For tens of thousands of San Franciscans, the 38-Geary bus is an institution. It's the primary transit artery for the entire northwestern side of the city, connecting some of the city's busiest neighborhoods to downtown. The Geary corridor was once the home to San Francisco's first streetcar in 1912, the A and B lines. These lines were decomissioned in 1956 and replaced by the 38-Geary bus line. This project asks a simple question: Is a bus line enough for a corridor of this magnitude?
The title of this project, "44,000 Riders, Zero Trains," is the conclusion I reached after a deep-dive analysis of the data. This project makes the data-driven case that the Geary corridor has long outgrown its bus-only infrastructure.
The evidence will show that Geary's combination of high population density, high resident transit dependency, and massive ridership demand makes it the most underserved transit corridor in San Francisco.
The first step in making the case for a new subway is to understand where people live and how they get around. Using data from Census Reporter, DataSF, and BART this interactive map visualizes two key stories for San Francisco's census tracts.
By default, the map shows population density. The story is immediately clear, the bright red/orange spine running through the northwestern part of the city into downtown is the Geary corridor, one of the densest population centers in all of San Francisco.
Clicking the "Equity" toggle will switch to an equity map, showing the percentage of households in each tract that have zero vehicles. We can see that the same dense corridor is also home to thousands of households that are highly transit-dependent.
From this map we can see just how barren the northwestern side of the city is. Other dense corridors such as Market Street and Mission Street are served by both Muni and BART. In stark contrast, the Geary corridor is left with just the 38-Geary, a single line struggling to its growing demand.
The map gave us a better understanding of where people live, this chart quantifies how many of them are on transit.
To create a true apples-to-apples comparison, this chart groups major bus routes into the corridors they serve. Crucially, it combines the ridership of the 14-Mission and 14R-Mission Rapid into a single "Mission Corridor" and adds the ridership from the two BART stations (16th & 24th St.) that serve it. The data for this graph was sourced from SFMTA and BART.
The data is staggering. The Mission corridor serves 46,230 people daily. That number is not even including the BART ridership and 49 Van Ness/Mission, that both partially serve the Mission corridor. All together they have 93,960 daily riders, appropriately served by three major bus lines and a heavy-rail subway.
The Geary corridor is also in a league of its own as the clear #2 when it comes to bus demand, with over 44,000 daily riders. Despite its clear #2 status Geary does not have any form of rail along its corridor whatsoever unlike the Mission corridor. Geary's massive, bus-only demand is a clear indication that rail would be beneficial for this corridor.
A common counter-argument to new transit projects in the U.S. is the post-pandemic decline in ridership. The chart below addresses that concern directly by tracking the average weekday ridership for San Francisco's busiest bus corridors from 2019 to 2025 with data provided by SFMTA.
In 2019, the Geary Corridor (blue) was in a class of its own, leading all other bus corridors with over 53,000 daily riders. While it has fallen to the 2nd most ridden bus corridor, it is on pace to reclaim its throne as the busiest bus corridor in San Francisco.
This chart proves that the demand on Geary is not a temporary spike, it is a permanent and resilient feature of the city's transit landscape. The 44,000+ daily riders are not an anomaly, they are part of a strong recovery back to a pre-pandemic norm that was already overwhelming for a bus-only system.
The previous charts established that the Geary corridor has massive, resilient demand. This visualization aims to answer the most important question, "so what?"
The data for this graph is once again from SFMTA. Crowded is defined as when "vehicles are above capacity for 10% or more of the stops." This chart illustrates the human cost of that demand, the passenger "pain point." It shows the Max Peak Crowding for the city's top 15 bus routes, calculated by finding the average percentage of trips that are at the official crowding threshold during their single busiest commute (either AM inbound or PM outbound).
The 38R Geary Rapid is the 3rd most crowded route in all of San Francisco, with over 21% of its peak-commute trips being over capacity. This proves that the current bus system is failing to meet the corridor's immense demand.
A Geary subway could help alleviate this strain on the 38-Geary bus line while also relieving some stress from the 1-California line too. The 1-California and 38-Geary are both East-West running lines that have a lot of overlap amongst the communities they serve.
When viewed together the data provides an undeniable story.
First, the Density & Equity Map established a clear geospatial problem, a "rail desert" in the northwestern quadrant of the city, which is simultaneously one of the densest and most transit-dependent areas in San Francisco yet to be served by rail.
Next, the Ridership Analysis quantified this problem. It proved that the Geary corridor is the #1 most underserved corridor in the city. Its 44,250 daily bus-only riders rivals the Mission corridor, but unlike the Mission corridor it isn't also served by a rail line.
Then, the Ridership Trends chart rebutted any counter-arguments about the pandemic. It showed that Geary's massive demand is not a temporary spike, it's a resilient, structural trend that was massive pre-pandemic (53,000+ daily riders) and is recovering fast and will soon reach or even surpass its pre-pandemic demand.
Lastly, the Crowding Analysis provided the "smoking gun." The 38R Geary Rapid is one of the top 3 most crowded bus lines in the city, proving that the current infrastructure is at its breaking point and is failing to provide adequate service for its passengers.
The 38-Geary is not just a "busy bus line." The data proves it's a high-capacity rail line in disguise, forced to operate with the infrastructure of a local route. The conclusion is clear, the 44,250 daily riders and the thousands more who are discouraged by the current system's crowding are being underserved. This isn't just an inconvenience, it's an equity issue. The data shows the demand is there, the demand is resilient, and the current system is failing. The best time to build the subway was 50 years ago. The second-best time is now. It's time to build the subway, it's time for the B-Geary to run along Geary once again.