Caltrans will close a stretch of northbound Interstate 280 through San Francisco beginning at 2 p.m. today through the end of Labor Day as part of the final phase of a nearly $4 million project to replace four bridge hinges for structural integrity.
The two remaining hinges needing work -- both located in the northbound section, one close to Cesar Chavez Street and the other near Evans Avenue -- follow the replacement of a hinge in the southbound section of I-280 over Memorial Day weekend and another in the northbound direction over the July Fourth weekend.
"This is something we've been planning for years. This has nothing to do with what happened in Napa," Steven Williams, a Caltrans spokesman, said referring to the magnitude-6.0 quake Sunday. "The freeway was built in 1966 and the hinges that are going in there are much stronger, and the seismic standards have changed since the structure was erected."
Northbound onramp closures through Tuesday 5 a.m. include Alemany Boulevard, the U.S. Highway 101 connector to I-280, Indiana, 25th and 18th streets, while offramp closures include Cesar Chavez, Mariposa, Sixth and King streets.
"We're closing at 2 [p.m.] instead of the normal 9 p.m. to give Caltrans and the contractor a little more breathing room to make sure we're able to accomplish this," Williams said.
Southbound I-280 will remain open.