WESTWOOD (CBSLA.com) — Lane closures on Sepulveda Boulevard will be extended through Thursday due to delays caused by rain, officials said Monday.

Work to re-grade and reposition the heavily traveled road between Church and Montana avenues began last week.

Sepulveda will continue to be limited to one lane in each direction from 6 a.m. to 9 p.m.  From the hours of 9 p.m. to 6 a.m., the entire stretch of roadway will be closed to all traffic.

The closure is part of the $1 billion 405 Freeway construction and widening project.

The new Sepulveda Boulevard alignment slices through a hill east of the freeway, where a large retaining wall has been built.

The repositioning and re-grading of Sepulveda will allow Metro crews to build a new carpool lane and exits on the northbound 405.

According to Metro, the closest detour will be the 405 Freeway.