CASTAIC (CNS) — The northbound Golden State (5) Freeway in the Castaic area will close again Monday evening for a 12-hour period as crews continue repair work on two miles of roadway that was damaged by the Route Fire.

Two lanes of the roadway have been closed in the area since the Route Fire.

The first full closure began at 10 p.m. Thursday and the freeway reopened at 10 a.m. Friday. During that closure, crews worked to place 2,400 feet of asphalt concrete in an already-excavated section under construction.

The freeway was closed again at 11:59 p.m. Sunday, reopening at 7:30 a.m. Monday — about 2 1/2 hours ahead of schedule. The closure will be repeated Monday night, Tuesday night and Wednesday night, with the freeway scheduled to reopen the following mornings at 10 a.m. During the closures, crews will work on the existing asphalt shoulder for 6,000 feet just north of the concrete section and re-stripe the lanes.

By Thursday, three lanes of the northbound freeway will be open, according to Caltrans.

During the closures, the turnaround gate at Parker Road will be opened to redirect northbound traffic back south. That will necessitate blocking the three left lanes of the southbound freeway to ensure trucks have room to negotiate the turn, according to Caltrans.

Motorists were advised to avoid the area altogether by taking the Antelope Valley (14) Freeway north of Sylmar, state Route 126/Newhall Ranch Road. Southbound motorists were urged to take the eastbound state Route 138 to the southbound 14 Freeway.

"The safety of the motorists and truckers is our primary goal," said Caltrans District 7 Acting District Director Gloria Roberts. "The Route Fire caused extensive damage to the two retaining walls, and traffic cannot travel on the two right lanes until more permanent repairs are completed."

The damage caused to the retaining walls by the Route Fire included warped steel columns, broken tiebacks and possibly damaged anchors, Caltrans reported. Additionally, cracks in the asphalt have widened and wooden lagging on the retaining walls has been burned.

The Route Fire, which began around noon on Aug. 31 alongside the Golden State (5) Freeway north of Lake Hughes Road, burned 5,208 acres, destroyed two structures and led to seven heat-related firefighter injuries.

Due to the traffic impacts of the project, Los Angeles County Supervisor Kathryn Barger sent an open letter to residents Friday saying she has asked Gov. Gavin Newsom to make all resources available to allow Caltrans to complete the repairs as quickly as possible.

She said she has asked the Department of Public Works to establish some local-access-only routes in the area to ensure residents can negotiate the area.