For many people, the long Memorial Day weekend is the unofficial kickoff to the summer driving season.
But some motorists heading across the bay from the Peninsula Friday night might be in for a rude awakening: the Dumbarton Bridge may be closed.
According to Caltrans officials, the 1.6-mile span will be closed to traffic in both directions 10 p.m. Friday through 5 a.m. Tuesday for a seismic retrofit project. It also will be closed to pedestrians and bicyclists.
While the bridge is closed, Caltrans officials are urging motorists to plan ahead and allow extra time to get to their destinations using alternate routes.
To detour around the Dumbarton Bridge, Caltrans suggests using Highway 237 to the South and Highway 92 and San Mateo Bridge to the north.
The three day retrofit project involves replacing an existing joint on the western side of the bridge with a larger, seismically safe joint. Workers also will raise sections of the bridge by as many as five inches to allow for the future installation of seismic bearings that will provide independent movement of the bridge deck from its concrete piers.
The work is part of the ongoing Dumbarton Bridge Seismic Safety Project.
Real-time updates on the closure will be available by calling 511 or visiting http://www.511.org/.
-- Bay City News Service contributed to this report.