Here’s the advisory from Metro:

Metro work crews will conduct system maintenance on Flower Street in downtown Los Angeles, impacting both the Metro Blue Line and Expo Line. The work will begin at 9 p.m., Saturday, Dec. 29, and continue into the morning hours of operation on Sunday, Dec. 30.

Trains will run on one track in the area. Patrons can expect service delays of 20 to 30 minutes during that time and should plan travel time accordingly. Metro apologizes for the inconvenience and strives to minimize delays or disruption of service.

Follow @metroLAalerts on Twitter for frequent updates. Link to updated planned service advisory reports at metro.net. (http://www.metro.net/service/advisories/rail/)