ORINDA (CBS SF) – Fire safety drills were taking place in the Caldecott Tunnel’s new fourth bore Monday in preparation for the bore’s opening later this month.

The drills—which involve the state fire marshal’s office, the California Highway Patrol, the Moraga-Orinda Fire District, the Oakland Fire Department and other agencies—are part of extensive fire and life-safety systems testing for the new bore, and will take place from 10 a.m. to 4 p.m., Caltrans officials said.

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Drivers using state Highway 24 may see flashing emergency lights, firefighters in full gear and unusual activity, but are advised to remain focused on the road, not the drills.

“It’s just a test, they shouldn’t be alarmed by it. It’s just part of the safety drills we’re doing,” Caltrans spokeswoman Ivy Morrison said.

In addition to the training exercises, roadway work will reduce traffic to one bore in each direction late tonight and into Tuesday morning, according to Caltrans.

That work is expected to take place between 10 p.m. Monday and 4 a.m. Tuesday. Motorists should expect delays, Caltrans officials said.

The $417 million fourth bore project is intended to alleviate traffic congestion. The new bore is scheduled to open later this month.

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The target opening date was reported to be Nov. 16, but Morrison said this morning the timeline largely depends on the weather. She explained that there is still roadway striping and other work that needs to be done.

“If it rains, we’re not able to do that,” she said.

Additionally, a “smoke test” will be conducted before the bore’s

opening to test the new tunnel’s jet fans, Morrison said. The fans are designed to clear smoke and carbon monoxide out of the tunnel and bring in fresh air in the event of a fire.

(Copyright 2013 by CBS San Francisco and Bay City News Service. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)

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