Construction on I-5 could cause long backups Saturday morning near the Highway 16 interchange.

Crews are working through Friday night replacing concrete roadway panels on the freeway, and they won’t be finished until 10 a.m. Saturday.

That’s an hour later than they have been working, and State traffic engineers say that could cause delays.

“Our traffic modeling shows that unless people divert to other routes or delay their I-5 travel until after 10 a.m., we could see several miles of backups on southbound I-5,” said Washington State Transportation spokeswoman Claudia Bingham Baker.