From an Alameda County Public Works Agency press release:
The Alameda bridge leaf of the Park Street Bridge will be closed to all marine vessel traffic from Monday July 9, through Wednesday July 18, 2012 to facilitate electrical repairs and to conduct operational testing. The Oakland leaf of the bridge will remain operable for any vessel traffic.
Neither bridge vertical clearances nor vehicle traffic will be impacted during this repair work. Existing bridge streetlights will remain operational; however, there
may be minimal intermittent interruption during the repair work. Motorists are
advised to exercise caution and adhere to all traffic regulations.
For additional information, contact Arthur Valderrama at (510) 670-5260.