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RR503

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RR503 last won the day on March 8 2021

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  1. Pretty much all of these issues boil down to "we'd need to run more trains to implement plan x." That isn't always true! Let's run through the common proposals: - / swap: you really should bump up service by 1-2tph given how popular the connection at Lex-63 has become with the , but you don't have to, and the running time differences btwn the two routes are like 1 minute. - CPW: again, you should increase service, but it's totally feasible without that. Assuming - 168 local, - BPB local, - 207 exp and - 205 exp, essentially swap and service levels for the CPW peaks (so s/b AM and n/b PM). The is about 10 mins shorter than the (comparing 59-EUC to 59-STL), but some of that is made up for by the fact that s relay and s don't. Either way, minimal changes in overall service-hours spent - Dekalb: all of the S. Brooklyn Manhattan Bridge routes have, to a first approximation, the same service profile in the Brooklyn peaks. So that's an easy one. Now for the harder ones: - 34 St: you basically need to add 7.5tph of service to make up for lost s. Some of the service-hours you need for that can come from the fact that 96 St is 11 mins closer to 34 than Astoria, but you'll end up spending money there. - Rogers: Peak hour service levels are close enough to the that you could probably get away with not adding service here, but the whole point of this investment is that the IRT express routes run well below need, especially for Brooklyn peaks and on the West Side. - Something more extensive in Queens: I think the need to add service when you do and to Astoria is pretty self evident? Also note: for most merges, you'll likely achieve some running time savings through merge elimination. Nothing earth shattering, but with knock on effects in reduced OT, dispatcher workload, switch maintenance...it's money!
  2. FWIW: in the world where we don't have 10 car s or an express station at 36 St, I think the best QBL deinterlining plan is the light touch / swap. Lex-63 is an awful place to merge services -- you're making a 34 St copy at the beginning of the 30+ tph QBL trunk -- and you can realize a good bit of reliability and speed benefits by fixing CPW and Dekalb while you wait.
  3. 179 is likely to be limited by the same problems that afflict Forest Hills: train clearing, and poor coordination of recrewings. It'll likely run a bit better because there's no diverging move immediately after the inbound platform (and CBTC is still something of an X factor in all of this) but we're talking about the difference between 20 and 22 or 23, not 20 and 30. Also: take those terminal capacity estimates with a (small) grain of salt. A lot of them look about right, but, for example, Utica sees hours where it turns 15tph on its two relay tracks. Really the best way to figure out this sort of question is to go and time train movements during peak hours...
  4. You actually do get sped up! The NTTs come programmed with two acceleration curves: the "cold curve" for use on fixed block portions of the system, and the "hot curve," for use in CBTC territory. During peak hours, you're going to be gaining as much from higher quality close-in operations as you are from faster speeds, but the difference is significant.
  5. To the curvature point: I think the precedent that most thoroughly puts the lie to the whole "curvature and length compromises OPTO" argument is Paris's RER. Many of its lines have been OPTO since the 1990s, and some run ten car trains of bilevel EMUs through stations which are packed and often quite curvy. Successful implementation obviously requires good investments in CCTV infrastructure (some of which the L already has), but it's really not impossible. (London's Thameslink is another good one)
  6. This is a good question. The reason s are sent up Culver is because the weakest link in the entire "everything up the wall after 7:30" GO is Dekalb. North of 36 St, there isn't any way of getting s and s back onto the express tracks, so you have a few hours every evening where the are all sharing A2 track through Dekalb Avenue station. That can get *quite* messy quite quickly, so reducing train volumes there is a must -- hence Culver. My big question about the via Culver, fwiw, is why those intervals don't run via B4 track. Sending them up the local -- which seems to be the norm -- seems a waste of time and money, to say nothing of delay around Church. Not going to touch the Wally proposal, because ✨self care summer✨
  7. This, IMO, speaks more to a need for advocates to get better at speaking the pols' language rather than just quitting. Totally agree that it's a hill (and a half) to climb, but there are some spots of hope in recent history. The way Oddo worked _in coalition_ with MTA to push the SI Exp redesign through, for example, seems a great precedent -- albeit one from a rather marginal political figure in the grand scheme of NYC politics. Anyway, my point in posting was more to inform the technical conversations.
  8. Gonna leave this here https://homesignalblog.wordpress.com/2021/06/15/deinterlining-some-quantitative-evidence/
  9. Great post, TM5. Despite all the signal mods made since your time, the "don't risk flying into a red home @ 108-ball" is still the cause of much slowing at the Astor Curve. If I may make one little correction, though: the "C" signs are now gone, and if you're operating totally textbook you're good for MAS from the "R10" sign beyond the curve leaving BB to the 35mph sign entering Spring, and then from when clear of those curves to wherever you choose to slow for Astor (there is no sign there, so you're not technically doing anything wrong if you go MAS)
  10. This is how it's operating *now*, not how it's planned to operate forever. AWS on QBL will not support much more than a 5 min headway (like the ), speeds will increase, etc. And FWIW, the did tons of off peak section-level testing until full cutover -- not unlike the overnight periods seen on QBL. There wasn't such an extended mingling period, yes, but it wasn't a hard transition either.
  11. Amusingly, some on that list were ones from years ago (ex: the and changes mentioned). They've made new changes, but for whatever reason decided to highlight old ones.
  12. Not to state the obvious here, but: congestion pricing is most fundamentally a means of internalizing an externality. When car n + 1 enters the Manhattan highway network, it imposes costs on other drivers (congestion) and society (increased traffic accidents, emissions, road wear), which it does not have to pay for. Extremely for this serving broader goals of road capacity and VMT reduction -- which are critical to keeping Manhattan, much less the Rockaways above sea level by the end of the century -- but you need not go far beyond basic economics to prove the worth of the cordon pricing scheme.
  13. I think modern day transit planners are all too aware of the dangers associated with interlining. Just because we don’t hear deinterlining proposals doesn’t mean that the agency doesn’t want them — politics are a critically important mediating force here. And at any rate “this is how it’s always been done” =/= “this is how it should be done,” with the qualification that you need to be cognizant of adaptive infrastructure changes when shifting paradigms.
  14. Yeah, all credit to Vanshnook for that idea (which is great and I still support) I see the fundamental issue with SAS 3/4 as being that they cement interlining across the entire B division and don't actually add any core capacity. Any comprehensive route simplification scheme requires routing the to 96; there is not space for the and to run up SAS today at full service levels. Similarly, there is no way to fill lower SAS (assuming continues to upper SAS) without interlining a train onto 63 St -- which blocks an reroute there. This is all a fancy way of making the capacity point. Today, there are 6 B division track pairs in Manhattan's core (8th local/express, Bway local/express, 6th local/express), and 6 track pairs leaving the core to the north (CPW local/express, 53, 60, 63, SAS). Thus, any addition of capacity in the core without addition of other northern routes constitutes a redistribution of capacity away from tracks which already exist -- this is what SAS does today. I have yet to find a fix for this problem which I really love, but I think it's fair to say that as proposed, SAS 3/4 have low-to-negative network ops value.
  15. You only need that flexibility when you make major fleet planning mistakes. Shortages of late have been the result of the aberrantly tortured introduction of the R179 class in conjunction with the R44's early retirement. Better planning and better contract management can make up much of the difference here -- and what it can't can be solved by relinking sets if you absolutely must. As the saying goes, organization > electronics > concrete.
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