BART riders counting on quick cross-bay trips are about to hit the brakes. On three upcoming Sundays, trains will run every 30 minutes systemwide while crews work on lighting inside the Transbay Tube. Only the Blue, Yellow and Orange lines will be in service, with Red and Green trains taking the day off. Riders heading beyond SFO will need to transfer at the airport, where a Yellow Line shuttle between SFO and Millbrae will run all day to keep Peninsula trips connected.
Service changes and dates
According to BART, an advisory updated last Wednesday lays out the schedule: lighting work inside the Transbay Tube is planned for next Sunday (April 26), then again on Sunday, June 7 and Sunday, July 19. On each of those days, trains will show up every 30 minutes and only the Blue, Yellow and Orange lines will operate, while Red and Green line service stays suspended. The agency says its Trip Planner will carry temporary schedules so riders can map out connections and transfers in advance instead of being surprised on the platform.
Why crews will single-track the Tube
Per BART, crews will "replace lights in the tube," and that seemingly simple job comes with a big operational catch. The work requires using only one track through the Transbay Tube for the entire day, which cuts capacity and train frequency. With trains sharing a single track through the corridor, waits get longer and there is no room in the schedule for Red and Green line service to run through the Tube at all. The district is telling riders to budget extra travel time and be ready for busier trains and platforms during the affected Sundays.
How this fits into bigger upgrades
While the lighting swap is a short-term project, it is part of a much larger push to modernize the core Transbay corridor. Documents from the Federal Transit Administration show BART moving ahead with a Transbay Corridor Core Capacity program, including communications‑based train control and additional railcars, aimed at boosting throughput toward a 28 to 30 trains-per-hour target. Those multi-year upgrades are meant to pay off with faster, more frequent service in the long run, but they also bring recurring weekend work like this that can temporarily snarl the schedule.
How to plan your trip
For now, riders are being urged to plan carefully on the impacted Sundays. Check schedules, allow extra time, and think about backup options if you are on a tight clock. SF Bay Ferry offers several routes across the Bay, and AC Transit runs transbay buses that can help pick up the slack when trains are thinned out. If you are traveling to or from the Peninsula, expect the Yellow Line shuttle between SFO and Millbrae to act as the main rail link and be prepared for those trains to feel crowded.
Looking ahead
This round of Tube work follows a series of maintenance and signal-modernization efforts that have already reshaped some weekend service. Earlier this year, we noted an overnight BART blitz tied to related projects around Millbrae and San Bruno. We will keep tracking agency advisories and share future schedule shifts as they come down the line.
