The closure of the Bay Bridge has not caused any major traffic problems so far.
Traffic has been a little heavier than usual around other Bay Area bridges that drivers are using to cross the bay.
The Bay Bridge was shut down at 8-o-clock last night and is expected to open before Tuesday's morning commute.
Work crews are using the three-day Labor Day weekend to replace a football field-size section of the bridge approaching Yerba Buena Island from Oakland.
Caltrans spokesman Bart Ney says so far the work is proceeding ahead of schedule.
Caltrans has spent has spent about $1 million on a statewide campaign to warn motorists about the bridge closure.