(KRON) -- A major route connecting the San Francisco Peninsula to the San Mateo County coastside will be shut down overnight between Thursday and Friday, the California Department of Transportation announced.

Both directions of Highway 1 at the Tom Lantos Tunnels, just south of Pacifica, will close at 8 p.m. Thursday and are expected to reopen at 4:30 a.m. Friday, Caltrans said. The temporary closure will be in place amid an annual mandatory emergency response drill.

The emergency exercise “will include testing of fire suppression and communication systems, exercise scenarios, and multi-agency coordination,” Caltrans said. Agencies involved include the California Highway Patrol, State Fire Marshals, the San Mateo County Sheriff’s Office, Pacifica fire and police departments, North County

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