BART Launching Overnight Modernization Work in Millbrae, San Bruno

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BART is set to begin a months-long overnight construction project in Millbrae and San Bruno to install a new communications-based train control system. The work, which will run from February through June 2026, is aimed at improving reliability and eventually allowing more trains to run through the Transbay Tube. Residents and riders along the corridor can expect nighttime activity and intermittent noise between roughly 9 PM and 4 AM during the construction period.

Why it matters

The CBTC upgrade is a critical step in BART's Transbay Corridor Core Capacity Program, which aims to increase the maximum number of trains per hour through the Transbay Tube from 24 to 30. This will allow for more frequent peak-hour service and improved reliability along the entire BART system.

The details

Crews will first mobilize near Center Street in Millbrae, then move north along San Antonio Avenue toward Cupid Row in San Bruno. The 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. BART is replacing its decades-old fixed-block signal system with the new CBTC technology, which allows trains to safely run closer together and reduces headways.

• The construction window runs from February through June 2026, with most activity planned overnight from 9 PM to 4 AM.
• Crews will first mobilize near Center Street in Millbrae, then move north along San Antonio Avenue toward Cupid Row in San Bruno.

What’s next

Affected homes and businesses will receive mailed courtesy notices outlining schedules, contact information and what to expect as the project moves along the corridor. Residents are urged to check the mailed notices or reach out to the city's public works office with immediate questions.