All northbound lanes of the Santa Ana (5) Freeway will be closed between Artesia Boulevard and Valley View Avenue in La Mirada early Wednesday.
The closure is scheduled to last until about 5 a.m., according to Caltrans.
In addition, the westbound Artesia (91) Freeway connector to the northbound Santa Ana Freeway will be closed until 5 a.m., as will the left lane of the southbound Santa Ana Freeway between Valley View Avenue and Artesia Boulevard.
The closures, which will allow crews to move and pin K-rail, are subject to change, according to Caltrans.