BART announced in a rather confusing manner that there will be delays through the Transbay Tube this weekend and next. What it boils down to is that passengers traveling between San Francisco/Peninsula and the East Bay can expect 20-40 minute delays between the 24-hour period of 2:30 p.m. Sunday through 2:30 p.m. Monday, this weekend and next.
Starting Friday night, BART will be performing "vital maintenance and repair work to electric cables" in the Transbay Tube. But don't worry, they're only working through the night on Friday and Saturday, between the last and first trains each night and morning. Then they'll put the pedal to the metal from Sunday afternoon at 2:30 p.m. through Monday at 2:30 p.m.
Also during this time period, riders traveling toward Dublin or Fremont from SF will need to take a Pittsburg/Bay Point-bound train across the Bay, and both inbound and outbound Dublin and Fremont passengers will need to transfer at the 12th Street station in Oakland.
Additionally, remember that BART is running on a holiday schedule on Monday during the glorious Memorial Day. Enjoy!