Lefty O'Doul Bridge near AT&T Park in SF closed for rehab through January 26

SAN FRANCISCO (KGO) -- If you've noticed unusually heavy traffic by San Francisco's "Lefty O'Doul Bridge" near AT&T Park, that's because it is closed for rehab.

RELATED: Live traffic maps

Crews have raised the bridge and locked it in the upright position to start repairing aging steel parts.

The work is expected to take eighteen months - and the bridge will be closed during some of that time.

This first closure lasts until January 26th.

The Lefty O'Doul Bridge is on Third Street - one of the main routes into China Basin and Mission Bay.

Those trying to get from I-280 to the Embarcadero may have trouble as well. It's best to find an alternative route as gridlock has been reported on Mariposa Street and side streets leading up to Third.

Click here for more information on the closures, rehab schedule and possible alternative routes.