Crazy Transit Pitches

[ritchiew]

View attachment 56423
I guess my question is: Is the cost of a TBM for that length worth it when we can probably get away with reusing the existing ROW and then a much shorter (probably doable without a TBM) tunnel segment under Chelsea Creek and 1A. It's a longer trip, but it seems like it would save a lot of money (that map has the track loop around the terminals to serve each one, but obviously you can do as many or few stations as you want).

A very reasonable question that I can't answer for certain. But yeah, I think it's worth it.

The route you've drawn is about twice as long. With the extra curves, steep bridge over the Mystic, and extra stop in the middle, it'll average less than half the speed of my proposal. That could end up being more like 15-20 minutes from Logan to South Station. Then many times of the day, it's not faster than driving, or it's a wash. That's the tipping point in a lot of people's decision for whether or not to take transit, and it means lots more people will opt to drive or take a cab. I think the difference between an ok link to the airport and a really spectacular link to the airport could mean a huge difference in mode share split. That translates into thousands or likely tens of thousands fewer cars going to and from Logan every day.

As for the cost, I assume you're right that my proposal is more expensive. I'm not sure your proposal is exactly cheap, but I'm also not sure what your plan would be for each segment of that route. The existing ROW in Chelsea is being used by the Silver Line, so tunnel under it, or lose the local transit path, which would be a major loss. Tunnel under Chelsea Creek, yeah, not huge, but adds to the cost. Digging under 1A could be done cut-and-cover in part, but also some chunks of expensive mining, and maybe moving or shoring up highway supports, plus moving utilities. That's also the kind of complicated work where small, unexpected problems turn out to add a lot of cost. (Oh, and there might be some well studied, cheap solution for your exact route. Let me know if I'm just talking out of my ass here.)

And as for the cost difference between out two proposals, I really do think mine will attract significantly more riders. Even if my plan is twice as expensive, it's still worth it if it attracts twice as many passengers, which I think is possible.

And last, I do like that idea of a loop at the airport. It's a small enough space that I think one central terminal is better, but that's interesting to consider.

Yeah if we're digging a deep bore tunnel then we may as well just start from Chelsea. No need to go nearly as deep like you would need to for connecting to NSRL if you do that either.

If you're alternative is to deep bore the whole way from Chelsea to the airport, then I'm pretty certain my proposal is better. That's still almost two miles of tunneling, compared to my three, and again the extra mile is not significantly more expensive. Deep boring from Chelsea would be in the same ballpark cost of my proposal, but at add 10+ minutes to every train trip to Logan. That's worse.

 

[TheRatmeister]

but at add 10+ minutes to every train trip to Logan.

This number is just wrong. Assuming an average speed of 40 MPH between North Station and Logan given that we're presumably traveling non-stop here, the direct tunnel is 4.32 miles for ~6:30 of travel time, while the Chelsea route is about 6.78 miles for ~10:20 of travel time, so less than 4 minutes difference. It's not nothing, but I don't think it's worth adding a few hundred million to the project over.

The Chelsea option also lets you run for example a Fitchburg/Lowell->Logan service for no added cost, whereas adding such a service to a tunnel connection to NSRL means doubling the size of the underground flying junction you'd presumably want. You could even add some local Chelsea-Logan trains for local airport workers.

 

[F-Line to Dudley]

The route you've drawn is about twice as long. With the extra curves, steep bridge over the Mystic, and extra stop in the middle, it'll average less than half the speed of my proposal. That could end up being more like 15-20 minutes from Logan to South Station. Then many times of the day, it's not faster than driving, or it's a wash. That's the tipping point in a lot of people's decision for whether or not to take transit, and it means lots more people will opt to drive or take a cab. I think the difference between an ok link to the airport and a really spectacular link to the airport could mean a huge difference in mode share split. That translates into thousands or likely tens of thousands fewer cars going to and from Logan every day.

Your route has even sharper curves. Deep underground, where NSRL is only going to average a 15-20 MPH crawl on the labyrinthine grades. How does this wash at all? It's going to be an extremely slow train. If you think minutes/seconds matter to a schedule, you'd never build it the way you've sketched it out because it's going to be ass-slow.

As for the cost, I assume you're right that my proposal is more expensive. I'm not sure your proposal is exactly cheap, but I'm also not sure what your plan would be for each segment of that route. The existing ROW in Chelsea is being used by the Silver Line, so tunnel under it, or lose the local transit path, which would be a major loss. Tunnel under Chelsea Creek, yeah, not huge, but adds to the cost. Digging under 1A could be done cut-and-cover in part, but also some chunks of expensive mining, and maybe moving or shoring up highway supports, plus moving utilities. That's also the kind of complicated work where small, unexpected problems turn out to add a lot of cost. (Oh, and there might be some well studied, cheap solution for your exact route. Let me know if I'm just talking out of my ass here.)

Yours will cost multiple billions. Because you're doing the same thing that NSRL is doing on another equal-length tunneling appendage through a non-cleared space (unlike the CA/T alignment) through a nasty flood map. It's significantly more expensive for not significantly more ridership.

And as for the cost difference between out two proposals, I really do think mine will attract significantly more riders. Even if my plan is twice as expensive, it's still worth it if it attracts twice as many passengers, which I think is possible.

Y'all need to read more Alon Levy. Pedestrian Observations blog has built a career out of debunking Airport connector ridership arguments. They're HUGELY overrated as a class of transit projects, and there's almost no way that a splitting-hairs difference in travel time via your slow sharp-curved tunnel is going to produce an orders-of-magnitude difference in ridership. That's the bright red warning sign right there that you're overrating the airport's importance as a ridership generator bigtime. Don't forget...Logan Airport was only the 29th highest-ridership rapid transit station on the T in the last Blue Book, and SL1 + a Red-Blue assist aren't going to bring the airport up past any of the major and mid-major bus hubs in overall ridership-generating importance. Logan's a big airport nationally, but its transit ridership-generating heft is a niche audience relative to all else that uses the T.

 

[ritchiew]

Your route has even sharper curves. Deep underground, where NSRL is only going to average a 15-20 MPH crawl on the labyrinthine grades. How does this wash at all? It's going to be an extremely slow train. If you think minutes/seconds matter to a schedule, you'd never build it the way you've sketched it out because it's going to be ass-slow.

How slow? You phrased this as if to suggest my new proposed tunnel would average 15-20 mph. That's ridiculous. The route I drew has a half mile curve radius, then over a mile and and a half of straight track.

And the grade can be extremely level. This could connect to NSRL tunnels 100 feet underground, and keep that depth all the way around to East Boston. From there it's more than a mile to the proposed station. It's about a 1.5% grade on a straightaway. This would be an extremely fast connection to downtown.

Y'all need to read more Alon Levy. Pedestrian Observations blog has built a career out of debunking Airport connector ridership arguments. They're HUGELY overrated as a class of transit projects

Yes, I know airport connectors tend to be overrated. I said that in the last paragraph of my post.

I've also been reading Alon Levy. Yes, he says airport connectors are overrated, but makes very clear that doesn't mean they're all bad. Here's the important quote,

However, overrated does not mean bad. There exist airport connector projects with reasonable cost per rider. They’re still overrated, which means they’ll be built concurrently with even more cost-effective non-airport projects, but they’re good enough by themselves.

and a goofy meme he posted suggesting that a commuter rail connection might be more valuable than rapid transit via the Seaport.

 

[F-Line to Dudley]

How slow? You phrased this as if to suggest my new proposed tunnel would average 15-20 mph. That's ridiculous. The route I drew has a half mile curve radius, then over a mile and and a half of straight track.

And the grade can be extremely level. This could connect to NSRL tunnels 100 feet underground, and keep that depth all the way around to East Boston. From there it's more than a mile to the proposed station. It's about a 1.5% grade on a straightaway. This would be an extremely fast connection to downtown.

It's not going to connect to NSRL 100 feet below ground. Your junction is north of North Station where the tracks are mid-ascent on a maximally steep 3% grade. You're going to have to go back DOWN...on a curve...to get underneath Charlestown. Assuming it's even feasible to shiv in a junction in the middle of a 3% grade, lest you have to send all of NSRL back into design at untold cost bloat. Yes...it will be a 15-20 MPH slog, for damn sure. You're not considering the third dimension at all with that drawing.

Yes, I know airport connectors tend to be overrated. I said that in the last paragraph of my post.

I've also been reading Alon Levy. Yes, he says airport connectors are overrated, but makes very clear that doesn't mean they're all bad. Here's the important quote,

and a goofy meme he posted suggesting that a commuter rail connection might be more valuable than rapid transit via the Seaport.
View attachment 56451

The onus is kind of on you to project ridership for this thing that backs up the premise that it's only going to be slightly overrated instead of hideously, scandalously overrated. And that's required to be a very, very high number given that you're spending $2B+ to do this tunnel as a very complexly interacting NSRL appendage. The entire Commuter Rail southside today doesn't have bad Airport access on account of SL1 being right downstairs from the terminal, and it won't have bad Airport access tomorrow when Regional Rail spiffs up their frequencies. So quantify what the +1 one-seat actually means to southside Regional Rail. Especially with NSRL also potentially serving up a Blue Line transfer as an alternate route to SL1. What cost per rider are we talking for the billions it's going to take to build?

I can't possibly see how this is not going to be hideously freaking overrated at that cost-per-rider. It would probably have to be in the same ridership stratosphere as today's North Station to possibly make fiscal sense, and there's no possible way to extrapolate that much Logan potential from the current middling transit numbers the airport does from this whole region with its not-at-all-bad transit access. The potential is an order of magnitude shy of fiscal sanity. Are you actually expecting that the southside suburbs alone are going to ride to Logan daily at a North Station-ridership level? And if so, where have all those people been hiding all these decades?

 

[TheRatmeister]

and a goofy meme he posted suggesting that a commuter rail connection might be more valuable than rapid transit via the Seaport.

I do agree that there is potential for a future Acela/NER connection and that this could be extremely valuable. Getting New London to be a 1:45 train away from Logan is pretty big.

But if we acknowledge that as one of if not the primary benefit, we should also acknowledge that turning that into a 1:41 journey isn't really going to convince or turn anyone away.

Don't forget...Logan Airport was only the 29th highest-ridership rapid transit station on the T in the last Blue Book

Sounds like we should get that number up. I'm sure Massport and their parking revenue accountants would object, but over 130k passengers per day used Logan in June of this year. Of those, let's be generous and say around 20k ish were to/from Airport Station, another 5k ish were to/from SL1, and Logan Express is another ~10k a day. So for public transport, we've accounted for about about 25% of Logan Airport users.

So, how serious is Massachusetts and Massport about reaching climate goals? If the answer is any amount more than "a little bit" then maybe reducing the 20+ thousand private vehicles traveling to Logan each day would be a good start. Or if we care about having a city that's nice to be around, maybe we should try and reclaim the large swaths of land in Seaport, Eastie, and Chelsea currently used for private Airport parking. Or if just care about Logan and want to expand the passenger or cargo facilities there, maybe removing some of the 25k current parking spaces would be a good way to do that. If we're doing any of these things we need some kind of better rail connection to the airport, and to convince people to actually use it either by carrot or by stick.

 

[F-Line to Dudley]

Put it this way...if we're going to be chasing overrated things, shouldn't we be aiming to make them only slightly overrated like Levy says? In that case, the 4-minute longer trip on the existing Eastern Route tracks + a 3000 ft. small slice of SL3 surface ROW + a 2500 ft. under-Creek & highways tunneled segment is much much more slightly overrated than the extremely overrated $2B NSRL appendage with complex vertical junctioning that saves only 4 minutes (but probably not even that) from the same trip.

And if the ridership really, truly is amazing enough that this will seriously cut into the 20K private vehicles heading to Logan (I doubt it, but I'll humor myself for a reasoned possibility)...can't we easily afford to capped-cut tunnel the Urban Ring underneath the surface ROW for a measly 3000 ft. so we can have our cake and eat it too? When did that become a binary modal choice requiring $2B in ROW duplication??? If we're truly going to drive that kind of maximal transit shares to the Airport, don't we need both the UR and the RER and doesn't running the mainline trains on the roof of the ultra-shallow and cheaply dug UR trolley tunnel maximize our cost-per-rider yield tremendously more than NSRLNE?


Interesting thought experiment, but it's focusing on the wrong steel-and-concrete targets.