Completing the grid: The Tenderloin gap, part II

Last time, I talked about what I felt was a gap in Muni service. I’ll try and sketch out a line that would fill in this gap.

Since we are talking about a gap in service between Van Ness and Stockton, the best way to start would be to try and send a line right down the middle. As they are nine blocks apart, the middle lies between Leavenworth and Jones. We’re going to want to pick one of those streets to serve as the base for our line. A bus along this corridor will serve:

  • Civic Center Station
  • Boedekker Park on Eddy
  • Tenderloin Playground on Ellis
  • St. Francis Hospital on Bush
  • Grace Cathedral and Huntington Park on California, bordering which are many large hotels as well
  • The Pacific Ave neighborhood commercial district
  • Michelangelo Playground on Greenwich
  • The squiggly bit of Lombard for tourists, Yick Wo Elementary, and George Sterling Park if you’re willing to hike up to it
  • Fay Park and the San Francisco Art Institute on Chestnut
  • Russian Hill Park on Francisco
  • Conrad Square, Aquatic Park, and Fisherman’s Wharf

We should also allow easy transfers to east-west lines in the area, which would be the 1, 2, 3, 5, 10, 12, 30, 31, 38, 45, and 47. Of these, the 1, 5, 30, 38, and 47 are part of the frequent grid, so connections with these are especially important.

Designing the line

Our first instinct might be to use both streets in a one-way split, but one-way splits have a number of drawbacks. They make lines more confusing, as I talked about last time. They also reduce the area that is within walking distance of both directions of the line—a good explanation of why (and why we want to avoid this) can be found here, with diagrams. Our hope is to minimize use of one-way splits where possible.

Leavenworth and Jones are zoned similarly in Nob Hill and Russian Hill, so that’s not going to inform our decision. Since the 19 exists on the Van Ness side, and northbound buses south of Geary are further away than Stockton, let’s try Jones first.

North of California, Jones is a two-way street, so we’ll use it for both directions of this new bus line. Most buses in this area go up to North Point, so that’s our main destination, and then riders will easily be able to transfer to the 47 to head east and west. The 30, E and F are also very close to North Point & Jones. We’re also going to need to turn the bus around, and we can do so with a small one way loop like on the 19, extending from North Point to Beach.


If we look closely at this map, though, we’ve done something impossible—Columbus Ave has a median in some areas, and one such place is right where Jones would cross it. We can’t go through here. Our proposal might include breaking up this median and only allowing Muni vehicles to cross. This would require a lot of extra signaling and would complicate traffic patterns on Columbus that the median was presumably intended to simplify, so I’m going to consider this unsatisfactory. We can look at some changes in routing that avoid this problem section of Columbus.


Both strategies take us to North Point. Each one has its own complication: the first suggestion makes the line a bit wiggly, and the one-way loop terminating the second option is needlessly large. I’ll choose the first option for now.

Below California, Jones is a one-way street running south. We can make the bus use Leavenworth for the northbound leg, turn right on California, left on Jones, and continue up with the path as mentioned before. We’re trying to avoid one-way splits as much as possible, but here it seems justified. These streets are one-way, and since they are less than 500 feet apart, the one-way split doesn’t affect the service area too much.


For now we are running the bus down to McAllister, which is right before it hits Market. Let’s try out our route. We send an imaginary bus up from Market on Leavenworth, where it turns right on California, and left up Jones. We get to Green St and start going down a huge hill… in fact, this hill is so steep that our bus goes into free-fall!

The steepest grade any Muni vehicle negotiates is 22.8%, which is along the 24-Divisadero as it travels on Noe St between 26th St and Cesar Chavez. The 24 uses trolleybuses specifically because this hill was too steep for motorcoaches to climb at the time. Modern motorcoaches can do the job, as you might find when a Castro street fair closes off a whole bunch of streets and they can’t use the overhead wires anymore. The buses and trolleybuses might be able to transit steeper grades, but we’ll consider it an upper bound for now, since we don’t actually know if anything steeper will work. Jones between Green and Union is a 26.2% grade—even if we could get down this hill, it’s immediately followed by a 29% grade between Union and Filbert, and going back up later is definitely out of the question. (You can find official grade maps here.)

We can try and route around this hill as well, but we risk making the route too complicated. I’d rather move the base of the route from Jones to Leavenworth. The steepest part of the line north of California is a comfortable 22.2% grade between Union and Filbert, and the end of our route already moves over to Leavenworth anyway. This generally serves the same area while keeping the line as simple as possible. We’ll still try to use Jones south of California because Leavenworth is one-way northbound during that segment.


Let’s try the imaginary bus again. We send it up Leavenworth, where it makes it all the way to North Point, loops around and starts back towards Market. We come down to California, make a left and then a right around the odd guard rail… and promptly bottom out on the crest! Jones has a 24.7% grade between California and Pine, so putting a bus on it is not a safe bet. This means we can’t use Jones here, either! We have to explore some backup plans.

  1. Use Hyde to get to Bush or Post, take it to Jones, and use that to go towards Market.
  2. Use Mason to get to Pine or Sutter and take it to Jones.
  3. Use Hyde the whole way down to Market.
  4. Turn one lane of Leavenworth into a contraflow bus lane.


Option #1 recreates some of the leapfrog one-way splits we saw in the confusing 27 route, which we’re trying to avoid in creating this line, so that’s not a good idea. Option #2 entails a 3 block wide one-way split, which is one of the problems with the 8 and 30 that we are trying to work around by having a mid-Tenderloin line. Option #3 is workable, but risks nudging the service area a little too close to the Van Ness bus brigade. It does not require drastic infrastructural changes, so we can keep it on the table for now.

Option #4 is very interesting. Contraflow bus lanes are often used to turn one-way streets into two-way streets for transit purposes. Other traffic will only be able to go northbound on Leavenworth, but buses will have exclusive access to a southbound lane. I don’t believe they are currently used in San Francisco. This requires a little bit of infrastructure work such as painting the lane red and adding proper signage, as well as adding traffic lights at each intersection. An intermediate proposal might use a contraflow lane for a short time until the bus can get over to Jones, probably via Bush or Post. However, Leavenworth is a large street south of Geary. If we are going to use the contraflow lane north of it to avoid the California crest on Jones, we might as well take a lane out of the wide part to improve simplicity and speed.

Here are our possible alignments:


Through any of these options, we can connect Fisherman’s Wharf with Market at Civic Center Station.

Stop selection

Local buses in San Francisco stop every two to three blocks, so we can follow this model when picking stops. Ideally, we want to line up the stops with the east-west lines, so we can maximize its usefulness as a grid line.


If both the northbound and southbound trips use Leavenworth, then all of the stops north of Market are marked here. If we use Hyde for the southbound leg, we can use the same set of cross streets, but we’ll want an extra stop on Grove before continuing southeast on 8th St. The McAllister and Grove stops are very close to Civic Center Station. I also added an optional stop on Bush to serve the hospital more directly, since hospitals are destinations that you might want to add stops next to even if there are other stops nearby. For precedent on this in the current Muni network, check out the 9R-San Bruno Rapid, which stops in front of SF General Hospital on Potrero Ave even though it stops again one block away on 24th St.

Unfortunately, we are not done—this route only takes us to Market, and grid lines are more useful when you don’t have to think about where they start and stop. In the next installment, I’ll draw the rest of the line south of Market, and we can decide what a good anchor for the other side of this frequent line would be.

Completing the grid: The Tenderloin gap, part I

If you look at a transit map of San Francisco, you might find some surprising holes in the coverage. Perhaps we can learn something about network planning by trying to fill them in.

One of the more confusing examples of this is the lack of north-south lines running through the Tenderloin, Nob Hill, and Russian Hill. The Tenderloin is one of the densest areas in the city and has a lot of below-market-rate housing, so adding service would increase mobility for a lot of people. Nob Hill and Russian Hill are also very dense and poorly connected by transit, which means we have a big opportunity here.

Fisherman’s Wharf employers have trouble filling positions because the area is out of the way, and having more service there could bring in more employees and tourists. Because it is such a big destination and it just north of Russian Hill, it can serve as an anchor for one end of the line. Another important point on this line would be a connection to Muni Metro and BART.

Lastly, if we want a frequent grid that functions well, we have to make sure the grid lines are not spaced too far apart, or our reliably-covered areas will have huge gaps.

Let’s look at the current map of north-south lines to see what we’re up against.


You might look at this and say, “Coverage seems fine!” That’s true, but for such an important area, there is startlingly little frequent transit, and the lines aren’t very simple. If we evaluate each of these lines, the picture comes out much bleaker.

First, let’s look at the 19-Polk. North of the Tenderloin, this bus is basically a less reliable Van Ness bus. It runs less frequently, there is no owl coverage, and any speed problems plaguing Van Ness buses will be put to rest by Van Ness BRT in a few years anyway. I’d wager that any time the 19 saves by going faster is cancelled out by the extra wait. The portion in the Tenderloin has one-way splits, and they cross over each other a few times, making the route harder to remember. Perhaps it is useful for connecting some areas to Civic Center Station, but it seems to me more like the old 26-Valencia, which was an infrequent bus next to a bunch of really important and frequent lines running on Mission. The 26-Valencia was discontinued in 2009 for this reason.

Let’s update the map.


Next, let’s talk about the 27-Bryant. This bus has a number of problems. First and foremost, it does serve the Tenderloin, but its route is plagued with so many leapfrogging one-way splits that it’s impossible to remember where the stops are! It seems like planners were trying to follow an imaginary extension of 5th St northwest on the other side of Market. Dragging this diagonal line across a normal grid is a recipe for disaster and the incredibly confusing route proves this.

This line also has a poorly-anchored terminus at Van Ness between Washington and Jackson. I don’t know of anything there that will attract riders other that the connection to the 47 and 49 lines and possibly the Academy of Art. It seems like the decision to terminate the line there was an attempt to keep Tenderloin bus riders out of Russian Hill, especially when you compare the route of the 27 to its neighboring cable car routes (which we’ll get to in a minute).

In addition to problems with the alignment, the bus is not that frequent. I don’t think this is a suitable north-south line in the frequent grid. One more time:


The cable cars are interesting, because they are actually quite frequent. They are anchored at both ends by Union Square in the south and Fisherman’s Wharf/Aquatic Park and North Beach in the north. However, they are specifically routed around the Tenderloin, likely to avoid serving its residents. This shows they are aimed at wealthy Russian Hill/Nob Hill residents and tourists, and aren’t a useful part of the grid, either.

It is important to note that the Tenderloin used to have more cable car routes, and the cable cars used to be a more equitable mode of transit. This fell apart in the mid-1950s when the city government was trying to dismantle the Tenderloin. One of their weapons was removal of cable cars that went through the neighborhood, which city officials claimed were “dragging down” the city. The city said the cable cars were slowing down automobile traffic in Union Square, which it was desperately trying to expand into the Tenderloin. They also promised to replace the affected lines with buses as part of a “modernization” effort.[1]

It’s clear that this was a move to contain the Tenderloin and its people rather than improve the transit network. It wrecked transit access in the Tenderloin and we can still see the effects today. Here’s what we’re left with.


This is the north-south component of our frequent grid in this area. It looks a little bare, doesn’t it? This, too, has problems for anyone living in the center. The one-way splits on the 8-Bayshore and 30-Stockton are extremely wide (4 blocks apart!) and so the area which you can really call “covered” by those buses is greatly diminished. The 8-Bayshore is split all the way up to Columbus, making it especially useless in the middle area.

The distance between the Van Ness buses and the Stockton buses is also very far:


Keep in mind that all of the northbound Stockton buses use Kearny when they are south of Sutter. That means your nearest frequent bus might be half a mile away, and south of O’Farrell, it might be even worse! In the average case, it’s still 8/10 of a mile between routes. Noted transit planner Jarrett Walker often talks about frequent grids in network design and says that parallel lines should be generally 1/2 mile apart and at most 3/4 mile apart, so a gap this large means we are underserving the middle area.

I think we’ve laid out the case for having another frequent north-south line here. Next time I’ll discuss what we should think about when we design it.

  1. The Tenderloin: Sex, Crime, and Resistance in the Heart of San Francisco by Randy Shaw, pp. 96-98