Southbound Interstate 280 from downtown San Francisco to the Pennsylvania Avenue on-ramp remains closed through Tuesday morning at 5 a.m.
The closure is necessary in order to replace one bridge hinge on southbound I-280, Caltrans said.
Additional closures are planned for the Fourth of July and Labor Day holiday weekends to replace bridge hinges on northbound I-280.
Drivers heading to San Francisco over the weekend may experience additional traffic because of the closure.
Southbound on-ramp closures include the Mariposa Street/18th Street on-ramp, 6th Street/Brannan on-ramp and King Street on-ramp.
Southbound I-280 traffic will detour to Highway 101. Mariposa Street/18th Street traffic can also detour to the southbound I-280 Pennsylvania Avenue on-ramp.