the portion south of AC. But not doing it would mean building rapid transit that goes a long way to skip over the densest part of town.

So first, this is the most population dense part of Arlington. Most of the town is single family homes, but this area isn’t. It’s all duplexes on small lots, plus some pockets of apartment buildings. To roughly quantify it, I was just looking at populations in census blocks within a quarter mile from different possible stations in Arlington. AH = 3589; AC = 3109; EA = 4792. That ordering holds true any way I can find to look at. And there are other draws to that intersection, like restaurants, shops, and a historic movie theater. It' small, but there's stuff there.

This becomes all-the-clearer when looking at the population density map above; Arlington south/east of Arlington Center is way denser than the north (comparable to Allston/Brighton) and is centered on Mass Ave, not the Minuteman.

If we're gonna need to tunnel (and all the more so if we're gonna need to use a TBM to avoid disrupting the surface -- whether Mass Ave or the Minuteman), then it seems worth tunneling to the places where more people live and where new subway stations will be more useful.

~~~

Finally -- and I'm aware this is off-topic and represents a larger political gripe of mine -- from what I can tell, the Minuteman is estimated to have 2 million users per year. That comes out to an average of five or six thousand users per day. To put that number into context, that's around the same number of riders as at a single station like Braintree or Jackson Square or Fields Corner. It also happens to be less than the total ridership of the 77, which has roughly 7,000 daily riders.

The Minuteman is a beautiful linear park and obviously is valuable to its surrounding communities. But (temporarily) closing it for construction of a much higher capacity subway is not unreasonable.

 

[JeffDowntown]

Concerning tunneling along the Minuteman Trail, I have to think there is a (more expensive) variant on cut-and-cover that allows you to work, section by section, and perhaps keep one side of the linear park open with a cover while tunneling under the other side. Certainly more expensive, but perhaps the kind of compromise needed to get the extension built.

We tend to think very absolutely about these options (close the entire path, dig it all up simultaneously). The elevated Central Artery was kept open while the entire space under it was tunneled out.

 

[F-Line to Dudley]

Concerning tunneling along the Minuteman Trail, I have to think there is a (more expensive) variant on cut-and-cover that allows you to work, section by section, and perhaps keep one side of the linear park open with a cover while tunneling under the other side. Certainly more expensive, but perhaps the kind of compromise needed to get the extension built.

We tend to think very absolutely about these options (close the entire path, dig it all up simultaneously). The elevated Central Artery was kept open while the entire space under it was tunneled out.

Why do that? It's not like the trail is going to be out-of-commission for 10 years, and biking through a construction zone is not exactly going to be a pleasant experience with all the noise and dust. Just shut Thorndike-Lake St., Lake St.-Arlington Center, and Arlington Center-Mill St. in separate chunks. Like 1 year out-of-service for each chunk...maybe longer for the Arlington Center station cut (though that's the easiest segment to bike around). It's a capped-cut tunnel everywhere except under the Arlington Center station cut and street grid which would be traditional C&C. Capped cut is not a massive tunneling works production.

 

[kdmc]

Concerning tunneling along the Minuteman Trail, I have to think there is a (more expensive) variant on cut-and-cover that allows you to work, section by section, and perhaps keep one side of the linear park open with a cover while tunneling under the other side. Certainly more expensive, but perhaps the kind of compromise needed to get the extension built.

We tend to think very absolutely about these options (close the entire path, dig it all up simultaneously). The elevated Central Artery was kept open while the entire space under it was tunneled out.

Alernatively, if there were a nice wide shared path along Alewife Brook Parkway between Alewife and Mass Ave, as well as a great sidewalk-level cycletrack up Mass Ave to Arlington Heights, then cyclists would have an alternative high-quality route to use during construction.

This something we could advocate for now, it'd be valuable now, it'd be valuable when Minuteman is closed, and it'd valuable after construction too.