Only one lane will remain open in each direction on the Santa Ana (5) Freeway between L.A. and Orange counties during overnight hours, starting Sunday, Caltrans said.
The 5 is in the midst of a $96 million widening project, and crews will need room to pour concrete along the new median, officials said.
The lanes closures will last from 10 p.m. Sunday until 5 a.m. Monday, and will be in effect for both directions between the San Gabriel (605) Freeway and Florence Avenue, officials said.
Motorists were advised to use the 91 and 605 freeways to avoid heavy traffic anticipated in the closure area, and drivers heading from the East L.A. Interchange heading to Orange County can avoid anticipated congestion at the 605 Freeway by using the 710 Freeway south to the 91 east, or even the 405.
The 5 Freeway, opened as U.S. 101 in the mid 1950s, is being widened from its original 6 lanes to up to 12 lanes, between the 605 and the Orange County line.
In Santa Clarita, crews planned to realign southbound Interstate 5 traffic onto new concrete this week. That will eliminate a "split lanes" arrangement where traffic was split onto two parallel detours, as the freeway there is rebuilt, Caltrans officials said.
