Two lanes of the Bay Bridge will shut down as part of security precautions during the Asia-Pacific Economic Cooperation (APEC) summit in San Francisco this month, likely causing traffic chaos.

The rightmost lane of I-80 westbound and the leftmost lane of I-80 eastbound will shut down from Nov. 14 at 5 a.m. to Nov. 17 at 9 p.m., according to Caltrans.

The Bay Bridge pedestrian and bike path will have controlled access during the closure, and bus service across the bridge will still run. On- and off-ramps accessing Treasure Island will remain open, as will the I-80 off-ramp at Fremont Street.

The Standard has reached out to Caltrans to clarify what controlled access involves for cyclists and walkers.

The lane closures are to allow unfettered access for California Highway Patrol vehicles for APEC security, according to Cheryl Chambers, Caltrans deputy district director of external affairs.

READ MORE: Feds Release Security Details for San Francisco’s APEC Summit, Including Central Subway Closure

Other parts of Bay Area highways will also be affected.

The northbound U.S. 101 Dana Bowers Vista Point off-ramp will be closed from Nov. 14 to Nov. 18, and there will be no access to Dana Bowers Vista Point for any vehicles, bikes or pedestrians.

Chambers said signage will be posted on highways as far north as Sacramento, as well as around the Bay Area, warning of the highway on-ramp closures to let people know to expect traffic delays starting Monday.

Chambers said Caltrans encourages people to take public transit to San Francisco during APEC.

“We want people to come to San Francisco, but we don’t want them stuck in heavy delays,” Chambers said.

Locally, parts of San Francisco’s SoMa neighborhood near the Moscone Center will be shut off to private car traffic for part of the summit, drawing criticism from older and disabled residents who depend on driving to get around.

APEC is a multinational summit being held at San Francisco’s Moscone Center. It is the biggest, most important gathering of international heads of state in the city since the 1945 signing of the U.N. Charter.