BART riders should be prepared for delays in weekend service in four locations – including the Transbay Tube – until the end of December, the transit agency said Tuesday.
The delays are due to seismic safety work and needed track maintenance, BART said.
The Transbay Tube work includes "critical emergency power supply improvements between Embarcadero and West Oakland stations," BART said.
The Tube work will occur during first two hours of service on Saturdays and Sundays, during which time only one track will be in service, the agency said.
"Service through the Transbay Tube during those hours may experience a 10-15 minute delay between Embarcadero and West Oakland stations," according to BART. "We will do everything possible to keep the delays to a minimum."
BART apologized for the inconvenience and said the work is taking longer than expected.
"The work required takes more time than our regular overnight maintenance window allows and is taking longer than originally expected," the agency said. "We have chosen this time in an effort to cause the least inconvenience to our customers. We apologize for the delay."
The other areas where delays are expected to occur are between the South Hayward and Fremont stations, between Balboa Park and Daly City, and between Lafayette and Concord.
Further details on each can be found the following BART web pages: