Edit: Oh, whoops, sorry for the subway details in the LIRR forum. I knew there was a reason I'd assumed we were talking about LIRR capacity!
DogBert wrote: ↑
Thu Oct 17, 2019 10:02 pm
On the queens blvd subway, at the moment, no. But they're installing new signals so maybe in 10 years assuming it takes as long to get CBTC running as it did for the 7 line. They *could* divert one of the local lines through. Only three stops would lose a little local service. They could also bring the G back up Queens blvd.
So far as I know the main constraint for subways would be actual subway cars.
Oh, sorry. Here's a summary.
The current capacity limitations are how many trains they can turn at 71 Av/Continental without it becoming a conga line, 53 St Tunnel, and the Broadway Local tracks (with the limit there being at 34 St due to the merge).
RBB would nicely alleviate the 71 Av issues and only short-change 67 Av, since 71 Av customers will mostly take the express, and the portals are directly after 63 Dr according to Vanshnookenraggen.
It's hard to add capacity on 53 St-8 Av because Canal St and WTC are both close to capacity, and hard on 53 St-6 Av because that involves merging with the E and then with the F.
It's comparatively easy to add capacity on Broadway. Since the current capacity limitation is the merge, just remove the merge! Send all Broadway Express trains to 2 Av and all the Astoria and QBL trains down 4 Av Local (which could use more service anyhow) plus some terminating at Whitehall. Deinterlining at 34 St would have massive positive repercussions for the whole system and I expect it will be necessary due to increased SAS demand after Phase II is complete. So you could imagine running all M trains down QBL and R trains to 71 or vice versa (or some mix as proposed here) and at the same time increasing capacity by increasing the number of R trains and deinterlining 34 (since 71 won't be an issue).
The proposal to run G trains is challenging because this would create a *very* complicated merge at Queens Plaza, with three lines joining onto one track, with both the M and the R causing backups if delayed. Also, this would result in even fewer customers staying on the local at Forest Hills than we have today: one limitation on QBL is that there is no more space on the inside
of the trains on the QBE tracks (to which many people transfer at Forest Hills). Also, it would be hard to fit more G trains on Culver Local without causing merge delays with the F, or without running more F expresses (which some people on this forum would love, but which overall cause more inconvenience than they are worth because they will dump some G riders on the A/C at Hoyt/Schermerhorn, which are overcrowded because of the capacity limit in the Cranberry tunnel).
In the long run, the obvious but costly solution is a build-out of QB Super-Express as was planned decades ago. By running the super express trains, the express trains would be more able to take the capacity generated by RBB (which would all transfer at Woodhaven, which has provisions for express-stop conversion; the Rego Park provisions for RBB are express-only).
This is all assuming that RBB is actually built, and built to LIRR or subway specs, which seems unlikely since the study proposed such high costs (whether or not they are accurate) and the project would probably have less impact than other possibilities (SAS phases III/IV or Bronx extension; QB Super Express; smaller capacity expansion projects like reconfiguring Rutgers, Crown Heights/Utica Ave, 149 St/GC, Astoria Blvd, or a personal favorite of mine, hooking up the Montague tubes to the Fulton local tracks to fix the Cranberry capacity issue and give deinterlined Broadway Local trains a southern sink).