Caltrans is reconfiguring the lanes as part of its ongoing effort to rebuild the span to make it more seismically safe.
"After this weekend traffic is going to be detoured in this fashion here. We'll be moving things to the south. It's an easier curve that should be easier to navigate," Caltrans Spokesman Bart Ney said.
Caltrans says motorists may experience slight delays as the lanes begin closing tonight, but Ney says this change will actually benefit commuters.
"It's one of the few times that a temporary detour actually improves your commute," he said.
If you plan on traveling by BART, be aware that repairs to a cable damaged by fire last December will close one track in the Transbay tube; that means that BART riders will have to transfer at 12th Street Oakland station to get in and out of San Francisco.
"What that means is that the Pittsburg-Bay Point to San Francisco trains in both directions will have to share the remaining track through the trans-bay tube," Paul Oversier from BART said.
This work means that BART riders will hopefully only be inconvenienced this weekend.