As part of the seismic retrofit of the Dumbarton Bridge, workers began installing on April 7 steel plates on west- and eastbound lanes of the bridge connecting Menlo Park with Fremont. The installations will require some lane closures on weeknights and weekends, project spokesperson Bart Ney said.
On weeknights, there will be closures of westbound lanes 1 and 2 or lanes 2 and 3 starting as early as 7 p.m. All westbound lanes will reopen by 5 a.m. the next day, Mr. Ney said.
Eastbound lanes 2 and 3 may be closed as early as 8 p.m. and will reopen by 6 a.m. the next day.
On weekends, there will be extended hours of lane closures starting as early as 4 p.m. for westbound traffic and 6 p.m. for eastbound. Both directions will reopen by 1 p.m. the following day, Mr. Ney said.
Motorists will drive over the plates, which are being installed to give workers access inside the bridge to complete the seismic retrofit. The speed limit on the 1.6-mile-long bridge will remain at 65 mph.
The first four plates -- each about 9 foot by 10 foot and 1.5-inches thick -- will be installed April 7, Mr. Ney said in an announcement. Ultimately, 16 such plates will be installed in each of the westbound and eastbound roadways.
The plates will remain until the retrofit project is completed, which is expected by the fall of 2012, he said.
The retrofit project includes reinforcing the existing concrete slab bridge, replacing major deck joints, and installing isolation bearings, Mr. Ney said. The contractor is Shimmick Construction Co. of Oakland.
About 61,000 vehicles use the bridge each day, he said. The existing structure opened in 1982, replacing the 1927 Dumbarton Bridge.
For updates on lane closures, go to DumbartonBridgeInfo.org.