Crazy Transit Pitches

[F-Line to Dudley]

Would it ever be possible to run a GLX to Belmont Center and preserve the commuter rail as well? I’m guessing the ROW just isn’t wide enough, right?

The Fitchburg was historically quad-track out to the West Cambridge freight yard (reason why they were able to do GLX-Union pretty easily), and tri-track from West Cambridge to the split with the Central Mass after Beaver St. in Waltham because the Central Mass used to have its own running track along the Fitchburg ROW (residue from when it was a competing RR). Through Belmont Center station it's quad-width because the Central Mass leased a blank spot for an expansion track that never came. So you'd have no issues getting to Belmont Center, though I would assume GLX would outright be eating the station instead of side-by-sideing a superstation (a little too much width).

Past Belmont Ctr. (if the eventual goal is a GLX-Waltham) the ROW narrows down to tri-track along Pleasant St., though embankment reshaping can easily add the 4th berth. Waverley station is a 1955 grade crossing elimination so it was only ever provisioned as double-track; would need some substantial retaining wall and bridge work to quad-up, but is feasible because the station really isn't abutted by anything within the square except its own parking lot. Past there it's back to tri-width with embankments that can be traded for retaining walls. And then you'd have to swap the Fitchburg mainline to the Central Mass out to 128 to free up the Waltham Center-Brandeis tracks for GLX because that definitely was only double-track and has some dense abutters. It'd be less of a megaproject than GLX-Medford was widening a historically 2-track ROW, but probably isn't anyone's idea of a top priority because :15 Urban Rail service to 128 is probably worth a generation's worth of growth absorption.

 

[FK4]

The Fitchburg was historically quad-track out to the West Cambridge freight yard (reason why they were able to do GLX-Union pretty easily), and tri-track from West Cambridge to the split with the Central Mass after Beaver St. in Waltham because the Central Mass used to have its own running track along the Fitchburg ROW (residue from when it was a competing RR). Through Belmont Center station it's quad-width because the Central Mass leased a blank spot for an expansion track that never came. So you'd have no issues getting to Belmont Center, though I would assume GLX would outright be eating the station instead of side-by-sideing a superstation (a little too much width).

Past Belmont Ctr. (if the eventual goal is a GLX-Waltham) the ROW narrows down to tri-track along Pleasant St., though embankment reshaping can easily add the 4th berth. Waverley station is a 1955 grade crossing elimination so it was only ever provisioned as double-track; would need some substantial retaining wall and bridge work to quad-up, but is feasible because the station really isn't abutted by anything within the square except its own parking lot. Past there it's back to tri-width with embankments that can be traded for retaining walls. And then you'd have to swap the Fitchburg mainline to the Central Mass out to 128 to free up the Waltham Center-Brandeis tracks for GLX because that definitely was only double-track and has some dense abutters. It'd be less of a megaproject than GLX-Medford was widening a historically 2-track ROW, but probably isn't anyone's idea of a top priority because :15 Urban Rail service to 128 is probably worth a generation's worth of growth absorption.

In fantasy mode where you actually did run GLX to 128, tho, would this offer a reasonable commuter time to get downtown? I’m guessing that light rail can accelerate faster but maybe not run as fast in between stations vs commuter rail? What about compared to when the Fitchburg line gets electrification?

 

[KCasiglio]

I’m guessing that light rail can accelerate faster but maybe not run as fast in between stations vs commuter rail?

My understanding based off of similar conversations that have been had about replacing CR service to Needham with a green line branch is that there is a speed tradeoff that is supposed to be made up for with improved frequency. 4 trains per hour vs 10. In the case of Waltham, you're not really eliminating the CR option, you're just shifting it north to the Mass Central RoW.

 

[F-Line to Dudley]

In fantasy mode where you actually did run GLX to 128, tho, would this offer a reasonable commuter time to get downtown? I’m guessing that light rail can accelerate faster but maybe not run as fast in between stations vs commuter rail? What about compared to when the Fitchburg line gets electrification?

It depends on how many intermediate stations there are. TransitMatters, for instance, specced adding four of them to Urban Rail: Brickbottom, Union Square, Alewife, and Warrendale. That's going to keep top speeds way down on Urban Rail so the acceleration advantage of LRV's starts to take over at those kinds of densities. And there's more possible infills still because it's a fairly dense corridor. Ultimately what will make light rail slightly slower on the clock is that you'd lean much heavier on infills to get LRT-like stop spacing. Done with the same number of stations TransitMatters specced you'd probably be making equal or better time, but if it's going to be true Green Line you'd probably add a few more on top of that. It has the upside of tapping a much broader audience with the denser stop selection at much higher frequencies, so in the end you come out way ahead. Like anything, it's a balance. But I think here you go straight at the density and don't fret too much about the comparative run times.

For reference, in 2020 I diagrammed out a GLX-Waltham layout. Note how many new intermediates there are compared to Commuter Rail.


EDIT: Also, what @KCasiglio said...Purple Line isn't going away, it's just changing to a Porter-128 express and dramatically speeding up travel times to the past-128 stops on the Fitchburg. Alignment misses Waltham Center, but you can backtrack from the 128 superstation at good-enough time if seconds on the clock truly matter.

 

[Riverside]

Also keep in mind that the nearby Riverside Branch does just fine, at a similar distance, and into an even less dense (less walkable) neighborhood. In a world where Auburndale is a viable alternative with frequent service, perhaps that would change. But the D currently runs Riverside <> Kenmore in about 31 min, averaging 17.4 mph; at those speeds, Waltham <> North Station takes 33 minutes, which seems pretty reasonable to me, especially at rapid transit frequencies and eliminating a transfer at North Station.

 

[FK4]

Interesting. I somehow thought Waltham was more than that. So yeah, half an hour-ish seems very reasonable for Waltham. And since F'burg is such a long line, seems like a benefit to shave off a few stops in the burbs, and have it operate as a 128-Porter-Boston shuttle once you're inside 128.

 

[TheRatmeister]

If we're doing capital projects to serve Waltham though, I don't think GL from Union Sq is the best way to do that. I'm again going to point to the Aqua Line, bringing rapid transit frequencies and capacity not only to Waltham but also to Watertown, Allston and West Station, before making a new connection along the Grand Junction. This would still allow for the removal of Brandeis/Roberts as a stop for all Fitchburg Line trains, with an express to Littleton/495 operating once per hour in the peak.

Instead, use the extra space along the Fitchburg Line for express tracks and passing sidings to allow for a skip-stop service, plus the rush hour Littleton/495 super express.

 

[F-Line to Dudley]

Instead, use the extra space along the Fitchburg Line for express tracks and passing sidings to allow for a skip-stop service, plus the rush hour Littleton/495 super express.

Fitchburg is never going to have dense enough service to require extra express tracks. It's branchless (and figures to remain that way because the Central Mass to Hudson is a poor-ridership candidate with lots of station siting problems) making dispatching very straightforward, there's no freight Littleton-inbound, and you'd only need a few extra crossovers to skip-stop or super-express. If the inside-128 Worcester Line can juggle an even bigger service layer cake on 2 tracks with 1-2 more crossovers than today, then so can Fitchburg.

 

[Riverside]

If we're doing capital projects to serve Waltham though, I don't think GL from Union Sq is the best way to do that. I'm again going to point to the Aqua Line

Also:

This is why I now prefer an East Somerville alignment for this concept. Via GLMF, you manage to miss not one but both of the radial transit lines you cross. I can live with missing Union (Union Sq itself should have a 1SR bus ride to Kendall, and points further west can transfer to Red at Porter), but the communities served by the Medford Branch are so ridiculously close to Kendall that it seems absurd that they shouldn't have a 2SR. If we're gonna spend $$$ building this thing, a proper connection at East Somerville seems worth it to include.

 

[Riverside]

Interesting. I somehow thought Waltham was more than that.

Yeah, I think a century of only having slow surface transit and low frequency commuter rail has made it seem more distant. (Probably a similar story for Lynn, tbh.) But yeah, it’s no further than Newton is.