The Dumbarton Bridge, a 1.6 mile span from Menlo Park to Fremont and carries an estimated 60,000 vehicles daily, will close during Memorial Day Weekend. The bridge will be closed from 10 p.m. Friday, May 25, to 5 a.m. Tuesday, May 29. It's all a part of Caltrans and the contractor to replace a major seismic joint on all lanes of traffic. According to the press release, "This will complete a significant milestone in the overall seismic retrofit of the Dumbarton Bridge, currently slated to complete in early 2013."
Suggested detour routes include the San Mateo Bridge or, at the risk of sounding like The Californians, just take the 880 to the 237 to the 101.