Caelestor

Merges are okay because branches have lower frequencies than the trunks they're merging onto. Crossovers are not because you are blocking two parallel tracks are reducing overall capacity on both tracks. The most noticeable offenders are the and the . On Broadway, send the to 96 St and make the a full time line (interline it with the late nights). The should stay on the express tracks, but the optimal configuration is for the to run local on CPW and to run express. For that, there needs to be a crossover installed between the local and express tracks south of 50 St.

The MTA should focus on maximizing the capacity of the existing Broadway trunk line and its branches, including SAS. That means running more, if not all trains up to 96 St (and a corresponding increase in trains from Astoria). Down the road, the SAS needs to not only be extended to Lex Ave/125 St, but also crosstown to Broadway. The tail tracks at the Broadway terminal might not be very long due to the proximity of the Hudson River, so it would be worth looking into building the extremely cost-effective extension to 3 Ave - 149 St. The inevitable extension to Fordham would be deferred until the ideal route (3 Ave, Webster Ave, or MNR ROW) is determined. Constructing the SAS south of 72 St also needs to be deferred, as it actually reduces the maximum capacity of the existing Broadway express tracks. Conversely, there is capacity along the Montague St and Rutgers St tunnels, so I lean towards building that section as an extension of some East River crossing from Brooklyn, e.g. Montague Street or Manhattan Bridge north. The can terminate below the existing 72 St station, allowing for a future extension to 116 St (express), and further into the Bronx as previously discussed. Alternatively, the can take over upper SAS, and the can be rerouted to the lower level platforms at 72 St in preparation for a 79 St - Astoria Blvd extension to LGA / College Point, but that's a proposal for another day.

My understanding is that the max capacity of both the local and express tracks is 20 tph, due to DeKalb Junction and the Cortlandt St curve respectively. Whitehall St and Bay Ridge can only turn 8 tph and 10 tph respectively, but any excess trains should just run to / from Sea Beach like trains currently do, so the only restriction is the fleet availability. During the AM rush, there are 10 + 1 trains coming from 96 St and 8 + 7 + 9 trains coming from Queens. These combine into 19 trains on the express tracks and 16 trains on the local tracks. Going to 40 tph (14 percent capacity increase) is achievable by running more trains and shifting some trains to 96 St, and halving the merges will reduce delays and enable the additional capacity: 4 from Astoria, 6 from 96 St 10 from 96 St 9 from QBL 11 from Astoria Long-term, the should just run together up SAS, the should take over all of Astoria with additional short-turns at Queens Plaza, and all QBL trains should run via 53 or 63 Sts only, but that's a topic for another thread.

I'd be be okay with adding all those stops with two exceptions. Assuming mainline trains are used, the IBX platforms should be longer than the standard subway platforms, and so Coney Island Ave would be a couple blocks away from the west end of Avenue H . While Wilson Ave would be a better transfer to the , its station catchment area isn't great because of the nearby cemetery, and both Metropolitan Ave and Broadway Junction are good transfer stations. On the other hand, I'd be down for building a new station at Wyckoff and Cypress Streets instead.

What mode the IBX should should use is dependent on the northern extension, but I'm definitely leaning towards heavy rail. Specifically mainline trains, since the IBX will probably be extended towards Coop City / New Rochelle. The IBX can be the first "C Division" line, which consists of all the local mainline / regional rail branches that should be separated from the express branches of the LIRR. So IBX would be "Line 1", the PW branch would be "Line 2", and so forth. An alternative would be to send the line via Astoria Blvd, 86 St, and 10 Ave to connect with the and form one really complex line. As a circumferential line, IBX needs to stop at every major subway and bus transfer station, so: Brooklyn Army Terminal 8 Ave / Fort Hamilton Pkwy New Utrecht Ave McDonald Ave / Avenue I Avenue H Nostrand-Flatbush Aves / Brooklyn College Utica Ave - Kings Hwy (Future Utica Ave Line) Remsen Ave Junius St - Livonia Ave ENY / Atlantic Ave - Broadway Junction Myrtle Ave - Fresh Pond Rd Metropolitan Ave Juniper Valley - Eliot Ave Grand Ave Queens Blvd - 51 Ave Broadway - Roosevelt Ave Northern Blvd (Future Northern Blvd Line)

Deinterlining is just a way to increase capacity by optimizing train slots and reducing potential merge delays. Perhaps unsurprisingly, the have the best service of all the subway lines. On the other hand, the current services actually reduce the overall capacity of the 8 Ave, Culver, 63 St, Broadway, and Second Ave lines. It's unclear whether those lines actually need the extra trains given the current pandemic, but assuming ridership eventually rebounds, relatively easy gains in capacity can be made by reorganizing services while new megaprojects such as lower 2 Ave slowly get built out. That said, deinterlining should be a gradual process, as it does increase the fleet requirement and riders will need time to get used to new service tterns. The optimal capacity of the Market St tunnel is 30 tph, but pre-COVID all 5 branches (J, K, L, M, N) ran ~8 tph each. All those branches also get delayed by street traffic, so service was not great, to say the least. Long-term, it's clear that at least one branch needs to be removed from the subway entirely, to increase service on the remaining branches. Of the 5 branches, the J Church runs only 1-car trains and doesn't run the entirety of the tunnel, so it's the obvious candidate to be removed from the subway. The K Ingleside also only has 1-car platforms, but it isn't as challenging to convert the branch into 2-car operation. Nonetheless, the K Ingleside was supposed to be interlined with the L Taraval so that only the M Ocean View and the N Judah entered the tunnel, with 3-car subway-only S shuttles providing more than enough capacity for riders transferring from the K and L lines. Fast forward to today, and the Market St tunnel has plenty of capacity. Only 3 branches (K, M, N) are running at ~6 tph, and the L is suspended until 2024, so the J Church can be temporarily reinstated without causing significant delays. Long-term, the plan should be to run only the K, L, and M branches into the subway at 10 tph, run the J Church as a streetcar line along Market St and Embarcadero to Fisherman's Wharf, and give the N line its own tunnel.

I'm of the opinion that both the and need to run local west of Broadway Junction. Even with the pandemic, that part of Brooklyn has a lot of gentrification potential and trains really should be running every 5 minutes at all those stations. Without any major construction on the Jamaica Line, one possibility would be to run the like the : local trains between Jamaica and Manhattan every 10 minutes, with additional trains running between Crescent St and Broad St. This would reduce ridership on the outer portion of the line but the inner portion of the line should more than make up for it. Jamaica to Downtown riders could be accommodated with LIRR fare integration instead. Otherwise, the only real candidate for removal would be to retire the , reroute the to Astoria, and add some replacement line on QBL, but that would require a new or rerouted service.

The BMT through Midtown is currently not at its full capacity. Broadway is under capacity because of the express to local merge at 34 St, and the 8 Ave Line only has 3 services. While it can be argued that 8 Ave doesn't need its 4th service at the moment, Broadway really needs to be decongested and so the needs to be sent up 63 St in some manner. My preference is to send it to 96 St, but I can understand rerouting it to QBL since the will serve Astoria full-time and the WTC - QB service may not be available due to budget reasons. The is definitely more useful than the but long-term it restricts capacity along the Rutgers tunnel and so there should be some long-term discussions on rerouting the Jamaica Line uptown, perhaps up 2 Ave. It may be the only way to add new trunk capacity through Midtown, as the key impediment to adding a new trunk line has always been a new East River crossing. With lower Nassau St temporarily removed from service, the line can be rehabilitated to link up to a 2 Ave express line or a 3 Ave relief line instead. There could also be a discussion on sending the Broadway local at Whitehall St onto the Fulton St local and connecting Nassau St to the 4 Ave local full time.

In an ideal world, both 2 Ave and 3 Ave would have a subway line. However, SAS needed to be built first because it has a larger catchment area, and one aim of the subway should be to spur development around its stops. Between 14 and 72 Sts, 1 Ave has a lot of destinations, including hospitals, universities, and riverside properties, that are much better served using 2 Ave. The LES would also benefit more from a 2 Ave line, though that neighborhood ultimately needs a line under Ave B or Ave C in the long term. That said, 3 Ave / Bowery is a good candidate for another trunk line; the transfers to the Nassau St, Houston St, 14 St, 42 St, 53 St, 59 St, and 63 St crosstown lines are all better there than 2 Ave, and it could turn east under 72 St to connect to SAS before heading into Queens.

Assuming the stays via Manhattan Bridge and there's some variant of the / via 63 St and the via 53 St to maximize Queens capacity in the near future, lower SAS will have no obvious branch that it can connect to at its northern end. As for the its southern end, lower SAS can have direct access to the Financial District and Brooklyn, by building the Whitehall St - Court St tunnel first to extend the towards Euclid Ave. This frees up the Montague tunnel for the Nassau St line, and then it, and perhaps the Chrystie St -Williamsburg Bridge connection, can be redirected up 2 Ave. Essentially, Phases 3 and 4 would be swapped for construction feasibility purposes. Terminating the at a lower level beneath the existing 72 St station is probably the best plan for "Phase 3" until a northern continuation can be identified. Track connections to upper SAS and 63 St can be built to increase flexibility in the meantime but they won't be used in regular service because the 63 St lines should be maxed out. Maybe the could continue express up 2 Ave, stopping only at 116 St before going into the Bronx; alternatively, it can turn east into Queens and run under Astoria Blvd towards Flushing.

Connecting an underground line with an elevated in a built-up area would probably have been too costly and disruptive. If the IND had endless money, a better plan may have been to send the up 31 St (replacing the Astoria El) and then west via Governor's Island into Manhattan along 125 St, forming a really effective circumferential line. Then all 60 St tunnel trains could then run onto the QBL local tracks via the 11 St Cut, and the 63 St line a generation later could have been run to Woodside / Forest Hills as the QBL bypass or under Northern Blvd. Regarding the deinterlining plan: I think the 168 / 207 St - WTC line has to be entirely local, mainly to keep service to the upper level of 50 St. That station really should have much more ridership given its location, but it's hamstrung by the only running 5-6 tph offpeak. Plus, 6 Ave is more central to most commuters than 8 Ave. It's totally possible to run all QBL express trains via 63 St with 10 cars, but it requires the to go back to Nassau St and the to run to Church Ave, at least until the BMT Eastern Division platforms are lengthened. There may be some merit to doubling service along the Culver Line and removing the capacity limits that comes with interlining the 6 Ave and Jamaica lines via Chrystie St.

We shouldn't be terminating trains at City Hall, right outside the high-ridership Financial District. Just continue to turn the 6-7 tph at Whitehall St, and run the excess trains to Bay Ridge. The doesn't lack destinations and there's ridership to be induced with frequency increases. The does a good job reducing crowding on the IRT lines between Fulton St and Atlantic Ave, but it makes too many slow turns through lower Manhattan to be an effective Midtown - Downtown - Brooklyn trunk line. Due to its lack of curves, Nassau St is actually the second best trunk line through lower Manhattan after Lex Ave, but its crippling flaw is that it doesn't serve any part of Midtown. The line could be well-patronized if it could be rerouted up 2 Ave or Bowery / 3 Ave, but that would require the line to be shut down and reconstructed with ten-car platforms and a deep tunnel north of Canal Street (which I'm not certain is technically feasible).

I'm of the opinion that the only way to achieve interlining on the IND is to run all 8 Ave / CPW trains local between 207 Ave and WTC. The stops at Spring St, 23 St, and 50 St, all of which are fairly busy stations, wouldn't add too much running time to the express trains. Those who want to skip the local CPW stations can cross-platform transfer at 59 St and 125 St. That said, this necessitates service to run CPW express (not too difficult) and trains to go into Brooklyn and ultimately Far Rockaway. The wouldn't have issues along the 53 St - QBL local tracks or Fulton because the whole line would be one trunk, but there's definitely some concern running trains all the way to Far Rockaway. Alternatively, reconstruct 50 St, deactivate the upper level local tracks and extend the platforms to the express tracks. Then the can stay on the express tracks all the way into Brooklyn.

If trains aren't running full, then fewer passengers will be inconvenienced if the express trains make a couple extra stops. Overall ridership will benefit because riders at Yonkers and Marble Hill would have 2 trains per hour instead of 1, which makes a big difference.

From a connectivity standpoint, the off-peak Hudson Line express trains should be stopping at Yonkers and Marble Hill. Yonkers is one of the largest cities in NY state and has a nice downtown area that can attract commuters and leisure travel. Marble Hill has the transfer and better UWS access, and the proposed alternate Hudson Line Penn Access service is probably a few decades away/ Adding these two stops might add 2-4 minutes of travel time to GCT but a lot of new travel options would open up. Off-peak express trains used to stop at Yonkers and Marble Hill, so there's precedent, and in a post-COVID world, MNR needs to be increasing connectivity on existing routes. Basically, the ideal service plan is to operate 4 tph on the Hudson Line off-peak. Two local trains making all stops between GCT and Croton-Harmon, and two Poughkeepsie express trains stopping at Marble Hill, Yonkers, Tarrytown, and Ossining. That way, any rider going to any station has at most a 30 minute wait. and probably less, for the next train.