Overnight construction is about to get a lot more noticeable between Millbrae and San Bruno, as BART crews begin a months-long modernization push that will keep workers on the tracks from late evening into the early morning hours.
The City of San Bruno says the work will install a new communications-based train control system designed to improve reliability and eventually allow more trains to move through the Transbay Tube. Residents and riders along the corridor can expect nighttime activity and intermittent noise between roughly 9 PM and 4 AM in the coming months.
When And Where The Work Will Happen
According to the City of San Bruno, the construction window runs from February through June 2026, with most activity planned overnight from 9 PM to 4 AM.
🚆 BART Modernization Work Coming SoonHey San Bruno! BART is installing a new communication-based train control system to improve reliability and expand future service. Once complete, this upgrade will allow BART to increase service through the Transbay Tube from 24 to 30… pic.twitter.com/0xCasjx2bm
— City of San Bruno (@CityofSanBruno) February 21, 2026
Crews will first mobilize near Center Street in Millbrae, then move north along San Antonio Avenue toward Cupid Row in San Bruno. The city notes that construction could involve pile driving, vacuum trucks, generators, work lights and vehicles with backup alarms, so the corridor will not be especially quiet while crews are active.
What BART Is Installing And Why It Matters
BART is replacing its decades-old fixed-block signal system with Communications-Based Train Control, or CBTC, which allows trains to safely run closer together and reduces headways. BART’s Transbay Corridor Core Capacity Program identifies the CBTC upgrade as a critical step toward increasing Transbay Tube capacity from a maximum of 24 trains per hour to a target of 30 trains per hour…