Measure R Planning - Valley-Westside Rail Tunnel

[fissure]

I don't think it's people waiting to transfer, I think it's people getting on at the interim stations and heading south instead of north to transfer to Sepulveda. That stacks with Orange Line transfers and people buying Volkswagens to overload it.

[andert]

Sepulveda video is up here: youtu.be/xJdbCgVkH3w
with a shorter tl;dw version here: youtu.be/XAXVAHhlUQA

[bzcat]

That is such a good video. Great job andert!

The poor transfer design is my biggest problem with BYD. It's like they designed a metro train without ever seeing how one works in real life.

Also... LOL at the short one.

[culvercitylocke]

my biggest take away from the video was how BYD is nothing but broken connections and Bechtal is nothing but superb connections. And all transit is about connectivity, so screwing up that fundamental is especially horrific.

Fantastic illustrations and breakdown. Truly a great piece.

And my god, I didn't know that's where the 101 station was, the horror the horror.

[andert]

Thanks both of you! One thing I noticed is that metro's own prelim engineering drawings for the ESFV line have the metrolink connector station south of keswick, which is bad for connecting to the metrolink and will be really bad for connecting with sepulveda. I'm not sure what constraints caused them to put the station so far south, but hopefully by the time it's shovel-ready, they'll have moved the station up to be under the future sepulveda station. That's the one transfer that will be difficult no matter what right now, and it's an important one.

[culvercitylocke]

Judging by the air quality outcry that is killing the 710 freeway expansion, I think air quality/racism tactic used to stop that freeway expansion would work extremely well against the monorail.

Sure you can ride the monorail, but you have to suck in massive amounts of freeway pollution. Forcing transit riders to suck in massive pollution to use a system is really just a deliberate attack on on the quality of life of POC.

At the very least it'd put BYD on the defensive and add a couple hundred million dollars of much needed expensive air filtration designs to stations and consists.

[andert]

After reading through their documents and the SR60 gold line stuff, I'm increasingly convinced that caltrans mitigations are the biggest hidden cost. This is subjective, but reading between the lines of the document I get a *strong* sense that they designed and priced the line as if mitigations wouldn't be required, met with caltrans and said, "is there any universe in which you're comfortable with this?" and they said yes, but you'll have to do xyz. BYD simply publishes 'caltrans said yes!' and then a few lines later (paraphrased) 'we'll follow up on looking into mitigations.' They never explicitly say that caltrans said "yes, IF" instead of just "yes", but putting the pieces together it's pretty easy to see. I think caltrans would make them shift the side-running ROW over so that BYD would need property acquisitions along the entire route (what caltrans wanted them to do for SR60), and it seems there were design changes required for the median sections that were briefly alluded to under possible mitigations that almost certainly would cost an arm and a leg more.

The thing is, the real price should more or less get nailed down by the metro study, so I'm wondering if BYD is just hoping that by winning initial public support they can overcome the inevitable moment when the price crashes back to reality, or if their strategy relies on sherman oaks homeowners kicking up enough of a fuss. I feel like they maybe didn't count on so many traditional westside nimbys (minus bel-air) putting their weight behind heavy rail. And I also wonder if their lack of familiarity with... everything made them think they could get away without any mitigations and then by the time reality hit they were too deep in. But I think no matter what we'll get the real cost out of metro and public support will then evaporate pretty quick, forcing even conflicted politicians to back off, so you really gotta wonder what their next move is.

[bzcat]

I mentioned this several pages back. It feels like BYD's plan was to knock out all the heavy rail PPP options before the DEIR so they would be only competing with Metro's own HRT concepts. The plan I believe was then to attack Metro for bias towards its own HRT plan if the BYD monorail failed to advance to FEIR. Except they probably didn't count on Bechtel putting in such a great bid with detailed design on all the stations with very high transfer quality.

I called out the dishonest sleight of hands too early on but I just didn't have the time to read through every single page of the document. But thanks to numble and andert, I think we have a clear picture of what is going on now.

The most disappointing part of this trainwreck monorail debacle is the deafening silence from the usual people/groups that would be all over this terrible piece of fake transit kabuki theater (all it is missing is a red hat and a catchy phrase... make monorail great again!). It seems that all our traditional 501c transit advocate groups (which I will not name because I have no proof) must have received funding from BYD and signed non-disparagement agreements.

[andert]

Ah yeah that makes a WHOLE lot of sense actually. It was probably unusual that metro advanced 2 P3s rather than just one. If it was the only P3 on the table BYD would then have the acceleration argument firmly in their corner no matter how bad the line was. The upside is they're in even more of a tight spot now, then. I feel like the one major obstacle (other than byd's influence) to selecting bechtel is sherman oaks homeowners. Bel Air should hopefully be appeased by a single bore combined with the prospect of 405 construction. I'd be unsurprised if ultimately the option gets exercised in bechtel to put the ventura station underground to avoid demolishing homes where the tunnel portal would be (they threw it in in case the political situation demanded it, but didn't mention the cost that I saw). Could probably bump them to closer to 11.5B though, which isn't fantastic.

[Guest]

May 12, 2021 22:10:35 GMT -8 bzcat said:

But thanks to numble and andert, I think we have a clear picture of what is going on now.

Numble and Andert have done excellent work for our region, and I believe are truly making a big difference on the future of this city with their transit activism. Thank you both for your work, it's pretty incredible that we have such dedicated people who do this extensive education and advocacy for free on their own time.

[andert]

That's very kind, thank you both. Definitely couldn't do anything without the advice and collaboration of the whole community here though, especially numble.

[JerardWright]

May 12, 2021 11:15:48 GMT -8 andert said:

One thing I noticed is that metro's own prelim engineering drawings for the ESFV line have the metrolink connector station south of keswick, which is bad for connecting to the metrolink and will be really bad for connecting with sepulveda. I'm not sure what constraints caused them to put the station so far south, but hopefully by the time it's shovel-ready, they'll have moved the station up to be under the future sepulveda station. That's the one transfer that will be difficult no matter what right now, and it's an important one.

One possible constraint is the cost to widen the underpass at the Van Nuys Station and flatten the grade for LRT tracks and have a wide enough platform for escalators/elevators etc.

Keswick is a short distance away with a short walk to the entrance to the current Metrolink/Amtrak and future Sepulveda Pass platforms which I believe would be easier to move towards Van Nuys and Keswick. I am sure its easier to improve the pedestrian pathways to the Van Nuys Station as a result through a covered canopy along the pathway.

[numble]

Andrew E shared with my Bechtel's fly-through video of their Sepulveda heavy rail proposal:

[andert]

Well, glad they're touting their system connectivity and putting out something visual and public-facing, but they still need a good design team. Even sticking with the uninspiring metro kit of parts for the actual architecture, you can still dress it up to look real nice. BYD's renderings are so sunny and gleaming, with that vibrant purple color theme that feels futuristic and fresh, and they've even thrown in public art works in their designs. Untextured google earth overlays are not the same thing. People need to feel how inviting and exciting the space will be to get excited about it.

[culvercitylocke]

exciting stuff, glad they put that together. maybe a bit risky identifying every house it passes under beneath the pass but transparency and sunlight is probably good. better than being coy about it.

[bzcat]

I feel like andert can do a better video than Bechtel did

But this was pretty good effort for them to show exactly where the stations will be located.

[numble]

Here is the recording of Metro's community outreach meeting for the Sepulveda Transit Corridor project that was held on June 8, 2021:

[usmc1401]

Just heard on KNX radio today 08/04/2021 that Metro board is moving ahead with sepulveda pass project. Not final aproval but a step.

[numble]

Metro has started the environmental scoping period for the Sepulveda Transit Corridor. They have refined it to 6 alternatives, 3 monorail and 3 heavy rail.

[bzcat]

Here is my take

• Alt 1 - A bus connection to UCLA that will add 30 minutes to the trip? How much did BYD bribe everyone to keep this one in the running?
  
• Alt 2 - So let me get this right... instead of building the line properly to serve UCLA, we are going to build yet another different train, an APM that connects UCLA to Wilshire/Westwood so we end up with 3 different modes and out of station transfers for all 3? Does anyone working at Metro actually use public transportation?
  
• Alt 3 - Underground monorail... ugh. The worst part as we pointed out before... if you are going to deviate from 405 (a good thing), just continue south on Sepulveda. Why would go veer back to the freeway after leaving Wilshire/Westwood? Makes no sense.
  
• Alt 4 - Good, but all the SFV stations are elevated so it will be a huge fight and endless lawsuits.
  
• Alt 5 - So we bury the line below ground in the Valley for no apparent reason other than to appease NIMBY but then why does it still follow the the same deviating route? Just go straight from Metrolink Station to Orange line/Sepulveda station.
  
• Alt 6 - This actually makes the most sense so naturally it is the last alt to make the cut. Best for transfers and best for final destinations. However, I think the prelim study had said that projected peak transfer from subway to ESFV will overwhelm the ESFV line... Metro will need to study this more carefully.

[numble]

The CEQA notice on the Sepulveda Transit Corridor, published today, has very detailed descriptions of the 6 alternatives. For some reason, the descriptions of Alternatives 4-5 say they use automated 3-4 car trains but Alternative 6 will use driver-operated 2-6 car trains. Its odd that they would differentiate the modes like that, but hopefully those aren't anywhere near final. I guess its because the P3 contractor (Bechtel) proposed options that look like Alts 4-5, and Metro will continue studying Alt 6 based on their traditional HRT designs?

ceqanet.opr.ca.gov/2021110432

Alternative 1: Monorail with aerial alignment in Interstate 405 (I-405) corridor and electric bus connection to UCLA. Alternative 1 would utilize monorail technology, with automated train operations and planned peak frequencies of 2 minutes. Trains would consist of two to eight cars and are expected to consist of six cars during peak periods, with each car having a capacity of 76 to 79 passengers. The southern terminus station would be adjacent to the Metro E Line Expo/Sepulveda Station, and the northern terminus station would be adjacent to the Van Nuys Metrolink Station. The length of the alignment between the terminus stations would be 15.3 miles. The monorail guideway would be entirely aerial and generally located within the Interstate I-405 right-of-way and then adjacent to the Metrolink Ventura County Line railroad tracks between I-405 and the Van Nuys Metrolink Station. In some areas, including all stations, the guideway and passenger platforms would be located on one side of the freeway. Alternative 1 would have eight aerial monorail stations: Exposition Bl (Metro E Line), Santa Monica Bl, Wilshire Bl (Metro D Line), the Getty Center, US-101, Metro G Line, Sherman Way and the Van Nuys Metrolink Station. At Wilshire Bl, an aerial station would be located on the west side of I-405, and an electric bus shuttle would provide service along a 1.4-mile route between the Metro D Line Westwood/VA Station and UCLA Gateway Plaza, with intermediate stops at Wilshire Bl/Veteran Av and Westwood Bl/Le Conte Av. The electric bus shuttle would operate at the same frequency as the monorail. A maintenance and storage facility (MSF) for monorail vehicles would be located above the existing parking lot at the Metro G Line Sepulveda Station. Electric buses would be maintained within the existing UCLA BruinBus maintenance facility on Veteran Avenue north of Kinross Avenue.

Alternative 2: Monorail with aerial alignment in Interstate 405 (I-405) corridor and aerial automated people mover connection to UCLA. Alternative 2 would utilize monorail technology, with automated train operations and planned peak frequencies of 2 minutes. Trains would consist of two to eight cars and are expected to consist of six cars during peak periods, with each car having a capacity of 76 to 79 passengers. The southern terminus station would be adjacent to the Metro E Line Expo/Sepulveda Station, and the northern terminus station would be adjacent to the Van Nuys Metrolink Station. The length of the alignment between the terminus stations would be 15.8 miles. The monorail guideway would be entirely aerial and generally located within the I-405 right-of-way and then adjacent to the Metrolink Ventura County Line railroad tracks between I-405 and the Van Nuys Metrolink Station. In some areas, including all stations, the guideway and passenger platforms would be located on one side of the freeway. Alternative 2 would have eight aerial monorail stations: Exposition Bl (Metro E Line), Santa Monica Bl, Wilshire Bl (Metro D Line), the Getty Center, US-101, Metro G Line, Sherman Way and the Van Nuys Metrolink Station. South of Santa Monica Bl and north of Sunset Bl, the alignment of Alternative 2 would be the same as that of Alternative 1. At Wilshire Bl, an aerial station would be located on the south side of the street along Veteran Av. To provide a connection to the UCLA campus, a pedestrian bridge across Wilshire Bl would connect to an aerial Automated People Mover (APM) station on the north side of the street. From there, the APM would travel on a 1.0-mile aerial guideway located primarily along Gayley Avenue to an aerial APM station near the west end of Bruin Walk on the UCLA campus. The APM would operate at the same frequency as the monorail. An MSF for monorail vehicles would be located above the existing parking lot at the Metro G Line Sepulveda Station, and an MSF for APM vehicles would be located above the existing UCLA BruinBus maintenance facility on Veteran Avenue north of Kinross Avenue.

Alternative 3: Monorail with aerial alignment in Interstate 405 (I-405) corridor and underground alignment between the Getty Center and Wilshire Bl. Alternative 3 would utilize monorail technology, with automated train operations and planned peak frequencies of 2 minutes. Trains would consist of two to eight cars and are expected to consist of six cars during peak periods, with each car having a capacity of 76 to 79 passengers. The southern terminus station would be adjacent to the Metro E Line Expo/Sepulveda Station, and the northern terminus station would be adjacent to the Van Nuys Metrolink Station. The length of the alignment between the terminus stations would be 16.2 miles. The monorail guideway would be aerial for most of the alignment, with a 3.3-mile tunnel segment between the Getty Center and Wilshire Bl. The aerial alignment would generally be located within the I-405 right-of-way and then adjacent to the Metrolink Ventura County Line railroad tracks between I-405 and the Van Nuys Metrolink Station. South of Santa Monica Bl and north of the Getty Center, the alignment of Alternative 3 would be the same as that of Alternatives 1 and 2. Just south of Wilshire Bl, the alignment would diverge from the I-405 median, transition to below grade north of Wilshire Bl, and travel underneath Westwood Village and UCLA, before returning to the I-405 corridor just south of the proposed Getty Center Station. In some areas, including all aerial stations, the guideway and passenger platforms would be located on one side of the freeway. Alternative 3 would have one underground monorail station at UCLA Gateway Plaza and eight aerial monorail stations: Exposition Bl (Metro E Line), Santa Monica Bl, Wilshire Bl (Metro D Line), the Getty Center, US-101, the Metro G Line, Sherman Way and the Van Nuys Metrolink Station. An MSF for monorail vehicles would be located above the existing parking lot at the Metro G Line Sepulveda Station.

Alternative 4: Heavy rail with underground alignment south of Ventura Bl and aerial alignment generally along Sepulveda Bl in the San Fernando Valley. Alternative 4 would utilize steel-wheel heavy rail transit (HRT) trains, with automated train operations and planned peak frequencies of 2.5 minutes. Trains would typically consist of three cars, with each car having a capacity of 170 passengers, but could be increased to four cars. The southern terminus station would be adjacent to the Metro E Line Expo/Sepulveda Station, and the northern terminus station would be adjacent to the Van Nuys Metrolink Station. The length of the alignment between the terminus stations would be approximately 14 miles. The alignment would be underground between the southern terminus and a portal south of Ventura Bl in the San Fernando Valley. Between this portal and Ventura Bl, the guideway would be aerial on the east side of I-405. North of Ventura Bl, the guideway would generally be located above Sepulveda Bl until curving southeast to parallel the Metrolink Ventura County Line railroad tracks. Alternative 4 would have four underground stations at Exposition Bl (Metro E Line), Santa Monica Bl, Wilshire Bl (Metro D Line) and UCLA Gateway Plaza, and four aerial stations at Ventura Bl, the Metro G Line, Sherman Way and the Van Nuys Metrolink Station. An MSF for HRT vehicles would be located west of Woodman Av south of the Metrolink Ventura County Line railroad tracks.

Alternative 5: Heavy rail with underground alignment including along Sepulveda Bl in the San Fernando Valley. Alternative 5 would utilize steel-wheel HRT trains, with automated train operations and planned peak frequencies of 2.5 minutes. Trains would typically consist of three cars, with each car having a capacity of 170 passengers, but could be increased to four cars. The southern terminus station would be adjacent to the Metro E Line Expo/Sepulveda Station, and the northern terminus station would be adjacent to the Van Nuys Metrolink Station. The length of the alignment between the terminus stations would be approximately 14 miles. The alignment would be the same as that of Alternative 4, but it would be underground between the southern terminus and a portal south of the Metrolink Ventura County Line railroad tracks. Near the northern terminus, the alignment would be aerial parallel to the Metrolink Ventura County Line railroad tracks. Alternative 5 would have seven underground stations at Exposition Bl (Metro E Line), Santa Monica Bl, Wilshire Bl (Metro D Line), UCLA Gateway Plaza, Ventura Bl, the Metro G Line and Sherman Way, and one aerial station at the Van Nuys Metrolink Station. An MSF for HRT vehicles would be located west of Woodman Av south of the Metrolink Ventura County Line railroad tracks.

Alternative 6: Heavy rail with entirely underground alignment including along Van Nuys Bl in the San Fernando Valley and southern terminus station on Bundy Dr. Alternative 6 would utilize the same driver-operated steel-wheel HRT trains as used on the Metro B and D lines, with planned peak frequencies of 4 minutes. Trains would consist of two, four or six cars and are expected to consist of six cars during peak periods, with each car having a capacity of 133 passengers. The southern terminus station would be adjacent to the Metro E Line Expo/Bundy Station, and the northern terminus station would be adjacent to the Van Nuys Metrolink Station. The length of the alignment between the terminus stations would be 12.6 miles. The alignment would be entirely underground, with the segment on the Westside running generally northeast between the Metro E Line Expo/Bundy Station and the UCLA campus, and the segment in the San Fernando Valley located along Van Nuys Bl. Alternative 6 would have seven underground stations at Olympic Bl (Metro E Line), Santa Monica Bl (West LA Civic Center), Wilshire Bl (Metro D Line), UCLA Gateway Plaza, Ventura Bl, the Metro G Line and the Van Nuys Metrolink Station. An MSF for HRT vehicles would be located east of Van Nuys Bl north of the Van Nuys Metrolink Station.

[andert]

I think this puts the thumb on the scale for 4/5 to win out over 6, and the decision between 4/5 depends on the power of NIMBYs vs cost. On the monorail side 1/2 are so obviously unworkable with their UCLA connections that 3 is what will seriously get studied. So, essentially, 3 vs 4/5. I think the thing that concerns me most, as I just mentioned on twitter, is that BYD's presented their hypothetical max capacity while Bechtel has not, even though BYD's would require platform extensions and Bechtel's would only requiring increasing headways from 2.5m to 1.5m with no infrastructure changes. Presumably though the study will carefully parse the cost of each capacity maximum and compare them accordingly.

[bluelineshawn]

Dec 1, 2021 10:50:51 GMT -8 numble said:

The CEQA notice on the Sepulveda Transit Corridor, published today, has very detailed descriptions of the 6 alternatives. For some reason, the descriptions of Alternatives 4-5 say they use automated 3-4 car trains but Alternative 6 will use driver-operated 2-6 car trains. Its odd that they would differentiate the modes like that, but hopefully those aren't anywhere near final. I guess its because the P3 contractor (Bechtel) proposed options that look like Alts 4-5, and Metro will continue studying Alt 6 based on their traditional HRT designs?

It makes sense to study using equipment that is compatible with existing train technology if metro anticipates that at some point they will end up maintaining the fleet either because the P3 isn't selected or maybe it's ended. Or maybe they want to join with the B/D one day? What's weird is saying that it would only have 4-minute headways and would be driver operated. The metro B/D lines have headway limitations based on the ventilation shaft locations with the longest distances being the 4-minute gaps between NoHo/Universal and Universal/Highland, hence the max headway is 4 to 5 minutes. The large bore tunnel is supposed to get rid of that requirement and there shouldn't be any reason that headways couldn't be more frequent. Lots of driver-based systems around the world have 2-min headways. But then the other weird thing is that the B/D lines were designed to be automated. Unless something has changed (and maybe it has) the only thing that train operators do on the B/D lines is open and close doors.

[numble]

Dec 3, 2021 7:46:11 GMT -8 bluelineshawn said:

Dec 1, 2021 10:50:51 GMT -8 numble said:

The CEQA notice on the Sepulveda Transit Corridor, published today, has very detailed descriptions of the 6 alternatives. For some reason, the descriptions of Alternatives 4-5 say they use automated 3-4 car trains but Alternative 6 will use driver-operated 2-6 car trains. Its odd that they would differentiate the modes like that, but hopefully those aren't anywhere near final. I guess its because the P3 contractor (Bechtel) proposed options that look like Alts 4-5, and Metro will continue studying Alt 6 based on their traditional HRT designs?

It makes sense to study using equipment that is compatible with existing train technology if metro anticipates that at some point they will end up maintaining the fleet either because the P3 isn't selected or maybe it's ended. Or maybe they want to join with the B/D one day? What's weird is saying that it would only have 4-minute headways and would be driver operated. The metro B/D lines have headway limitations based on the ventilation shaft locations with the longest distances being the 4-minute gaps between NoHo/Universal and Universal/Highland, hence the max headway is 4 to 5 minutes. The large bore tunnel is supposed to get rid of that requirement and there shouldn't be any reason that headways couldn't be more frequent. Lots of driver-based systems around the world have 2-min headways. But then the other weird thing is that the B/D lines were designed to be automated. Unless something has changed (and maybe it has) the only thing that train operators do on the B/D lines is open and close doors.

The issue with using the current Metro trains is that they require the trains to be very long, with space for driver compartments that aren't used except in one car. This leads to stations needing to be over 2x as long as the stations proposed by the P3 contractor. Underground station cost is the main cost for underground rail, costing a magnitude more than the tunneling. Purple Line 3 was split up into tunneling and station contracts. The stations contract was $1.4 billion for 2 stations (investors.tutorperini.com/press-releases/press-release-details/2019/Tutor-Perini-Receives-Notice-of-Intent-to-Award-a-14-Billion-Contract-for-the-Purple-Line-Extension-Section-3-Stations-Project/default.aspx). The tunneling contract was $410 million for 2.6 miles of tunnels (investors.tutorperini.com/press-releases/press-release-details/2018/Tutor-Perini-Receives-Notice-of-Intent-to-Award-a-410-Million-Contract-for-the-Purple-Line-Extension-Section-3-Tunnels-Project/default.aspx).

[fissure]

The existing B/D trains are 75-foot cars in 3 married pairs. They already run shorter trains off-peak, so a line with 300-foot platforms would be compatible. The width and platform height are much bigger concerns than length.

[numble]

Dec 3, 2021 10:41:21 GMT -8 fissure said:

The existing B/D trains are 75-foot cars in 3 married pairs. They already run shorter trains off-peak, so a line with 300-foot platforms would be compatible. The width and platform height are much bigger concerns than length.

They can't run just 4 cars of the existing trains on this line during peak service because of their capacity limits. They need to have room for at least 6 cars, and leave room for expanded capacity. The P3 proposal proposed platforms of 280 feet, and that still allows them to add a car if they need to expand capacity in the future. In any event, the P3 proposal said that their stations will be less than half the length of Metro's station design requirements for its existing heavy rail trains.

[bluelineshawn]

Dec 3, 2021 11:31:31 GMT -8 numble said:

Dec 3, 2021 10:41:21 GMT -8 fissure said:

The existing B/D trains are 75-foot cars in 3 married pairs. They already run shorter trains off-peak, so a line with 300-foot platforms would be compatible. The width and platform height are much bigger concerns than length.

They can't run just 4 cars of the existing trains on this line during peak service because of their capacity limits. They need to have room for at least 6 cars, and leave room for expanded capacity. The P3 proposal proposed platforms of 280 feet, and that still allows them to add a car if they need to expand capacity in the future. In any event, the P3 proposal said that their stations will be less than half the length of Metro's station design requirements for its existing heavy rail trains.

I don't think that they would spec the same cars that they ordered 25 years ago, so that's not what would be compared.The new CRRC cars appear to have an open gangway for each married pair. 300 ft long CRRC trains should have a similar capacity to 280 ft Bechtel trains as long as they have the same headway. My question is why wouldn't they?

[numble]

Dec 3, 2021 12:34:24 GMT -8 bluelineshawn said:

Dec 3, 2021 11:31:31 GMT -8 numble said:

They can't run just 4 cars of the existing trains on this line during peak service because of their capacity limits. They need to have room for at least 6 cars, and leave room for expanded capacity. The P3 proposal proposed platforms of 280 feet, and that still allows them to add a car if they need to expand capacity in the future. In any event, the P3 proposal said that their stations will be less than half the length of Metro's station design requirements for its existing heavy rail trains.

I don't think that they would spec the same cars that they ordered 25 years ago, so that's not what would be compared.The new CRRC cars appear to have an open gangway for each married pair. 300 ft long CRRC trains should have a similar capacity to 280 ft Bechtel trains as long as they have the same headway. My question is why wouldn't they?

Because each married pair has a driver compartment. On a six-car train, there are 3 driver compartments, 2 of which are empty.

The CRRC trains have a passenger capacity of 251 per married pair. So 502 passengers for 4 cars (300 feet).
thesource.metro.net/2019/12/05/riders-react-to-side-facing-seats-on-future-subway-vehicles/

The Bechtel trains have 170 passengers per car, which means 510 passengers for 3-cars (215 feet) and 680 passengers for 4 cars (285 feet).

[bluelineshawn]

Thanks for the specs for the CRRC cars. That helps, but I'm not convinced that we're comparing apples to apples. I think that I commented on this months ago, but the Bechtel estimate is using an estimated density of 4 riders per square meter. The CRRC estimate appears to be using a density just below 3.

[fissure]

The driver compartments are only about 5 feet deep, or 10 per married pair. So a 300-foot train with them is the same as a 280-foot train without them. Bluelineshawn is right; it must be using different seating arrangements or standing density to compute the capacity. Given that the existing subway is designed for 75-foot cars, it makes no sense to use a train length that isn't a multiple of 75 feet. Having a different number of "inner" cars if we move to open gangways means there's no hot swapping of rolling stock between systems, but the designs can be standardized to make procurement simpler.