This isn't going to start till the spring. you have some time.

by Shaun on Jul 25, 2008 9:50 am  

I agree with you. If the maintenance is truly necessary (which it is) and this is the best way to do it (it might be), WMATA needs to get a move on. Deferred maintenance has crippled the system repeatedly over the past few years and a complete overhaul of the lines is overdue.

One possibility that this new method of rehab opens up is later service. One of the reasons that WMATA says it needs to close so early (Metro is the first heavy rail system in the US to start closing--except Fri and Sat) is to do maintenance. What this announcement indicates is that they can start doing maintenance before the system closes. Because headways are already so low, single-tracking can occur without causing massive backups.

If the maintenance is already on-going at 10PM, there's nothing to stop WMATA running the system for an extra 30 minutes or hour at night. This would primarily serve service industry workers and yuppies going out on the town, but really, does our nation's capital really deserve a subway that starts to close 36 minutes before midnight?

See my study on US heavy rail closing times at:

http://tracktwentynine.blogspot.com/2008/07/last-train-out.html

by Matt' on Jul 25, 2008 9:51 am  

If I knew for certain that I would never have to wait more than 10 minutes for a train on weekends and evenings, I would ride far more often than I do. Currently I walk or drive to avoid the 15-20 minute waits. So definitely an extra 5 minutes of waiting will ensure I fail to ride Metro on weekends and evenings, and I presume I'm in the majority.

I think Metro needs to run more 2 or 3 car trains like New York. Sure they would have to pay more train operators, but they'd make more money because more people would ride, -- if Metro advertised that there were at most only 10 minutes of waiting.

by Mary on Jul 25, 2008 9:51 am  

Mary: I totally agree about 5 minutes making a difference. I won't take Metro to someplace like Virginia on a weekend (if I go, which is rarely) because I already have to switch lines, and it'll take forever. It should be easier.

New York doesn't run any 2 or 3 car trains, though. Every train in the NYC subway system is 8-10 cars, except the C line which is shorter, and the 7 line which is so crowded they squeeze in 11 cars. (Numbered lines have narrower and shorter cars, so they run 10 cars while lettered lines run 8 bigger cars).

At one point, NYC discussed closing some of the cars on late night trains for safety. Since trains have few riders at 2 am, they could make everyone sit in the center few cars, cutting down on empty cars. However, that would force people to run down the platform if they arrived when a train was in the station, and would require labor to lock and unlock the cars. (They can't run shorter trains because it would take even more labor to disconnect cars from each other and reconnect them in the morning.)

by David Alpert on Jul 25, 2008 10:01 am  

Mary, I'm not sure how smaller trains help in this regard. Keep in mind that under normal circumstances, the trains are pretty much centrally controlled (in fact, in those cases where trains are under manual control, the system is much less reliable). During rush hours especially, Metro needs as much capacity as it can get, which means running as many 6 and 8 car trains as possible.

Also, a 3 car train is not really possible on the Metro system. Cars are always paired together and then pairs are linked to form trains.

by Adam on Jul 25, 2008 10:02 am  

Wouldn't it be possible to simply run one 8 car as a shuttle in the single tracked zone, back and forth? Sure, it would require passengers from the ends of the lines to switch trains, but might that not be faster overall?

Say there's single tracking between NY Ave and Farragut North. Trains run regularly between Shady Grove and Farragut, then turn abound and head back to Shady Grove. Same between Glenmont and NY Ave. In between the two, one 8-car train simply shuttles back and forth, back and forth. So, someone coming from Silver Spring to, say, Metro Center would have to get off at NY Ave and switch trains, but assuming the shuttle trains could complete their 'loop' faster than the proposed headway that would otherwise occur with single tracking, wouldn't that be an improvement?

by Alex B. on Jul 25, 2008 10:19 am  

Not really. What if I'm going from Fort Totten to Dupont? Then I have to change twice. The Metro system was designed so that no one has to make more than one transfer to get anywhere within the rail system. The only time this isn't true is on the 4th of July, when Green and Red Line riders have no connection to the Blue Line.

It's not inefficient to run trains all the way from Shady Grove to Glenmont--even with single tracking. What WMATA typically does is run half of its trains all the way through and has turnback service on either side of the trackwork. This method allows through passengers to have a one-seat trip.

by Matt' on Jul 25, 2008 10:27 am  

@Mary:

According to this summary of economic transit information, "the elasticity of transit use with respect to transit service frequency (called a headway elasticity) averages 0.5".

Mary, that means that doubling the frequency of trains is only likely to increase ridership by 50%. Since that will mean the trains will run less full, it's unlikely that WMATA would "make money" (assuming that means revenues exceeding costs) by running trains more frequently.

I fully support running trains more frequently during off-peak (I would say that WMATA should set a minimum standard of 12 minute headways for all service hours), but I think it's best not to assume that they could make money on the deal.

Increasing the availability and desirability of unlimited access passes would help off-peak ridership tremendously and would likely result in reduced headways.

by Michael on Jul 25, 2008 10:28 am  

Now that I think about it a little more, I can see that you're not talking about rush hours (which will be crowded no matter how often long trains are run, and increasingly so) but nights and weekends, when there's less demand. In those cases, running smaller trains more often will certainly make the system more attractive.

Of course, you then run up against the problem of maintenance as discussed in the above post. Specifically, when do you do it? If it's in those lower-demand periods, then you're back where you started. You have to have longer headways to allow for safe passage through work zones. The maintenance has to happen, so the current solution (long trains, long headways) really looks like the only viable one.

by Adam on Jul 25, 2008 10:37 am  

Matt - that's my point. The system was designed for that one transfer deal, but when you have to remove tracks for maintenance, the system will not function as designed. That consideration is largely irrelevant.

What I'm asking is this: Would you transfer twice if it meant getting to your destination faster? I sure would.

WMATA also doesn't seem to run the turnback service nearly enough (i.e. not enough trains turn back, and the headways on the double-tracked portions still stink) when they do this kind of trackwork. That's essentially what I'm proposing, just with a dedicated train. Even if you don't have a dedicated shuttle train, most of the trains should turn back, allowing faster headways on the double-tracked portion of the line.

Of course, more turn-backs means a lot more transfers, which is why I brought it up - the current arrangement seems far too focused on maintaining a one-seat ride. I think they need to scrap that mentality and focus on getting people through the system as fast as reasonably possible when they're doing track work. All too often, this does not seem to be a concern.

by Alex B. on Jul 25, 2008 10:52 am  

As David hints at, they really need to work on optimizing operations during single-tracking times: I can't believe they're getting as much service through as they could. The first thing is figure out what the maximum number of through-trains could be. They need to pour over all their ridership data and decide what the ratio of inbound to outbound through trains should be. Then try as best as possible to run a full schedule of trains that terminate at the stations nearest the single-tracked zone. Perhaps they put together four or five potential service plans: then take all the ridership data and run simulations to see how long the trips would be with single-tracking as compared to regular service.

Maybe they're already doing this, but as a customer traveling during single-tracking times, it really doesn't seem like it. They capture an enormous amount of ridership data, but I don't know if they do anything useful with it.

by thm on Jul 25, 2008 11:01 am  

If it meant faster travel, I would not mind transferring twice. However, I am not convinced that it would mean faster travel.

You are correct in asserting that single-tracking is not a normal system condition. While I can't speak to WMATA, it's sister system, MARTA, was designed so that even in single-tracking situations, trains can operate at 10-12 minute headways. Crossovers are placed about 4 minutes apart in the system, allowing for 2 minutes for switches to be realigned, a single tracking segment can accomodate a train in each direction every 12 minutes. WMATA's crossovers are designed in a similar fashion.

Anyway, how would operating a shuttle train make the system operate any more efficiently in a single-tracking environment?

I can think of several challenges to this approach.

First, the shuttle train would need a platform to arrive on and depart from at each end. So would trains arriving from the ends of the system. This means that their terminals would be single tracked. Therefore, instead of one single-tracking zone, you've just created 3.

Secondly, as a subset of the first comment, crossovers need to be appropriately placed for this to work. In your example, you cited single tracking between New York Ave and Farragut North. In this case, assuming the Glemont track (Track 1) was being worked on, the shuttle train would operate on Track 2, (Shady Grove). Track 2 would therefore be reserved for shuttle trains at Farragut and New York Ave. This presents a problem. Trains coming from Shady Grove would service the Glenmont platform at Farragut North before turning back, but because the next crossover is not until North of Dupont, these trains would share one track at Farragut and Dupont. On the other end, trains coming from Glenmont would have to cross over onto the Glenmont-bound track, but they'd have to do it before Rhode Island Ave because that's the last cross over opportunity. So they'd share the same track with Glenmont-end Red Line trains at Rhode Island Ave and New York Ave.

Thridly, as mentioned before, you are increasing the number of transfers. While you and I might not mind walking across a platform, most people do. I don't have the formula in front of me, but for each transfer required, ridership goes down. There are also ADA issues in efficiency. The trains would have to hold for several minutes at each terminal while the handicapped, elderly, and tourists made their way across the platform. At side-platform stations, this move would also require the use of stairs, escalators, or elevators, further increasing the time.

Also, additional operators would be needed, negating any cost savings in reduced headways. Why? To save time, operators would need to be at each end of the shuttle train. They would probably also need to have a standby operator at each end of the platform so that trains could depart before the next train arrives. (This is currently the practice at Fort Totten and Mount Vernon Square so that trains can turnback without waiting for the operator to walk the length of the train).

My earlier statement was meant to indicate that WMATA already was doing it the most efficient way possible. They could probably support some increase in headways, but that depends on demand. The point is that in every other heavy rail system I've experienced single-tracking on (several), they do it the way WMATA currently does it.

If a shuttle train would be more efficient, please explain why.

by Matt' on Jul 25, 2008 11:14 am  

I like the emphasis on optimizing public transit as opposed to emphasizing punishing private transit. Keep up the discussion. I think this is the way to go. The more constructive pressure residents put on government, officials, the more likely it is there will be real results.

by Jazzy on Jul 25, 2008 11:23 am  

Was there any debate decades ago on why the WMATA subway was some dependent upon 2 track rather then 3 or 4 track segments?

As a historian of the highway system (a history that overlaps with that of WMATA) I have not found anything on this. Has anyone else?

by Douglas Willinger on Jul 25, 2008 12:09 pm  

Not as far as I can tell. Zachary Schrag wrote a book called "Great Society Subway: A History of the Washington Metro." The book doesn't report on any debates like that, although when I heard the author speak at UMD's school of Public Policy, he said that the Red & Orange/Blue lines between Farragut Square and Union Station/Capitol South essentially serve the purpose since there was originally only going to be one trunk line.

But really, the reason that it's a two track system is because all of the modern heavy rail systems are in the US. Only New York, Chicago, and Philadelphia even have express/local tracks. That's the exception rather than the rule.

For more information:

http://tracktwentynine.blogspot.com/2008/07/metro-lack-of-foresight-or-realized.html

and

http://goodspeedupdate.com/2008/2243

by Matt' on Jul 25, 2008 12:14 pm  

Matt,

I threw the shuttle out there as an idea. I have no idea if it would be more efficient. If the idea won't work, so be it. The point is the status quo for singletracking operations is unacceptable. Quite frankly, efficiency shouldn't be the goal here - speed should.

You assert in your second to last paragraph that WMATA is already doing it in the most efficient manner possible. I can accept that. However, if your second statement is also true (that they could still increase the headways), then they're not doing it in the best manner possible. If they can run trains more frequently via single tracking, they need to do so, regardless of how much extra work is involved on their end with turnbacks, additional operators, etc.

WMATA needs to, like many other transportation issues, approach this as a quality of life issue, not a level of service one. 25 minute headways are unacceptable. If they actually have the ability to operate faster than that, then it's particularly unacceptable. If the added costs of doing so eats into the costs saved by doing track work when the system is open, then perhaps it's either a) not worth it or b) just part of the cost of doing business.

by Alex B. on Jul 25, 2008 12:17 pm