Why not express?

krtaylor wrote: I believe that the Orange Line runs at or pretty close to minimum headways, at least past Rosslyn. So there's no room to bunch. Dunno about the Red Line, maybe there's more room to work with there.

What are they going to do when the Silver Line comes online? This is what I can't figure out? I've seen the plans to reroute the Blue Line and let the Orange line have sole access to the Rosslyn tunnel. Any other plans?

My understanding is that they plan to reduce Orange and Blue service so as to make room for Silver trains. I think the idea is that a fair number of current Orange passengers actually live closer to the Silver line and will start using that once it's open. Considering how jammed Orange trains are, though, I wonder if this is actually true.

There has been talk about another tunnel under the Potomac for years. Pigs will fly first.

I've also seen proposals for the Blue line to be split, so only half of the Blue trains actually stay Blue; the other half, in effect, turn into Yellow at Pentagon and go over the bridge into DC instead of up through Rosslyn. That would remove some load from the tunnel and solve the immediate Silver problem, but might cause other problems too, not the least of which being passenger confusion.

Considering how jammed 66 is, they need to extend Orange out past Manassas to the Gainesville 29 split, and build a massive terminus and parking complex there. Don't see that happening either.

krtaylor wrote:

justalurker66 wrote:The trouble is all you are really doing is bunching up trains. How close can trains run? If they are already near their minimum headway then bunching to create expresses isn't possible.

I believe that the Orange Line runs at or pretty close to minimum headways, at least past Rosslyn. So there's no room to bunch. Dunno about the Red Line, maybe there's more room to work with there.

The minimum (current) headway for the system is 2.5 minutes, which is used on the Red Line between Grovenor and Silver Spring. The headway for the Orange Line is 6 minutes during rush hour (the combined Orange and Blue Lines have a headway of 3 minutes).

So the Potomac tunnel is not quite at minimum headway but almost, and while the Orange Line by itself has plenty of space, that's not helpful because it has to combine with the Blue. Right, makes sense.

I doubt if the headway can be reduced below 2.5 minutes. The dwell times at rush hour can't reliably be shortened and there has to be enough time to accelerate and decelerate. I know that trains can accelerate faster than the Metro trains do, I've been on suburban (Keio) lines in Japan that take off like rockets, but I'd be surprised if the Metro trains were designed to have much better acceleration performance that isn't being used. Could be wrong though, does anyone know?

krtaylor wrote:So the Potomac tunnel is not quite at minimum headway but almost, and while the Orange Line by itself has plenty of space, that's not helpful because it has to combine with the Blue. Right, makes sense.

I doubt if the headway can be reduced below 2.5 minutes. The dwell times at rush hour can't reliably be shortened and there has to be enough time to accelerate and decelerate. I know that trains can accelerate faster than the Metro trains do, I've been on suburban (Keio) lines in Japan that take off like rockets, but I'd be surprised if the Metro trains were designed to have much better acceleration performance that isn't being used. Could be wrong though, does anyone know?

Metro trains could perform better if they were run in automatic mode. Right now all trains are run in manual mode, because of maintenance issues iirc. (Yeah, yeah we know M is so "incompotent & corrupt"). Currently the merger of the Blue and Orange Lines at Rosslyn is the biggest bottleneck in the system, and last year they were start sending about half the blue line trains over the Yellow Line's Potomac River bridge and run them up to Greenbelt. For some reason that never happened, despite what I perceived to be a large number of supporters.

"dpan"
What are they going to do when the Silver Line comes online? This is what I can't figure out? I've seen the plans to reroute the Blue Line and let the Orange line have sole access to the Rosslyn tunnel. Any other plans?

Actually the plan is to reroute selected Blue line trains. For every Silver line train that comes off the K route there will be one less Blue train coming up the C Route from Pentagon.

Headways on the K route between East Falls Church an Court House will be:
XX:00 Orange
XX:03 Silver
XX:06 Orange
XX:12 Silver
XX:15 Orange
XX:18 Silver
XX:24 Orange
XX:27 Silver
XX:30 Orange

Headways on the C and D route between Rosslyn an Stadium-Armory will be:
XX:00 Orange
XX:03 Silver
XX:06 Orange
XX:09 Blue
XX:12 Silver
XX:15 Orange
XX:18 Silver
XX:21 Blue
XX:24 Orange
XX:27 Silver
XX:30 Orange

The above is likely subject to change based on what the actual boarding patterns turn out to be on the N Route.

The Blue line trains that lost their slots through Rosslyn will be sent across the river over the Fenwick Bridge and up the Mid City E and F Routes. Selected Orange line trains will terminate at Largo to fill in the schedule from the rerouted Blue line trains.

justalurker66 wrote:On the question of "Why not express?" ...
We're obviously past the design phase where extra tracks could be added. We've discussed what it would take to add extra crossovers to allow trains to pass other trains. Is the ability to pass express enough?

It would be a big help not just for express, but passing stalled trains. I claim that 90+% of breakdowns are in a station, but can't prove that.

Is it a given that express is needed? What are the problems?

Express gets the end-to-end travel time down. That's a big selling point for airport service especially, but also on any long run.

We've discussed A/B service ... it can be confusing and one has to identify stations properly and decide which can be skipped. A/B could speed up the journey (as long as you don't end up parking trains at signals waiting for the train ahead instead of at platforms serving customers) but it also doubles the headways for the stations skipped.

And it hurts those going an odd number of stations; say Silver Spring to Takoma.

farecard wrote: And it hurts those going an odd number of stations; say Silver Spring to Takoma.

Which is the vast minority - something that benefits 90% of users while inconveniencing a few should at least be looked at (assuming that WMATA has the data to determine how to implement it to hurt the least amount of people).

HokieNav wrote:

farecard wrote: And it hurts those going an odd number of stations; say Silver Spring to Takoma.

Which is the vast minority - something that benefits 90% of users while inconveniencing a few should at least be looked at (assuming that WMATA has the data to determine how to implement it to hurt the least amount of people).

A) I don't know that is true. Of the passengers boarding at Takoma, what percentage will get off at Galley Place; what percentage at Metro Center?

B) I thought of a short-term skip scheme for recovering from breakdowns, but I doubt WMATA would use it.

Say you have a Red Line breakdown at Metro Center, & trains stack up back to Takoma.
So instead of every train slogging through every stop; once the line restarts, jump each train multiple stations.

The Gallery Place train would go non-stop to oh Dupont; the train holding at Jud. Sq. goes to FargN, and so forth.

What would be needed to make it work would be announcements on held trains each BEFORE it leaves the holding station; so shanghaied passengers could choose to offload. OR they could take the skipping train past their destination, and catch the other track's train back a station or two. [They won't be mobbed.] My guess is this is faster than long dwell stops at every intermediate station.

The goal is to get as many trains moving normally again, as soon as possible.

That would be a fantastic idea if it were possible to hear and understand announcements on the train when delivered by the driver. But it isn't. To be fair, I can't really blame WMATA, as I've never encountered a metro system where the PA was intelligible. I sometimes wonder why the spend the money... It's not the speakers themselves, as the recordings come through just fine. Maybe the drivers just aren't trained as radio announcers.

Sand Box John wrote:"dpan"
What are they going to do when the Silver Line comes online? This is what I can't figure out? I've seen the plans to reroute the Blue Line and let the Orange line have sole access to the Rosslyn tunnel. Any other plans?

Actually the plan is to reroute selected Blue line trains. For every Silver line train that comes off the K route there will be one less Blue train coming up the C Route from Pentagon.

Headways on the K route between East Falls Church an Court House will be:
XX:00 Orange
XX:03 Silver
XX:06 Orange
XX:12 Silver
XX:15 Orange
XX:18 Silver
XX:24 Orange
XX:27 Silver
XX:30 Orange

Headways on the C and D route between Rosslyn an Stadium-Armory will be:
XX:00 Orange
XX:03 Silver
XX:06 Orange
XX:09 Blue
XX:12 Silver
XX:15 Orange
XX:18 Silver
XX:21 Blue
XX:24 Orange
XX:27 Silver
XX:30 Orange

The above is likely subject to change based on what the actual boarding patterns turn out to be on the N Route.

The Blue line trains that lost their slots through Rosslyn will be sent across the river over the Fenwick Bridge and up the Mid City E and F Routes. Selected Orange line trains will terminate at Largo to fill in the schedule from the rerouted Blue line trains.

That sounds like a very good plan, but it is awfully complicated. How will this be displayed on schedules/maps? Will The Vienna-Largo trains receive a new color? And what about the Franconia-Greenbelt trains? Suddenly, the Metro's service plan is looking awfully intricate, like a much smaller version of NYCTA's.

farecard wrote: A) I don't know that is true. Of the passengers boarding at Takoma, what percentage will get off at Galley Place; what percentage at Metro Center?

That doesn't matter, since all trains stop at all stations in the downtown core area, so we're talking about people that board at Tacoma and get off at Rhode Island Ave/Brentwood.

krtaylor wrote:That would be a fantastic idea if it were possible to hear and understand announcements on the train when delivered by the driver. But it isn't. To be fair, I can't really blame WMATA, as I've never encountered a metro system where the PA was intelligible. I sometimes wonder why the spend the money... It's not the speakers themselves, as the recordings come through just fine. Maybe the drivers just aren't trained as radio announcers.

Again, I don't know what trains you're riding - I very rarely hear the "Charlie Brown teacher" coming from the front of the train anymore.

M&Eman wrote:
That sounds like a very good plan, but it is awfully complicated. How will this be displayed on schedules/maps? Will The Vienna-Largo trains receive a new color? And what about the Franconia-Greenbelt trains? Suddenly, the Metro's service plan is looking awfully intricate, like a much smaller version of NYCTA's.

I agree, the metro has always been very simple for daily commuters and tourists and it seems this might even get confusing for some daily riders.

New colors would be helpful. Also, I'm guessing the stripes on the map will have to be thinner because showing the Bl, Or, Sl trains all on one route would be really wide with the current style.

Davis

"M&Eman"
That sounds like a very good plan, but it is awfully complicated. How will this be displayed on schedules/maps? Will The Vienna-Largo trains receive a new color? And what about the Franconia-Greenbelt trains? Suddenly, the Metro's service plan is looking awfully intricate, like a much smaller version of NYCTA's.

Past practices establishes line color based on line color at terminal of origin. As an example a train originating from Vienna regardless of the final destination would be Orange. Same for Blue, and Yellow. Mind you both of the southern terminals in Virginia have Blue, Yellow and Green destination codes. Same also applies to the eastern / northern terminals in Maryland Largo - Blue and Orange, New Carrollton - Blue and Orange, Greenbelt - Yellow, Green and Blue.