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.