On the other hand, slightly less than half of Riverside riders who do have alternate modes indicated "different MBTA service" as an option, so there's still a significant amount or them who see CR as viable.
Great analysis. (We truly live in a transit data renaissance.) I do agree that the data suggests that "opportunistic riders" make up a signficant fraction, though probably not a majority, of Riverside's passengers.
So, to circle back to the Regional Rail question: is terminating on a Riverside spur a matter of operational convenience, or is there better demand there than at other locations?
Here's why I've been wandering. I call it "Project Norumbega", because I'm dramatic like that.
We hope that sometime in the future there will be many more trains running on the B&A than there are today. We know this would be an effective way to provide transit to "the Newtons", and it reflects an overall transformation toward Regional Rail. The "inner/mid B&A" is particularly friendly to more frequent rail, as most of the stops between 128 and Framingham have reasonable pedestrian access and/or potential for TOD.
As discussed above, in general we've assumed that one "layer" of service would be a short-turn service within 128, and I think most of us have figured that service would terminate on a spur at Riverside station. Historically, there was a platform on the B&A main line
that was also called Riverside
, but it was some 1,800 feet away from the Green Line station, and saw low ridership. (For comparison, Woodland is 3,000 feet away.)
I was crayoning Regional Rail service patterns on the B&A a while back and got to thinking. On other "Metro Rail" corridors, I've felt that it was reasonable to layer on the "longer distance" services on top of the short-turns to reach high frequencies, and have the longer distance trains make most/all local stops. With infrastructure improvements to reduce travel times, I've mostly felt that expressing through the inner stops was unnecessary. But for the B&A, I'm less confident. Given Worcester's distance and the curvy route the tracks have to take through the hills, it seems possible that even in a Regional Rail world, we'll still want some Worcester expresses.
For comparison, pre-covid most peak Worcester trains skipped both the "mid" stops in Wellesley, as well as the "inner stops" in Newton.
took ~90 min to do so. Worcester is the commonwealth's second largest city
and by now is comfortably larger than Providence; it shouldn't take 90 minutes to reach Boston. So I think express services need to remain under consideration. Therefore, I don't want to rely on Worcester trains to increase the tph within 128 -- it may not be necessary, but I'd like to have alternatives.
I also think it's worth examining higher-frequency service to Wellesley, Natick, and Framingham. Though not as dense as the within-128 suburbs, there is a clear "arm" of density stretching west along Route 9
. Moreover, as mentioned above, most of the stations in those towns are located in well-built-up areas that are, or could be, friendly to frequent transit.
So, it might be possible that we'd want higher frequencies to the mid-B&A, and
that we'd still want to reserve slots for expresses to the outer B&A. In principle, this could be done via 4 tph express to outer B&A, 4 tph local to Framingham, and an additional 4 tph turning at Riverside. There's a lot that could work well about this, but that Riverside spur is a bit fragile and makes me nervous; if there were increased demand along the mid B&A, some of those Riverside trains probably be switched back over to the main line, which reduces Riverside Indigo frequencies below the 15-minute threshold. Once that happens, I think you're at significantly higher risk for a ridership death spiral.
Now, it's worth pausing for a second here, and noting that we are already pretty far down the rabbit hole here. There is a large extent to which "Project Norumbega" is a solution in search of a problem. I think an Indigo spur to Riverside, overall, makes sense, although I think there is also an argument for extending all those within-128 Metro trains to Framingham anyway.
But while we're down this rabbit hole...
The way to maximize frequencies -- under any scenario -- to the Riverside area -- i.e. to a P&R near 128 & Mass Pike -- is to put the station on the mainline. That gives you access to both short-turns and to through-run trains for maximum frequencies. As mentioned before, a mainline station was tried, and wasn't successful -- poor walkshed, limited parking (I think), and difficult transfer to the Green Line.
But what if, instead of extending the Indigo Line to meet the Green Line, we extended the Green Line to the mainline?
Thus, Norumbega Junction:
(Yes, it is true that "Norumbega" -- insofar as it even is a real place -- is about a mile to the northeast. But I couldn't think of a more specific name, and tbh thought that "Norumbega Junction" sounded pretty cool, so that was that.)
There are a lot of things that work surprisingly well here. That stretch of track just west of 128 is tangent and more than long enough for a full-length platform. This is the planned location for the beginning of the third track (which I've tried to represent here), meaning there already will be a passing track in place to avoid short-turns causing backups. The ROW to the east historically had 4 tracks, and is mostly unencroached. The bridge over the ramp on the east still has a quad-track footprint.
There are some downsides. For one, the interlockings for the third track would probably need to be a bit more complicated than currently planned. The width of the parcel is a bit narrow, which is why I've proposed essentially a pair of consecutive northside platforms for the Green Line -- crossplatform from the southern mainline track, essentially creating two "berths" to maintain high capacity for Green Line turns without requiring more than 2 platforms squeezed into the ROW overall.
A new bridge would need to be constructed over the Charles, through a park/nature recreation area. This is a non-trivial downside, though hopefully its construction could be paired with additional improvements to the park.
Not illustrated here is parking. There are two lots to the northeast of the station site -- one is about 40,000 sq ft, and the other I believe is 50,000 sq feet, which is the footprint of the Woodland garage. So, in principle there'd be space for robust PnR, especially with a garage.
The biggest downside I've seen so far is that access from the highways is... mixed.
- Route 128 from the south: not bad -- get off at Recreation Road and cross over
- Route 128 from the north: requires a jaunt on MA-30, which is okay not great
- Mass Pike from the west: kinda garbage -- exit to MA-30 and double-back
- Mass Pike from the east: easy -- off ramp directly to Park Rd
I think items 2 and 3 could be addressed via connections from ramps to Park Rd -- from the eastbound Mass Pike off-ramp, and from the (very long) soutbound 128-to-90 off-ramp. But I'm woefully uninformed about highway engineering, so those may not work.
So, in light of the above discussion, what would Norumbega Junction help with? And what does it leave lacking?
- Frequencies on mid-B&A
- Frequencies for a Metro short-turn service terminating at a Park-n-Ride
- Overall parking capacity at PnR stations in the area
- Reverse-commute options to Wellesley, Natick, Framingham and possibly Worcester, from Newton and Brookline
- Better transfers from Indigo to Green, potentially enabling more direct service to Longwood
- (definitely slower, but if D-to-E is built, the speed penalty might get outweighed by a shorter walk from LMA than from Lansdowne)
- Opportunistic riders who currently drive to Riverside as one option among several
- providing additional parking
- maximum frequencies from a single platform -- make a "game time" decision of boarding Indigo vs Green
- Avoids rebuilds at Riverside, including needing to fit a long 800 foot platform
- To avoid touching the yard, I think the platform would need to be about 500 feet away from the current Green Line platform
- Reconfiguring the loop and yard leads could bring it closer, but increases cost and disruption
- Frequencies from Riverside station itself
- although faster journeys may still be possible via a double-back: Riverside - Norumbega Jct - points east on the Indigo
- TOD at Riverside
- Folks who walk/bike to Riverside, who would see the same number of trains
- though there are already a few different trails that could be upgraded -- it would be about a 12 minute walk (and very pretty!) between the two stations, which would be too long for some, but could be possible for others
- Reverse commuters going to Riverside from Newtonville, Allston, Brighton, and other Indigo points east
- Though, again, they would likely have higher frequencies on Indigo and then be able to change to do a one-stop jog (or 12-minute walk) to Riverside