All northbound lanes on Highway 101 between Cesar Chavez and 10th Street will be closed for repaving two weekends in September, including Labor Day weekend, and the southbound lanes will be closed for two weekends in October.

Caltrans is warning drivers to stay away from the affected stretch of US 101 Bayshore Freeway in San Francisco, called Hospital Curve, during the closures — between Cesar Chavez and 10th Street, when crews will work around the clock to repave the freeway, as SFGate reports. The first shutdown will begin with the northbound lanes Friday, September 4, at 11 pm, and they’re expected to reopen by 6 am Monday, September 7.

The second northbound closure is scheduled for September 18–21, followed by southbound closures beginning Friday, October 2, and Saturday, October 17. Each closure is expected to last about 55 hours.

Caltrans spokesperson Lori Shepherd told SFGate that northbound drivers should consider taking Interstate 280 toward the Bay Bridge or getting off at Cesar Chavez Street and using Potrero Avenue through the Mission to reach downtown.

“We’re making sure folks stay far away,” she said. “That’s going to be full lane closure of all northbound lanes.”

These closures come after partial closures on 101 at Hospital Curve last weekend, with two lanes blocked in each direction, as Caltrans conducted critical drainage work in preparation for the larger closures.

Caltrans has reportedly been preparing for the detours ahead of the first closure, including canvassing the Mission to alert residents and businesses and coordinating with Zuckerberg San Francisco General Hospital and Trauma Center. Emergency transportation services have also been notified about the expected increase in traffic on Potrero Avenue, according to SFGate.

The agency has been coordinating with Chase Center as well, since one of the closures overlaps with a Golden State Valkyries game against the Seattle Storm on September 19. 

The first of these closure falls on Labor Day weekend, which is typically busy in the Bay Area.

“We know it’s busy, but it’s a choice weekend — there won’t be as much commuter traffic,” Shepherd said, speaking to SFGate. “The pavement is very weather dependent, and since it’s still summer, moisture and rain cannot be in this work.”

Caltrans completed the preliminary work on the Hospital Curve section Monday, including installation of a new drainage system designed to prevent flooding ahead of the winter season, as El Niño is expected to be particularly rough this year.

The closures are part of Caltrans’ ongoing US 101 Hospital Curve Rehabilitation Project, which began last fall and is expected to continue through 2028. The project covers 15.4 lane miles of concrete pavement between Candlestick Point Recreation Area and the Mission District, including pavement rehabilitation as well as upgrades to the freeway’s drainage systems and median barrier.

The work follows a similar rehabilitation project on 19th Avenue that Caltrans completed this spring.

Related: 19th Avenue Repaving Project to Cause Significant West Side Traffic This Weekend