The Reseda Boulevard offramp to the westbound state Route 118 (Ronald Reagan Freeway) will close to traffic at 9 p.m. on Thursday.
The offramp could be closed for six months, according to the California Department of Transportation. Motorists are advised to use the Balboa Boulevard or Tampa Avenue offramps as alternatives.
While the ramp is closed, the department will replace a damaged drainage pipe with a new, concrete enforced pipe under the ramp. Crews will then repave the ramp, according to Caltrans.
The ramp construction is part of a $2.1 million Caltrans project that will also upgrade the irrigation system, embankments, and landscaped areas around the Reseda Boulevard offramp, according to Caltrans.