Transit
Directional rider flows on Metro
In July, I analyzed how people travel within the Metro system, using a survey to estimate riders' choice of alternate routes.
Because the data used was for average daily travel between origin and destination stations, it was not possible to determine which stations were primarily 'commute from' stations and which were primarily 'commute to' stations. However, after my July post, WMATA offered to give me time-specific data, which allows us to look at commuting patterns. The data used for this revised analysis looks at trips taking place between system opening and 9:30AM. The dataset comes from an averaging of AM Peaks from early May 2009.
The methodology used to assign trips to each link in the system is the same used for the initial model and analysis, published in July. In the above graphic, each segment of the Metro line comprises two lines. One line represents inbound trips, the other represents outbound. The thickness of each line represents the total volume on any given segment.
From the graphic it is clear that, not surprisingly, most AM peak trips on Metro are inbound. Most of the reverse commuting in the region seems to occur on the Shady Grove branch of the Red Line, the Vienna end of the Orange Line, and the common Blue and Yellow Line segment in Arlington and Alexandria.
This analysis also gives us a good estimate of the proportion of passengers traveling on different lines at the junction points. For instance, at Rosslyn, 65% of inbound passengers entering the station do so on the Orange Line, while 35% come in on the Blue Line. Outbound trips are slightly more balanced, with 60% on the Orange Line and 40% on the Blue Line.
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In addition to measuring volume on each line segment, this analysis allows us to consider each station based on how "busy" it is. Metro's faregates keep a record of the number of entries and exits at each station, but they are unable to determine where people transfer. As a result, stations like Metro Center and L'Enfant Plaza appear less busy (on paper) because the people transferring there are not counted. Below is a list showing Metro stations ranked on their level of traffic.
Note that the "transfers" column does not count passengers who don't change platforms. This is because for someone changing to a train on the same track with multiple common stations, it is not clear where they transfer. Transfers in the table below only refer to passengers who change platforms, from the outbound Blue to the inbound Yellow at Pentagon, for instance.
| Overall Rank | Station | Entries | Exits | Transfers | Total |
|---|---|---|---|---|---|
| 1 | Metro Center | 1,660 | 17,388 | 29,117 | 48,165 |
| 2 | L'Enfant Plaza | 2,867 | 14,402 | 24,498 | 41,407 |
| 3 | Gallery Place | 1,564 | 9,945 | 21,007 | 32,517 |
| 4 | Union Station | 10,240 | 13,106 | - | 23,346 |
| 5 | Farragut West | 1,212 | 16,626 | - | 17,838 |
| 6 | Farragut North | 1,121 | 16,630 | - | 17,750 |
| 7 | Rosslyn | 4,758 | 7,173 | 3,842 | 15,773 |
| 8 | Pentagon | 7,482 | 6,033 | 9 | 13,524 |
| 9 | McPherson Sq | 1,604 | 11,840 | - | 13,444 |
| 10 | Dupont Circle | 4,621 | 8,552 | - | 13,173 |
| 11 | Foggy Bottom | 2,268 | 10,046 | - | 12,314 |
| 12 | Shady Grove | 10,400 | 902 | - | 11,302 |
| 13 | Crystal City | 4,219 | 6,812 | - | 11,031 |
| 14 | Vienna | 10,019 | 671 | - | 10,690 |
| 15 | Fort Totten | 3,713 | 984 | 5,204 | 9,919 |
| 16 | Silver Spring | 6,410 | 2,796 | - | 9,206 |
| 17 | Ballston | 4,598 | 4,044 | - | 8,642 |
| 18 | West Falls Church | 6,894 | 1,390 | - | 8,284 |
| 19 | Federal Triangle | 210 | 8,066 | - | 8,276 |
| 20 | New Carrollton | 7,155 | 1,046 | - | 8,201 |
| 21 | Pentagon City | 5,592 | 2,306 | - | 7,898 |
| 22 | Judiciary Sq | 487 | 7,230 | - | 7,717 |
| 23 | Franconia-Springfield | 6,891 | 502 | - | 7,393 |
| 24 | Huntington | 6,648 | 441 | - | 7,089 |
| 25 | Smithsonian | 372 | 6,433 | - | 6,805 |
| 26 | Bethesda | 3,947 | 3,204 | - | 6,643 |
| 27 | King Street | 3,085 | 3,204 | 189 | 6,478 |
| 28 | Capitol South | 790 | 5,677 | - | 6,467 |
| 29 | Archives | 371 | 5,941 | - | 6,312 |
| 30 | Columbia Heights | 4,099 | 1,804 | - | 5,903 |
| 31 | Friendship Heights | 3,360 | 2,194 | - | 5,554 |
| 32 | Branch Avenue | 5,243 | 298 | - | 5,541 |
| 33 | Greenbelt | 4,725 | 590 | - | 5,315 |
| 34 | Suitland | 4,075 | 1,018 | - | 5,093 |
| 35 | Anacostia | 3,645 | 1,347 | - | 4,992 |
| 36 | Court House | 3,334 | 1,599 | - | 4,932 |
| 37 | Navy Yard | 661 | 4,195 | - | 4,856 |
| 38 | Southern Avenue | 4,314 | 483 | - | 4,797 |
| 39 | Federal Center SW | 475 | 4,214 | - | 4,690 |
| 40 | Takoma | 3,602 | 1,026 | - | 4,629 |
| 41 | Glenmont | 4,244 | 209 | - | 4,453 |
| 42 | Medical Center | 1,100 | 3,313 | - | 4,413 |
| 43 | Brookland | 2,219 | 2,137 | - | 4,356 |
| 44 | Grosvenor | 3,941 | 369 | - | 4,310 |
| 45 | Tenleytown | 1,923 | 2,311 | - | 4,234 |
| 46 | Van Ness | 2,942 | 1,290 | - | 4,232 |
| 47 | Largo Town Center | 3,552 | 410 | - | 3,962 |
| 48 | Rhode Island Ave | 2,652 | 1,197 | - | 3,848 |
| 49 | Dunn Loring | 3,028 | 812 | - | 3,840 |
| 50 | Woodley Park | 2,761 | 900 | - | 3,661 |
| 51 | Braddock Road | 2,590 | 826 | - | 3,416 |
| 52 | Rockville | 2,519 | 886 | - | 3,405 |
| 53 | U Street | 2,026 | 1,346 | - | 3,372 |
| 54 | Eastern Market | 2,311 | 1,059 | - | 3,371 |
| 55 | Twinbrook | 2,385 | 898 | - | 3,283 |
| 56 | New York Ave | 1,087 | 2,023 | - | 3,109 |
| 57 | Georgia Ave-Petworth | 2,156 | 881 | - | 3,037 |
| 58 | College Park | 2,123 | 873 | - | 2,996 |
| 59 | East Falls Church | 2,639 | 256 | - | 2,895 |
| 60 | Wheaton | 2,471 | 386 | - | 2,857 |
| 61 | White Flint | 1,515 | 1,335 | - | 2,850 |
| 62 | Prince George's Plaza | 2,089 | 728 | - | 2,817 |
| 63 | Virginia Sq | 1,817 | 1,000 | - | 2,817 |
| 64 | Cleveland Park | 2,428 | 310 | - | 2,738 |
| 65 | Van Dorn Street | 2,437 | 300 | - | 2,737 |
| 66 | Addison Road | 2,392 | 329 | - | 2,720 |
| 67 | Potomac Ave | 2,148 | 492 | - | 2,641 |
| 68 | Clarendon | 1,773 | 786 | - | 2,559 |
| 69 | Mt. Vernon Sq | 1,164 | 1,106 | - | 2,270 |
| 70 | Naylor Road | 2,012 | 248 | - | 2,260 |
| 71 | West Hyattsville | 2,045 | 201 | - | 2,246 |
| 72 | Minnesota Ave | 1,360 | 840 | - | 2,201 |
| 73 | National Airport | 670 | 1,486 | - | 2,156 |
| 74 | Shaw | 1,222 | 933 | - | 2,155 |
| 75 | Stadium-Armory | 1,157 | 686 | 231 | 2,073 |
| 76 | Landover | 1,859 | 151 | - | 2,010 |
| 77 | Benning Road | 1,715 | 283 | - | 1,998 |
| 78 | Forest Glen | 1,773 | 143 | - | 1,916 |
| 79 | Eisenhower Ave | 723 | 1,068 | - | 1,791 |
| 80 | Congress Heights | 1,442 | 286 | - | 1,728 |
| 81 | Waterfront | 1,098 | 607 | - | 1,706 |
| 82 | Capitol Heights | 1,442 | 286 | - | 1,728 |
| 83 | Deanwood | 1,049 | 279 | - | 1,328 |
| 84 | Morgan Blvd | 1,119 | 149 | - | 1,267 |
| 85 | Cheverly | 1,081 | 144 | - | 1,224 |
| 86 | Arlington Cemetery | 22 | 262 | - | 284 |
Looking at the 'exits' field reveals some interesting attributes. This field can be considered a reasonable proxy for office access. The first station in exits outside of downtown Washington is Arlington's Rosslyn station at #12. Medical Center is Montgomery County's leading station for exits at #21 and is followed by #22, King Street as the highest in Alexandria. Fairfax's most exited station in the AM Peak is West Falls Church at #33. Prince George's County's New Carrollton comes in at #42. In the case of West Falls Church, it is likely that many of the exits are passengers transferring to buses headed for Tysons or Reston.
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by Tsar Bomba on Nov 17, 2009 12:07 pm • link • report
1) The Orange/blue thing in Rosslyn makes perfect sense. There are twice as many orange trains as blue trains. All of them are full, so that yields a near perfect 1:2 ratio in traffic.
2) What is surprising is that the blue line has higher ridership compared to the yellow line in Pentagon and King St.
Based on that, can anybody explain me why people want to re-direct the blue line along the yellow line? The blue line is stuffed to the max, and more so than the yellow line.
I am surprised how few people transfer at King St.
I am curious to see if the pm numbers show the complete opposite.
by Jasper on Nov 17, 2009 12:20 pm • link • report
by Froggie on Nov 17, 2009 12:23 pm • link • report
@Jasper,
The ratio of Orange to Blue trains at Rosslyn is roughly 3 to 2, so not quite twice as many.
The issue with rerouting the Blue Line right now is not particularly clear cut. However, once the Silver Line opens, WMATA will have little choice in the matter.
One particularly interesting phenomenon is the imbalance at the junction points. Take L'Enfant Plaza, for instance. 62% of inbound passengers come in on the Green Line, a large majority. But outbound passengers are 56% on the Yellow Line. Pentagon and King Street show similar cases, where the dominant demand is on opposite lines for the inbound and outbound tracks.
by Matt Johnson on Nov 17, 2009 12:29 pm • link • report
by David Alpert on Nov 17, 2009 12:39 pm • link • report
Based on my own personal experience, your hypothesis about WFC exits being mostly bus transfers is correct. I get off there every morning to bus to Reston, and nearly everyone else seems to also get on the buses to the Reston, Tysons, Herndon, AOL @ Dulles, Dulles Airport, etc. Can't imagine there's too many jobs within walking distance of WFC Metro.
by Chris Loos on Nov 17, 2009 12:57 pm • link • report
Thanks for the confirmation. I think that says a lot about the lack of (balanced) TOD in Fairfax and Prince George's. Fairfax and Prince George's Counties only have one station each in the top half under exit volume, WFC and New Carrollton.
by Matt Johnson on Nov 17, 2009 1:03 pm • link • report
The number of entrances and exits at Union Station surprised me. Entrances I expected: transfers from MARC/VRE. But I didn't quite appreciate how many people work around there. An argument for the separated blue line to come through Union Station.
That there are more exits than entrances at Eisenhower Ave. is interesting. There's a destination there. An argument for cross-bridge transit (an extension of the green line from Branch Ave.) into Eisenhower East, perhaps.
by jim on Nov 17, 2009 1:13 pm • link • report
by JTS on Nov 17, 2009 1:22 pm • link • report
Think about it - the front entrance of the Convention Center on the square (K St, essentially) is just as close to the Mt Vernon Sq entrance as it is to the Chinatown station entrance.
by Alex B. on Nov 17, 2009 1:28 pm • link • report
More seriously, Tenleytown is more of a destination than you would think. Some of that must be for Homeland Security and AU, but that's still unusual.
by Neil Flanagan on Nov 17, 2009 1:29 pm • link • report
In terms of boardings, Mount Vernon Square is comprable (and slightly better than) Shaw, so the residential side of things isn't so bad.
In terms of the "exit" statistic, though, remember that convention-goers have different travel profiles than many working people.
If conventioneers come to conferences after 9:30, they're not shown in these statistics. That may be more likely because Metro's day passes don't work until after 9:30. But really, if you compare Mt Vernon Sq to the other downtown stations, there aren't all that many offices. And since the station is so close to Gallery Place, workers coming from the Red Line might just walk from 7th/H instead of transferring.
by Matt Johnson on Nov 17, 2009 1:30 pm • link • report
by Rich on Nov 17, 2009 1:39 pm • link • report
@ David: Ah. I didn't get that. That doesn't surprise me.
@ Jim: Eisenhower has quite some government around it. Patent Office, Federal Courthouse and Hoffman also has a big government building.
by Jasper on Nov 17, 2009 1:45 pm • link • report
Actually it's not that simple.
I wrote about this a while back: http://tracktwentynine.blogspot.com/2008/11/understanding-blue-line-reroute.html.
Anyway, if it helps, think of it this way.
Any track at a junction point can handle a train every 135 seconds.
Essentially, this means that every 12 minutes, the inbound track at Rosslyn can handle 5.3 trains. The current configuration is OR, BL, OR, OR, BL (3 Oranges, 2 Blues). This means that the Orange Line has a headway of 4 minutes during rush periods (12/3) and the Blue Line has a headway of 6 minutes (12/2).
When the Silver Line opens, there are a few things we could do for headways, none of which are particularly helpful.
SL, OR, BL, SL, OR (Silver-6mins, Orange-6mins, Blue-12mins)
or
SL, OR, BL, OR, BL (Silver-12mins, Orange-6mins, Blue-6mins)
or
SL, OR, BL, SL, BL (Silver-6mins, Orange-12mins, Blue-6mins).
Metro is picking door number 1.
by Matt Johnson on Nov 17, 2009 1:54 pm • link • report
by Cavan on Nov 17, 2009 2:03 pm • link • report
Also, the outbound green line past L'Enfant and even more so past Navy Yard is gloriously empty. Maybe 10 people in a car, most of whom are going to the Suitland federal complex.
by Paul on Nov 17, 2009 2:15 pm • link • report
"Metro is picking door number 1"
There are some alternatives. They could alternate 2S2O1B and 2S1O2B (door number 1.5?) to give average 8 minute headways on both orange and blue, for example. Looking at the thicknesses of the paths on C6 and K6, it's not clear that one set of riders should be favoured over the other (particularly since some of the WFC riders will move to the silver line once it opens), and, as I noted above, there's a fair amount of blue/orange interchange at Rosslyn which dropping blue to 12 minute headways would kill.
by jim on Nov 17, 2009 2:44 pm • link • report
by rg on Nov 17, 2009 2:49 pm • link • report
by Neil Flanagan on Nov 17, 2009 3:05 pm • link • report
The model is not all-or-nothing. Based on survey reponses, different trips are assigned to different links (where an option exists) based on percentages.
I don't have the model in front of me, but I believe that a trip from Silver Spring to Suitland would assign 100% of the trips on links B9-2, B8-2 and on links F1-2 through F9-2. It would assign 50% of those trips to links E6-2 through E1-2 and B7-2 through B2-2.
But it's not always that simple and it's not always 50%.
@Neil, Thanks. Bethesda has been fixed.
by Matt Johnson on Nov 17, 2009 3:17 pm • link • report
by fedward on Nov 17, 2009 4:11 pm • link • report
or-or-bl
so 2 oranges for every blue.
Did not know it was
or-or-bl-or-bl
so 3 oranges, 2 blues.
I still don't get why they have to think in fives. If they go to
si-or-bl
they keep the rough ratio of two trains west, one south the same, and they even need to change the track less. Would save time, not?
I know that the orange line gets ridiculously busy, but so does the blue line. Because the frequency is lower, and because some trains a 6 car trains. It often takes to Braddock or King St until I get s seat.
Anyway, he true solution is not messing with that switch. It's building an M St line, and a street car from Rosslyn to Georgetown across Key Bridge. Or a line along Route 50 (Annapolis-Middleburg). Too bad our politicians keep thinking that toll roads are the unicorns of traffic problems.
by Jasper on Nov 17, 2009 4:54 pm • link • report
Metro doesn't think in 12s they think in 60s. Their measurement is TPH, trains per hour. However, for the sake of creating a graphic, 12 (1/4 of 60) is an excellent divisor. And it comes out so that the train headways are correct. It's a lowest-common-denominator thing.
by Matt Johnson on Nov 17, 2009 4:58 pm • link • report
sorry, that should have been 1/5 of 60. I type faster than I read sometimes.
by Matt Johnson on Nov 17, 2009 4:59 pm • link • report
e.g. the recent GGW post recommending that the trolley going down Rhode Island Avenue not get entangled into the other Metro stations.
Also, my oft-mentioned hobby horse of pedestrian tunnels linking Gallery Plc/Metro Ctr and Farragut N and W.
by SJE on Nov 17, 2009 7:32 pm • link • report
When I stay at my fiance's place in Reston, if I don't leave for work before 6am there's a significant chance that driving the 25 miles to Pentagon City will take me longer than the 2 hrs it would take me to bike it. And that makes the 13-minute blue line headways not seem so bad. Nothing makes me appreciate Metro in all its crappy, run-down glory like sitting in fairfax county gridlock.
by lilybelle on Nov 17, 2009 8:13 pm • link • report
Im betting stations such as Stadium Armory, Van Ness, Pentagon City, Wheaton, Largo Town Center, Ballston change different times of the year.
Stadium Armory is almost a ghost town during the summer when Eastern High is out and the same for Van Ness when UDC is closed
Largo, Wheaton, Ballston & Pentagon City are always packed during the holiday shopping season ( day after thanksgiving, christmas eve, day after christmas etc) I have been to each on those days and they are packed with people coming from the adjacent malls/shopping centers.
by kk on Nov 17, 2009 9:17 pm • link • report
As noted at the bottom right portion of the diagram and also in the paragraph immediately preceding the diagram, the data used in this analysis comes from averaging origins and destinations taking place during the AM Peak (opening-9:30AM) on May 5, 6, and 7, 2009.
by Matt Johnson on Nov 17, 2009 9:27 pm • link • report
by Ben Ross on Nov 17, 2009 9:29 pm • link • report
by The Kleiner on Nov 17, 2009 9:35 pm • link • report
The Circulator might also account for some of the low traffic at Mt. Vernon Square. That's the closest metro to where I work, but frankly there just aren't a lot of businesses over there. People are either going to Howard (so the Shaw station) or downtown (so Gallery Place).
by Stacy on Nov 17, 2009 9:40 pm • link • report
by David C on Nov 17, 2009 10:12 pm • link • report
by Cavan on Nov 18, 2009 11:17 am • link • report
by Cavan on Nov 18, 2009 11:19 am • link • report
by Jasper on Nov 18, 2009 11:49 am • link • report
by Alex B. on Nov 18, 2009 11:52 am • link • report
by David C on Nov 18, 2009 1:36 pm • link • report
If you're able to provide me an n x n table (where n = number of stations) which corresponds to Trip Start vs. End, I'd be happy to piece together a visualization using a tool called Circos: http://mkweb.bcgsc.ca/circos/. You would probably have to model transfers in the data model as well.
by Stefan on Nov 19, 2009 7:30 am • link • report
How could you allow bikes on only certain segments of a line? Seems impractical.
I'm not surprised about Union Station. It would be interesting to see how many of the exits are transferring onto Amtrak versus exiting into the neighborhood for work, etc. My guess is that there are quite a few people who have Amtrak on their mind....
I was definitely surprised not to see more people transferring from inbound Orange to outbound Blue. You always get so many people getting on outbound at Rosslyn in the PM, I assumed it was at least a good number going home from their jobs in Pentagon City, etc. Maybe not?
by Josh S on Nov 19, 2009 10:30 am • link • report
As I mentioned they do it on BART.
http://www.bart.gov/guide/bikes/bikeRules.aspx
It's pretty simple. Step 1 identify sections/stations of Metro where cyclists are allowed to use Metro during rush hour. This may be different for the morning rush than the evening rush Step 2: State rules about this publicly. Step 3: Enforce rules same as you do now, but with new exceptions.
by David C on Nov 19, 2009 10:58 am • link • report
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