The Patsaouras Transit Plaza and undergound parking structure at the East Portal entrance to Union Station is closed to pedestrians and all vehicles during the daytime hours of Saturday, Dec. 29, for maintenance.

Here’s the advisory from Metro:

Construction to restrict daytime access to the Patsaouras Transit Plaza and East Portal parking structure of Union Station on Saturday, Dec. 29.

• Plaza bus stops will be temporarily relocated nearby. Board Flyaway at Amtrak bus bay; Megabus on Alameda St. in front of Union Station
• Enter at Alameda Street entrance to park at Union Station.
• Cars and pedestrians may not enter or exit from the East Portal area underground parking structure during the closure.

Weather permitting: Construction to replace cooling towers on the highrise rooftop of the Metro Headquarters in downtown Los Angeles will restrict access to the Patsaouras Transit Plaza and parking structure at the East Portal entrance to Union Station from 6 a.m. to 4 p.m. on Saturday, Dec. 29. Cesar Chavez Avenue and Vignes Street adjacent to the Metro Headquarters building will be closed during that time.

Pedestrians, buses and other vehicles will not be allowed in or out of Patsaouras Plaza and the parking structure or the surrounding streets. All Metro and Metrolink rail service will run normal operations and schedule. The public is advised to use the Alameda Street entrance of Union Station to access the Metro Red, Purple, and Gold Lines and Metrolink and Amtrak trains between the hours of 6 a.m. and 4 p.m. on Dec. 29.

Passengers will need to approach the west end of Union Station rather than the east end Patsaouras Plaza for connections with any service that normally operates out of the East Portal (Metro bus lines, LAX FlyAway, Megabus and City of Commerce shuttle bus). Metro will have personnel in the tunnels to provide printed and verbal information on bus detours and alternate boarding locations.

A helicopter will be used to bring the old cooling towers down and lift the new cooling towers and related equipment onto the roof of the Metro Headquarters building.

To ensure safety during this work, the Federal Aviation Administration has required the closures of E. Cesar E. Chavez Avenue (from Mission Street to N. Alameda Street)  and Vignes Street (from the 101 Freeway exit to Bauchet Street) adjacent to the Metro Headquarters building. Also closed to pedestrian and vehicle access are the Gateway parking garage, Patsaouras Plaza and the three Union Station tracks closest to the Headquarters Building. A second lift is scheduled for Jan. 26 to complete the cooling system maintenance.

The following bus stop relocations will be in effect during the plaza closure:
• Line 40: Board southbound buses at regular stops south of Temple Street.
• Lines 68, 70, 71, 78, 79, 378, 770: board eastbound buses at temporary stop on Aliso Stret at Los Angeles Street or at regular stops south of Broadway. on Cesar E. Chavez Avenue.
• Line 704: Board westbound buses at temporary stop on Temple Street west of Broadway.
• Lines 733, 745: Board westbound buses at temporary stop on Temple Street west of Alameda Street.
• City of Commerce shuttle: Board at Line 40 regular stop on Alameda in front of Union Station.
• Megabus: Board at Line 40 regular stop on Alameda in front of Union Station.
• LAX FlyAway: Board at one of the Amtrak bus bays on the noth side of Union Station. Entrance is off of Cesar chavez Avenue.