Comments on Where the Metro riders are, and aren't - Greater Greater Washington

Comment by Matt Johson

Wed, 05 Aug 2009 12:03:14 EDT

@Jantos,

1. With better data, we could indeed visualize how "inboundy" a station is. However, with the data provided by WMATA, we don't have enough information at this time.

2. Now, this would be easier with better data from WMATA, but is theoretically possible with the data already in my possession. However, my model was not designed to spit out those numbers. It would require a redesign of the model to get that, and that would take a bit of time.

Anyway, should WMATA provide better data, look forward to more interesting posts in the future.

Comment by Alex B.

Fri, 31 Jul 2009 11:53:18 EDT

James D,

Not sure I follow your logic. For one, the data shows that extending the New Blue line to Union Station would be extremely beneficial as well. Furthermore, the idea of simply having a stub line terminate in the middle of DC without connecting to anything else would be an operational nightmare - that's why all the proposals continue on to Stadium-Armory (or thereabouts).

Comment by James D

Fri, 31 Jul 2009 11:00:42 EDT

This looks like a very good case for a Mount Vernon Sq to Rosslyn Link, rather than the conventional Stadium-Amory to Rosslyn separate Blue Line.

Comment by Nathanael

Thu, 30 Jul 2009 16:18:03 EDT

It looks like there ought to be a downtown relief route. Perhaps just grabbing the local short-hop traffic, or diverting people off the Metro further from downtown....

Exclusive lanes for streetcars anyone?

Comment by Michael

Wed, 29 Jul 2009 15:18:07 EDT

I agree with some of the above comments: directionality would be a great thing to add to this map. I would love to see what percentage of the trips between stations are in which direction. This sort of analysis is very important for maximizing the current system's capacity. Lots of empty trains are going east in the morning due to the lack of Metro-accessible job sites in Prince George's county. It would be great if this map could help illustrate where WMATA's core capacity is really reaching its limit and where there are opportunities for moving more people on the existing system.

Comment by Reza

Wed, 29 Jul 2009 12:29:22 EDT

Jantos:

That is an interesting question. Certainly the downtown transfer stations on the Red Line have very high turnover as people finish the extent of their suburb-to-downtown commute on the line and either exit the station or transfer to another line to complete their journey.

It seems likely that inner stations that have a lot of TOD nearby (Columbia Heights, R-B corridor, Bethesda) will have a more equitable distribution of people using it as either an origin or destination station compared to single-use stations (commuter stations are primarily used as origin stations while Federal City stations are primarily used as destination stations during the morning commute).

Another thing to consider is that typically the last few stations on each line that are TOD-oriented (and also usually lack parking) will mark the limit to the extent of people traveling outbound to jobs or other destinations around those stations. Case in point, King Street on the Yellow/Blue lines, Bethesda and Medical Center on the Red Line A route, Silver Spring on the Red Line B route, Ballston on Orange Line, PG Plaza (though this station does have parking) on the Green Line.

I'll defer to Matt on whether this model can be used to more definitively answer your question, however.

Comment by jantos

Wed, 29 Jul 2009 09:23:05 EDT

Great work, a couple of follow-on thoughts:

1- Could you visualize how "inboundy" or "outboundy" each station is? I.e., what percent of boardings are headed towards downtown, vs. away from downtown?

2- Is there a way to visualize how much turnover there is at each station? This would be a useful supplement to loading. For example, it looks like loads north and south of U Street are fairly similar, which indicates that boardings and deboardings are roughly equal - but how many boardings and deboardings were there? How high was the turnover?

I guess in other words, is there a good way to visualize the connection between ridership by link (well done here) and ridership by node/station?

Comment by Lindemann

Tue, 28 Jul 2009 18:25:53 EDT

This is great! I'm glad I participated in the survey.

Comment by Sand Box John

Tue, 28 Jul 2009 18:24:10 EDT

A little history: Original plans (system map displayed aboard trains when first segment opened) showed the future Yellow line operating between points west of Van Dorn Street and Greenbelt. The future Blue line was shown operating between Huntington and Addison Road.

When WMATA was ready to extend service south of National Airport in 1983, WMATA did not have enough rolling stock to extend the Blue line to Huntington. After analyzing the rolling stock distribution they discover they could open the segment if they ran the trains as Yellow line trains.

As the 2 and 3k series cars became available and WMATA opened Van Dorn Street, WMATA chose not to switch the line colors back to the pre 1983 line colors.

The 2 and 3k series cars became available well after service was extended to Huntington.

As to the issue about a pocket track north of Union Station. The original plans for the New York Avenue station called for converting the now abandoned northbound track B1 into a passing track. Plans called for using it to short turn trains at Union Station. The track was not converted to a passing track because of funding. WMATA can in the future when money becomes available connect the abandoned track to the existing mainline.

Comment by Distantantennas

Tue, 28 Jul 2009 17:37:19 EDT

Really? Interesting. I've only ever seen data get published with overall boardings (So many hundred thousand today) or with individual station boardings in a day. It's good they have more detailed data - just never seen it published. Thanks for the info.

Comment by Matt Johnson

Tue, 28 Jul 2009 15:40:11 EDT

@Anderkoo, @Bossi,
We don't need to use video cameras.

There are more than 6 stations anyway. For instance, someone coming from Franconia and going to Mount Vernon Square could transfer at King Street or Pentagon (both marked on the map with a transfer target) or they could transfer anywhere in between or at L'Enfant.

The point-to-point data is already collected. That's how I knew how thick to make the lines. Every so often, Metro conducts a survey of a statistical sample of riders. They're asked several questions, including:
(a)The address of their origin for THIS trip,
(b)The mode they used to get to the station where they entered the system (walk, bike, bus, drive, rode with a driver, etc),
(c)If they used a bus, what was the number and operator,
(d)The station they will exit the system at,
(e)What mode they will use to get from the station to their final destination,
(f)If a bus, what number and operator,
(g)The address of their final destination,
(h)The purpose of their trip,
etc.

All WMATA needs to do is ask them to mention which station(s) the'y be using to transfer (if applicable), and we'll have real data on route choices. So, since WMATA already conducts a survey, all they need to do is rethink the questions in order to get better data.

@Johanna,
Metro does collect data on time of entry. However, I do not have access to that data. My methodology would need to be reworked before that data could be included, however, because I would need to have two lines for each segment (representing direction of travel).

@Dharm,
You make an excellent point. And I made exactly the same point some time ago: http://tracktwentynine.blogspot.com/2008/11/understanding-blue-line-reroute.html

That will be the case once the Silver Line opens. However, until that happens, it is not necessary for WMATA to reroute trains on the Blue Line.

That said, I'm not positing anything other than the fact that WMATA needs to try and collect data about how people travel (route choice).

I argued before, and I'll continue to argue today, that the time loss for travelers going to the Rosslyn/Farragut Areas is not huge. A simple readjustment of time of arrival at Franconia or Van Dorn will nullify any loss of time (increase in travel or wait times).

However, if this estimation is accurate, every Blue Line train going through Rosslyn is going to double its load. That will increase dwell times between Rosslyn and L'Enfant and will just make riders more irritable.

On another note, WMATA does keep track of metrics for level of service. One of those is train crowdedness. They try and keep train loads under a certain threshold. If the Blue Line reroute puts the Blue Line over that threshold (and I say if, I don't know that it will), it will start failing on LOS measures, and they'll have to take steps to rectify that.

@Distantantennas,
That data already is collected by WMATA. I could tell you how many people *on average* travel from any station 'x' to any station 'y'.

What I couldn't tell you (prior to this survey) was which route people took to get from x to y.

Comment by Distantantennas

Tue, 28 Jul 2009 14:28:51 EDT

While I'm sure this would set off some conspiracy types (and I'm not sure I'm comfortable with it either), it'd be fascinating if WMATA actually collected station to station data. You could say 'Of the X thousand people who got on at Ballston today, Y got off at Foggy Bottom, Z got off at Metro Center' and so on.

This could potentially identify good locations for new routings and service increases. Track it even more closely and you could know which exits from which stations are busiest, to know where to add fare gates (Capitol South seems to jam up more than it should).

This data already exists, since it's on the fare cards to charge correctly. I assume that the fare gates have no way of reporting the data, though, and it'd be prohibitive to upgrade them. It'd be nice, though.

Comment by J

Tue, 28 Jul 2009 14:15:10 EDT

This looks like a good TRB paper... abstracts due Aug. 1!

Comment by Dharm

Tue, 28 Jul 2009 13:57:30 EDT

This is great analysis by Matt. However, I take objection ot the following statement:

"Dropping the percentage of rush hour Blue Line trains at Rosslyn 40 percent to only 20 percent, as Metro proposes, would make the most sense if about 80 percent of riders at Rosslyn were on the Orange Line."

This statement assumes the decision to build the Silver Line wasn't already made. Since that decision has already been made, slots need to be freed up for the Silver Line and then the question becomes how do you go about doing this the most efficient way. With that in mind, the Blue line diversion during rush hours is the best solution given the constraints. The system through the core is so heavily utilized, there are no win-win solutions. Sombebody has to lose and in this case its the people going to Rossyln, Foggy Bottom, Farrugut West and McPhereson Square. No amount of complaining from those who lose is going to change the reality that somebody has to lose.

Comment by Reza

Tue, 28 Jul 2009 13:19:09 EDT

I also notice that there's a pretty big jump percentage-wise on the Green Line at Suitland -- I'm assuming that people are commuting to that station for jobs in the Federal Center. I would have assumed that commuters from Southern Maryland that drive to Branch Ave would make the Green Line taper more as it went away from the city as opposed to a big jump.

Comment by Johanna

Tue, 28 Jul 2009 13:04:44 EDT

Great map. Does Metro break the ridership data down between peak periods and off-peak periods? If so, it would be interesting to see the difference.

It's worth noting that if the number of people using every station were exactly equal, you'd expect about a 20% drop in ridership west of Ballston and a 33% drop west of West Fall Church: of every 100 people approaching Ballston from the east, 20 would get off at Ballston, 20 would get off at East Falls Church, and so on (and only a few people would get on at these stations and go west). The drop in ridership as you approach the ends of the lines is not evidence that the outer stations are underutilized. The number of riders between Vienna and Dunn Loring will always be tiny compared to the number between Farragut West and McPherson Square.

Comment by w

Tue, 28 Jul 2009 12:31:51 EDT

as anyone who has lived in DC all thru the history of Metro can tell you, Ward #9 citizens prefer driving cars over transit. Just look at the lack of transit oriented development around their stations- they are isolated and not at all comforting places- and in this way they actually discourage ridership. If they would only see /wake up to the idea that density around transit hubs increses safety , things would go for the better.

I also place blame on the metro board members- who all drive and almost NEVER use Metro.

Comment by Paul

Tue, 28 Jul 2009 12:27:34 EDT

What's interesting to me is the strength of the ridership in the "favored quadrant" and the weakness of the suburban legs elsewhere.

Comment by Bossi

Tue, 28 Jul 2009 12:07:06 EDT

You'd have to look at how the stations are aligned & the paths people would take... but I'd think getting *everyone* would be a daunting task. Some people may get off the train and go the wrong direction; there could be multiple routes people may take; routes may overlap with those entering/exiting the station; and simply watching all those faces could be tricky.

However... by numbers alone: with a statistically significant sampling I think that could work. It might be done manually with surveyers simply asking where the travler what stations they started at & are going to. It'd take a 30-second converation, of which half of it is spent on the surveyor identifying him/herself. The tough part would be getting travelers to stop for those 30 seconds as they briskly travel between platforms. When I'm transfering, my mentality is always "there's a train waiting for me right now, and if I don't make it I'll miss it".

Personally, I think Matt's approach is just as well... posit to people, while they're sitting at the computers, to think about how'd they'd act. It may not be as accurate as catching people while they're actually doing it, but it'd be far easier to conduct & organise.

Or another option would be instead of on-site interviews, hand out business card sized forms with 4 lines to fill in: origin, transfer 1, transfer 2, destination; and then put a box at the exit gates. The back of the card could explain the reasoning for the data & a phone number or mailing address.

Comment by Anderkoo

Tue, 28 Jul 2009 11:54:36 EDT

Points taken. Just thinking out loud here -- if Metro decided - perhaps temporarily - to collect O/D data, maybe the task of conducting a study could be boiled down to counting transfers at the five possible stations? Could strategically-positioned video cameras do the trick for later machine or human analysis?

Comment by Matt Johnson

Tue, 28 Jul 2009 11:41:46 EDT

@Anderkoo,

No it is not.

For instance, I used to commute from Prince George's Plaza to Union Station. My SmarTrip card would have told Metro this, but Metro would not have any way of knowing whether I transferred at Fort Totten and used Red via Brookland or transferred at Gallery Place and used Green via Columbia Heights.

Similarly, they don't know if a trip from Pentagon to Capitol South generates a single-seat ride on the Blue Line or a two seat ride on Yellow and Blue.

That was why we needed to determine rider preference and create a decision tree in order to assign riders to certain links.

@Beau,
The main reason I suggested a pocket track at Ballston is because of the ridership jumps. Once the Silver Line opens, trains coming from Ashburn/Ryan Road will have had plenty of time to fill.

According to riders on the A-Shady Grove Route, after the Metro crash with no Grosvenor short turns, it was impossible to get on a Red Line train at, say, Van Ness. They were already too full.

Ridership is only going to increase. What Metro does with its data is up to them, but using a study like this would go a long way to figuring out where good locations for pocket tracks are.

Comment by Bossi

Tue, 28 Jul 2009 11:40:37 EDT

@Anderkoo-
I don't believe the existing data is tied to origin/destination to make specific pairings. So essentially you get volumes at stations, but don't know what other stations the traveler specifically originated from or is destined for; nor the path they'll take in between.

I don't think converting the existing system to collect O-D pairs would be difficult, but I'm pretty sure I read somewhere that Metro has explicitly decided not to... I think it was privacy issues. Others may be able to correct me on this. One caveat is that even if the fare system was converted to gather O-D pairs, its present configuration wouldn't capture the route people take.

Comment by Beau

Tue, 28 Jul 2009 11:36:28 EDT

If there were a pocket track after Ballston, Metro could create a peak-time Arlington Local service running from Ballston to the Airport, or an A-A Local to King Street. It could be the only station to serve Arlington Cemetery whenever it's running. This would be great for Arlingtonians who don't like crowds; would there be any other merit?

Comment by Adam F

Tue, 28 Jul 2009 11:36:07 EDT

Really interesting analysis. Thanks!

Comment by Anderkoo

Tue, 28 Jul 2009 11:34:56 EDT

Since Metro collects data on riders both entering and exiting through its fare system, isn't the data all there?

Comment by Matt Johnson

Tue, 28 Jul 2009 11:19:19 EDT

If anyone wants the full report, they can contact me at mcjohnson@ggwash.org.

That includes methodology and such.

Comment by Bossi

Tue, 28 Jul 2009 11:15:58 EDT

Great work!

Even though it wasn't that long ago, my memory has failed me in that I can't recall how the survey was conducted. It might help just to touch upon that so that people taking this data any further would understand the foundations upon which it's built. Was GGW the primary tool for getting responses?

Comment by SG

Tue, 28 Jul 2009 10:49:39 EDT

GREAT map! It shows how underutilized the non-TOD stations are on the Eastern side of the city/MD.

Comment by tom veil

Tue, 28 Jul 2009 10:29:08 EDT

Fascinating! Thanks, Matt!