A wayside train control failure shut down BART's Yellow Line through Walnut Creek for roughly 90 minutes Monday morning, disrupting commutes during the peak of the morning rush.

BART closed the Yellow Line between the Pleasant Hill and Lafayette stations from about 5:30 a.m. to 7 a.m. on Monday, July 27, according to BART spokesperson Chris Filippi. The Walnut Creek station sits between those two stops, placing it squarely in the dead zone.

"A wayside train control issue affected BART's ability to get trains to the Walnut Creek station," Filippi told the East Bay Times.

Engineers resolved the problem by about 7 a.m., Filippi said, but the damage to the morning commute was done. Delays of at least 20 minutes persisted on the Yellow Line in both the Antioch and San Francisco Airport directions as of 8 a.m.

BART first alerted riders to the problem at approximately 5:50 a.m., according to Patch. The agency did not immediately release details about what caused the equipment failure or what steps it would take to prevent a recurrence.

The disruption hit one week after BART restored 10-car trains on the Yellow Line and Red Line during peak commute periods, a capacity boost that began Monday, July 20, for the first time in more than six years. BART reported its highest monthly ridership since the pandemic in June 2026, with an 18.6% increase over June 2025.

BART's Yellow Line runs from Antioch in eastern Contra Costa County to San Francisco International Airport, serving Contra Costa commuters daily.

More planned delays ahead

Yellow Line riders should also prepare for additional planned disruptions in early August. Crews will perform overnight rail "destressing" work between the North Concord and Pittsburg/Bay Point stations from Tuesday, August 4 through Thursday, August 6, according to Patch. That maintenance segment is farther east on the line and would not directly affect the Walnut Creek station, but riders heading to or from Antioch should expect delays of 20 to 25 minutes on those nights.

BART also faces a projected $375 million structural operating deficit beginning in fiscal year 2027, when roughly $2 billion in one-time federal and state emergency funding will be exhausted. The Connect Bay Area Act, a regional sales tax measure on the November 2026 ballot, could deliver $310 million annually to BART if voters in five Bay Area counties, including Contra Costa, approve it.

BART's communications office did not respond to a request for additional comment on the cause of the failure by publication time.