ORINDA (CBS SF) – Caltrans is shutting down the third bore of the Caldecott Tunnel on Highway 24 overnight on June 23 and June 24, due to maintenance work. Motorists should expect delays.

Crews will begin working Wednesday night, June 25. The westbound number three bore will be temporarily closed from 9 p.m until 5 a.m.

Work will resume on Thursday, June 26. The third bore will be shut down overnight again, between 9 p.m and 5 a.m..

At least one bore in each direction will remain open to traffic at all times, according to Caltrans.

Drivers are advised to allow extra time and proceed with caution through the construction zone.

For more information, go to 511.org.