Westbound I-80 in downtown San Francisco to close for weekend repaving. Here's what to know.

Drivers heading into San Francisco from the East Bay on the Bay Bridge should expect major delays as westbound Interstate 80 in downtown will be closed for repaving.

Caltrans has planned a full weekend closure of the westbound lanes from 5th Street, just off the Bay Bridge, to 15th Street, where I-80 meets up with Highway 101. The closure is scheduled to begin at 11 p.m. on Friday, Oct. 23 and will continue until 6 a.m. on Monday, Oct. 26.

Officials said the work is necessary for crews to place polyester concrete on the freeway deck. The work will complete a broader repaving project that began on the eastbound lanes earlier this year.

"The Central and Bayshore freeway viaducts are 71 years old and carry thousands of vehicles daily near the San Francisco–Oakland Bay Bridge corridor. With constant exposure to heavy traffic loads, weather, and seismic demands, the structures require timely rehabilitation to prevent further deterioration," Caltrans said in a statement.

During the closure, all traffic on westbound 80 will be forced to exit at the 5th Street off-ramp. Drivers can enter Highway 101 at the on-ramp at 10th and Harrison streets.

Caltrans is urging people to use public transit or to use the San Mateo, Dumbarton or Richmond-San Rafael bridges to get from the East Bay to San Francisco.

All lanes of eastbound I-80 in downtown San Francisco will remain open this weekend.

In addition to the I-80 closure, Caltrans is also closing a stretch of Highway 37 in the North Bay throughout the weekend to perform El Niño-related winter storm preparations.