The Toll Bridge Oversight Committee voted unanimously at a public meeting to approve a temporary fix for the bolts and open the span on September 3.
The decision came days after federal transportation officials signed off on the temporary fix.
In a letter made public Tuesday, Vincent Mammano of the Federal Highway Administration told the bridge committee that the agency was "impressed" with the level of expertise used to come up with the temporary fix and saw no reason to delay opening the bridge to traffic before long-term repairs are finished.
The cracked bolts, which secure earthquake shock absorbers to the deck of the bridge, were discovered in March. Officials determined it would take until December or longer to fix them, but days later engineers came up with the temporary solution that would allow for the September opening. The bridge will close on Aug. 28 and reopen on Sept. 3 while final work is done, officials said Thursday.
The short-term fix involves installing steel plates in the area of the broken bolts to help prevent movement during an earthquake, and would remain in place while workers install a permanent steel saddle that would replace the clinching function of the failed bolts.
The temporary plates could most likely be installed in a single day, said Randy Rentschler a spokesman for the Metropolitan Transportation Commission, and the fix would still be safer than the current eastern span.
But Abolhassan Astaneh-Asl, a civil engineering professor at the University of California, Berkeley, said opening before the long-term repairs are finished would be unsafe, and he was surprised at the federal decision to allow it.
Astaneh-Asl said earlier this week that the short-term fix "can do more harm to the bridge if an earthquake hits than good" because it did not make up for the loss of a critical device called a "shear key," which is designed to resist lateral earthquake motion.
The $6.4 billion bridge project was undertaken because the existing eastern span, built in the 1930s and damaged in the 1989 Loma Prieta earthquake, was not considered seismically safe.
Even before the bolts cracked, the project had experienced years of cost overruns and construction and design delays.