Is the San Francisco Central Subway Project Worth It?

Jack Turner
9 min readMar 31, 2021


Photo by Josh Wilburne on Unsplash

14 Years After Construction and Yet Still No Vehicles Transverse the Corridor

In 2007 the city of San Francisco began a major project to connect Chinatown to the CalTrain 4th & King station through a subway. Fourteen years later in 2021, the city is 4years behind on the project and more than a billion dollars over what its original expected cost was. This may seem like an absurd amount of money, which it is, but many city residents are excited about the prospects of the extension. After all, Chinatown is one of the most under-served transit communities, and the existing light rail network makes it really difficult to go from the south sidethe city to the north of the city without having to take a bus. In fact, the Muni light rail doesn’t even run north to south above Judah Street, leaving a gaping transit gap that can only be filled by slow buses. So, this brings up the question: is the Central Subway Project worth it in the long term or should the money be spent elsewhere?

Photo from Mliu92, Wikipedia

Project Goals

Chinatown is one of the most densely populated parts of the city, as is the 4th and King area. The buses that serve the area, the 45-Union-Stockton and the 30-Stockton face overcrowding issues, meaning that one of the most diverse parts of the city has relatively poor transit service. The project’s primary goal is to build a new tunnel that can connect with existing infrastructure and serve parts of the city that have otherwise lackluster service quality, such as Chinatown. After the 1989 Loma Prieta Earthquake and the destruction of the Embarcadero Freeway, Chinatown residents have been hoping for better transit access. Chinatown is served by cable cars, but slow speeds, high prices, crowds, and minimal transfer possibilities make a new subway tunnel a much more appealing option.

Project Status

As of March 2021, the project is expected to be completed mid-2022, which as many people will note, is not when it was originally expected to open (2018 was the original opening date). At one point last year, mid-2021 was the goal, but with the impacts of the pandemic and design changes occurring, some time in 2022 is the new scheduled date. To many, this should bring relief because construction nuisances are almost over and train testing can finally begin.

Opportunity Cost

While the project itself will be transformational in improving San Francisco’s public transit network, the sheer cost of the project does provoke questions of its actual worth. Is it actually necessary to spend more than a billion dollars on a light rail project when bus improvements could achieve similar results? Well, we first have to look at the benefits of light rail and metro in the first place. The first key advantage that the Central Subway Project brings is it takes a lot of traffic underground. People traveling to Chinatown or 4th and King can be transported underground rather than taking a long, indirect light rail ride or even worse, driving. Vehicles will be taken off of the street which will increase safety and make the city more pleasant. These benefits are all great. That said, is there a better alternative that is cheaper and could be used going forward in other cities?

Before I get into any of the other alternatives, it is important to mention that any non-light rail alternative will run into transfer waiting delays that increase travel time and lower passenger satisfaction. With that out of the way, let’s move into the options.

Above Ground Light Rail

In terms of the frequency and ease of access, instituting a light rail along the corridor extending to Conrad Square would offer the same benefits as the Central Subway. It could probably also make more stops if it wanted to given the cheaper cost of at-grade stations. However, actually making an efficient connection to Chinatown and eventually Conrad Square would be difficult due to the street layout necessitating one-way trains on 4th Street and very narrow streets leading up to Union Square. This layout is not super accommodating to light rail. In all likelihood, a light rail would offer significantly lower speeds than a subway — as I wrote in my Centralization article, the auto to transit speed ratio around the Central Business District is very high —and light rail is a major victim to this.

When it comes to cost, this project would be significantly cheaper — on average it costs $35 million per mile to construct light rail, and this project is at max around 3 miles long, meaning that it would cost around $100 million total, far less than the $1.6 billion spent on the Central Subway Project. That said, many projects around the country far exceed that total; the Phoenix light rail extension is estimated to cost more than $200 million per mile! Even with that high of a cost, the 1.7 mile length will still guarantee the project is cheaper than a subway. Given the general failure of San Francisco to carry out construction projects, I would estimate that a light rail project serving this corridor would cost around $1.2 billion. Ultimately, though, the street structure is important for light rail projects and the wide array of one way streets in the service area makes a light rail a non-viable option.

Bus or Bus Rapid Transit (BRT)

While Buses and BRT are very different modes of transport — BRT can offer similar service quality to that of light rail and even subways, but at a cost closer to buses. Regular Bus service largely already exists on this corridor, but as mentioned before, it is slow, crowded, and not amazing. BRT would be a huge upgrade, but would also carry additional cost. Similar to light rail, many routes would be split on different streets due to many streets being one-way. This would also force passengers to transfer from either Muni light rail or CalTrain if coming from or going to the 4th and King area. BRT certainly is more viable as it is easier/convenient to build one way bus routes, but is it worth it compared to a subway?

The amount of street overhaul that would have to take place would be enormous. While it would not require streets to be torn up to dig tunnels, many lanes would have to be restricted, which could be very difficult considering many streets going north towards Union Square are narrow. The Van Ness BRT project, which just like the Central Subway, is delayed significantly as well, is expected to cost a minimum of $300 million. This is far less than the Central subway although the amount of BRT that would have to built if it were to be chosen instead of a subway is far larger. Given this, and using the fact that light rail is about 1.2 times as expensive per mile than BRT to build, I would expect a BRT project to be close to $1 billion dollars (using the $1.2 billion light rail estimate). While I did not do in depth calculations for either, both BRT and light rail are less than the $1.6 billion.

Rebuilding the Embarcadero Freeway

This is an interesting alternative, and it would be improper for me to not include it. Many opponents to the Central Subway project call it a “Subway to Nowhere”, highlighting how Muni’s projection of around 35,000 daily riders pales in comparison to the 60,000 vehicles that passed through Chinatown on the Embarcadero Freeway before it was torn down (see my article on a Car-Free Central Business District for more info on that project, also passing through a region is not the same as contributing economically to it). Rebuilding the freeway would be cheaper than the Central Subway — the estimated cost to rebuild it after the Loma Prieta Earthquake only cost $120 million in today’s dollars (this seems cheap, but makes sense given the on average $11 million per mile to build a freeway). Freeways, of course, have devastating benefits themselves and usually destroy the culture/local vibe of the areas they are built through. If you ask me, a new freeway is a horrible idea. It is also unclear if the freeway itself would bring people to Chinatown directly as parking is still an issue — transit avoids that issue.

Verdict on Alternatives

While there could in theory be other alternatives such as a cable car extension, the four I mentioned above are really the only feasible and legitimate contenders. Of the four— bus, BRT, light rail , and highway— it is clear that BRT is by far the best alternative and could seriously have been a better option than the Central Subway. So why wasn’t it chosen (besides the fact that BRT wasn’t as popular when planning for the Central Subway Project began)?

Ultimately, in terms of actually construction feasibility, a subway is probably the better option. It would be really difficult to both build a BRT on the corridor and have good service and frequency at the same time given the congestion and short length. Given the auto-oriented nature of BRT, buses still have to deal with stoplights and intersections, and it is much easier to maintain service headway with a subway project. While in the short term the construction could be a pain for residents, once it’s done it is by far better than a BRT system. Trains will have no obstructions or impediments and service will be of very high quality. Going back to the main goal of connecting the densest parts of the city, a subway is much more highly capable of doing that than a BRT. BRTs, with the exception of TransMilenio in Bogota, often are found in middle-sized cities usually catering to busy routes, but not overly crowded ones. The Emerald Express in Eugene is a good example of a typical BRT. BRTs face problems when demand is high and TransMilenio is often extraordinarily crowded. Building a higher capacity subway with generally better frequencies can help serve the demand better.

Photo by Scarbor Siu on Unsplash


QGIS map of Job Accessibility and Transit Speed

The question I proposed at the beginning of this article is a loaded question — is the Central Subway Project worth it? To me, any transit project is worth it, and if I had my way, every city would have buses, light rails, or subways running at perfectly timed intervals in every city depending on demand. Obviously, this can’t be the case because of scarce resources. That’s why we have to continually question and scrutinize transit decisions — a $1.6 billion project is certainly going to garner a lot of backlash, and the Central Subway project is no different (it is also contributing to San Francisco’s budget deficit). The cost, construction, and theorized uselessness are just some of the reasons for backlash. That said, with essentially less than a year before testing on the line can start, I am very optimistic about the success that the project will experience. It may take a while to actually bring $1.6 billion back into the economy, but it will take cars off the road and increase access to jobs. I believe, considering the alternatives, the money is totally worth it. The project offers significant leeway for MUCH needed extensions to the Presidio area or Pacific Heights area (both in the northwest part of the city). Both of those areas, as shown in the QGIS map above, have less connectivity to jobs on transit, and the Central Subway is a chance to expand San Francisco’s underground network to under-served areas.



Jack Turner

College Freshman; I have interests in transit, sports, aviation, politics, progressivism, and everything in between.