The sparseness of the rapid network

San Francisco has complicated geography. While the hills are nice to look at and offer some great views and parks, they’ve also forced Muni to do some suboptimal network design. Hills will break up the street grid and be very hard to pass over. We can see this quite clearly with Mt. Sutro and the Twin Peaks, which cut off the Castro/Noe Valley street grid from the Sunset one. This makes it difficult to design an east-west line that fills in the gap between the N and the L. The 7 tries to avoid this by coming in from Lincoln Way, and the 48 up from West Portal (though only during peak hours), but large areas are still left uncovered and the innermost bits of the Sunset aren’t well served by this sort of design. Hills also break up Noe Valley and Glen Park, making continuous north-south lines difficult.

In addition, I think that the hills and narrower streets that some of the highest-ridership lines traverse have prevented them from getting rapid buses added to them. I would expect the criteria for adding a rapid bus to be something like the following:

  • High ridership
  • Lots of transfers to other high-ridership lines
  • Long route
  • Dense stop spacing on the local

If we look at just the rapid network, it seems to be very commute-focused, with few crosscutting lines except for the 28-19th Avenue. Entire areas of the city also seem to be lacking in rapid service.

sf-rapids
I excluded the 7R-Haight/Noriega Rapid here because it skips so few stops that it might as well be a local.

Just about every line here serves to get people downtown! By contrast, the area just west of downtown LA seems to have no problem implementing a rapid grid in addition to its locals.

west-la-rapids

It’s missing a few pieces—perhaps rapid lines on Beverly and La Brea—but the grid structure is clear here. Can we look at something similar for SF? First, we need to decide which lines are due for rapid upgrades. The Van Ness section of the 47 and 49 will essentially be rapid once Van Ness BRT is complete, so that’s a start. Having a 49R to complete the rest of that journey would be nice as well, and Muni does seem to be planning something along these lines. I have some ideas for other upgrades, ranked roughly from what I think are the best options to the worst:

  • 29-Sunset (19k riders/weekday, crosstown line, connections to most rapids and Balboa Park Station)
  • 44-O’Shaughnessy (17k riders/weekday, crosstown line, connections to most rapids and Glen Park Station)
  • 1-California (26k riders/weekday, 29k with express routes, adds service north of Geary)
  • Either the 22-Fillmore (16k riders/weekday) or 24-Divisadero (10k riders/weekday, but longer route and denser spacing)
  • 45-Union/Stockton (10k riders/weekday, goes through an area with little rapid coverage, though the route is shorter)

 

So what’s stopping us from upgrading these lines? One of the interesting things about rapid buses is that if they are deployed along frequent local bus lines, they won’t really save much time or go much faster if they can’t pass the local buses. This means that trolleybus lines that are potentially too steep for a full motorcoach are immediately off the table! The 1, 22, 24, and 45 won’t be able to have rapid service for this reason. This is a real bummer, since the 22 or 24 would have filled a nice gap in the middle and added a crosstown rapid line. Additionally, the stop spacing on the 24 is so dense in some areas that it stops are not even 600 feet apart—sometimes even under 300 feet! It would have been nice to have a fast ride at times other than the middle of the night, but it’s not looking too good right now.

Can we at least add rapid service to the 29 and 44? Passing on normal two-lane streets is harder, but still possible. From the Presidio terminus to about Holloway & 19th Ave, the 29 is mostly on large streets where passing is easy. The same is true while it’s on Ocean. Otherwise, the streets are narrow and might not allow passing, and passing on Mansell would probably be dangerous for bikers. The 44 spends a lot of time on large roads as well, and Silver is a better street to pass on than most with only one lane in each direction.

What does the rapid network look like with these additions?

sf-rapids-2.png

 

Still not perfect, but it’s getting there! We have some semblance of a grid in the southern and western areas of the city now. Twin Peaks has a faster way to go crosstown. The northern areas are still underserved, but I’m not sure there’s a good solution to that short of a Union St subway. Perhaps something could be done using Broadway since it is flat, wide, and the area seems like it could use the service, but it wouldn’t line up with any existing line and would probably be the result of some rejiggering of the lines that are already in the area.

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A downtown subway grid

Recently, the SFCTA, SFMTA and various other transportation organizations released a website called Subway Vision. It aims to collect ideas from everybody about where to install new subways in SF. The Subway Master Plan is supposed to ensure that we are always building a subway, and we currently have the Central Subway under construction, along with planning for the M subway and construction hopefully in the not-too-distant future. Future expansion plans are also being considered right now, as the Rail Capacity Strategy report released back in February gives an outline of what Muni thinks its next steps will be.

People spend a lot of time talking about Geary whenever new subways are discussed. And that’s great! Having high-capacity transit on Geary is extremely important given that its bus lines ferry the same ridership as Caltrain. BRT will definitely help, and we’ll see how this develops in the future. However, I think the need for new subways downtown is often overshadowed by this discussion. Our current rail network has one subway that goes from downtown outwards, through which a large percentage of its 150,000 daily riders go. This is a huge bottleneck! Problems that occur in the subway here are liable to delay many people and cause lots of gaps and bunches. If there is one thing we can learn from New York here, it is that these problems are way more tolerable when there is some redundancy.

Having extra subways parallel to the Market Street Subway downtown is hardly a new idea. SPUR advanced the idea in this report and has implied it in various materials concerning a second Transbay Tube. By pulling together some ideas from these and the Rail Capacity Strategy, we can come up with a nice grid-like structure for subways in downtown SF.

First, if we look at the Rail Capacity Strategy, we find that Muni eventually wants to put LRT on Geary. LRT will improve capacity even more than BRT, but the most interesting part about the plan is the fact that it might be a hybrid subway/surface line. Muni gives cost estimates for all of the involved projects in the report, and the lowest estimate for Geary LRT appears to be the cost of installing surface rail along its entire length at a cost of about $1.4 billion. By using the estimated cost of installing other subways and doing some math, we can figure out that the $3 billion upper bound makes sense if Muni installs a mile of subway and 5 miles of surface rail. One mile of subway takes us from Market to about Van Ness along Geary, which is a reasonable option.

But why should we stop at Market? Merging into the Market Street Subway is probably not feasible, since it’s not possible to fit a flyover junction when there is already another subway below. Even if it were possible, it would probably be ill-advised, as we’d get one extra stop at the expense of subjecting the new subway to all of the same problems we get by combining the other lines. But there are other options—the report also has lots of figures for job and population density in various sections of the city, and we can use those to extend the route. 2nd St in particular has a very high density of both, and a subway in the Geary area could connect through Mongtomery Station and continue into SoMa along 2nd St. This line could be anchored at AT&T Park, which is surrounded by a commercial district, and which often relies on the easily-overwhelmed Muni Metro Extension to get people in and out on game days. 2nd St is also slated for an upgrade to LRT in the distant future, according to the Rail Capacity Strategy.

It might seem like overservice, and while the redundancy with the Central Subway is nice, that’s not really what we’re after. The grid really comes together when we install a subway along Folsom. Folsom is considered one of twelve high-priority corridors for expansion by Muni. By pulling a line out of the Market Street Subway between Church and Van Ness and instead sending it up Folsom, we solve a number of problems:

  • Fewer lines are merging at Van Ness, which means we can mitigate a bottleneck there
  • The already-existing flyover junction would make construction of the other one less disruptive, since we wouldn’t have to reconfigure the current subway
  • In the event of backups in the Market Street Subway, all KLM trains could reroute into the Folsom Street Subway instead, mitigating delays (J and N trains could stop at Church & Duboce for transfer) and still allowing decent access to Montgomery and Powell areas via the 2nd/Geary and Central Subways

In this proposal I choose the L train to be pulled out in standard service because we can’t pull out the J or N, as the new trains will leave the MSS before the J or N merge in; the M is going to improve capacity in the MSS after its subway expansion and use of longer trains, which is important; and the K can only run short trains at the time being, and may still be used to serve the Muni Metro Extension.

The end result is a grid-like structure centered on 2nd, 4th, Market and Folsom Sts, with additional transfer points along the Embarcadero and on King. Here’s what it looks like:

names
Above-ground stops are circled with gray, and Van Ness BRT is shown as the green dashed line.

There’s also room for further expansion: Leavenworth, Civic Center and 7th St stations all line up quite nicely, for instance (and would be easily connected by the bus I laid out in earlier articles). If the Caltrain railyard is rebuilt underground and the 280 spur is at least partially torn down, this could open up enough land that extending the Muni Metro Extension out to 7th St and building more rail along 7th St makes sense, as well. Some ideas for extending high-capacity transit along Van Ness send it down 11th St and Potrero Ave, in which case they would also fit nicely into this grid; extensions down Mission could also use the transfer to the new station at Duboce Ave. Sadly, I think the Chinatown T stop is too far north to have a really easy transfer, but a line down Sacramento St might be useful and connect Van Ness BRT with Embarcadero and Main St Stations. The T would be within reasonable walking distance of such a line.

This expansion provides a lot of extra options for people to move around on corridors that Muni considers important, and getting them into a shape where they work well together. Having redundant infrastructure makes the system more resilient and also makes it easier to justify arbitrary planned service changes, which people will need to deal with if we ever eventually want 24-hour rail service.

But don’t just take my word for what subways are worthwhile to build. With Subway Vision, Muni is giving all of us an opportunity to influence the evolution of the city. We should use this opportunity to tell them what we think!

The one-seat slowdown

In the article about the 19th Avenue Subway, I wrote briefly about the plans for the J to cover the portion of the M route in Ocean View (Randolph, Broad, and San Jose). Residents of Ocean View are now faced with a trade-off when trying to get downtown. They will experience a faster ride if they take the J to SFSU Station and transfer to long, fast M trains to continue inbound. However, some people are not happy about the loss of a reasonably quick one-seat ride, since their current route will be replaced with the J coming all the way around through Balboa Park. The J is going to spend a lot more time in mixed traffic than the M does currently, and so taking it downtown from Ocean View is likely to be a slow and unreliable ride. While we should think about what will keep the J reliable, we might also want to consider doing something else to mitigate the concerns of Ocean View residents.

Let’s take a look at the N. A large percentage of this route is at-grade, and getting from one end to the other is very slow. This sounds familiar! During commute hours, when subway space is limited and people from the forties need to get downtown in a reasonable amount of time, Muni runs an express route along this line. The NX-Judah Express aims to get people from further out to downtown quickly by skipping lots of stops in the middle and using faster one-way, timed-light roads where possible to keep the buses moving. Plenty of bus routes have matching express routes during commute hours. The 1-California and 38-Geary each have two express routes which use Bush and Pine to get downtown quickly. The 7X-Noriega Express uses Oak, Fell, Franklin, Gough, Golden Gate, and Turk. Express routes for the 8 and 14 use freeways. But most light rail lines do not need an express route since the subway generally obviates the need for them. To support a light rail express line, we need to be able to get people from far-flung areas onto fast roads and keep them there until we get close to downtown. With the J extension to SFSU, the line might become eligible for such treatment.

280 and 101 can be used to transport people express from the Glen Park areas to downtown more quickly than it would take to crawl all the way around and finally get into the subway. Stops between 19th Ave & Randolph St and San Jose Ave & Santa Rosa Ave would be serviced by the express bus, after which it would take 280 via Baden and either Circular Ave or Monterey Blvd. From there, it can get on 101 via the Alemany Maze interchange. The Central Freeway will allow the bus to exit on Mission to service Van Ness & Market. The bus can make normal J stops up Market from there. (Other designs might make different stops downtown or use a different route to get there, as the NX tries to serve the Financial District more specifically. I tried to make this serve existing downtown J/M stops as closely as possible.)

map

Now that the JX services stops up to Santa Rosa, we can turn around more J trains at Glen Park. This already happens during commute hours, but it’s rare, and with the JX to supplement service past Glen Park we will be able to get away with turning some trains around more quickly than we would be otherwise. This would help keep the route more reliable for residents further inbound on the route.

Of course, there are other concerns at play here. I don’t normally like introducing express buses, because they are an expensive proposition with regard to how much service they actually provide. Muni will be forced to increase its peak bus fleet to accommodate the extra commute-time load. The J station at Glen Park is somewhat confusing if trains are turning back there, since trains can’t cross over to the inbound track from the outbound side. I’m not sure how expensive installing this extra track would be. Furthermore, extremely heavy traffic on the freeways may mean the bus won’t save any time after all! However, if this idea gets more people on board with the 19th Avenue Subway by assuaging concerns over the reliability of the J and preservation of a somewhat quick one-seat ride to downtown from Ocean View, then I think it’s worth studying.

The Tenderloin gap, part III

The last two parts (12) of this series focused on a north-south bus north of Market, but we never laid out the remainder of its journey further south. I think there are two major strategies for such a route—bring it into a major connection point or continue with the north-south gridline. What would these look like?

The most easily accessible major connection point is 3rd & 20th, with connections to the T, 22, and 48. With such a design, this route would effectively be participating in a secondary downtown radial pattern along with these routes. The T brings people in from the north and south, the 22 from the west and far northwest, and the 48 from the southwest. This bus would then bring people in from between the 22 and the T. This is even more prominent once the T is sent through the Central Subway.

3rd-20th-option

If we were to do this, land use at the nexus would need to support this anchoring of many frequent lines. Mission Bay is nearby, but the neighborhood is somewhat concerned about its expansion southward. The area is already zoned “urban mixed use” (UMU), which is a conversion from old industrial land use types to support more residential and commercial development. Think lofts built in old warehouses with ground-floor retail, and the like. While we like mixed use zoning, most of the parcels in this area have height limits of between 40 and 68 feet. This does not allow for very much density, and surely would not be able to support a second radial pattern. Perhaps the new Warriors stadium will provide the Planning Commission with a reason to raise the height limits in the area, but I wouldn’t hold my breath for that. Given that the T and 22 are such high-frequency and high-capacity lines and we plan to add another one, we’d probably want to raise height limits to at least 100 feet to take advantage of this. The AHBP might have been useful to provide taller buildings with more affordable housing in the area. While raising the height limits is a possibility, it is a remote one and we might be overserving this area quite a bit in the meantime.

If we were to continue the gridline to the south, we have a perfectly nice candidate already available—the 19-Polk! Given that the 19 is already bracketed by this bus and the 47/49, all of which are designed to be more frequent, we can scrap the 19 and use its southern leg for this bus instead, which leads to an increase in service for those riders. Since the 19 hits Market so close to where this bus would, it seems duplicative to try and fit an extra gridline in Potrero Hill, and we would probably have to introduce some confusing hopscotch to serve 6th St instead of 8th. This isn’t ideal because 6th St doesn’t cross over into Potrero like 7th and 8th do, but 8th St would be overserved if we ran both this bus and the 19 on it.

19-option

Muni Forward

SFMTA’s Muni Forward plan has a number of service changes planned which, if implemented, change the calculus for the two options outlined above. Under the proposed changes, there will be a lot of rerouting on the east side. The 9R-San Bruno Rapid has added a stop in front of San Francisco General Hospital, so the 33-Ashbury/18th will no longer turn down Potrero Ave and go down to the hospital. Instead, riders will be expected to transfer at 16th St and take the 9R one stop south. The 33 will instead continue eastward and take over this current leg of the route for the 22-Fillmore, which uses 17th and 18th Sts to eventually end up at 3rd & 20th. The 22 will then be rerouted to use the current route of the 55-16th St, and serve Mission Bay. The 19 is also rerouted to serve SFGH under this plan, with the 48-Quintara/24th taking over its route to Hunter’s Point. A new 58-24th St will take over the eastern part of the 48’s route and go to 3rd & 20th.

This would break up the 3rd & 20th radial hub, as the frequent 22 is replaced with the less frequent 33, and the fairly frequent 48 is replaced with the infrequent new 58. Add all this to the zoning changes needed to maximize the benefit from creating this radial hub, and it looks like this option will not work for us in the long term.

On the other hand, replacing the 19 south of Market is still a good idea: our frequent gridline has an anchor (SFGH) and the route is fairly straight. Thus, our bus can take over for the 19 no matter how many of the Muni Forward recommendations are implemented.

19-option-muni-forward

This new route also has the advantage of getting rid of that confusing bit it encounters as it crosses over Cesar Chavez, although the route is shorter, so some riders will have to take the post-Muni Forward 48 to 23rd & De Haro or Rhode Island to get on the new bus. In any case, this is still better than the other option should the Muni Forward recommendations come to pass. The pain of making this connection will be ameliorated by the increase in frequency.

Overall I like rejiggering the 19 instead of creating an entirely new line, since I think it works better with the land use. The other option looks nicer from a network perspective, but it is viable only if Muni does not follow through on some of its proposed changes, and if we get some help from the city to upzone the 3rd & 20th area. In effect, this ends up being a change of the 19 route, which shouldn’t be such a big deal—Muni Forward is already full of big route changes!

The affordability balancing act

I apologize for the long break, but personal issues kept me from putting together posts or coherent thoughts of any reasonable length about transit recently. I decided to broach land use because we will vote tomorrow on a number of things that are going to affect it for the foreseeable future. This is always going to be a topic that consumes much of the political energy in San Francisco unless we have a miracle or a really deep recession.

A lot of my arguments for transit development rely on transit being the great equalizer. Everyone in the city should be able to get anywhere reliably, reasonably quickly, and inexpensively. This makes it especially tragic when transit access is a reason for gentrification or displacement. We have seen this in the past—a well-known recent example is the gentrification along the L train in Brooklyn. Many have argued that running BART through the Mission was one of the primary reasons for its gentrification, as well. Other efforts to expand and improve transit in SF, such as Geary BRT, have raised concerns because they might lead to gentrification in the western areas. But this seems to put us in a bind! If we don’t improve transit in low-income, minority and poorly-connected communities, we fail to enact the goal of transit, which is to serve those people as well as everyone else. If we do, then improved access is seen as a nice amenity for wealthy people who want to move in, and when that happens, we’re not serving low-income and minority communities anymore!

What this means is that transit activists must also be affordable housing activists, or transit activism won’t be worth nearly as much. Housing along high-capacity transit lines must be dense and include lots of affordable housing. A number of policy developments are taking shape in this area. Proposition C, which we will vote on tomorrow, seeks to push the inclusionary zoning (IZ) percentage up to 25%, grandfathering in current projects between 13% and 14.5% depending on when they were proposed, and allow the Board of Supervisors to change the IZ percentage without bringing it to ballot. We gain a lot of flexibility in housing policy by passing this, so if we find that 25% is too high, it can be dropped later after study determines what requirement produces the highest number of affordable units. The Affordable Housing Bonus Program is an attempt to give developers density bonuses in exchange for more affordable housing, and eligible areas are generally centered on frequent transit lines. It’s been reduced in scope in response to fears about displacement, but will still be useful. Aaron Peskin wants to expand Scott Wiener’s in-law unit legislation to the entire city, which could potentially unlock a new source of rent-controlled units, as well.

The other major policy statement has come from Gov. Jerry Brown. Mr. Brown wants to institute as-of-right development if projects meet existing zoning codes and have 20% of their units as affordable, or 5-10% if in a “transit priority area.” This is defined as the area within a half mile of major bus lines, trains, or ferries. I think as-of-right development is generally a good idea as it is what has allowed Seattle and Brooklyn to get a handle on their increasing rents, and the amount of process required to approve projects in SF is absolutely brutal. It seems like the lower IZ requirement near transit lines is meant to remove as many barriers as possible to transit-oriented development, which is well-intentioned. However, transit line catchment areas are exactly the places we should be building the most affordable housing, and I’m afraid that this might backfire as proposed. Without lots of upzoning or enormous density bonuses, both of which would likely face huge political battles, it would be difficult to ensure a meaningful number of transit-accessible affordable units are developed. And we might have an even bigger problem than that—depending on the definition of “major bus line,” most of San Francisco might fall into the transit priority zone, and the effective IZ requirement might drop precipitously across the whole city!

I imagine the insanity of the crisis and of local housing policy led Mr. Brown to propose something so sweeping. It’s good to see that people are not only thinking about simple, incremental changes that won’t ruffle any feathers. However, we need to make sure this doesn’t gut our ability to provide transit-accessible housing for everyone, or we’ve missed the point of having good transit to begin with.

The 19th Avenue Subway

The Market Street Subway is a bottleneck for the Muni Metro system, since each of its lines eventually merges into it. Early documents show plans for a four-track subway under Market; alas, we didn’t commit to that project and now we are stuck with a two-track subway. Combine this with the fact that the surface segments of each line force Muni to run one- and two-car trains where the stations could handle a lot more and it’s easy to see that we’re leaving tons of capacity on the table.

The Central Subway pulls half a line out of the Market Street Subway, which probably won’t improve the situation since we still have five lines in the subway at all times. In addition, the new Parkmerced developments are going to add thousands of daily riders to the M Ocean View line, which runs in mixed traffic on 19th Ave and is prone to some of the worst gaps and delays in the whole system. Muni decided to look at improving this line next. They did some studies, offered some suggestions that seemed lacking in the long term, and collected a bunch of community feedback.

Last month, something interesting happened: Muni greatly increased the scope of the project. The details can be found here, and I encourage you to go read those before I poison your thoughts with my editorializing.

If completed, Muni will have built its first fully grade-separated metro line, and it would improve the situation throughout the system. The M would be free of just about all gaps and delays, and it would use 4-car trains, greatly expanding the capacity of the Market Street Subway. West Portal will be able to handle many more trains and people. St. Francis Circle will be free of the crazy signaling, the intersection will be less complicated, and pedestrians will be able to make more use of the metro there. 19th Avenue will generally become more pedestrian-friendly and the line will better serve SFSU and Parkmerced. It’s a fantastic proposal, in my opinion. There are a few interesting details I’d like to point out as topics for further discussion or clarification.

J Ocean View

If this project completes as planned, the J will take over service in Ocean View. (We might need to rename some lines, but I digress.) The choice of the J to take over this part of the journey is interesting because it has a number of features limiting its capacity at the moment. One of the more frustrating issues with the J is the inability to run even 2-car trains along the line, because some of the stops would render the second car inaccessible. However, the plan explicitly talks about running 2-car J trains. Muni plans to remove one of the problem stops (Liberty St on the private right-of-way), but I’m not sure that this is the only one (21st St might be too short, and possibly Glen Park). This might boil down to adding a few square feet of concrete here and there, but it’s something that Muni hasn’t mentioned to date in its other Muni Forward plans.

This also means that the J will spend a much higher percentage of its time above ground and in mixed traffic, since it doesn’t look like there are plans to give it a red lane south of 16th St. This might not be an issue for Ocean View commuters trying to get downtown because I assume they will take the J outbound to SFSU Station and transfer over to the M, and it will probably be faster than what they have now. However, we have to be careful that we aren’t getting rid of delays on the M by simply passing them on to the J. The J will need extra reliability improvements so it can remain a useful part of the rapid network.

The Curious Case of St. Francis Circle

If you look at the rail map in the project details, you might notice the very strangely laid out subway station at St. Francis Circle.

st-francis-circle.png

At first, I took this to mean that the M trains coming through would always stop on the west side of the platform no matter which direction they are headed towards, and similarly for the K on the east side.

one-level-platform

This seemed like a strange interpretation because Muni is making this immense capital expenditure to get rid of delays and yet this seems like it might cause a lot of them. This limits the maximum frequency of trains through St. Francis Circle because they must maintain stopping distance while a train from the other direction is passing through. It also means that the M and K have the same maximum frequency in the station, which is not the most efficient way to do things—as extra capacity is needed, it would be more useful to swap out K trains for M trains and have some K trains terminate at St. Francis Circle. Riders could then transfer to the longer M trains for the rest of the journey. The K seems to have the same problem as the J in that it can’t support trains longer than 1 car, so running more frequent M trains through seems like a no-brainer.

I did some digging around in NYC Subway track maps to see if I could find an analog for this sort of station, and the closest thing I found was Queensboro Plaza:

queensboro-plaza

From the map alone it seems like Queensboro Plaza is structured the same way, with one track going through the station for the 7 and <7> and the other track for the N and Q. This doesn’t make sense when you’re running trains every two minutes in both directions. However, Queensboro Plaza is actually a two-level station, where the Manhattan-bound trains from each line stop on one level and the outbound trains stop on the other level. Each train has two tracks going through the station. It’s possible SFMTA is planning a similar structure for St. Francis Circle station!

two-level-platform

The structure is a bit harder to see here, but the western side of the station would have M trains, and the eastern side would have K trains. This would allow them to run trains in both directions without a bottleneck, and would provide a way for the M and K to cross over each other without sharing a single switch. There are some drawbacks—building this station and track layout is probably way more expensive than the one-level layout, and the inbound and outbound tracks for each individual line don’t actually meet anywhere, meaning we couldn’t terminate K trains at this station like we wanted to. In the one-level world, we can pull a train into the station and just back it out when it’s ready to turn around. With the two-level design, we’d probably have to run them to West Portal and turn them around there, which defeats the point. (This might still help since we can pull the K trains back before the L trains merge into the subway towards Forest Hill, but M trains might be stuck waiting for K trains to turn around at West Portal anyway.)

I guess the moral of the story here is that I’m not really sure what they want to do with this station, but the track layout they’ve picked makes me a little worried that we will again run into capacity issues sooner than we’d like.

The Daly City Extension

The plan leaves room for the extension of the subway to Daly City BART. BART and Muni already have plenty of connections at Balboa Park, but this one would be pretty useful because data from the Transit Effectiveness Project/Muni Forward on how people use the 28 and 28R (formerly 28L) show that Daly City BART is a good anchor for the line. Linking SFSU with Daly City by a direct subway connection is probably a really good idea since those are the busiest stops along the corridor.

This would also offer a kind of redundancy with BART in that there would be two discrete grade-separated lines from Daly City to Embarcadero, which would improve the resilience of the whole system in San Francisco. If BART is having problems in the city, the M might be a good substitute for people commuting up from the south. Of course, this might cast the lack of integrated fares into sharp relief, but that’s a much more complicated issue for another post.

Similarities to New Muni Metro

Back at the end of 2014, Nextransit published the first part of their New Muni Metro plan. The principles behind the Ocean View plan and the New Muni Metro plan are similar, though New Muni Metro didn’t expect to launch into multi-billion dollar capital projects for a long time. But they realized that we already have a fully-grade separated line if we end the Market Street Subway lines at West Portal. All of the other lines are streetcars only and people transfer to the Market Street Subway at West Portal (K, L, M), Church (N, J), or Embarcadero (T). The New Muni Metro plan also involves some line fusion, with the J taking over the surface portion of the K, and the L taking over the surface portion of the M. This means we could run all of the surface lines more often without worrying about whether we’re overloading the subway, and the subway will be able to run longer trains all of the time because there won’t be any short stations along its path. Higher surface line frequencies plus long, extremely frequent subway trains will mean way more capacity and generally shorter trips, even if you have to transfer.

I think the most interesting part about the similarity is that it means Muni could probably experiment with this same kind of service, should capacity become an issue. I alluded to this in terms of substituting K trains for M trains in the St. Francis Circle station design, but we could theoretically do this with any type of train. Forcing people to transfer probably wouldn’t make everyone happy, but the trains would be less crowded this way, so it might work out!

However the details fall out, this is incredibly exciting news. Transit agencies often avoid making grand plans like this because the funding for grand plans has dried up, but if we know that we’ll be getting something this useful out of it, the political situation might be workable after all. We shouldn’t be afraid to dream big—even if these projects seem expensive, they’re necessary, and nobody will look back on it in the future and think it was money poorly spent. Let’s see how Muni builds on this in the coming years!

Missing the point with a second tube

I figured I’d talk about BART some more because they’ve made it into the news recently. They’re currently fighting a lot of issues, and people are understandably mad, but I don’t think the absurd set of constraints the agency has to operate under gets enough airtime. It’s made even worse by the fact that people are demanding more and more of them as time goes on. Please be patient with them!

As I wrote about last time, talk of running BART around the clock seems to be reaching a fever pitch. One of the big topics here has been the second Transbay Tube, and it seems like people believe that this is necessary and sufficient for 24-hour BART. I think we badly need the second tube, but for completely different reasons. It also seems unlikely to me that this is all we’d have to do to get the trains running all night and we’ll be sorely disappointed if we use this as a justification.

The second tube is an absolutely necessary capacity upgrade, and we can see why from BART’s planning documents. Right now, the Transbay Tube carries 24 trains per hour during peak commute time. This means we can put about 23,000 people across the Bay in one direction in an hour. Unfortunately, it seems like we’re coming close to hitting this number already! This is a huge problem, because we won’t be laying another tube for decades. In the meantime, BART has some ideas to squeeze a little extra capacity out of the current tube. One is to make all Transbay trains 10 cars long. They currently don’t have enough train cars for this one, but the Fleet of the Future promises a massive expansion. They’ll also have to work out those crazy voltage spikes and power issues. When all is said and done, it’ll allow a modest capacity increase to 25,000 or 26,000 people per hour. Another relies on signal upgrades which should be included in the next BART bond. The benefits include an increase in frequency from 24 trains per hour to 30, pushing the capacity further up to around 32,000 people per hour. This is a big help, and is definitely the best short-term strategy, but the Bay Area is expanding so quickly that this will only help for so long.

Enter the second tube: BART projects we’ll be approaching the 32,000 passenger per hour limit in about 35 years, so we should probably begin planning this tube now. It will roughly double Transbay capacity and keep BART humming along even if it surpasses 1 million daily riders. It would also provide some badly-needed redundancy in case something goes wrong with the current tube or a station approaching it. Because of the improvements to capacity and robustness of the whole system, it’s definitely a worthy investment.

The redundancy aspect has people setting their sights on 24-hour BART. After all, if you can run the trains in one tube, you can close the other one for maintenance. If you switch off between the tubes on consecutive days, you should always be able to keep one of the tubes open, and we can run trains all night, every night!

There are a number of problems with this line of thought. For example, just because we have four tracks crossing the Bay doesn’t mean we have four tracks anywhere else in the system (save MacArthur, but that’s not really useful for this aspect). The new tube could play out in one of two ways. One is that it crosses the Bay, connecting up to the existing Market Street Subway in San Francisco. Another is that it creates a new BART line within SF city limits with some connection to the current subway. The most popular formulation of this concept has the connection at Montgomery and the new line running down Post or Geary.

Both of these plans have choke points that aren’t the tube itself—namely, they dump out into two-track subways, and if you close those down, you still won’t be able to run trains. While studying the New York City Subway, I realized that the decision to quadruple-track the trunk lines was one of the most brilliant decisions they made, as it allowed them to run trains along those lines no matter what happened. Unless we have quadruple-track subways, we’ll never reach that same level of availability.

Of course, New York City runs the trains all night on every line, not just the ones with four tracks. Plenty of lines run on two tracks when they leave Manhattan. Some lines, such as the L, have only two tracks the whole way through! I wasn’t sure what to make of this, so I asked my dad (an ex-MTA employee) how it was possible. He gave me two answers: Bus substitution, and the dreaded Planned Service Changes.

Anyone who has been in a subway station in New York has likely seen the enormous boards detailing all of the ways in which service will deviate from the official patterns in the near future. Trains might skip particular stops or there might be breaks in service along the line, requiring free bus bridges along the gap, or transferring to other trains. Trains from one line might use tracks from another line for some duration of their trip to allow maintenance on their own tracks. These service changes allow the trains to run all night, every night, but they have some cost. First, they rely on the network’s massive amounts of redundancy to continue functioning. Second, they make everything really complicated. The NYC Subway is already this huge, complex system with many lines and hundreds of miles of track, and remembering the standard service pattern is hard enough. It must be impossible to keep up if they have to change it all the time!

In either of the scenarios for the second tube, this same strategy of service changes to avoid maintenance areas isn’t going to cut it. The system simply doesn’t have enough redundancy to support the kind of service changes the MTA can pull off, and building that infrastructure now would require many billions of dollars. Let’s look at what we’d have to do even if we only built extra tracks between MacArthur and 24th St Mission, which is basically the smallest area for which it makes sense. We’d be paying for an extra 3 miles of two-track subway on the SF side and 2 miles of one-track subway on the Oakland side, and we’d have to rework the wacky subway-to-elevated transition as the C tracks move into the 980 median. This would add at least $4 billion to the total, and that’s in the absolute best case scenario. Reworking the transition and construction in the stations would probably cause service outages. It would also only grant us 24-hour service on a very limited section of BART. (This isn’t necessarily a bad thing, since we may only want to run trains all night in the areas dense enough with the kind of activity to support them. I assume demand for all-night BART to Pittsburg-Bay Point is pretty low. It is meant to highlight the immense expense of adding this infrastructure.)

What can we do? I know I was something of a killjoy last time when talking about the problems with running BART all night on weekends, but I think the conclusions there are valid here as well. If we can’t rely on service changes and we don’t have the infrastructure to do maintenance concurrently with service, then we’re going to have to turn to our old friend, bus substitution. As I stated before, even the NYC Subway resorts to this, so it shouldn’t feel like a cop-out. Bus substitution isn’t ideal because it drops capacity and doesn’t provide service as rapid as with trains. If we’re going to provide 24/7 service, we might need to do bus substitution at any hour, even during the commute rush. This could be really painful for a lot of people, especially while BART is already having capacity issues! We can do a little damage control by adding more switches in between stops so we’ll only have to substitute over one station, but this requires some extra infrastructure and is probably a ways off if so. We can see examples of this in the wild, though: Chicago’s L has switches between most stations on the two-track segments of its Red and Blue lines, and this is no doubt an integral component to their ability to run trains all night on those lines.

I think the new tube and 24-hour service are often tied together needlessly in discussions about the future of BART in a way that makes it hard to talk about what the former is actually necessary for, and what is actually necessary for the latter. My position on it is:

  1. If we want to be running trains all night, every night, then we do need to wait for the second tube, but that’s not even close to everything we need. Miles of extra subway and lots of new infrastructure will need to be built. Whether or not that’s a worthy investment is beyond the scope of this post, but we shouldn’t make the mistake of thinking we can build the extra tube and be done with it.
  2. If we’re comfortable with bus substitution, then we can mostly already get 24-hour service, if we are willing to tolerate substitution across arbitrary segments of lines and possibly at arbitrary times. This is, again, a value judgement, but given the outcry over the recent issues on the PBP line, I think this would be unpopular.

It’s great to see the Bay Area taking aim at New York here, but we do have to realize that their system is much better suited to 24-hour service than ours is, and we have a lot of work to do if that’s something we want as well. Either way, we are going to need the new tube. We simply shouldn’t delude ourselves into believing it will solve our 24-hour issue as well.