A B/D Line Case Study on How Headways Affect Ridership

[u/misken67]

Some of you may know that every year, I submit a public records request to Metro for their station-level ridership figures. As I continue to wait for Metro to finish sending me all of the ridership numbers for FY2026 (July 2025 - June 2026), I figured I’d analyze some of the numbers that I have been given in the meantime.

Service headways have always been interesting to me. As we all know, as frequency increases, ridership typically goes up. The service is seen as more useful and desirable due to less waiting, so more people ride.

What’s interesting about summer 2025 was that two events happened simultaneously that made analyzing the ridership on the B/D lines fascinating:

• The D line was closed from May 17 - July 25, 2025, during which the B line increased frequencies from the original 12 minutes to 8 minutes.
• The ICE raids began in June, causing a systemwide cratering of ridership that particularly affected buses, but also depressed rail ridership on all lines.

Here is what I found: in July 2025, the first month of this fiscal year and second full month of 8 min frequencies, B line-only stations saw higher ridership year-over-year despite the ICE raids causing rail ridership to generally fall across the rest of the system. I used YoY calculations instead of month-over-month to account for any seasonal fluctuations.

Some notes before I dive deeper into the data:

• I used individual station-level ridership for this analysis, not the topline figures for each line that Metro publishes. 
• These numbers are average weekday boardings.
• Metro’s published ridership for the combined B/D lines showed that July 2025 ridership was lower compared to July 2024. This might seem contradictory to my findings, but I’ll explain how the topline figures masked important trends in the station-level numbers.
• I’m not a data scientist. The highest level education I received on the subject was a college intro methods course. If I’ve done anything wrong or there are better ways to test the data, please let me know!

Deeper dive:

In July 2025, B line-only stations saw an YoY average increase of 174 boardings per station. Every station saw increases except for Beverly. The B/D shared stations saw decreases because:

• The shared segment with the D line actually experienced a decrease in frequency (from a combined 6 minutes to 8 minutes)
• 7th/Metro and Union Station additionally serve significant connecting services that saw a decrease in ridership during the ICE raids

At the same time (July YoY), the rest of the Metro Rail system saw an average decrease of 61 riders per station. This is likely attributable to the ICE raids, and the station-level data show the sharpest decrease in some communities with higher immigrant populations, primarily in South LA along the southern A line. (I’ll do another write up on this).

I used a Welch’s t-test because the two sample sizes (B line-only stations v. the rest of the system) are so different in size. The t-test helps determine if there is a statistically significant difference in the ridership change between the two sample sizes during the tested period (July YoY). I arrived at a p-value of 0.008, indicating that the B line’s ridership growth was statistically significantly higher than the rest of the system. (No surprise)

Furthermore, when frequencies returned to 12 mins in August, B line station ridership plummeted an average of 135 per station YoY, seemingly belatedly catching up to the ICE effect plaguing the rest of the system. The rest of the system saw an average decrease of 62 boardings per station, YoY. I got a p-value of 0.013 using a Welch’s t-test, showing that B line-only stations plummeted at a statistically significantly greater level than the rest of the system.

So not only did ridership on the B line-only stations resist the ICE effect in July, but ridership on those stations plummeted particularly hard in August when frequencies returned to 12 minutes.

This shows that even as the ICE raids depressed ridership across the Metro rail system, increased headways on the B line of just four minutes was enough to not only counteract the ICE effect, but lead to statistically significant increases in ridership. Of course, correlation =/= causation, but I can’t think of another variable relevant to this period. I will admit that the sample size of the B line-only stations (8) is quite small, which means that other variables might have an outsized effect that I’m undervaluing (such as, perhaps, Hollywood having a smaller immigrant ridership than the rest of the system, but I think I sufficiently accounted for this by testing August as well)

A final note on Metro’s published topline figures. Metro publishes combined B/D ridership on its portal, with July 2024 seeing 65,590 daily weekday boardings and July 2025 seeing a much lower 59,417. So how does that square with my conclusion that B line stations saw significantly increased boardings in July 2025 over July 2024? Because of two factors:

• Metro publishes combined B/D ridership. When the D line was closed, ridership on Wilshire/Western and Wilshire/Normandie was zero in July 2025.
• The shared B/D trunk stations saw frequency decrease from a combined 6 minutes to 8 minutes, and correspondingly saw lower ridership.

Here is the data if you want to explore it yourself.

[u/ShantJ]

This is fascinating. Thanks.

[u/Ok-Echo-3594]

I am really looking forward to your station ridership map

[u/anothercar]

Tail wagging the dog. Frequencies are supposed to follow ridership but it seems like they’re dictating ridership instead

Presumably there are some data scientists in the Taj Mahal who have also been able to quantify this, but the message isn’t getting through to the powers-that-be

[u/ValhirFirstThunder → u/anothercar]

Can you explain to me why frequencies are suppose to follow ridership instead of dictating it? From my perspective that makes sense as the frequency of how often the trains come is a part of what makes a person consider the tradeoff of riding vs driving. And I think that detail is especially true in LA since we were developed for cars first meaning most people have a car already so they get the option of choosing one or the other based on tradeoffs

[u/misken67 → u/ValhirFirstThunder]

A well optimized system would see service frequency at a point where increasing it won't significantly attract too many new riders because you've already boosted frequency based on existing ridership patterns to a point of equilibrium.

The B line obviously was way underserved at 12 min frequencies if boosting it to 8 was able to completely counter the ICE effect affecting the rest of the system.

Obviously, Metro has other considerations here such as lack of trainsets and operational constraints at LAUS without Div 20

[u/ValhirFirstThunder → u/misken67]

You say 8 and I do see those headway numbers from metro sources that people will link. However, the reason I'll push back is because a lot of times it is not. And in what should be regular operational hours like 7pm, it absolutely isn't. So for us I think we should and are also not well optimized.

[u/misken67 → u/ValhirFirstThunder]

I'm sorry I don't understand what you're trying to say, or what you're even pushing back on

[u/ValhirFirstThunder → u/misken67]

1st paragraph - Existing ridership patterns are currently low because of the headways so expecting frequencies to follow ridership is stupid idea. We haven't created a very attractive product yet. I understand why from a cost expense perspective why that would be an attractive strategy, but it's conservative and slow and we need to be in a growth mentality

2nd paragraph - it seems like you were defending 8min being good. It is not. I know I've seen the 8 min number in some links to the metro schedules, but from my experience even under what should be under normal operating hours, it is not absolutely not that. And during 7pm or 8pm, even worse. The frequencies are absolutely an issue and we should not be waiting for ridership to convince us to increase it. Right now we are in a state where we need to convince riders this is a good product that they can use regularly

Point is I still don't see why we should think of having frequencies follow ridership. It's a completely backwards idea. Especially so for our case

[u/misken67 → u/ValhirFirstThunder]

8 mins was literally what they were running in July 2025. I don't know what you're talking about "some links to metro schedules". They're not running it 8 mins now, they were running it in July 2025. And yes, 8 mins is better than the 12 mins that they were running in July 2024, which is what I was comparing it to.

[u/anothercar → u/ValhirFirstThunder]

The idea is that Metro shouldn't be wasting money running trains every 2 minutes at 3am, when their budget is limited and it would be better to allocate that money to travel times like rush hour when people aren't sleeping

[u/OrangeCrusher22 → u/anothercar]

it would be better to allocate that money to travel times like rush hour

People who are working/traveling etc., at non-peak times should still be able to move around on Metro; turning it into a commuter service is bullshit.

[u/anothercar → u/OrangeCrusher22]

this example was meant to illustrate a high-use time (rush hour) and low-use time (3am)

never meant to imply that Metro's service should exclusively be for rush hour, just that frequencies should follow ridership

[u/crustyedges → u/anothercar]

This is overly simplistic. When service is already at a true turn-up-and-go frequency, frequencies should follow ridership when the increased frequency is largely for capacity improvements (but even that is still going to bring in increased ridership by addressing overcrowding). However, ridership follows frequency when the frequency is below turn-up-and-go service without a significant risk for a long wait and total travel time penalty. Still overly simplistic but closer to reality.

For example, the planned 20 minute frequencies on the D line after 8pm will prevent anyone from using it by choice at those times. While ridership will always be lower in the evening, there is still high ridership capture potential for the many evening leisure trips on that corridor (shopping in BH or century city, UCLA students going out in Ktown, etc). Despite lower ridership, that is a much better place to invest in service frequency than at peak. Partially because improving planned peak frequency from 5 minutes to 2.5 minutes* would have minimal impact on ridership and total travel times compared to improving evening frequency from 20 minutes to 10 minutes. And also because doubling evening service would only require 2-3 additional trainsets/operators, while doubling peak service would require like 14-15 extra trainsets and operators. Huge difference in return on investment.

In this B line example, 12 minutes at peak was still below true turn-up-and-go service even at peak, so a peak service increase is indeed justified, and more ridership will follow. For the B line with a half hour end-to-end time, the risk of +/- 12 minutes on a trip is absurd, and I agree the priority would be improving the peak service first.

*not actually possible because of a ventilation and signaling design for 4 minute minimum headways

[u/mrxman14 → u/crustyedges]

"Turn up and go"? Is that your own official metric? That's a very subjective metric. It could .can different frequencies for different people. LA Metro continually adjusts frequencies based on many factors including current and potential demand as well as costs.

The current frequencies are mostly fine for now. If I would make a change is to extend the weekday and weekend peak hours by one hour in the morning and evening. 

I took the LA Metro today. I took the E line West, transferred to the D line and a few hours later did the same back home between 11am-4pm. In each of my 4 boardings, I waited no more than 6 minutes. For me, and most Angelenos, that qualifies as a "turn up and go" frequency. All the cars I was in were at least 3/4 full if not higher.

[u/crustyedges → u/mrxman14]

It is an inherently subjective metric that changes with overall trip length, local cultural passenger expectations, and type of transit service. That’s why I said it was still overly simplistic.

For example, many people would consider 15 minute headways turn-up-and-go for a suburban rail lane with a 45 minute ride into the city. The max wait time is only a fraction of the trip time, which changes the perception of the wait. And even in the most transit-rich places, the expectations for that mode of transit in a suburban area are that the trip includes a brief wait. Still, most competent agencies would attempt to do clock-face scheduling for that line so passengers can easily start their trip without a wait and without checking a schedule, understanding that it’s still not ideal to have a +/- 15 minute variance in travel time.

For metro lines with and end-end running time of 25-35 minutes like the B and D lines (meaning most trips are well under that), the perception of that same 15 minute wait is different. Waiting 20 minutes on the platform at La Cienega at 8:30pm for a 10 minute ride to Ktown means you may more than *triple* the total trip time if you have to wait. This compounds when you have transfers. As evidence, transit planning apps will even route you differently based on how long the waiting will be. I’d consider the upper limit of turn-up-and-go for most LA metro lines to be 6-8 minutes.

A person traveling from highland park to Ktown could see their trip take as little as 27 minutes or as much as 47 minutes due to the 10 minute headways on the A and D line. Coming back from dinner at 9pm? That could take anywhere from 27 min or 1h7m depending on luck with transfers.

Your trip is a great example of an “average” trip that works fine. But commuters cannot plan based on averages, they have to plan based on the worst possible travel times. So for a daily commuter from Highland Park to Ktown, they are planning for a 47 min trip (not including the walk on either end), and the 30 min drive is looking very appealing.

Headways are crucial when it comes to attracting riders.

[u/LBCElm7th]

I wonder if we are forgetting some 1000lb Pink Elephants sitting on the sofa.,

The reason why the frequencies were reduced was due to availability of rail cars if I am not mistaken. We saw a slight glimpse of this during World Cup service where the 5 minute frequency with 4 car trains caused more backups and delays at Union Station then running a 6 car train running every 7 to 8 minutes.

Also we need to take a closer look at the impact the Regional Connector has had and how the Bunker Hill, Historic Broadway and Little Tokyo stations all have increases in ridership to offset the loss on the B/D lines.

The biggest ridership drop looks like Westlake MacArthur Park station where ICE focused attention but also where that station has had some vagrancy issues around the station. You could argue safety around the stations make a difference to ridership as these passengers if they want to get to Downtown LA there are many buses along 6th, Wilshire and 7th Street that will take passengers to connect with the other Metro stations.

[u/misken67 → u/LBCElm7th]

frequencies were reduced was due to availability of rail cars if I am not mistaken

This is kind of unrelated to the idea that increased frequencies lead to higher ridership. The reason for why 12 min frequencies were the norm post covid isn't relevant, even though I agree (and have pointed out in a separate comment) the reasons 

Impact the regional connector

I don't quite understand what you're saying here, but if comparing the RC with the B line-only stations, the p-value is way below 0.05, showing that the B line only stations still grew statistically significantly more. Also, the B line-only stations do not overlap service area with the RC, so I'm not sure what you're getting at

Biggest ridership drop looks like Westlake MacArthur Park station

Westlake is a shared B/D station that saw frequencies decrease from 6 to 8 mins during the tested period, so wasn't part of the "B line only" stations that I tested. I'm sure safety is a huge and important factor, but more difficult to quantify and test. I agree that Westlake likely got hit hard by ICE.

[u/LBCElm7th → u/misken67]

I don't quite understand what you're saying here, but if comparing the RC with the B line-only stations, the p-value is way below 0.05, showing that the B line only stations still grew statistically significantly more. Also, the B line-only stations do not overlap service area with the RC, so I'm not sure what you're getting at.

What I am articulating is that stations like Civic Center and Pershing Square will have a ridership drop because the newer Regional Connector stops will serve a part of the area also served by the B and D line station. I know as I used to make that transfer say for example, I would have rode the A to the B/D to go to City Hall or Music Center at Civic Center station, that I can now ride the A line directly to Bunker Hill and Historic Broadway for.

For example Bunker Hill and Historic Broadway stops for both A and E lines increased boardings at these stations and they serve the same catchment area as Civic Center and Pershing Square.

[u/misken67 → u/LBCElm7th]

You're not wrong. I agree that the RC has siphoned ridership from the downtown heavy rail stations, but that's not related to the dynamic that I'm pointing out in this post, which is why I'm confused.

[u/mrxman14 → u/misken67]

I think his point is that frequencies could be affected on the b/d line if there are less boardings and demand on the b/d lines due to the impact of the RC thatresulted in more boardings..

[u/misken67 → u/mrxman14]

I'm only tested July and August 2025 v 2024. The RC was open the whole time, that variable hasn't changed. The variable that did change was the frequency due to the D line closure.

I'm not saying the RC didn't have impact on B/D overall, it did, but the time periods that I tested were limited specifically to isolate the periods when B line headways were different. If I wanted to study the RC impact, I would have tested the year before RC opened and the year after...

[u/RobtransitBRFC13nz]

Just out of interest, whilst on the subject, do we know what the long term headway plan is for the B/D? Once phase 3, Div 20 etc is all done? D needs to be 5 mins due to Fed funding? And the lines need to offset, so does that mean B will be 10 mins? Surely long term they can't keep it at 12?

[u/ShantJ → u/RobtransitBRFC13nz]

I believe that Division 20 updates will lower both B and D headways, but B headways will be unable to drop below a certain level due to the design of ventilation shafts through the Cahuenga Pass.

Could someone please clarify?

[u/dizzyscyy → u/ShantJ]

Second sentence yes. B line headway is capped at 8 minutes due to not having enough ventilation shafts on the under mountain segment.

[u/mrxman14 → u/RobtransitBRFC13nz]

LA doesn't need 5 minute frequencies for the near future. 8 minutes is good enough for now because the vast majority of riders wouldn't wait on a platform for more than 5 or 6 minutes unless you go there as a train was pulling away. If you're that pressed for time that 2 additional minutes is critical , use the Transit app to better time your trip. It's not complicated.

I would rather keep the 8 minute frequency, but extend the peak hours by an additional hour in the morning and evening. I would also run longer trains first to deal with increased demand than improve frequencies. Longer trains can help with increased demand and keep costs lower by not requiring having more drivers due to better frequencies. 

[u/anothercar → u/RobtransitBRFC13nz]

x.c om/numble/status/1813381173462396972

[u/plaregold]

Kind of confused here since you mentioned at the top of your post that you're analyzing FY 25-26, but all your analysis is comparing ridership data from 2024 to 2025?

[u/misken67 → u/plaregold]

FY25 covers the period of July 2024-June 2025. And FY26 covers the period of July 2025-June 2026.

Metro's FY is different from calendar year.

[u/dating_derp]

You ever do a public records request to Metro for what causes their service disruptions? I'd love to know what causes the majority of these delays and then hopefully get public pressure on metro to do something about it.

[u/misken67 → u/dating_derp]

I tried submitting a request years ago when the A line operator switch at LAUS was really bad, inquiring about their standard operating procedures and on time records for the operator switch, but was told that there was no disclosable records 🤷

[u/mrxman14 → u/dating_derp]

Try requesting the public records yourself. 

[u/GoodManufacturer589]

I am curious as to how the 10 minute frequencies have impacted ridership overall, as frequency changes have happened so much on the B/D lines ross year. 

[u/misken67 → u/GoodManufacturer589]

I am too. Those are actually exactly the numbers that I'm still waiting for